/*
 #
 #  File        : gmic.cpp
 #                ( C++ source file )
 #
 #  Description : GREYC's Magic for Image Computing - G'MIC Language interpreter
 #                ( http://gmic.eu )
 #
 #  Copyright   : David Tschumperle
 #                ( http://tschumperle.users.greyc.fr/ )
 #
 #  License     : CeCILL v2.0
 #                ( http://www.cecill.info/licences/Licence_CeCILL_V2-en.html )
 #
 #  This software is governed by the CeCILL  license under French law and
 #  abiding by the rules of distribution of free software.  You can  use,
 #  modify and/ or redistribute the software under the terms of the CeCILL
 #  license as circulated by CEA, CNRS and INRIA at the following URL
 #  "http://www.cecill.info".
 #
 #  As a counterpart to the access to the source code and  rights to copy,
 #  modify and redistribute granted by the license, users are provided only
 #  with a limited warranty  and the software's author,  the holder of the
 #  economic rights,  and the successive licensors  have only  limited
 #  liability.
 #
 #  In this respect, the user's attention is drawn to the risks associated
 #  with loading,  using,  modifying and/or developing or reproducing the
 #  software by the user in light of its specific status of free software,
 #  that may mean  that it is complicated to manipulate,  and  that  also
 #  therefore means  that it is reserved for developers  and  experienced
 #  professionals having in-depth computer knowledge. Users are therefore
 #  encouraged to load and test the software's suitability as regards their
 #  requirements in conditions enabling the security of their systems and/or
 #  data to be ensured and,  more generally, to use and operate it in the
 #  same conditions as regards security.
 #
 #  The fact that you are presently reading this means that you have had
 #  knowledge of the CeCILL license and that you accept its terms.
 #
*/

// Add G'MIC-specific methods to the CImg library.
//------------------------------------------------
#ifdef cimg_plugin

static CImg<T> append_CImg3d(const CImgList<T>& images) {
  if (!images) return CImg<T>();
  if (images.size()==1) return +images[0];
  CImg<charT> error_message(1024);
  unsigned int nbv = 0, nbp = 0;
  ulongT siz = 0;
  cimglist_for(images,l) {
    const CImg<T>& img = images[l];
    if (!img.is_CImg3d(false,error_message))
      throw CImgArgumentException("append_CImg3d(): image [%d] (%u,%u,%u,%u,%p) "
                                  "is not a CImg3d (%s).",
                                  l,img._width,img._height,img._depth,img._spectrum,img._data,
                                  error_message.data());
    siz+=img.size() - 8;
    nbv+=cimg::float2uint((float)img[6]);
    nbp+=cimg::float2uint((float)img[7]);
  }

  CImg<T> res(1,siz + 8);
  const T **const ptrs = new const T*[images.size()];
  T *ptrd = res._data;
  *(ptrd++) = (T)('C' + 0.5f); *(ptrd++) = (T)('I' + 0.5f); // Create object header.
  *(ptrd++) = (T)('m' + 0.5f); *(ptrd++) = (T)('g' + 0.5f);
  *(ptrd++) = (T)('3' + 0.5f); *(ptrd++) = (T)('d' + 0.5f);
  *(ptrd++) = (T)cimg::uint2float(nbv);
  *(ptrd++) = (T)cimg::uint2float(nbp);
  cimglist_for(images,l) { // Merge object points.
    const CImg<T>& img = images[l];
    const unsigned int nbv = cimg::float2uint((float)img[6]);
    std::memcpy(ptrd,img._data + 8,3*nbv*sizeof(T));
    ptrd+=3*nbv;
    ptrs[l] = img._data + 8 + 3*nbv;
  }
  ulongT poff = 0;
  cimglist_for(images,l) { // Merge object primitives.
    const unsigned int
      nbv = cimg::float2uint((float)images[l][6]),
      nbp = cimg::float2uint((float)images[l][7]);
    for (unsigned int p = 0; p<nbp; ++p) {
      const unsigned int
        nbi = cimg::float2uint((float)*(ptrs[l]++)),
        _nbi = nbi<5?nbi:nbi==5?2:nbi/3;
      *(ptrd++) = (T)cimg::uint2float(nbi);
      for (unsigned int i = 0; i<_nbi; ++i) *(ptrd++) = (T)cimg::uint2float(cimg::float2uint(*(ptrs[l]++)) + poff);
      for (unsigned int i = nbi - _nbi; i; --i) *(ptrd++) = *(ptrs[l]++);
    }
    poff+=nbv;
  }
  ulongT voff = 0;
  cimglist_for(images,l) { // Merge object colors.
    const unsigned int nbc = cimg::float2uint((float)images[l][7]);
    for (unsigned int c = 0; c<nbc; ++c)
      if (*(ptrs[l])==(T)-128) {
        *(ptrd++) = *(ptrs[l]++);
        const unsigned int
          w = (unsigned int)*(ptrs[l]++),
          h = (unsigned int)*(ptrs[l]++),
          s = (unsigned int)*(ptrs[l]++);
        if (!h && !s) { *(ptrd++) = (T)(w + voff); *(ptrd++) = 0; *(ptrd++) = 0; }
        else {
          *(ptrd++) = (T)w; *(ptrd++) = (T)h; *(ptrd++) = (T)s;
          const ulongT whs = (ulongT)w*h*s;
          std::memcpy(ptrd,ptrs[l],whs*sizeof(T));
          ptrs[l]+=whs; ptrd+=whs;
        }
      } else { *(ptrd++) = *(ptrs[l]++); *(ptrd++) = *(ptrs[l]++); *(ptrd++) = *(ptrs[l]++); }
    voff+=nbc;
  }
  voff = 0;
  cimglist_for(images,l) { // Merge object opacities.
    const unsigned int nbo = cimg::float2uint((float)images[l][7]);
    for (unsigned int o = 0; o<nbo; ++o)
      if (*(ptrs[l])==(T)-128) {
        *(ptrd++) = *(ptrs[l]++);
        const unsigned int
          w = (unsigned int)*(ptrs[l]++),
          h = (unsigned int)*(ptrs[l]++),
          s = (unsigned int)*(ptrs[l]++);
        if (!h && !s) { *(ptrd++) = (T)(w + voff); *(ptrd++) = 0; *(ptrd++) = 0; }
        else {
          *(ptrd++) = (T)w; *(ptrd++) = (T)h; *(ptrd++) = (T)s;
          const ulongT whs = (ulongT)w*h*s;
          std::memcpy(ptrd,ptrs[l],whs*sizeof(T));
          ptrs[l]+=whs; ptrd+=whs;
        }
      } else *(ptrd++) = *(ptrs[l]++);
    voff+=nbo;
  }
  delete[] ptrs;
  return res;
}

CImg<T>& append_string_to(CImg<T>& img, T* &ptrd) const {
  if (!_width) return img;
  if (ptrd + _width>=img.end()) {
    CImg<T> tmp(3*img._width/2 + _width + 1);
    std::memcpy(tmp,img,img._width*sizeof(T));
    ptrd = tmp._data + (ptrd - img._data);
    tmp.move_to(img);
  }
  std::memcpy(ptrd,_data,_width*sizeof(T));
  ptrd+=_width;
  return img;
}

static CImg<T>& append_string_to(const char c, CImg<T>& img, T* &ptrd) {
  if (ptrd + 1>=img.end()) {
    CImg<T> tmp(3*img._width/2 + 2);
    std::memcpy(tmp,img,img._width*sizeof(T));
    ptrd = tmp._data + (ptrd - img._data);
    tmp.move_to(img);
  }
  *(ptrd++) = c;
  return img;
}

CImg<T>& color_CImg3d(const float R, const float G, const float B, const float opacity,
                      const bool set_RGB, const bool set_opacity) {
  CImg<char> error_message(1024);
  if (!is_CImg3d(false,error_message))
    throw CImgInstanceException(_cimg_instance
                                "color_CImg3d(): image instance is not a CImg3d (%s).",
                                cimg_instance,error_message.data());
  T *ptrd = data() + 6;
  const unsigned int
    nbv = cimg::float2uint((float)*(ptrd++)),
    nbp = cimg::float2uint((float)*(ptrd++));
  ptrd+=3*nbv;
  for (unsigned int i = 0; i<nbp; ++i) { const unsigned int N = (unsigned int)*(ptrd++); ptrd+=N; }
  for (unsigned int c = 0; c<nbp; ++c)
    if (*ptrd==(T)-128) {
      ++ptrd;
      const unsigned int
        w = (unsigned int)*(ptrd++),
        h = (unsigned int)*(ptrd++),
        s = (unsigned int)*(ptrd++);
      ptrd+=w*h*s;
    } else if (set_RGB) { *(ptrd++) = (T)R; *(ptrd++) = (T)G; *(ptrd++) = (T)B; } else ptrd+=3;
  if (set_opacity)
    for (unsigned int o = 0; o<nbp; ++o) {
      if (*ptrd==(T)-128) {
        ++ptrd;
        const unsigned int
          w = (unsigned int)*(ptrd++),
          h = (unsigned int)*(ptrd++),
          s = (unsigned int)*(ptrd++);
        ptrd+=w*h*s;
      } else *(ptrd++) = (T)opacity;
    }
  return *this;
}

CImg<T> get_color_CImg3d(const float R, const float G, const float B,
                         const float opacity, const bool set_RGB, const bool set_opacity) const {
  return (+*this).color_CImg3d(R,G,B,opacity,set_RGB,set_opacity);
}

CImg<T>& convert_primitives_CImg3d(const unsigned int mode) {
  CImg<char> error_message(1024);
  if (!is_CImg3d(false,error_message))
    throw CImgInstanceException(_cimg_instance
                                "convert_primitives_CImg3d(): image instance is not a CImg3d (%s).",
                                cimg_instance,error_message.data());
  CImgList<uintT> primitives;
  CImgList<floatT> colors, opacities;
  CImg3dtoobject3d(primitives,colors,opacities,false);
  const unsigned int psiz = primitives.size();
  CImg<uintT> P;
  CImg<floatT> C, O;
  for (unsigned int p = 0; p<psiz; ++p) {
    primitives[p].move_to(P);
    colors[p].move_to(C);
    opacities[p].move_to(O);
    switch (P.size()) {
    case 1 : // Point.
      P.move_to(primitives);
      if (mode==2) {
        if (C.size()==3) C.move_to(colors);
        else C.get_vector_at(C._width/2,C._height/2).move_to(colors);
        if (O.size()==1) O.move_to(opacities);
        else O.get_vector_at(O._width/2,O._height/2).move_to(opacities);
      } else { C.move_to(colors); O.move_to(opacities); }
      break;
    case 2 : // Colored segment.
      if (mode) { P.move_to(primitives); C.move_to(colors); O.move_to(opacities); }
      else {
        CImg<uintT>::vector(P[0]).move_to(primitives);
        colors.insert(C); opacities.insert(O);
        CImg<uintT>::vector(P[1]).move_to(primitives);
        C.move_to(colors); O.move_to(opacities);
      }
      break;
    case 3 : // Colored triangle.
      if (mode==2) {
        P.move_to(primitives); C.move_to(colors); O.move_to(opacities);
      } else if (mode==1) {
        CImg<uintT>::vector(P[0],P[1]).move_to(primitives);
        colors.insert(C); opacities.insert(O);
        CImg<uintT>::vector(P[1],P[2]).move_to(primitives);
        colors.insert(C); opacities.insert(O);
        CImg<uintT>::vector(P[2],P[0]).move_to(primitives);
        C.move_to(colors); O.move_to(opacities);
      } else {
        CImg<uintT>::vector(P[0]).move_to(primitives);
        colors.insert(C); opacities.insert(O);
        CImg<uintT>::vector(P[1]).move_to(primitives);
        colors.insert(C); opacities.insert(O);
        CImg<uintT>::vector(P[2]).move_to(primitives);
        C.move_to(colors); O.move_to(opacities);
      }
      break;
    case 4 : // Colored quadrangle.
      if (mode==2) {
        P.move_to(primitives); C.move_to(colors); O.move_to(opacities);
      } else if (mode==1) {
        CImg<uintT>::vector(P[0],P[1]).move_to(primitives);
        colors.insert(C); opacities.insert(O);
        CImg<uintT>::vector(P[1],P[2]).move_to(primitives);
        colors.insert(C); opacities.insert(O);
        CImg<uintT>::vector(P[2],P[3]).move_to(primitives);
        colors.insert(C); opacities.insert(O);
        CImg<uintT>::vector(P[3],P[0]).move_to(primitives);
        C.move_to(colors); O.move_to(opacities);
      } else {
        CImg<uintT>::vector(P[0]).move_to(primitives);
        colors.insert(C); opacities.insert(O);
        CImg<uintT>::vector(P[1]).move_to(primitives);
        colors.insert(C); opacities.insert(O);
        CImg<uintT>::vector(P[2]).move_to(primitives);
        colors.insert(C); opacities.insert(O);
        CImg<uintT>::vector(P[3]).move_to(primitives);
        C.move_to(colors); O.move_to(opacities);
      }
      break;
    case 5 : // Sphere.
      if (mode==2) {
        P.move_to(primitives); C.move_to(colors); O.move_to(opacities);
      } else if (mode==1) {
        CImg<uintT>::vector(P[0],P[1],1,P[3],P[4]).move_to(primitives);
        colors.insert(C); opacities.insert(O);
      } else {
        const float
          x0 = (float)(*this)(P[0],0),
          y0 = (float)(*this)(P[0],1),
          z0 = (float)(*this)(P[0],2),
          x1 = (float)(*this)(P[1],0),
          y1 = (float)(*this)(P[1],1),
          z1 = (float)(*this)(P[1],2);
        (*this)(P[0],0) = (T)((x0 + x1)/2);
        (*this)(P[0],1) = (T)((y0 + y1)/2);
        (*this)(P[0],2) = (T)((z0 + z1)/2);
        CImg<uintT>::vector(P[0]).move_to(primitives);
        colors.insert(C); opacities.insert(O);
      }
      break;
    case 6 : // Textured segment.
      if (mode==2) {
        CImg<uintT>::vector(P[0],P[1]).move_to(primitives);
        C.get_vector_at(P[2]>=C._width?C._width - 1:P[2],
                        P[3]>=C._height?C._height - 1:P[3]).move_to(colors);
        if (O.size()!=1) CImg<floatT>::vector(O._atXY(P[2],P[3])).move_to(opacities);
        else O.move_to(opacities);
      } else if (mode==1) {
        P.move_to(primitives); C.move_to(colors); O.move_to(opacities);
      } else {
        CImg<uintT>::vector(P[0]).move_to(primitives);
        C.get_vector_at(P[2]>=C._width?C._width - 1:P[2],
                        P[3]>=C._height?C._height - 1:P[3]).move_to(colors);
        if (O.size()!=1) CImg<floatT>::vector(O._atXY(P[2],P[3])).move_to(opacities);
        else opacities.insert(O);
        CImg<uintT>::vector(P[1]).move_to(primitives);
        C.get_vector_at(P[4]>=C._width?C._width - 1:P[4],
                        P[5]>=C._height?C._height - 1:P[5]).move_to(colors);
        if (O.size()!=1) CImg<floatT>::vector(O._atXY(P[4],P[5])).move_to(opacities);
        else O.move_to(opacities);
      }
      break;
    case 9 : // Textured triangle.
      if (mode==2) {
        CImg<uintT>::vector(P[0],P[1],P[2]).move_to(primitives);
        C.get_vector_at(P[3]>=C._width?C._width - 1:P[3],
                        P[4]>=C._height?C._height - 1:P[4]).move_to(colors);
        if (O.size()!=1) CImg<floatT>::vector(O._atXY(P[3],P[4])).move_to(opacities);
        else O.move_to(opacities);
      } else if (mode==1) {
        CImg<uintT>::vector(P[0],P[1],P[3],P[4],P[5],P[6]).
          move_to(primitives);
        C.move_to(colors); opacities.insert(O);
        CImg<uintT>::vector(P[1],P[2],P[3],P[4],P[7],P[8]).
          move_to(primitives);
        colors.insert(colors.back(),~0U,true); opacities.insert(O);
        CImg<uintT>::vector(P[2],P[0],P[7],P[8],P[1],P[3]).
          move_to(primitives);
        colors.insert(colors.back(),~0U,true); O.move_to(opacities);
      } else {
        CImg<uintT>::vector(P[0]).move_to(primitives);
        C.get_vector_at(P[3]>=C._width?C._width - 1:P[3],
                        P[4]>=C._height?C._height - 1:P[4]).move_to(colors);
        if (O.size()!=1) CImg<floatT>::vector(O._atXY(P[3],P[4])).move_to(opacities);
        else opacities.insert(O);
        CImg<uintT>::vector(P[1]).move_to(primitives);
        C.get_vector_at(P[5]>=C._width?C._width - 1:P[5],
                        P[6]>=C._height?C._height - 1:P[6]).move_to(colors);
        if (O.size()!=1) CImg<floatT>::vector(O._atXY(P[5],P[6])).move_to(opacities);
        else opacities.insert(O);
        CImg<uintT>::vector(P[2]).move_to(primitives);
        C.get_vector_at(P[7]>=C._width?C._width - 1:P[7],
                        P[8]>=C._height?C._height - 1:P[8]).move_to(colors);
        if (O.size()!=1) CImg<floatT>::vector(O._atXY(P[7],P[8])).move_to(opacities);
        else O.move_to(opacities);
      }
      break;
    case 12 : // Textured quadrangle.
      if (mode==2) {
        CImg<uintT>::vector(P[0],P[1],P[2],P[3]).move_to(primitives);
        C.get_vector_at(P[4]>=C._width?C._width - 1:P[4],
                        P[5]>=C._height?C._height - 1:P[5]).move_to(colors);
        if (O.size()!=1) CImg<floatT>::vector(O._atXY(P[4],P[5])).move_to(opacities);
        else O.move_to(opacities);
      } else if (mode==1) {
        CImg<uintT>::vector(P[0],P[1],P[4],P[5],P[6],P[7]).
          move_to(primitives);
        C.move_to(colors); opacities.insert(O);
        CImg<uintT>::vector(P[1],P[2],P[6],P[7],P[8],P[9]).
          move_to(primitives);
        colors.insert(colors.back(),~0U,true); opacities.insert(O);
        CImg<uintT>::vector(P[2],P[3],P[8],P[9],P[10],P[11]).
          move_to(primitives);
        colors.insert(colors.back(),~0U,true); opacities.insert(O);
        CImg<uintT>::vector(P[3],P[0],P[10],P[11],P[4],P[5]).
          move_to(primitives);
        colors.insert(colors.back(),~0U,true); O.move_to(opacities);
      } else {
        CImg<uintT>::vector(P[0]).move_to(primitives);
        C.get_vector_at(P[4]>=C._width?C._width - 1:P[4],
                        P[5]>=C._height?C._height - 1:P[5]).move_to(colors);
        if (O.size()!=1) CImg<floatT>::vector(O._atXY(P[4],P[5])).move_to(opacities);
        else opacities.insert(O);
        CImg<uintT>::vector(P[1]).move_to(primitives);
        C.get_vector_at(P[6]>=C._width?C._width - 1:P[6],
                        P[7]>=C._height?C._height - 1:P[7]).move_to(colors);
        if (O.size()!=1) CImg<floatT>::vector(O._atXY(P[6],P[7])).move_to(opacities);
        else opacities.insert(O);
        CImg<uintT>::vector(P[2]).move_to(primitives);
        C.get_vector_at(P[8]>=C._width?C._width - 1:P[8],
                        P[9]>=C._height?C._height - 1:P[9]).move_to(colors);
        if (O.size()!=1) CImg<floatT>::vector(O._atXY(P[8],P[9])).move_to(opacities);
        else opacities.insert(O);
        CImg<uintT>::vector(P[3]).move_to(primitives);
        C.get_vector_at(P[10]>=C._width?C._width - 1:P[10],
                        P[11]>=C._height?C._height - 1:P[11]).move_to(colors);
        if (O.size()!=1) CImg<floatT>::vector(O._atXY(P[10],P[11])).move_to(opacities);
        else O.move_to(opacities);
      }
      break;
    default : // Other primitives.
      P.move_to(primitives);
      C.move_to(colors);
      O.move_to(opacities);
    }
  }
  if (psiz) {
    primitives.remove(0,psiz - 1);
    colors.remove(0,psiz - 1);
    opacities.remove(0,psiz - 1);
  }
  object3dtoCImg3d(primitives,colors,opacities,false);
  return *this;
}

CImg<T> get_convert_primitives_CImg3d(const unsigned int mode) const {
  return (+*this).convert_primitives_CImg3d(mode);
}

CImg<T>& copymark() {
  return get_copymark().move_to(*this);
}

CImg<T> get_copymark() const {
  if (is_empty()) return CImg<T>::string("~");
  CImg<T> res = get_resize(_width + 1,1,1,1,0);
  const char *const ext = cimg::split_filename(_data);
  if (*ext) {
    const int l = (int)(ext - _data - 1);
    if (l>0) {
      if (_data[l - 1]=='~') return +*this;
      std::memcpy(res._data,_data,l);
    }
    res[l] = '~'; res[l + 1] = '.';
    std::memcpy(res._data + l + 2,ext,_data + _width - ext);
  } else {
    const int l = (int)(ext - _data);
    if (_data[l - 1]=='~' || (l>1 && _data[l - 1]==']' && _data[l - 2]=='~')) return +*this;
    std::memcpy(res._data,_data,l);
    res[l] = '~';
    if (ext>_data && *(ext - 1)==']') cimg::swap(res[l],res[l - 1]);
    std::memcpy(res._data + l + 1,ext,_data + _width - ext);
  }
  return res;
}

template<typename tc>
CImg<T> get_draw_axes(const float x0, const float x1, const float y0, const float y1,
                      const tc *const color, const float opacity=1,
                      const int subdivisionx=-60, const int subdivisiony=-60,
                      const float precisionx=0, const float precisiony=0,
                      const unsigned int patternx=~0U, const unsigned int patterny=~0U,
                      const unsigned int font_height=13) const {
  return (+*this).draw_axes(x0,x1,y0,y1,color,opacity,subdivisionx,subdivisiony,
                            precisionx,precisiony,patternx,patterny,font_height);
}

CImg<T> get_draw_circle(const int x, const int y, const int r, const T *const col,
                        const float opacity) const {
  return (+*this).draw_circle(x,y,r,col,opacity);
}

CImg<T> get_draw_circle(const int x, const int y, const int r, const T *const col,
                        const float opacity,
                        const unsigned int pattern) const {
  return (+*this).draw_circle(x,y,r,col,opacity,pattern);
}

CImg<T> get_draw_ellipse(const int x, const int y, const float r0, const float r1,
                         const float angle, const T *const col, const float opacity) const {
  return (+*this).draw_ellipse(x,y,r0,r1,angle,col,opacity);
}

CImg<T> get_draw_ellipse(const int x, const int y, const float r0, const float r1,
                         const float angle, const T *const col, const float opacity,
                         const unsigned int pattern) const {
  return (+*this).draw_ellipse(x,y,r0,r1,angle,col,opacity,pattern);
}

CImg<T> get_draw_fill(const int x, const int y, const int z,
                      const T *const col, const float opacity,
                      const float tolerance, const bool is_high_connectivity) const {
  return (+*this).draw_fill(x,y,z,col,opacity,tolerance,is_high_connectivity);
}

template<typename t, typename tc>
CImg<T> get_draw_graph(const CImg<t>& data,
                       const tc *const color, const float opacity=1,
                       const unsigned int plot_type=1, const int vertex_type=1,
                       const double ymin=0, const double ymax=0,
                       const unsigned int pattern=~0U) const {
  return (+*this).draw_graph(data,color,opacity,plot_type,vertex_type,ymin,ymax,pattern);
}

template<typename tc>
CImg<T> get_draw_grid(const float sizex, const float sizey,
                      const float offsetx, const float offsety,
                      const bool invertx, const bool inverty,
                      const tc *const color, const float opacity=1,
                      const unsigned int patternx=~0U, const unsigned int patterny=~0U) {
  return (+*this).draw_grid(sizex,sizey,offsetx,offsety,invertx,inverty,color,opacity,
                            patternx,patterny);
}

CImg<T> get_draw_image(const int x, const int y, const int z, const int c,
                       const CImg<T>& sprite, const CImg<T>& mask, const float opacity,
                       const float max_opacity_mask) const {
  return (+*this).draw_image(x,y,z,c,sprite,mask,opacity,max_opacity_mask);
}

CImg<T> get_draw_image(const int x, const int y, const int z, const int c,
                       const CImg<T>& sprite, const float opacity) const {
  return (+*this).draw_image(x,y,z,c,sprite,opacity);
}

CImg<T> get_draw_line(const int x0, const int y0, const int x1, const int y1, const T *const col,
                      const float opacity, const unsigned int pattern) const {
  return (+*this).draw_line(x0,y0,x1,y1,col,opacity,pattern);
}

CImg<T> get_draw_mandelbrot(const CImg<T>& color_palette, const float opacity,
                            const double z0r, const double z0i, const double z1r, const double z1i,
                            const unsigned int itermax, const bool normalized_iteration,
                            const bool julia_set, const double paramr, const double parami) const {
  return (+*this).draw_mandelbrot(color_palette,opacity,z0r,z0i,z1r,z1i,itermax,
                                  normalized_iteration,julia_set,paramr,parami);
}

template<typename tp, typename tf, typename tc, typename to>
CImg<T> get_draw_object3d(const float x0, const float y0, const float z0,
                          const CImg<tp>& vertices, const CImgList<tf>& primitives,
                          const CImgList<tc>& colors, const CImgList<to>& opacities,
                          const unsigned int render_mode, const bool double_sided,
                          const float focale,
                          const float light_x, const float light_y,const float light_z,
                          const float specular_light, const float specular_shine,
                          CImg<floatT>& zbuffer) const {
  return (+*this).draw_object3d(x0,y0,z0,vertices,primitives,colors,opacities,render_mode,
                                double_sided,focale,light_x,light_y,light_z,specular_light,
                                specular_shine,zbuffer);
}

CImg<T> get_draw_plasma(const float alpha, const float beta, const unsigned int scale) const {
  return (+*this).draw_plasma(alpha,beta,scale);
}

CImg<T> get_draw_point(const int x, const int y, const int z, const T *const col,
                       const float opacity) const {
  return (+*this).draw_point(x,y,z,col,opacity);
}

template<typename t>
CImg<T> get_draw_polygon(const CImg<t>& pts, const T *const col, const float opacity) const {
  return (+*this).draw_polygon(pts,col,opacity);
}

template<typename t>
CImg<T> get_draw_polygon(const CImg<t>& pts, const T *const col, const float opacity,
                         const unsigned int pattern) const {
  return (+*this).draw_polygon(pts,col,opacity,pattern);
}

CImg<T>& gmic_autocrop(const CImg<T>& color=CImg<T>::empty()) {
  if (color.width()==1) autocrop(*color);
  else autocrop(color);
  return *this;
}

CImg<T> get_gmic_autocrop(const CImg<T>& color=CImg<T>::empty()) {
  return (+*this).gmic_autocrop(color);
}

CImg<T>& gmic_blur(const float sigma_x, const float sigma_y, const float sigma_z, const float sigma_c,
                   const bool boundary_conditions, const bool is_gaussian) {
  if (is_empty()) return *this;
  if (is_gaussian) {
    if (_width>1) vanvliet(sigma_x,0,'x',boundary_conditions);
    if (_height>1) vanvliet(sigma_y,0,'y',boundary_conditions);
    if (_depth>1) vanvliet(sigma_z,0,'z',boundary_conditions);
    if (_spectrum>1) vanvliet(sigma_c,0,'c',boundary_conditions);
  } else {
    if (_width>1) deriche(sigma_x,0,'x',boundary_conditions);
    if (_height>1) deriche(sigma_y,0,'y',boundary_conditions);
    if (_depth>1) deriche(sigma_z,0,'z',boundary_conditions);
    if (_spectrum>1) deriche(sigma_c,0,'c',boundary_conditions);
  }
  return *this;
}

CImg<Tfloat> get_gmic_blur(const float sigma_x, const float sigma_y, const float sigma_z, const float sigma_c,
                           const bool boundary_conditions, const bool is_gaussian) const {
  return CImg<Tfloat>(*this,false).gmic_blur(sigma_x,sigma_y,sigma_z,sigma_c,boundary_conditions,is_gaussian);
}

CImg<T>& gmic_blur_box(const float sigma_x, const float sigma_y, const float sigma_z, const float sigma_c,
                       const unsigned int order, const bool boundary_conditions) {
  if (is_empty()) return *this;
  if (_width>1) boxfilter(sigma_x,order,'x',boundary_conditions);
  if (_height>1) boxfilter(sigma_y,order,'y',boundary_conditions);
  if (_depth>1) boxfilter(sigma_z,order,'z',boundary_conditions);
  if (_spectrum>1) boxfilter(sigma_c,order,'c',boundary_conditions);
  return *this;
}

CImg<Tfloat> get_gmic_blur_box(const float sigma_x, const float sigma_y, const float sigma_z, const float sigma_c,
                               const unsigned int order, const bool boundary_conditions) const {
  return CImg<Tfloat>(*this,false).gmic_blur_box(sigma_x,sigma_y,sigma_z,sigma_c,order,boundary_conditions);
}

CImg<T>& gmic_blur_box(const float sigma, const unsigned int order, const bool boundary_conditions) {
  const float nsigma = sigma>=0?sigma:-sigma*cimg::max(_width,_height,_depth)/100;
  return gmic_blur_box(nsigma,nsigma,nsigma,0,order,boundary_conditions);
}

CImg<Tfloat> get_gmic_blur_box(const float sigma, const unsigned int order, const bool boundary_conditions) const {
  return CImg<Tfloat>(*this,false).gmic_blur_box(sigma,order,boundary_conditions);
}

CImg<T>& gmic_discard(const char *const axes) {
  for (const char *s = axes; *s; ++s) discard(*s);
  return *this;
}

CImg<T> get_gmic_discard(const char *const axes) const {
  return (+*this).gmic_discard(axes);
}

template<typename t>
CImg<T>& gmic_discard(const CImg<t>& values, const char *const axes) {
  if (is_empty() || !values || !axes || !*axes) return *this;
  for (const char *s = axes; *s; ++s) discard(values,*s);
  return *this;
}

template<typename t>
CImg<T> get_gmic_discard(const CImg<t>& values, const char *const axes) const {
  return (+*this).gmic_discard(values,axes);
}

CImg<T>& gmic_draw_text(const int x, const int y,
                        const char *const text, const T *const col,
                        const int bg, const float opacity, const unsigned int siz,
                        const unsigned int nb_cols) {
  if (is_empty()) {
    const T one[] = { (T)1 };
    assign().draw_text(x,y,"%s",one,0,opacity,siz,text).resize(-100,-100,1,nb_cols);
    cimg_forC(*this,c) get_shared_channel(c)*=col[c];
  } else draw_text(x,y,"%s",col,bg,opacity,siz,text);
  return *this;
}

CImg<T> get_gmic_draw_text(const int x, const int y,
                           const char *const text, const T *const col,
                           const int bg, const float opacity, const unsigned int siz,
                           const unsigned int nb_cols) const {
  return (+*this).gmic_draw_text(x,y,text,col,bg,opacity,siz,nb_cols);
}

CImg<T>& gmic_invert_endianness(const char *const stype) {

#define _gmic_invert_endianness(value_type,svalue_type) \
  if (!std::strcmp(stype,svalue_type)) \
    if (cimg::type<T>::string()==cimg::type<value_type>::string()) invert_endianness(); \
    else CImg<value_type>(*this).invert_endianness().move_to(*this);
  _gmic_invert_endianness(unsigned char,"uchar")
  else _gmic_invert_endianness(unsigned char,"unsigned char")
    else _gmic_invert_endianness(char,"char")
      else _gmic_invert_endianness(unsigned short,"ushort")
        else _gmic_invert_endianness(unsigned short,"unsigned short")
          else _gmic_invert_endianness(short,"short")
            else _gmic_invert_endianness(unsigned int,"uint")
              else _gmic_invert_endianness(unsigned int,"unsigned int")
                else _gmic_invert_endianness(int,"int")
                  else _gmic_invert_endianness(uint64T,"uint64")
                    else _gmic_invert_endianness(uint64T,"unsigned int64")
                      else _gmic_invert_endianness(int64T,"int64")
                        else _gmic_invert_endianness(float,"float")
                          else _gmic_invert_endianness(double,"double")
                            else invert_endianness();
  return *this;
}

CImg<T> get_gmic_invert_endianness(const char *const stype) const {
  return (+*this).gmic_invert_endianness(stype);
}

CImg<T>& gmic_patchmatch(const CImg<T>& patch_image,
                         const unsigned int patch_width,
                         const unsigned int patch_height,
                         const unsigned int patch_depth=1,
                         const unsigned int nb_iterations=5,
                         const unsigned int nb_randoms=5,
                         const bool is_score=false,
                         const CImg<T> *const initialization=0) {
  return get_gmic_patchmatch(patch_image,patch_width,patch_height,patch_depth,
                             nb_iterations,nb_randoms,is_score,initialization).move_to(*this);
}

CImg<T> get_gmic_patchmatch(const CImg<T>& patch_image,
                            const unsigned int patch_width,
                            const unsigned int patch_height,
                            const unsigned int patch_depth=1,
                            const unsigned int nb_iterations=5,
                            const unsigned int nb_randoms=5,
                            const bool is_score=false,
                            const CImg<T> *const initialization=0) const {
  CImg<floatT> score, res;
  res = _patchmatch(patch_image,patch_width,patch_height,patch_depth,
                    nb_iterations,nb_randoms,
                    initialization?*initialization:CImg<T>::const_empty(),
                    is_score,is_score?score:CImg<floatT>::empty());
  if (score) res.resize(-100,-100,-100,3,0).draw_image(0,0,0,2,score);
  return res;
}

const CImg<T>& gmic_print(const char *const title, const bool is_debug,
                          const bool is_valid) const {
  cimg::mutex(29);
  CImg<doubleT> st;
  if (is_valid && !is_empty()) st = get_stats();
  const ulongT siz = size(), msiz = siz*sizeof(T), siz1 = siz - 1,
    mdisp = msiz<8*1024?0U:msiz<8*1024*1024?1U:2U,
    wh = _width*_height, whd = _width*_height*_depth,
    w1 = _width - 1, wh1 = _width*_height - 1, whd1 = _width*_height*_depth - 1;

  std::fprintf(cimg::output(),"%s%s%s%s:\n  %ssize%s = (%u,%u,%u,%u) [%lu %s of %s%ss].\n  %sdata%s = %s",
               cimg::t_magenta,cimg::t_bold,title,cimg::t_normal,
               cimg::t_bold,cimg::t_normal,_width,_height,_depth,_spectrum,
               mdisp==0?msiz:(mdisp==1?(msiz>>10):(msiz>>20)),
               mdisp==0?"b":(mdisp==1?"Kio":"Mio"),
               _is_shared?"shared ":"",
               cimg::type<T>::string(),
               cimg::t_bold,cimg::t_normal,
               is_debug?"":"(");
  if (is_debug) std::fprintf(cimg::output(),"%p = (",(void*)_data);

  if (is_valid) {
    if (is_empty()) std::fprintf(cimg::output(),") [%s].\n",
                                 pixel_type());
    else {
      cimg_foroff(*this,off) {
        std::fprintf(cimg::output(),cimg::type<T>::format_s(),cimg::type<T>::format(_data[off]));
        if (off!=siz1) std::fprintf(cimg::output(),"%s",
                                    off%whd==whd1?"^":
                                    off%wh==wh1?"\\":
                                    off%_width==w1?";":",");
        if (off==11 && siz>24) { off = siz1 - 12; std::fprintf(cimg::output(),"(...),"); }
      }
      std::fprintf(cimg::output(),")%s.\n  %smin%s = %g, %smax%s = %g, %smean%s = %g, "
                   "%sstd%s = %g, %scoords_min%s = (%u,%u,%u,%u), "
                   "%scoords_max%s = (%u,%u,%u,%u).\n",
                   _is_shared?" [shared]":"",
                   cimg::t_bold,cimg::t_normal,st[0],
                   cimg::t_bold,cimg::t_normal,st[1],
                   cimg::t_bold,cimg::t_normal,st[2],
                   cimg::t_bold,cimg::t_normal,std::sqrt(st[3]),
                   cimg::t_bold,cimg::t_normal,(int)st[4],(int)st[5],(int)st[6],(int)st[7],
                   cimg::t_bold,cimg::t_normal,(int)st[8],(int)st[9],(int)st[10],(int)st[11]);
    }
  } else std::fprintf(cimg::output(),"%s%sinvalid pointer%s) [shared %s].\n",
                      cimg::t_red,cimg::t_bold,cimg::t_normal,
                      pixel_type());
  std::fflush(cimg::output());
  cimg::mutex(29,0);
  return *this;
}

CImg<T>& gmic_set(const double value,
                  const int x, const int y, const int z, const int v) {
  (*this).atXYZC(x,y,z,v,(T)0) = (T)value;
  return *this;
}

CImg<T> get_gmic_set(const double value,
                     const int x, const int y, const int z, const int v) const {
  return (+*this).gmic_set(value,x,y,z,v);
}

CImg<T>& gmic_shift(const float delta_x, const float delta_y=0, const float delta_z=0, const float delta_c=0,
                    const int boundary_conditions=0) {
  const int idelta_x = (int)delta_x, idelta_y = (int)delta_y, idelta_z = (int)delta_z, idelta_c = (int)delta_c;
  if (delta_x==(float)idelta_x && delta_y==(float)idelta_y && delta_z==(float)idelta_z && delta_c==(float)idelta_c) {
    // Integer displacement.
    return shift(idelta_x,idelta_y,idelta_z,idelta_c,boundary_conditions);
  }
  // Non-integer displacement.
  return _gmic_shift(delta_x,delta_y,delta_z,delta_c,boundary_conditions).move_to(*this);
}

// [note] get_gmic_shift() as it is avoids an additional buffer when non-integer displacement is used.
CImg<T> get_gmic_shift(const float delta_x, const float delta_y=0, const float delta_z=0, const float delta_c=0,
                       const int boundary_conditions=0) const {
  const int idelta_x = (int)delta_x, idelta_y = (int)delta_y, idelta_z = (int)delta_z, idelta_c = (int)delta_c;
  if (delta_x==(float)idelta_x && delta_y==(float)idelta_y && delta_z==(float)idelta_z && delta_c==(float)idelta_c) {
    return (+*this).shift(idelta_x,idelta_y,idelta_z,idelta_c,boundary_conditions); // Integer displacement.
  }
  return _gmic_shift(delta_x,delta_y,delta_z,delta_c,boundary_conditions); // Non-integer displacement.
}

CImg<T> _gmic_shift(const float delta_x, const float delta_y=0, const float delta_z=0, const float delta_c=0,
                    const int boundary_conditions=0) const {
  CImg<T> res(_width,_height,_depth,_spectrum);
  if (delta_c!=0) // 4D shift.
    switch (boundary_conditions) {
    case 0: // Dirichlet.
      cimg_pragma_openmp(parallel for collapse(3) if (res.size()>=4096))
      cimg_forXYZC(res,x,y,z,c) res(x,y,z,c) = linear_atXYZC(x - delta_x,y - delta_y,z - delta_z,c - delta_c,(T)0);
      break;
    case 1: // Neumann.
      cimg_pragma_openmp(parallel for collapse(3) if (res.size()>=4096))
      cimg_forXYZC(res,x,y,z,c) res(x,y,z,c) = linear_atXYZC(x - delta_x,y - delta_y,z - delta_z,c - delta_c);
      break;
    default: // Periodic.
      cimg_pragma_openmp(parallel for collapse(3) if (res.size()>=4096))
      cimg_forXYZC(res,x,y,z,c) res(x,y,z,c) = linear_atXYZC(cimg::mod(x - delta_x,(float)_width),
                                                             cimg::mod(y - delta_y,(float)_height),
                                                             cimg::mod(z - delta_z,(float)_depth),
                                                             cimg::mod(c - delta_c,(float)_spectrum));
    }
  else if (delta_z!=0) // 3D shift.
    switch (boundary_conditions) {
    case 0: // Dirichlet.
      cimg_pragma_openmp(parallel for collapse(3) if (res.size()>=4096))
      cimg_forC(res,c) cimg_forXYZ(res,x,y,z) res(x,y,z,c) = linear_atXYZ(x - delta_x,y - delta_y,z - delta_z,c,(T)0);
      break;
    case 1: // Neumann.
      cimg_pragma_openmp(parallel for collapse(3) if (res.size()>=4096))
      cimg_forC(res,c) cimg_forXYZ(res,x,y,z) res(x,y,z,c) = linear_atXYZ(x - delta_x,y - delta_y,z - delta_z,c);
      break;
    default: // Periodic.
      cimg_pragma_openmp(parallel for collapse(3) if (res.size()>=4096))
      cimg_forC(res,c) cimg_forXYZ(res,x,y,z) res(x,y,z,c) = linear_atXYZ(cimg::mod(x - delta_x,(float)_width),
                                                                          cimg::mod(y - delta_y,(float)_height),
                                                                          cimg::mod(z - delta_z,(float)_depth),c);
    }
  else if (delta_y!=0) // 2D shift.
    switch (boundary_conditions) {
    case 0: // Dirichlet.
      cimg_pragma_openmp(parallel for collapse(3) if (res.size()>=4096))
      cimg_forZC(res,z,c) cimg_forXY(res,x,y) res(x,y,z,c) = linear_atXY(x - delta_x,y - delta_y,z,c,(T)0);
      break;
    case 1: // Neumann.
      cimg_pragma_openmp(parallel for collapse(3) if (res.size()>=4096))
      cimg_forZC(res,z,c) cimg_forXY(res,x,y) res(x,y,z,c) = linear_atXY(x - delta_x,y - delta_y,z,c);
      break;
    default: // Periodic.
      cimg_pragma_openmp(parallel for collapse(3) if (res.size()>=4096))
      cimg_forZC(res,z,c) cimg_forXY(res,x,y) res(x,y,z,c) = linear_atXY(cimg::mod(x - delta_x,(float)_width),
                                                                         cimg::mod(y - delta_y,(float)_height),z,c);
    }
  else // 1D shift.
    switch (boundary_conditions) {
    case 0: // Dirichlet.
      cimg_pragma_openmp(parallel for collapse(3) if (res.size()>=4096))
      cimg_forYZC(res,y,z,c) cimg_forX(res,x) res(x,y,z,c) = linear_atX(x - delta_x,y,z,c,(T)0);
      break;
    case 1: // Neumann.
      cimg_pragma_openmp(parallel for collapse(3) if (res.size()>=4096))
      cimg_forYZC(res,y,z,c) cimg_forX(res,x) res(x,y,z,c) = linear_atX(x - delta_x,y,z,c);
      break;
    default: // Periodic.
      cimg_pragma_openmp(parallel for collapse(3) if (res.size()>=4096))
      cimg_forYZC(res,y,z,c) cimg_forX(res,x) res(x,y,z,c) = linear_atX(cimg::mod(x - delta_x,(float)_width),y,z,c);
    }
  return res;
}

template<typename t>
const CImg<T>& gmic_symmetric_eigen(CImg<t>& val, CImg<t>& vec) const {
  if (spectrum()!=3 && spectrum()!=6) return symmetric_eigen(val,vec);
  val.assign(width(),height(),depth(),spectrum()==3?2:3);
  vec.assign(width(),height(),depth(),spectrum()==3?2:6);
  CImg<t> _val, _vec;
  cimg_forXYZ(*this,x,y,z) {
    get_tensor_at(x,y,z).symmetric_eigen(_val,_vec);
    val.set_vector_at(_val,x,y,z);
    if (spectrum()==3) {
      vec(x,y,z,0) = _vec(0,0);
      vec(x,y,z,1) = _vec(0,1);
    } else {
      vec(x,y,z,0) = _vec(0,0);
      vec(x,y,z,1) = _vec(0,1);
      vec(x,y,z,2) = _vec(0,2);

      vec(x,y,z,3) = _vec(1,0);
      vec(x,y,z,4) = _vec(1,1);
      vec(x,y,z,5) = _vec(1,2);
    }
  }
  return *this;
}

template<typename t>
CImg<T>& inpaint(const CImg<t>& mask, const unsigned int method) {
  if (!is_sameXYZ(mask))
    throw CImgArgumentException("CImg<%s>::inpaint(): Invalid mask (%u,%u,%u,%u,%p) for "
                                "instance image (%u,%u,%u,%u,%p).",
                                pixel_type(),mask._width,mask._height,mask._depth,
                                mask._spectrum,mask._data,
                                _width,_height,_depth,_spectrum,_data);
  CImg<t> _mask(mask,false), _nmask(mask,false);
  bool is_pixel = false;

  do {
    is_pixel = false;

    if (depth()==1) { // 2d image.
      CImg_3x3(M,t);
      CImg_3x3(I,T);

      switch (method) {
      case 0: // Average 2d (low-connectivity).
        cimg_for3x3(_mask,x,y,0,0,M,t) if (Mcc && (!Mcp || !Mpc || !Mnc || !Mcn)) {
          is_pixel = true;
          const unsigned int wcp = Mcp?0U:1U, wpc = Mpc?0U:1U, wnc = Mnc?0U:1U, wcn = Mcn?0U:1U,
            sumw = wcp + wpc + wnc + wcn;
          cimg_forC(*this,k) {
            cimg_get3x3(*this,x,y,0,k,I,T);
            (*this)(x,y,k) = (T)((wcp*Icp + wpc*Ipc + wnc*Inc + wcn*Icn)/(float)sumw);
          }
          _nmask(x,y) = 0;
        }
        break;

      case 1: // Average 2d (high-connectivity).
        cimg_for3x3(_mask,x,y,0,0,M,t) if (Mcc && (!Mpp || !Mcp || !Mnp || !Mpc || !Mnc || !Mpn || !Mcn || !Mnn)) {
          is_pixel = true;
          const unsigned int
            wpp = Mpp?0U:1U, wcp = Mcp?0U:2U, wnp = Mnp?0U:1U,
            wpc = Mpc?0U:2U, wnc = Mnc?0U:2U,
            wpn = Mpn?0U:1U, wcn = Mcn?0U:2U, wnn = Mnn?0U:1U,
            sumw = wpp + wcp + wnp + wpc + wnc + wpn + wcn + wnn;
          cimg_forC(*this,k) {
            cimg_get3x3(*this,x,y,0,k,I,T);
            (*this)(x,y,k) = (T)((wpp*Ipp + wcp*Icp + wnp*Inp + wpc*Ipc +
                                  wnc*Inc + wpn*Ipn + wcn*Icn + wnn*Inn)/(float)sumw);
          }
          _nmask(x,y) = 0;
        }
        break;

      case 2: { // Median 2d (low-connectivity).
        T J[4];
        cimg_for3x3(_mask,x,y,0,0,M,t)
          if (Mcc && (!Mcp || !Mpc || !Mnc || !Mcn)) {
            is_pixel = true;
            cimg_forC(*this,k) {
              cimg_get3x3(*this,x,y,0,k,I,T);
              unsigned int ind = 0;
              if (!Mcp) J[ind++] = Icp;
              if (!Mpc) J[ind++] = Ipc;
              if (!Mnc) J[ind++] = Inc;
              if (!Mcn) J[ind++] = Icn;
              (*this)(x,y,k) = CImg<T>(J,ind,1,1,1,true).kth_smallest(ind>>1);
            }
            _nmask(x,y) = 0;
          }
      } break;

      default: // Median 2d (high-connectivity).
        T J[8];
        cimg_for3x3(_mask,x,y,0,0,M,t)
          if (Mcc && (!Mpp || !Mcp || !Mnp || !Mpc || !Mnc || !Mpn || !Mcn || !Mnn)) {
            is_pixel = true;
            cimg_forC(*this,k) {
              cimg_get3x3(*this,x,y,0,k,I,T);
              unsigned int ind = 0;
              if (!Mpp) J[ind++] = Ipp;
              if (!Mcp) J[ind++] = Icp;
              if (!Mnp) J[ind++] = Inp;
              if (!Mpc) J[ind++] = Ipc;
              if (!Mnc) J[ind++] = Inc;
              if (!Mpn) J[ind++] = Ipn;
              if (!Mcn) J[ind++] = Icn;
              if (!Mnn) J[ind++] = Inn;
              (*this)(x,y,k) = CImg<T>(J,ind,1,1,1,true).kth_smallest(ind>>1);
            }
            _nmask(x,y) = 0;
          }
      }

    } else { // 3d image.
      CImg_3x3x3(M,t);
      CImg_3x3x3(I,T);

      switch (method) {
      case 0: // Average 3d (low-connectivity).
        cimg_for3x3x3(_mask,x,y,z,0,M,t)
          if (Mccc && (!Mccp || !Mcpc || !Mpcc || !Mncc || !Mcnc || !Mccn)) {
            is_pixel = true;
            const unsigned int
              wccp = Mccp?0U:1U, wcpc = Mcpc?0U:1U, wpcc = Mpcc?0U:1U,
              wncc = Mncc?0U:1U, wcnc = Mcnc?0U:1U, wccn = Mccn?0U:1U,
              sumw = wcpc + wpcc + wccp + wncc + wcnc + wccn;
            cimg_forC(*this,k) {
              cimg_get3x3x3(*this,x,y,z,k,I,T);
              (*this)(x,y,z,k) = (T)((wccp*Iccp + wcpc*Icpc + wpcc*Ipcc +
                                      wncc*Incc + wcnc*Icnc + wccn*Iccn)/(float)sumw);
            }
            _nmask(x,y,z) = 0;
          }
        break;

      case 1: // Average 3d (high-connectivity).
        cimg_for3x3x3(_mask,x,y,z,0,M,t)
          if (Mccc && (!Mppp || !Mcpp || !Mnpp || !Mpcp || !Mccp || !Mncp || !Mpnp || !Mcnp ||
                       !Mnnp || !Mppc || !Mcpc || !Mnpc || !Mpcc || !Mncc || !Mpnc || !Mcnc ||
                       !Mnnc || !Mppn || !Mcpn || !Mnpn || !Mpcn || !Mccn || !Mncn || !Mpnn ||
                       !Mcnn || !Mnnn)) {
            is_pixel = true;
            const unsigned int
              wppp = Mppp?0U:1U, wcpp = Mcpp?0U:2U, wnpp = Mnpp?0U:1U,
              wpcp = Mpcp?0U:2U, wccp = Mccp?0U:4U, wncp = Mncp?0U:2U,
              wpnp = Mpnp?0U:1U, wcnp = Mcnp?0U:2U, wnnp = Mnnp?0U:1U,
              wppc = Mppc?0U:2U, wcpc = Mcpc?0U:4U, wnpc = Mnpc?0U:2U,
              wpcc = Mpcc?0U:4U, wncc = Mncc?0U:4U,
              wpnc = Mpnc?0U:2U, wcnc = Mcnc?0U:4U, wnnc = Mnnc?0U:2U,
              wppn = Mppn?0U:1U, wcpn = Mcpn?0U:2U, wnpn = Mnpn?0U:1U,
              wpcn = Mpcn?0U:2U, wccn = Mccn?0U:4U, wncn = Mncn?0U:2U,
              wpnn = Mpnn?0U:1U, wcnn = Mcnn?0U:2U, wnnn = Mnnn?0U:1U,
              sumw = wppp + wcpp + wnpp + wpcp + wccp + wncp + wpnp + wcnp + wnnp +
              wppc + wcpc + wnpc + wpcc + wncc + wpnc + wcnc + wnnc +
              wppn + wcpn + wnpn + wpcn + wccn + wncn + wpnn + wcnn + wnnn;
            cimg_forC(*this,k) {
              cimg_get3x3x3(*this,x,y,z,k,I,T);
              (*this)(x,y,z,k) = (T)((wppp*Ippp + wcpp*Icpp + wnpp*Inpp +
                                      wpcp*Ipcp + wccp*Iccp + wncp*Incp +
                                      wpnp*Ipnp + wcnp*Icnp + wnnp*Innp +
                                      wppc*Ippc + wcpc*Icpc + wnpc*Inpc +
                                      wpcc*Ipcc + wncc*Incc +
                                      wpnc*Ipnc + wcnc*Icnc + wnnc*Innc +
                                      wppn*Ippn + wcpn*Icpn + wnpn*Inpn +
                                      wpcn*Ipcn + wccn*Iccn + wncn*Incn +
                                      wpnn*Ipnn + wcnn*Icnn + wnnn*Innn)/(float)sumw);
            }
            _nmask(x,y,z) = 0;
          }
        break;

      case 2: { // Median 3d (low-connectivity).
        T J[6];
        cimg_for3x3x3(_mask,x,y,z,0,M,t)
          if (Mccc && (!Mccp || !Mcpc || !Mpcc || !Mncc || !Mcnc || !Mccn)) {
            is_pixel = true;
            cimg_forC(*this,k) {
              cimg_get3x3x3(*this,x,y,z,k,I,T);
              unsigned int ind = 0;
              if (!Mccp) J[ind++] = Iccp;
              if (!Mcpc) J[ind++] = Icpc;
              if (!Mpcc) J[ind++] = Ipcc;
              if (!Mncc) J[ind++] = Incc;
              if (!Mcnc) J[ind++] = Icnc;
              if (!Mccn) J[ind++] = Iccn;
              (*this)(x,y,z,k) = CImg<T>(J,ind,1,1,1,true).kth_smallest(ind>>1);
            }
            _nmask(x,y,z) = 0;
          }
      } break;

      default: { // Median 3d (high-connectivity).
        T J[26];
        cimg_for3x3x3(_mask,x,y,z,0,M,t)
          if (Mccc && (!Mppp || !Mcpp || !Mnpp || !Mpcp || !Mccp || !Mncp || !Mpnp || !Mcnp ||
                       !Mnnp || !Mppc || !Mcpc || !Mnpc || !Mpcc || !Mncc || !Mpnc || !Mcnc ||
                       !Mnnc || !Mppn || !Mcpn || !Mnpn || !Mpcn || !Mccn || !Mncn || !Mpnn ||
                       !Mcnn || !Mnnn)) {
            is_pixel = true;
            cimg_forC(*this,k) {
              cimg_get3x3x3(*this,x,y,z,k,I,T);
              unsigned int ind = 0;
              if (!Mppp) J[ind++] = Ippp;
              if (!Mcpp) J[ind++] = Icpp;
              if (!Mnpp) J[ind++] = Inpp;
              if (!Mpcp) J[ind++] = Ipcp;
              if (!Mccp) J[ind++] = Iccp;
              if (!Mncp) J[ind++] = Incp;
              if (!Mpnp) J[ind++] = Ipnp;
              if (!Mcnp) J[ind++] = Icnp;
              if (!Mnnp) J[ind++] = Innp;
              if (!Mppc) J[ind++] = Ippc;
              if (!Mcpc) J[ind++] = Icpc;
              if (!Mnpc) J[ind++] = Inpc;
              if (!Mpcc) J[ind++] = Ipcc;
              if (!Mncc) J[ind++] = Incc;
              if (!Mpnc) J[ind++] = Ipnc;
              if (!Mcnc) J[ind++] = Icnc;
              if (!Mnnc) J[ind++] = Innc;
              if (!Mppn) J[ind++] = Ippn;
              if (!Mcpn) J[ind++] = Icpn;
              if (!Mnpn) J[ind++] = Inpn;
              if (!Mpcn) J[ind++] = Ipcn;
              if (!Mccn) J[ind++] = Iccn;
              if (!Mncn) J[ind++] = Incn;
              if (!Mpnn) J[ind++] = Ipnn;
              if (!Mcnn) J[ind++] = Icnn;
              if (!Mnnn) J[ind++] = Innn;
              (*this)(x,y,z,k) = CImg<T>(J,ind,1,1,1,true).kth_smallest(ind>>1);
            }
            _nmask(x,y,z) = 0;
          }
      } break;
      }
    }

    _mask = _nmask;
  } while (is_pixel);
  return *this;
}

template<typename t>
CImg<T> get_inpaint(const CImg<t>& mask, const unsigned int method) const {
  return (+*this).inpaint(mask,method);
}

template<typename t>
CImg<T>& inpaint_patch(const CImg<t>& mask, const unsigned int patch_size=11,
                       const unsigned int lookup_size=22, const float lookup_factor=1,
                       const int lookup_increment=1,
                       const unsigned int blend_size=0, const float blend_threshold=0.5f,
                       const float blend_decay=0.02, const unsigned int blend_scales=10,
                       const bool is_blend_outer=false) {
  if (depth()>1)
    throw CImgInstanceException(_cimg_instance
                                "inpaint_patch(): Instance image is volumetric (should be 2d).",
                                cimg_instance);
  if (!is_sameXYZ(mask))
    throw CImgArgumentException(_cimg_instance
                                "inpaint_patch() : Sizes of instance image and specified mask "
                                "(%u,%u,%u,%u) do not match.",
                                cimg_instance,
                                mask._width,mask._height,mask._depth,mask._spectrum);
  if (!patch_size)
    throw CImgArgumentException(_cimg_instance
                                "inpaint_patch() : Specified patch size is 0, must be strictly "
                                "positive.",
                                cimg_instance);
  if (!lookup_size)
    throw CImgArgumentException(_cimg_instance
                                "inpaint_patch() : Specified lookup size is 0, must be strictly "
                                "positive.",
                                cimg_instance);
  if (lookup_factor<0)
    throw CImgArgumentException(_cimg_instance
                                "inpaint_patch() : Specified lookup factor %g is negative, must be "
                                "positive.",
                                cimg_instance,
                                lookup_factor);
  if (!lookup_increment)
    throw CImgArgumentException(_cimg_instance
                                "inpaint_patch() : Specified lookup increment is 0, must be "
                                "strictly positive.",
                                cimg_instance);
  if (blend_decay<0)
    throw CImgArgumentException(_cimg_instance
                                "inpaint_patch() : Specified blend decay %g is negative, must be "
                                "positive.",
                                cimg_instance,
                                blend_decay);

  // Find (dilated by 2) bounding box for the inpainting mask.
  unsigned int xm0 = _width, ym0 = _height, xm1 = 0, ym1 = 0;
  bool is_mask_found = false;
  cimg_forXY(mask,x,y) if (mask(x,y)) {
    is_mask_found = true;
    if (x<(int)xm0) xm0 = (unsigned int)x;
    if (x>(int)xm1) xm1 = (unsigned int)x;
    if (y<(int)ym0) ym0 = (unsigned int)y;
    if (y>(int)ym1) ym1 = (unsigned int)y;
  }
  if (!is_mask_found) return *this;
  xm0 = xm0>2?xm0 - 2:0;
  ym0 = ym0>2?ym0 - 2:0;
  xm1 = xm1<_width - 3?xm1 + 2:_width - 1;
  ym1 = ym1<_height - 3?ym1 + 2:_height - 1;
  int ox = (int)xm0, oy = (int)ym0;
  unsigned int dx = xm1 - xm0 + 1U, dy = ym1 - ym0 + 1U;

  // Construct normalized version of the mask.
  CImg<ucharT> nmask(dx,dy);
  unsigned char *ptrM = nmask.data();
  cimg_for_inXY(mask,xm0,ym0,xm1,ym1,x,y) *(ptrM++) = mask(x,y)?0U:1U;
  xm0 = ym0 = 0; xm1 = dx - 1; ym1 = dy - 1;

  // Start patch filling algorithm.
  const int p2 = (int)patch_size/2, p1 = (int)patch_size - p2 - 1;
  const unsigned int patch_size2 = patch_size*patch_size;
  unsigned int _lookup_size = lookup_size, nb_lookups = 0, nb_fails = 0, nb_saved_patches = 0;
  bool is_strict_search = true;
  const float one = 1;

  CImg<floatT> confidences(nmask), priorities(dx,dy,1,2,-1), pC;
  CImg<unsigned int> saved_patches(4,256), is_visited(width(),height(),1,1,0);
  CImg<ucharT> pM, pN;  // Pre-declare patch variables (avoid iterative memory alloc/dealloc).
  CImg<T> pP, pbest;
  CImg<floatT> weights(patch_size,patch_size,1,1,0);
  weights.draw_gaussian((float)p1,(float)p1,patch_size/15.0f,&one)/=patch_size2;
  unsigned int target_index = 0;

  while (true) {

    // Extract mask border points and compute priorities to find target point.
    unsigned int nb_border_points = 0;
    float target_confidence = -1, target_priority = -1;
    int target_x = -1, target_y = -1;
    CImg_5x5(M,unsigned char);

    cimg_for_in5x5(nmask,xm0,ym0,xm1,ym1,x,y,0,0,M,unsigned char)
      if (!Mcc && (Mcp || Mcn || Mpc || Mnc)) { // Found mask border point.

        float confidence_term = -1, data_term = -1;
        if (priorities(x,y)>=0) { // If priority has already been computed.
          confidence_term = priorities(x,y,0);
          data_term = priorities(x,y,1);
        } else { // If priority must be computed/updated.

          // Compute smoothed normal vector.
          const float
            // N = smoothed 3x3 neighborhood of M.
            Npc = (4.0f*Mpc + 2.0f*Mbc + 2.0f*Mcc + 2.0f*Mpp + 2.0f*Mpn + Mbp + Mbn + Mcp + Mcn)/16,
            Nnc = (4.0f*Mnc + 2.0f*Mac + 2.0f*Mcc + 2.0f*Mnp + 2.0f*Mnn + Map + Man + Mcp + Mcn)/16,
            Ncp = (4.0f*Mcp + 2.0f*Mcb + 2.0f*Mcc + 2.0f*Mpp + 2.0f*Mnp + Mpb + Mnb + Mpc + Mnc)/16,
            Ncn = (4.0f*Mcn + 2.0f*Mca + 2.0f*Mcc + 2.0f*Mpn + 2.0f*Mnn + Mpa + Mna + Mpc + Mnc)/16,
            _nx = 0.5f*(Nnc - Npc),
            _ny = 0.5f*(Ncn - Ncp),
            nn = std::sqrt(1e-8f + _nx*_nx + _ny*_ny),
            nx = _nx/nn,
            ny = _ny/nn;

          // Compute confidence term.
          nmask._inpaint_patch_crop(x - p1,y - p1,x + p2,y + p2,1).move_to(pM);
          confidences._inpaint_patch_crop(x - p1,y - p1,x + p2,y + p2,1).move_to(pC);
          confidence_term = 0;
          const unsigned char *ptrM = pM.data();
          cimg_for(pC,ptrC,float) confidence_term+=*ptrC**(ptrM++);
          confidence_term/=patch_size2;
          priorities(x,y,0) = confidence_term;

          // Compute data term.
          _inpaint_patch_crop(ox + x - p1,oy + y - p1,ox + x + p2,oy + y + p2,2).move_to(pP);
          float mean_ix2 = 0, mean_ixiy = 0, mean_iy2 = 0;

          CImg_3x3(I,T);
          CImg_3x3(_M, unsigned char);
          cimg_forC(pP,c) cimg_for3x3(pP,p,q,0,c,I,T) {
            // Compute weight-mean of structure tensor inside patch.
            cimg_get3x3(pM,p,q,0,0,_M,unsigned char);
            const float
              ixf = (float)(_Mnc*_Mcc*(Inc - Icc)),
              iyf = (float)(_Mcn*_Mcc*(Icn - Icc)),
              ixb = (float)(_Mcc*_Mpc*(Icc - Ipc)),
              iyb = (float)(_Mcc*_Mcp*(Icc - Icp)),
              ix = cimg::abs(ixf)>cimg::abs(ixb)?ixf:ixb,
              iy = cimg::abs(iyf)>cimg::abs(iyb)?iyf:iyb,
              w = weights(p,q);
            mean_ix2 += w*ix*ix;
            mean_ixiy += w*ix*iy;
            mean_iy2 += w*iy*iy;
          }
          const float // Compute tensor-directed data term.
            ux = mean_ix2*(-ny) + mean_ixiy*nx,
            uy = mean_ixiy*(-ny) + mean_iy2*nx;
          data_term = std::sqrt(ux*ux + uy*uy);
          priorities(x,y,1) = data_term;
        }
        const float priority = confidence_term*data_term;
        if (priority>target_priority) {
          target_priority = priority; target_confidence = confidence_term;
          target_x = ox + x; target_y = oy + y;
        }
        ++nb_border_points;
      }
    if (!nb_border_points) break; // No more mask border points to inpaint!

    // Locate already reconstructed neighbors (if any), to get good origins for patch lookup.
    CImg<unsigned int> lookup_candidates(2,256);
    unsigned int nb_lookup_candidates = 0, *ptr_lookup_candidates = lookup_candidates.data();
    const unsigned int *ptr_saved_patches = saved_patches.data();
    const int
      x0 = target_x - (int)patch_size, y0 = target_y - (int)patch_size,
      x1 = target_x + (int)patch_size, y1 = target_y + (int)patch_size;
    for (unsigned int k = 0; k<nb_saved_patches; ++k) {
      const unsigned int
        src_x = *(ptr_saved_patches++), src_y = *(ptr_saved_patches++),
        dest_x = *(ptr_saved_patches++), dest_y = *(ptr_saved_patches++);
      if ((int)dest_x>=x0 && (int)dest_y>=y0 && (int)dest_x<=x1 && (int)dest_y<=y1) {
        const int off_x = target_x - (int)dest_x, off_y = target_y - (int)dest_y;
        *(ptr_lookup_candidates++) = src_x + off_x;
        *(ptr_lookup_candidates++) = src_y + off_y;
        if (++nb_lookup_candidates>=lookup_candidates._height) {
          lookup_candidates.resize(2,-200,1,1,0);
          ptr_lookup_candidates = lookup_candidates.data(0,nb_lookup_candidates);
        }
      }
    }
    // Add also target point as a center for the patch lookup.
    if (++nb_lookup_candidates>=lookup_candidates._height) {
      lookup_candidates.resize(2,-200,1,1,0);
      ptr_lookup_candidates = lookup_candidates.data(0,nb_lookup_candidates);
    }
    *(ptr_lookup_candidates++) = (unsigned int)target_x;
    *(ptr_lookup_candidates++) = (unsigned int)target_y;

    // Divide size of lookup regions if several lookup sources have been detected.
    unsigned int final_lookup_size = _lookup_size;
    if (nb_lookup_candidates>1) {
      const unsigned int
        _final_lookup_size = std::max(5U,(unsigned int)cimg::round(_lookup_size*lookup_factor/
                                                                    std::sqrt((float)nb_lookup_candidates),1,1));
      final_lookup_size = _final_lookup_size + 1 - (_final_lookup_size%2);
    }
    const int l2 = (int)final_lookup_size/2, l1 = (int)final_lookup_size - l2 - 1;

#ifdef gmic_debug
    CImg<ucharT> visu(*this,false);
    for (unsigned int C = 0; C<nb_lookup_candidates; ++C) {
      const int
        xl = lookup_candidates(0,C),
        yl = lookup_candidates(1,C);
      visu.draw_rectangle(xl - l1,yl - l1,xl + l2,yl + l2,CImg<ucharT>::vector(0,255,0).data(),0.2f);
    }
    visu.draw_rectangle(target_x - p1,target_y - p1,target_x + p2,target_y + p2,
                        CImg<ucharT>::vector(255,0,0).data(),0.5f);
    static int foo = 0;
    if (!(foo%1)) {
      static CImgDisplay disp_debug;
      disp_debug.display(visu).set_title("DEBUG");
    }
    ++foo;
#endif // #ifdef gmic_debug

    // Find best patch candidate to fill target point.
    _inpaint_patch_crop(target_x - p1,target_y - p1,target_x + p2,target_y + p2,0).move_to(pP);
    nmask._inpaint_patch_crop(target_x - ox - p1,target_y - oy - p1,target_x - ox + p2,target_y - oy + p2,0).
      move_to(pM);
    ++target_index;
    const unsigned int
      _lookup_increment = (unsigned int)(lookup_increment>0?lookup_increment:
                                         nb_lookup_candidates>1?1:-lookup_increment);
    float best_ssd = cimg::type<float>::max();
    int best_x = -1, best_y = -1;
    for (unsigned int C = 0; C<nb_lookup_candidates; ++C) {
      const int
        xl = (int)lookup_candidates(0,C),
        yl = (int)lookup_candidates(1,C),
        x0 = std::max(p1,xl - l1), y0 = std::max(p1,yl - l1),
        x1 = std::min(width() - 1 - p2,xl + l2), y1 = std::min(height() - 1 - p2,yl + l2);
      for (int y = y0; y<=y1; y+=_lookup_increment)
        for (int x = x0; x<=x1; x+=_lookup_increment) if (is_visited(x,y)!=target_index) {
            if (is_strict_search) mask._inpaint_patch_crop(x - p1,y - p1,x + p2,y + p2,1).move_to(pN);
            else nmask._inpaint_patch_crop(x - ox - p1,y - oy - p1,x - ox + p2,y - oy + p2,0).move_to(pN);
            if ((is_strict_search && pN.sum()==0) || (!is_strict_search && pN.sum()==patch_size2)) {
              _inpaint_patch_crop(x - p1,y - p1,x + p2,y + p2,0).move_to(pC);
              float ssd = 0;
              const T *_pP = pP._data;
              const float *_pC = pC._data;
              cimg_for(pM,_pM,unsigned char) { if (*_pM) {
                  cimg_forC(pC,c) {
                    ssd+=cimg::sqr((Tfloat)*_pC - (Tfloat)*_pP); _pC+=patch_size2; _pP+=patch_size2;
                  }
                  if (ssd>=best_ssd) break;
                  _pC-=pC._spectrum*patch_size2;
                  _pP-=pC._spectrum*patch_size2;
                }
                ++_pC; ++_pP;
              }
              if (ssd<best_ssd) { best_ssd = ssd; best_x = x; best_y = y; }
            }
            is_visited(x,y) = target_index;
          }
    }

    if (best_x<0) { // If no best patch found.
      priorities(target_x - ox,target_y - oy,0)/=10; // Reduce its priority (lower data_term).
      if (++nb_fails>=4) { // If too much consecutive fails :
        nb_fails = 0;
        _lookup_size+=_lookup_size/2; // Try to expand the lookup size.
        if (++nb_lookups>=3) {
          if (is_strict_search) { // If still fails, switch to non-strict search mode.
            is_strict_search = false;
            _lookup_size = lookup_size;
            nb_lookups = 0;
          }
          else return *this; // Pathological case, probably a weird mask.
        }
      }
    } else { // Best patch found -> reconstruct missing part on the target patch.
      _lookup_size = lookup_size;
      nb_lookups = nb_fails = 0;
      _inpaint_patch_crop(best_x - p1,best_y - p1,best_x + p2,best_y + p2,0).move_to(pbest);
      nmask._inpaint_patch_crop(target_x - ox - p1,target_y - oy - p1,target_x - ox + p2,target_y - oy + p2,1).
        move_to(pM);
      cimg_for(pM,ptr,unsigned char) *ptr = (unsigned char)(1 - *ptr);
      draw_image(target_x - p1,target_y - p1,pbest,pM,1,1);
      confidences.draw_image(target_x - ox - p1,target_y - oy - p1,pC.fill(target_confidence),pM,1,1);
      nmask.draw_rectangle(target_x - ox - p1,target_y - oy - p1,0,0,target_x - ox + p2,target_y - oy + p2,0,0,1);
      priorities.draw_rectangle(target_x - ox - (int)patch_size,
                                target_y - oy - (int)patch_size,0,0,
                                target_x - ox + 3*p2/2,
                                target_y - oy + 3*p2/2,0,0,-1);
      // Remember patch positions.
      unsigned int *ptr_saved_patches = saved_patches.data(0,nb_saved_patches);
      *(ptr_saved_patches++) = (unsigned int)best_x;
      *(ptr_saved_patches++) = (unsigned int)best_y;
      *(ptr_saved_patches++) = (unsigned int)target_x;
      *ptr_saved_patches = (unsigned int)target_y;
      if (++nb_saved_patches>=saved_patches._height) saved_patches.resize(4,-200,1,1,0);
    }
  }
  nmask.assign();  // Free some unused memory resources.
  priorities.assign();
  confidences.assign();
  is_visited.assign();

  // Blend inpainting result (if requested), using multi-scale blending algorithm.
  if (blend_size && blend_scales) {
    const float _blend_threshold = std::max(0.0f,std::min(1.0f,blend_threshold));
    saved_patches._height = nb_saved_patches;

    // Re-crop image and mask if outer blending is activated.
    if (is_blend_outer) {
      const int
        b2 = (int)blend_size/2, b1 = (int)blend_size - b2 - 1,
        xb0 = std::max(0,ox - b1),
        yb0 = std::max(0,oy - b1),
        xb1 = (int)std::min(_width - 1,xb0 + dx + b1 + b2),
        yb1 = (int)std::min(_height - 1,yb0 + dy + b1 + b2);
      ox = xb0; oy = yb0; dx = xb1 - xb0 + 1U, dy = yb1 - yb0 + 1U;
    }

    // Generate map of source offsets.
    CImg<unsigned int> offsets(dx,dy,1,2);
    unsigned int *ptr = saved_patches.end();
    cimg_forY(saved_patches,i) {
      const unsigned int yd = *(--ptr), xd = *(--ptr), ys = *(--ptr), xs = *(--ptr);
      for (int l = -p1; l<=p2; ++l)
        for (int k = -p1; k<=p2; ++k) {
          const int xdk = (int)xd + k, ydl = (int)yd + l;
          if (xdk>=0 && xdk<=width() - 1 && ydl>=0 && ydl<=height() - 1 && mask(xd + k,yd + l)) {
            offsets(xd - ox + k,yd - oy + l,0) = xs + k;
            offsets(xd - ox + k,yd - oy + l,1) = ys + l;
          }
        }
    }
    unsigned int *ptrx = offsets.data(0,0,0,0), *ptry = offsets.data(0,0,0,1);
    cimg_forXY(offsets,x,y) {
      if (!mask(x + ox,y + oy)) { *ptrx = (unsigned int)(x + ox); *ptry = (unsigned int)(y + oy); }
      ++ptrx; ++ptry;
    }

    // Generate map of local blending amplitudes.
    CImg<floatT> blend_map(dx,dy,1,1,0);
    CImg_3x3(I,float);
    cimg_for3XY(offsets,x,y) if (mask(x + ox,y + oy)) {
      const float
        iox = std::max((float)offsets(_n1x,y,0) - offsets(x,y,0),
                        (float)offsets(x,y,0) - offsets(_p1x,y,0)),
        ioy = std::max((float)offsets(x,_n1y,1) - offsets(x,y,1),
                        (float)offsets(x,y,1) - offsets(x,_p1y,1)),
        ion = std::sqrt(iox*iox + ioy*ioy);
      float iin = 0;
      cimg_forC(*this,c) {
        cimg_get3x3(*this,x,y,0,c,I,float);
        const float
          iix = (float)std::max(Inc - Icc,Icc - Ipc),
          iiy = (float)std::max(Icn - Icc,Icc - Icp);
        iin+=std::log(1 + iix*iix + iiy*iiy);
      }
      iin/=_spectrum;
      blend_map(x,y) = ion*iin;
    }
    blend_map.threshold(blend_map.max()*_blend_threshold).distance(1);
    cimg_forXY(blend_map,x,y) blend_map(x,y) = 1/(1 + blend_decay*blend_map(x,y));
    blend_map.quantize(blend_scales + 1,false);
    float bm, bM = blend_map.max_min(bm);
    if (bm==bM) blend_map.fill((float)blend_scales);

    // Generate blending scales.
    CImg<T> result = _inpaint_patch_crop(ox,oy,ox + dx - 1,oy + dy - 1,0);
    for (unsigned int blend_iter = 1; blend_iter<=blend_scales; ++blend_iter) {
      const unsigned int
        _blend_width = blend_iter*blend_size/blend_scales,
        blend_width = _blend_width?_blend_width + 1 - (_blend_width%2):0;
      if (!blend_width) continue;
      const int b2 = (int)blend_width/2, b1 = (int)blend_width - b2 - 1;
      CImg<floatT>
        blended = _inpaint_patch_crop(ox,oy,ox + dx - 1,oy + dy - 1,0),
        cumul(dx,dy,1,1);
      weights.assign(blend_width,blend_width,1,1,0).
        draw_gaussian((float)b1,(float)b1,blend_width/4.0f,&one);
      cimg_forXY(cumul,x,y) cumul(x,y) = mask(x + ox,y + oy)?0.0f:1.0f;
      blended.mul(cumul);

      cimg_forY(saved_patches,l) {
        const unsigned int *ptr = saved_patches.data(0,l);
        const int
          xs = (int)*(ptr++),
          ys = (int)*(ptr++),
          xd = (int)*(ptr++),
          yd = (int)*(ptr++);
        if (xs - b1<0 || ys - b1<0 || xs + b2>=width() || ys + b2>=height()) { // Blend with partial patch.
          const int
            xs0 = std::max(0,xs - b1),
            ys0 = std::max(0,ys - b1),
            xs1 = std::min(width() - 1,xs + b2),
            ys1 = std::min(height() - 1,ys + b2);
          _inpaint_patch_crop(xs0,ys0,xs1,ys1,0).move_to(pP);
          weights._inpaint_patch_crop(xs0 - xs + b1,ys0 - ys + b1,xs1 - xs + b1,ys1 - ys + b1,0).move_to(pC);
          blended.draw_image(xd + xs0 - xs - ox,yd + ys0 - ys - oy,pP,pC,-1);
          cumul.draw_image(xd + xs0 - xs - ox,yd + ys0 - ys - oy,pC,-1);
        } else { // Blend with full-size patch.
          _inpaint_patch_crop(xs - b1,ys - b1,xs + b2,ys + b2,0).move_to(pP);
          blended.draw_image(xd - b1 - ox,yd - b1 - oy,pP,weights,-1);
          cumul.draw_image(xd - b1 - ox,yd - b1 - oy,weights,-1);
        }
      }

      if (is_blend_outer) {
        cimg_forXY(blended,x,y) if (blend_map(x,y)==blend_iter) {
          const float cum = cumul(x,y);
          if (cum>0) cimg_forC(*this,c) result(x,y,c) = (T)(blended(x,y,c)/cum);
        }
      } else { cimg_forXY(blended,x,y) if (mask(x + ox,y + oy) && blend_map(x,y)==blend_iter) {
          const float cum = cumul(x,y);
          if (cum>0) cimg_forC(*this,c) result(x,y,c) = (T)(blended(x,y,c)/cum);
        }
      }
    }
    if (is_blend_outer) draw_image(ox,oy,result);
    else cimg_forXY(result,x,y) if (mask(x + ox,y + oy))
           cimg_forC(*this,c) (*this)(x + ox,y + oy,c) = (T)result(x,y,c);
  }
  return *this;
}

// Special crop function that supports more boundary conditions :
// 0=dirichlet (with value 0), 1=dirichlet (with value 1) and 2=neumann.
CImg<T> _inpaint_patch_crop(const int x0, const int y0, const int x1, const int y1,
                            const unsigned int boundary=0) const {
  const int
    nx0 = x0<x1?x0:x1, nx1 = x0^x1^nx0,
    ny0 = y0<y1?y0:y1, ny1 = y0^y1^ny0;
  CImg<T> res(1U + nx1 - nx0,1U + ny1 - ny0,1,_spectrum);
  if (nx0<0 || nx1>=width() || ny0<0 || ny1>=height()) {
    if (boundary>=2) cimg_forXYZC(res,x,y,z,c) res(x,y,z,c) = _atXY(nx0 + x,ny0 + y,z,c);
    else res.fill((T)boundary).draw_image(-nx0,-ny0,*this);
  } else res.draw_image(-nx0,-ny0,*this);
  return res;
}

template<typename t>
CImg<T> get_inpaint_patch(const CImg<t>& mask, const unsigned int patch_size=11,
                          const unsigned int lookup_size=22, const float lookup_factor=1,
                          const int lookup_increment=1,
                          const unsigned int blend_size=0, const float blend_threshold=0.5,
                          const float blend_decay=0.02f, const unsigned int blend_scales=10,
                          const bool is_blend_outer=false) const {
  return (+*this).inpaint_patch(mask,patch_size,lookup_size,lookup_factor,lookup_increment,
                                blend_size,blend_threshold,blend_decay,blend_scales,is_blend_outer);
}

CImg<T>& max(const char *const expression, CImgList<T> &images) {
  return max((+*this)._fill(expression,true,true,&images,&images,"max",this));
}

CImg<T>& min(const char *const expression, CImgList<T> &images) {
  return min((+*this)._fill(expression,true,true,&images,&images,"min",this));
}

CImg<T>& operator_andeq(const char *const expression, CImgList<T> &images) {
  return operator&=((+*this)._fill(expression,true,true,&images,&images,"operator&=",this));
}

CImg<T>& operator_brseq(const char *const expression, CImgList<T> &images) {
  return operator<<=((+*this)._fill(expression,true,true,&images,&images,"operator<<=",this));
}

CImg<T>& operator_blseq(const char *const expression, CImgList<T> &images) {
  return operator>>=((+*this)._fill(expression,true,true,&images,&images,"operator>>=",this));
}

CImg<T>& operator_diveq(const char *const expression, CImgList<T> &images) {
  return div((+*this)._fill(expression,true,true,&images,&images,"operator/=",this));
}

template<typename t>
CImg<T>& operator_eq(const t val) {
  if (is_empty()) return *this;
  cimg_pragma_openmp(parallel for cimg_openmp_if(size()>=131072))
  cimg_rof(*this,ptrd,T) *ptrd = (T)(*ptrd == (T)val);
  return *this;
}

CImg<T>& operator_eq(const char *const expression, CImgList<T> &images) {
  return operator_eq((+*this)._fill(expression,true,true,&images,&images,"operator_eq",this));
}

template<typename t>
CImg<T>& operator_eq(const CImg<t>& img) {
  const ulongT siz = size(), isiz = img.size();
  if (siz && isiz) {
    if (is_overlapped(img)) return operator_eq(+img);
    T *ptrd = _data, *const ptre = _data + siz;
    if (siz>isiz)
      for (ulongT n = siz/isiz; n; --n)
        for (const t *ptrs = img._data, *ptrs_end = ptrs + isiz; ptrs<ptrs_end; ++ptrd)
          *ptrd = (T)(*ptrd == (T)*(ptrs++));
    for (const t *ptrs = img._data; ptrd<ptre; ++ptrd) *ptrd = (T)(*ptrd == (T)*(ptrs++));
  }
  return *this;
}

template<typename t>
CImg<T>& operator_ge(const t val) {
  if (is_empty()) return *this;
  cimg_pragma_openmp(parallel for cimg_openmp_if(size()>=131072))
  cimg_rof(*this,ptrd,T) *ptrd = (T)(*ptrd >= (T)val);
  return *this;
}

CImg<T>& operator_ge(const char *const expression, CImgList<T> &images) {
  return operator_ge((+*this)._fill(expression,true,true,&images,&images,"operator_ge",this));
}

template<typename t>
CImg<T>& operator_ge(const CImg<t>& img) {
  const ulongT siz = size(), isiz = img.size();
  if (siz && isiz) {
    if (is_overlapped(img)) return operator_ge(+img);
    T *ptrd = _data, *const ptre = _data + siz;
    if (siz>isiz)
      for (ulongT n = siz/isiz; n; --n)
        for (const t *ptrs = img._data, *ptrs_end = ptrs + isiz; ptrs<ptrs_end; ++ptrd)
          *ptrd = (T)(*ptrd >= (T)*(ptrs++));
    for (const t *ptrs = img._data; ptrd<ptre; ++ptrd) *ptrd = (T)(*ptrd >= (T)*(ptrs++));
  }
  return *this;
}

template<typename t>
CImg<T>& operator_gt(const t val) {
  if (is_empty()) return *this;
  cimg_pragma_openmp(parallel for cimg_openmp_if(size()>=131072))
  cimg_rof(*this,ptrd,T) *ptrd = (T)(*ptrd > (T)val);
  return *this;
}

CImg<T>& operator_gt(const char *const expression, CImgList<T> &images) {
  return operator_gt((+*this)._fill(expression,true,true,&images,&images,"operator_gt",this));
}

template<typename t>
CImg<T>& operator_gt(const CImg<t>& img) {
  const ulongT siz = size(), isiz = img.size();
  if (siz && isiz) {
    if (is_overlapped(img)) return operator_gt(+img);
    T *ptrd = _data, *const ptre = _data + siz;
    if (siz>isiz)
      for (ulongT n = siz/isiz; n; --n)
        for (const t *ptrs = img._data, *ptrs_end = ptrs + isiz; ptrs<ptrs_end; ++ptrd)
          *ptrd = (T)(*ptrd > (T)*(ptrs++));
    for (const t *ptrs = img._data; ptrd<ptre; ++ptrd) *ptrd = (T)(*ptrd > (T)*(ptrs++));
  }
  return *this;
}

template<typename t>
CImg<T>& operator_le(const t val) {
  if (is_empty()) return *this;
  cimg_pragma_openmp(parallel for cimg_openmp_if(size()>=131072))
  cimg_rof(*this,ptrd,T) *ptrd = (T)(*ptrd <= (T)val);
  return *this;
}

CImg<T>& operator_le(const char *const expression, CImgList<T> &images) {
  return operator_le((+*this)._fill(expression,true,true,&images,&images,"operator_le",this));
}

template<typename t>
CImg<T>& operator_le(const CImg<t>& img) {
  const ulongT siz = size(), isiz = img.size();
  if (siz && isiz) {
    if (is_overlapped(img)) return operator_le(+img);
    T *ptrd = _data, *const ptre = _data + siz;
    if (siz>isiz)
      for (ulongT n = siz/isiz; n; --n)
        for (const t *ptrs = img._data, *ptrs_end = ptrs + isiz; ptrs<ptrs_end; ++ptrd)
          *ptrd = (T)(*ptrd <= (T)*(ptrs++));
    for (const t *ptrs = img._data; ptrd<ptre; ++ptrd) *ptrd = (T)(*ptrd <= (T)*(ptrs++));
  }
  return *this;
}

template<typename t>
CImg<T>& operator_lt(const t val) {
  if (is_empty()) return *this;
  cimg_pragma_openmp(parallel for cimg_openmp_if(size()>=131072))
  cimg_rof(*this,ptrd,T) *ptrd = (T)(*ptrd < (T)val);
  return *this;
}

CImg<T>& operator_lt(const char *const expression, CImgList<T> &images) {
  return operator_lt((+*this)._fill(expression,true,true,&images,&images,"operator_lt",this));
}

template<typename t>
CImg<T>& operator_lt(const CImg<t>& img) {
  const ulongT siz = size(), isiz = img.size();
  if (siz && isiz) {
    if (is_overlapped(img)) return operator_lt(+img);
    T *ptrd = _data, *const ptre = _data + siz;
    if (siz>isiz)
      for (ulongT n = siz/isiz; n; --n)
        for (const t *ptrs = img._data, *ptrs_end = ptrs + isiz; ptrs<ptrs_end; ++ptrd)
          *ptrd = (T)(*ptrd < (T)*(ptrs++));
    for (const t *ptrs = img._data; ptrd<ptre; ++ptrd) *ptrd = (T)(*ptrd < (T)*(ptrs++));
  }
  return *this;
}

CImg<T>& operator_minuseq(const char *const expression, CImgList<T> &images) {
  return operator-=((+*this)._fill(expression,true,true,&images,&images,"operator-=",this));
}

CImg<T>& operator_modeq(const char *const expression, CImgList<T> &images) {
  return operator%=((+*this)._fill(expression,true,true,&images,&images,"operator%=",this));
}

CImg<T>& operator_muleq(const char *const expression, CImgList<T> &images) {
  return mul((+*this)._fill(expression,true,true,&images,&images,"operator*=",this));
}

template<typename t>
CImg<T>& operator_neq(const t val) {
  if (is_empty()) return *this;
  cimg_pragma_openmp(parallel for cimg_openmp_if(size()>=131072))
  cimg_rof(*this,ptrd,T) *ptrd = (T)(*ptrd != (T)val);
  return *this;
}

CImg<T>& operator_neq(const char *const expression, CImgList<T> &images) {
  return operator_neq((+*this)._fill(expression,true,true,&images,&images,"operator_neq",this));
}

template<typename t>
CImg<T>& operator_neq(const CImg<t>& img) {
  const ulongT siz = size(), isiz = img.size();
  if (siz && isiz) {
    if (is_overlapped(img)) return operator_neq(+img);
    T *ptrd = _data, *const ptre = _data + siz;
    if (siz>isiz)
      for (ulongT n = siz/isiz; n; --n)
        for (const t *ptrs = img._data, *ptrs_end = ptrs + isiz; ptrs<ptrs_end; ++ptrd)
          *ptrd = (T)(*ptrd != (T)*(ptrs++));
    for (const t *ptrs = img._data; ptrd<ptre; ++ptrd) *ptrd = (T)(*ptrd != (T)*(ptrs++));
  }
  return *this;
}

CImg<T>& operator_oreq(const char *const expression, CImgList<T> &images) {
  return operator|=((+*this)._fill(expression,true,true,&images,&images,"operator|=",this));
}

CImg<T>& operator_pluseq(const char *const expression, CImgList<T> &images) {
  return operator+=((+*this)._fill(expression,true,true,&images,&images,"operator+=",this));
}

CImg<T>& operator_xoreq(const char *const expression, CImgList<T> &images) {
  return operator^=((+*this)._fill(expression,true,true,&images,&images,"operator^=",this));
}

CImg<T>& pow(const char *const expression, CImgList<T> &images) {
  return pow((+*this)._fill(expression,true,true,&images,&images,"pow",this));
}

template<typename t>
CImg<T>& replace(CImg<t>& img) {
  return img.move_to(*this);
}

template<typename t>
CImg<T> get_replace(const CImg<t>& img) const {
  return +img;
}

CImg<T>& reverse_CImg3d() {
  CImg<char> error_message(1024);
  if (!is_CImg3d(false,error_message))
    throw CImgInstanceException(_cimg_instance
                                "reverse_CImg3d(): image instance is not a CImg3d (%s).",
                                cimg_instance,error_message.data());
  T *p = _data + 6;
  const unsigned int
    nbv = cimg::float2uint(*(p++)),
    nbp = cimg::float2uint(*(p++));
  p+=3*nbv;
  for (unsigned int i = 0; i<nbp; ++i) {
    const unsigned int nb = (unsigned int)*(p++);
    switch(nb) {
    case 2: case 3: cimg::swap(p[0],p[1]); break;
    case 6: cimg::swap(p[0],p[1],p[2],p[4],p[3],p[5]); break;
    case 9: cimg::swap(p[0],p[1],p[3],p[5],p[4],p[6]); break;
    case 4: cimg::swap(p[0],p[1],p[2],p[3]); break;
    case 12: cimg::swap(p[0],p[1],p[2],p[3],p[4],p[6],p[5],p[7],p[8],p[10],p[9],p[11]); break;
    }
    p+=nb;
  }
  return *this;
}

CImg<T> get_reverse_CImg3d() const {
  return (+*this).reverse_CImg3d();
}

CImg<T>& rol(const char *const expression, CImgList<T> &images) {
  return rol((+*this)._fill(expression,true,true,&images,&images,"rol",this));
}

CImg<T>& ror(const char *const expression, CImgList<T> &images) {
  return ror((+*this)._fill(expression,true,true,&images,&images,"ror",this));
}

template<typename t>
CImg<T>& rotate_CImg3d(const CImg<t>& rot) {
  CImg<charT> error_message(1024);
  if (!is_CImg3d(false,error_message))
    throw CImgInstanceException(_cimg_instance
                                "rotate_CImg3d(): image instance is not a CImg3d (%s).",
                                cimg_instance,error_message.data());
  const unsigned int nbv = cimg::float2uint((float)(*this)[6]);
  const T *ptrs = data() + 8;
  const float
    a = (float)rot(0,0), b = (float)rot(1,0), c = (float)rot(2,0),
    d = (float)rot(0,1), e = (float)rot(1,1), f = (float)rot(2,1),
    g = (float)rot(0,2), h = (float)rot(1,2), i = (float)rot(2,2);
  T *ptrd = data() + 8;
  for (unsigned int j = 0; j<nbv; ++j) {
    const float
      x = (float)ptrs[0],
      y = (float)ptrs[1],
      z = (float)ptrs[2];
    ptrs+=3;
    ptrd[0] = (T)(a*x + b*y + c*z);
    ptrd[1] = (T)(d*x + e*y + f*z);
    ptrd[2] = (T)(g*x + h*y + i*z);
    ptrd+=3;
  }
  return *this;
}

template<typename t>
CImg<T> get_rotate_CImg3d(const CImg<t>& rot) const {
  return (+*this).rotate_CImg3d(rot);
}

CImg<T>& scale_CImg3d(const float sx, const float sy, const float sz) {
  CImg<charT> error_message(1024);
  if (!is_CImg3d(false,error_message))
    throw CImgInstanceException(_cimg_instance
                                "scale_CImg3d(): image instance is not a CImg3d (%s).",
                                cimg_instance,error_message.data());
  const unsigned int nbv = cimg::float2uint((float)(*this)[6]);
  T *ptrd = data() + 8;
  for (unsigned int j = 0; j<nbv; ++j) { *(ptrd++)*=(T)sx; *(ptrd++)*=(T)sy; *(ptrd++)*=(T)sz; }
  return *this;
}

CImg<T> get_scale_CImg3d(const float sx, const float sy, const float sz) const {
  return (+*this).scale_CImg3d(sx,sy,sz);
}

CImg<T>& shift_CImg3d(const float tx, const float ty, const float tz) {
  CImg<charT> error_message(1024);
  if (!is_CImg3d(false,error_message))
    throw CImgInstanceException(_cimg_instance
                                "shift_CImg3d(): image instance is not a CImg3d (%s).",
                                cimg_instance,error_message.data());
  const unsigned int nbv = cimg::float2uint((float)(*this)[6]);
  T *ptrd = data() + 8;
  for (unsigned int j = 0; j<nbv; ++j) { *(ptrd++)+=(T)tx; *(ptrd++)+=(T)ty; *(ptrd++)+=(T)tz; }
  return *this;
}

CImg<T> get_shift_CImg3d(const float tx, const float ty, const float tz) const {
  return (+*this).shift_CImg3d(tx,ty,tz);
}

CImgList<T> get_split_CImg3d() const {
  CImg<charT> error_message(1024);
  if (!is_CImg3d(false,error_message))
    throw CImgInstanceException(_cimg_instance
                                "get_split_CImg3d(): image instance is not a CImg3d (%s).",
                                cimg_instance,error_message.data());
  CImgList<T> res;
  const T *ptr0 = _data, *ptr = ptr0 + 6;
  CImg<T>(ptr0,1,(unsigned int)(ptr - ptr0),1,1).move_to(res); // Header.
  ptr0 = ptr;
  const unsigned int
    nbv = cimg::float2uint(*(ptr++)),
    nbp = cimg::float2uint(*(ptr++));
  CImg<T>(ptr0,1,(unsigned int)(ptr - ptr0),1,1).move_to(res); // Nb vertices and primitives.
  ptr0 = ptr; ptr+=3*nbv;
  CImg<T>(ptr0,1,(unsigned int)(ptr - ptr0),1,1).move_to(res); // Vertices.
  ptr0 = ptr;
  for (unsigned int i = 0; i<nbp; ++i) ptr+=(unsigned int)(*ptr) + 1;
  CImg<T>(ptr0,1,(unsigned int)(ptr - ptr0),1,1).move_to(res); // Primitives.
  ptr0 = ptr;
  for (unsigned int i = 0; i<nbp; ++i) {
    const T val = *(ptr++);
    if (val!=-128) ptr+=2;
    else {
      const unsigned int
        w = cimg::float2uint(ptr[0]),
        h = cimg::float2uint(ptr[1]),
        s = cimg::float2uint(ptr[2]);
      ptr+=3;
      if (w*h*s!=0) ptr+=w*h*s;
    }
  }
  CImg<T>(ptr0,1,(unsigned int)(ptr - ptr0),1,1).move_to(res); // Colors/Textures.
  ptr0 = ptr;
  for (unsigned int i = 0; i<nbp; ++i) {
    const T val = *(ptr++);
    if (val==-128) {
      const unsigned int
        w = cimg::float2uint(ptr[0]),
        h = cimg::float2uint(ptr[1]),
        s = cimg::float2uint(ptr[2]);
      ptr+=3;
      if (w*h*s!=0) ptr+=w*h*s;
    }
  }
  CImg<T>(ptr0,1,(unsigned int)(ptr - ptr0),1,1).move_to(res); // Opacities.
  return res;
}

CImg<T>& texturize_CImg3d(const CImg<T>& texture, const CImg<T>& coords) {
  return get_texturize_CImg3d(texture,coords).move_to(*this);
}

CImg<T> get_texturize_CImg3d(const CImg<T>& texture, const CImg<T>& coords) const {
  CImgList<uintT> primitives;
  CImgList<T> colors;
  CImgList<floatT> opacities;
  const CImg<floatT> points = get_CImg3dtoobject3d(primitives,colors,opacities,false);
  if (coords)
    points.texturize_object3d(primitives,colors,texture,coords.get_resize(2,coords.size()/2,1,1,-1).transpose());
  else points.texturize_object3d(primitives,colors,texture,coords);
  return points.get_object3dtoCImg3d(primitives,colors,opacities,false);
}

//--------------- End of CImg plug-in ----------------------------

#else // #ifdef cimg_plugin

#include "gmic.h"
#include "gmic_stdlib.h"
using namespace cimg_library;
#undef min
#undef max

// Define convenience macros, variables and functions.
//----------------------------------------------------

// Define default pixel type.
#ifndef gmic_pixel_type
#define gmic_pixel_type float
#endif

// Macro to force stringifying selection for error messages.
#define gmic_selection_err selection2string(selection,images_names,1,gmic_selection)

// Return image argument as a shared or non-shared copy of one existing image.
inline bool _gmic_image_arg(const unsigned int ind, const CImg<unsigned int>& selection) {
  cimg_forY(selection,l) if (selection[l]==ind) return true;
  return false;
}
#define gmic_image_arg(ind) gmic_check(_gmic_image_arg(ind,selection)?images[ind]:\
                                       images[ind].get_shared())

// Macro to manage argument substitutions from a command.
template<typename T>
void gmic::_gmic_substitute_args(const char *const argument, const char *const argument0,
                                 const char *const command, const char *const item,
                                 const CImgList<T>& images) {
  if (is_debug) {
    if (std::strcmp(argument,argument0)) debug(images,"Command '%s': arguments = '%s' -> '%s'.",
                                               *command?command:item,argument0,argument); \
    else debug(images,"Command '%s': arguments = '%s'.",
               *command?command:item,argument0);
  }
}

#define gmic_substitute_args(is_image_expr) { \
  const char *const argument0 = argument; \
  substitute_item(argument,images,images_names,parent_images,parent_images_names,variables_sizes,\
                  command_selection,is_image_expr).move_to(_argument); \
  _gmic_substitute_args(argument = _argument,argument0,command,item,images); \
}

// Macro for computing a readable version of a command argument.
inline char *_gmic_argument_text(const char *const argument, CImg<char>& argument_text, const bool is_verbose) {
  if (is_verbose) return cimg::strellipsize(argument,argument_text,80,false);
  else return &(*argument_text=0);
}

#define gmic_argument_text_printed() _gmic_argument_text(argument,argument_text,is_verbose)
#define gmic_argument_text() _gmic_argument_text(argument,argument_text,true)

// Macro for having 'get' or 'non-get' versions of G'MIC commands.
#define gmic_apply(function) { \
    __ind = (unsigned int)selection[l]; \
    gmic_check(images[__ind]); \
    if (is_double_hyphen) { \
      images[__ind].get_##function.move_to(images); \
      images_names[__ind].get_copymark().move_to(images_names); \
    } else images[__ind].function; \
  }

// Macro for simple commands that has no arguments and act on images.
#define gmic_simple_command(command_name,function,description) \
  if (!std::strcmp(command_name,command)) { \
    print(images,0,description,gmic_selection.data()); \
    cimg_forY(selection,l) gmic_apply(function()); \
    is_released = false; continue; \
}

// Macro for G'MIC arithmetic commands.
#define gmic_arithmetic_command(command_name,\
                                function1,description1,arg1_1,arg1_2,arg1_3,value_type1, \
                                function2,description2,arg2_1,arg2_2, \
                                function3,description3,arg3_1,arg3_2, \
                                description4) \
 if (!std::strcmp(command_name,command)) { \
   gmic_substitute_args(true); \
   sep = *indices = *formula = 0; value = 0; \
   if (cimg_sscanf(argument,"%lf%c",&value,&end)==1 || \
       (cimg_sscanf(argument,"%lf%c%c",&value,&sep,&end)==2 && sep=='%')) { \
     const char *const ssep = sep=='%'?"%":""; \
     print(images,0,description1 ".",arg1_1,arg1_2,arg1_3); \
     cimg_forY(selection,l) { \
       CImg<T>& img = gmic_check(images[selection[l]]); \
       nvalue = value; \
       if (sep=='%' && img) { \
         vmax = (double)img.max_min(vmin); \
         nvalue = vmin + (vmax - vmin)*value/100; \
       } \
       if (is_double_hyphen) { \
         g_img.assign(img,false).function1((value_type1)nvalue).move_to(images); \
         images_names.insert(images_names[selection[l]].get_copymark()); \
       } else img.function1((value_type1)nvalue); \
     } \
     ++position; \
   } else if (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep,&end)==2 && sep==']' && \
              (ind=selection2cimg(indices,images.size(),images_names,command_name)).height()==1) { \
     print(images,0,description2 ".",arg2_1,arg2_2); \
     const CImg<T> img0 = gmic_image_arg(*ind); \
     cimg_forY(selection,l) { \
       CImg<T>& img = gmic_check(images[selection[l]]); \
       if (is_double_hyphen) { \
         g_img.assign(img,false).function2(img0).move_to(images); \
         images_names.insert(images_names[selection[l]].get_copymark()); \
       } else img.function2(img0); \
     } \
     ++position; \
   } else if (cimg_sscanf(argument,"'%4095[^']%c%c",formula,&sep,&end)==2 && sep=='\'') { \
     strreplace_fw(formula); print(images,0,description3 ".",arg3_1,arg3_2); \
     cimg_forY(selection,l) { \
       CImg<T>& img = gmic_check(images[selection[l]]); \
       if (is_double_hyphen) { \
         g_img.assign(img,false).function3((const char*)formula,images).move_to(images); \
         images_names.insert(images_names[selection[l]].get_copymark()); \
       } else img.function3((const char*)formula,images); \
     } \
     ++position; \
   } else { \
     print(images,0,description4 ".",gmic_selection.data()); \
     if (images && selection) { \
       if (is_double_hyphen) { \
         g_img.assign(gmic_check(images[selection[0]]),false); \
         for (unsigned int l = 1; l<(unsigned int)selection.height(); ++l) \
           g_img.function2(gmic_check(images[selection[l]])); \
         images_names.insert(images_names[selection[0]].get_copymark()); \
         g_img.move_to(images); \
       } else if (selection.height()>=2) { \
       const unsigned int ind0 = selection[0]; \
       CImg<T>& img = gmic_check(images[ind0]); \
       for (unsigned int l = 1; l<(unsigned int)selection.height(); ++l) \
         img.function2(gmic_check(images[selection[l]])); \
       remove_images(images,images_names,selection,1,selection.height() - 1); \
       }}} is_released = false; continue; \
   }

// Manage mutexes.
struct _gmic_mutex {
#if cimg_OS==2
  HANDLE mutex[256];
  _gmic_mutex() { for (unsigned int i = 0; i<256; ++i) mutex[i] = CreateMutex(0,FALSE,0); }
  void lock(const unsigned int n) { WaitForSingleObject(mutex[n],INFINITE); }
  void unlock(const unsigned int n) { ReleaseMutex(mutex[n]); }
#elif defined(_PTHREAD_H) // #if cimg_OS==2
  pthread_mutex_t mutex[256];
  _gmic_mutex() { for (unsigned int i = 0; i<256; ++i) pthread_mutex_init(&mutex[i],0); }
  void lock(const unsigned int n) { pthread_mutex_lock(&mutex[n]); }
  void unlock(const unsigned int n) { pthread_mutex_unlock(&mutex[n]); }
#else // #if cimg_OS==2
  _gmic_mutex() {}
  void lock(const unsigned int) {}
  void unlock(const unsigned int) {}
#endif // #if cimg_OS==2
};
inline _gmic_mutex& gmic_mutex() { static _gmic_mutex val; return val; }

// Thread structure and routine for command '-parallel'.
template<typename T>
struct st_gmic_parallel {
  CImgList<char> *images_names, *parent_images_names, commands_line;
  CImgList<st_gmic_parallel<T> > *threads_data;
  CImgList<T> *images, *parent_images;
  CImg<unsigned int> variables_sizes;
  const CImg<unsigned int> *command_selection;
  bool is_thread_running;
  gmic_exception exception;
  gmic gmic_instance;
#ifdef gmic_is_parallel
#if cimg_OS!=2
  pthread_t thread_id;
#else // #if cimg_OS!=2
  HANDLE thread_id;
#endif // #if cimg_OS!=2
#endif // #ifdef gmic_is_parallel
  st_gmic_parallel() { variables_sizes.assign(512); }
};

template<typename T>
#if cimg_OS!=2
static void *gmic_parallel(void *arg)
#else // #if cimg_OS!=2
static DWORD WINAPI gmic_parallel(void *arg)
#endif // #if cimg_OS!=2
{
  st_gmic_parallel<T> &st = *(st_gmic_parallel<T>*)arg;
  unsigned int pos = 0;
  try {
    st.gmic_instance.is_debug_info = false;
    st.gmic_instance._run(st.commands_line,pos,*st.images,*st.images_names,
                          *st.parent_images,*st.parent_images_names,
                          st.variables_sizes,0,0,st.command_selection);
  } catch (gmic_exception &e) {

    // Send all remaining running threads the 'abort' signal.
#ifdef gmic_is_parallel
    CImgList<st_gmic_parallel<T> > &threads_data = *st.threads_data;
    cimglist_for(threads_data,i) cimg_forY(threads_data[i],l)
      if (&threads_data(i,l)!=&st && threads_data(i,l).is_thread_running) {
        threads_data(i,l).gmic_instance.is_abort_thread = true;
#if cimg_OS!=2
        pthread_join(threads_data(i,l).thread_id,0);
#else // #if cimg_OS!=2
        WaitForSingleObject(threads_data(i,l).thread_id,INFINITE);
        CloseHandle(threads_data(i,l).thread_id);
#endif // #if cimg_OS!=2
        threads_data(i,l).is_thread_running = false;
      }
#endif // #ifdef gmic_is_parallel

    st.exception._command_help.assign(e._command_help);
    st.exception._message.assign(e._message);
  }
#if defined(gmic_is_parallel) && cimg_OS!=2
  pthread_exit(0);
#endif // #if defined(gmic_is_parallel) && cimg_OS!=2
  return 0;
}

// Return Levenshtein distance between two strings.
// (adapted from http://rosettacode.org/wiki/Levenshtein_distance#C)
int gmic::_levenshtein(const char *const s, const char *const t,
                       CImg<int>& d, const int i, const int j) {
  const int ls = d.width() - 1, lt = d.height() - 1;
  if (d(i,j)>=0) return d(i,j);
  int x;
  if (i==ls) x = lt - j;
  else if (j==lt) x = ls - i;
  else if (s[i]==t[j]) x = _levenshtein(s,t,d,i + 1,j + 1);
  else {
    x = _levenshtein(s,t,d,i + 1,j + 1);
    int y;
    if ((y=_levenshtein(s,t,d,i,j + 1))<x) x = y;
    if ((y=_levenshtein(s,t,d,i + 1,j))<x) x = y;
    ++x;
  }
  return d(i,j) = x;
}

int gmic::levenshtein(const char *const s, const char *const t) {
  const char *const ns = s?s:"", *const nt = t?t:"";
  const int ls = (int)std::strlen(ns), lt = (int)std::strlen(nt);
  if (!ls) return lt; else if (!lt) return ls;
  CImg<int> d(1 + ls,1 + lt,1,1,-1);
  return _levenshtein(ns,nt,d,0,0);
}

// Return true if specified filename corresponds to an existing file or directory.
bool gmic::check_filename(const char *const filename) {
  bool res = false;
#if cimg_OS==2
  const unsigned int attr = (unsigned int)GetFileAttributesA(filename);
  res = (attr!=~0U);
#else // #if cimg_OS==2
  std::FILE *const file = std::fopen(filename,"r");
  if (file) { res = true; std::fclose(file); }
#endif // #if cimg_OS==2
  return res;
}

// Return a 8-bits hashcode from a string.
unsigned int gmic::hashcode(const char *const str, const bool is_variable) {
  if (!str) return 0U;
  unsigned int hash = 0U;
  if (is_variable) {
    if (*str=='_') return str[1]=='_'?511U:510U;
    for (const char *s = str; *s; ++s) (hash*=31)+=*s;
    return hash%510;
  }
  for (const char *s = str; *s; ++s) (hash*=31)+=*s;
  return hash&511;
}

// Tells if the the implementation of a G'MIC command contains arguments.
bool gmic::command_has_arguments(const char *const command) {
  if (!command || !*command) return false;
  for (const char *s = std::strchr(command,'$'); s; s = std::strchr(s,'$')) {
    const char c = *(++s);
    if (c=='#' ||
        c=='*' ||
        c=='=' ||
        (c>'0' && c<='9') ||
        (c=='-' && *(s + 1)>'0' && *(s + 1)<='9') ||
        (c=='\"' && *(s + 1)=='*' && *(s + 2)=='\"') ||
        (c=='{' && (*(s + 1)=='^' ||
                    (*(s + 1)>'0' && *(s + 1)<='9') ||
                    (*(s + 1)=='-' && *(s + 2)>'0' && *(s + 2)<='9')))) return true;
  }
  return false;
}

// Compute the basename of a filename.
const char* gmic::basename(const char *const str)  {
  if (!str) return str;
  const unsigned int l = (unsigned int)std::strlen(str);
  if (*str=='[' && (str[l - 1]==']' || str[l - 1]=='.')) return str;
  const char *p = 0, *np = str;
  while (np>=str && (p=np)) np = std::strchr(np,'/') + 1;
  np = p;
  while (np>=str && (p=np)) np = std::strchr(np,'\\') + 1;
  return p;
}

// Replace special characters in a string.
char *gmic::strreplace_fw(char *const str) {
  if (str) for (char *s = str ; *s; ++s) {
      const char c = *s;
      if (c<' ')
        *s = c==gmic_dollar?'$':c==gmic_lbrace?'{':c==gmic_rbrace?'}':c==gmic_comma?',':
          c==gmic_dquote?'\"':c;
    }
  return str;
}

char *gmic::strreplace_bw(char *const str) {
  if (str) for (char *s = str ; *s; ++s) {
      const char c = *s;
      *s = c=='$'?gmic_dollar:c=='{'?gmic_lbrace:c=='}'?gmic_rbrace:c==','?gmic_comma:
        c=='\"'?gmic_dquote:c;
    }
  return str;
}

//! Escape a string.
// 'res' must be a C-string large enough ('4*strlen(str)+1' is always safe).
unsigned int gmic::strescape(const char *const str, char *const res) {
  const char *const esc = "abtnvfr";
  char *ptrd = res;
  for (const char *ptrs = str; *ptrs; ++ptrs) {
    const char c = *ptrs;
    if (c=='\\' || c=='\'' || c=='\"') { *(ptrd++) = '\\'; *(ptrd++) = c; }
    else if (c>=7 && c<=13) { *(ptrd++) = '\\'; *(ptrd++) = esc[c - 7]; }
    else if (c>=32 && c<=126) *(ptrd++) = c;
    else if (c<gmic_dollar || c>gmic_newline) {
      *(ptrd++) = '\\';
      *(ptrd++) = 'x';
      char d = c>>4;
      *(ptrd++) = d + (d<10?'0':'a'-10);
      d = c&15;
      *(ptrd++) = d + (d<10?'0':'a'-10);
    } else *(ptrd++) = c;
  }
  *ptrd = 0;
  return (unsigned int)(ptrd - res);
}

// Constructors / destructors.
//----------------------------
#if cimg_display!=0
#define gmic_new_attr commands(new CImgList<char>[512]), commands_names(new CImgList<char>[512]), \
    commands_has_arguments(new CImgList<char>[512]), \
    _variables(new CImgList<char>[512]), _variables_names(new CImgList<char>[512]), \
    variables(new CImgList<char>*[512]), variables_names(new CImgList<char>*[512]), \
    display_window(new CImgDisplay[10]), is_running(false)
#else
#define gmic_new_attr commands(new CImgList<char>[512]), commands_names(new CImgList<char>[512]), \
    commands_has_arguments(new CImgList<char>[512]), \
    _variables(new CImgList<char>[512]), _variables_names(new CImgList<char>[512]), \
    variables(new CImgList<char>*[512]), variables_names(new CImgList<char>*[512]), \
    display_window(0), is_running(false)
#endif // #if cimg_display!=0

CImg<char> gmic::stdlib = CImg<char>::empty();

gmic::gmic():gmic_new_attr {
  CImgList<gmic_pixel_type> images;
  CImgList<char> images_names;
  verbosity = -1;
  _gmic(0,images,images_names,0,true,0,0);
  verbosity = 0;
}

gmic::gmic(const char *const commands_line, const char *const custom_commands,
           const bool include_stdlib, float *const p_progress, bool *const p_is_abort):
  gmic_new_attr {
  CImgList<gmic_pixel_type> images;
  CImgList<char> images_names;
  _gmic(commands_line,
        images,images_names,custom_commands,
        include_stdlib,p_progress,p_is_abort);
}

gmic::~gmic() {
  cimg::exception_mode(cimg_exception_mode);
#if cimg_display!=0
  CImgDisplay *const _display_window = (CImgDisplay*)display_window;
  delete[] _display_window;
#endif
  delete[] commands;
  delete[] commands_names;
  delete[] commands_has_arguments;
  delete[] _variables;
  delete[] _variables_names;
  delete[] variables;
  delete[] variables_names;
}

// Decompress G'MIC standard library commands.
//---------------------------------------------
const CImg<char>& gmic::decompress_stdlib() {
  if (!stdlib) try {
      CImgList<char>::get_unserialize(CImg<unsigned char>(data_gmic_stdlib,1,size_data_gmic_stdlib,1,1,true))[0].
        move_to(stdlib);
    } catch (...) {
      cimg::mutex(29);
      std::fprintf(cimg::output(),
                   "[gmic] %s*** Warning *** Could not decompress G'MIC standard library, ignoring it.%s\n",
                   cimg::t_red,cimg::t_normal);
      std::fflush(cimg::output());
      cimg::mutex(29,0);
      stdlib.assign(1,1,1,1,0);
    }
  return stdlib;
}

// Get path to .gmic user file.
//-----------------------------
const char* gmic::path_user(const char *const custom_path) {
  static CImg<char> path_user;
  if (path_user) return path_user;
  cimg::mutex(28);
  const char *_path_user = 0;
  if (custom_path && cimg::is_directory(custom_path)) _path_user = custom_path;
  if (!_path_user) _path_user = getenv("GMIC_PATH");
  if (!_path_user) _path_user = getenv("GMIC_GIMP_PATH");
  if (!_path_user) {
#if cimg_OS!=2
    _path_user = getenv("HOME");
#else
    _path_user = getenv("APPDATA");
#endif
  }
  if (!_path_user) _path_user = getenv("TMP");
  if (!_path_user) _path_user = getenv("TEMP");
  if (!_path_user) _path_user = getenv("TMPDIR");
  if (!_path_user) _path_user = "";
  path_user.assign(1024);
#if cimg_OS!=2
  cimg_snprintf(path_user,path_user.width(),"%s%c.gmic",
                _path_user,cimg_file_separator);
#else
  cimg_snprintf(path_user,path_user.width(),"%s%cuser.gmic",
                _path_user,cimg_file_separator);
#endif
  CImg<char>::string(path_user).move_to(path_user);  // Optimize length.
  cimg::mutex(28,0);
  return path_user;
}

// Get path to the resource directory.
//------------------------------------
const char* gmic::path_rc(const char *const custom_path) {
  static CImg<char> path_rc;
  CImg<char> path_tmp;
  if (path_rc) return path_rc;
  cimg::mutex(28);
  const char *_path_rc = 0;
  if (custom_path && cimg::is_directory(custom_path)) _path_rc = custom_path;
  if (!_path_rc) _path_rc = getenv("GMIC_PATH");
  if (!_path_rc) _path_rc = getenv("GMIC_GIMP_PATH");
  if (!_path_rc) _path_rc = getenv("XDG_CONFIG_HOME");
  if (!_path_rc) {
#if cimg_OS!=2
    _path_rc = getenv("HOME");
    if (_path_rc) {
      path_tmp.assign(std::strlen(_path_rc) + 10);
      cimg_sprintf(path_tmp,"%s/.config",_path_rc);
      if (cimg::is_directory(path_tmp)) _path_rc = path_tmp;
    }
#else
    _path_rc = getenv("APPDATA");
#endif
  }
  if (!_path_rc) _path_rc = getenv("TMP");
  if (!_path_rc) _path_rc = getenv("TEMP");
  if (!_path_rc) _path_rc = getenv("TMPDIR");
  if (!_path_rc) _path_rc = "";
  path_rc.assign(1024);
  cimg_snprintf(path_rc,path_rc.width(),"%s%cgmic%c",
                _path_rc,cimg_file_separator,cimg_file_separator);
  CImg<char>::string(path_rc).move_to(path_rc);  // Optimize length.
  cimg::mutex(28,0);
  return path_rc;
}

// Create resources directory.
//----------------------------
bool gmic::init_rc(const char *const custom_path) {
  CImg<char> dirname = CImg<char>::string(path_rc(custom_path));
  if (dirname.width()>=2) dirname[dirname.width() - 2] = 0;
  if (!cimg::is_directory(dirname)) {
    std::remove(dirname); // In case 'dirname' is already a file.
#if cimg_OS==2
    return (bool)CreateDirectoryA(dirname,0);
#else
    return !(bool)mkdir(dirname,0777);
#endif
  }
  return true;
}

// Get current call stack as a string.
//-------------------------------------
CImg<char> gmic::callstack2string(const CImg<unsigned int> *const callstack_selection, const bool is_debug) const {
  if (callstack_selection && !*callstack_selection) return CImg<char>("./",3);
  CImgList<char> input_callstack;
  if (!callstack_selection) input_callstack.assign(callstack,true);
  else cimg_forY(*callstack_selection,l) input_callstack.insert(callstack[(*callstack_selection)[l]],~0U,true);
  CImgList<char> res;
  const unsigned int siz = (unsigned int)input_callstack.size();
  if (siz<=9 || is_debug) res.assign(input_callstack,false);
  else {
    res.assign(9);
    res[0].assign(input_callstack[0],false);
    res[1].assign(input_callstack[1],false);
    res[2].assign(input_callstack[2],false);
    res[3].assign(input_callstack[3],false);
    res[4].assign("(...)",6);
    res[5].assign(input_callstack[siz - 4],false);
    res[6].assign(input_callstack[siz - 3],false);
    res[7].assign(input_callstack[siz - 2],false);
    res[8].assign(input_callstack[siz - 1],false);
  }
  cimglist_for(res,l) {
    if (!verbosity && !is_debug) {
      char *const s = res(l,0)!='*'?0:std::strchr(res[l],'#');
      if (s) { *s = 0; CImg<char>(res[l].data(),(unsigned int)(s - res[l].data() + 1)).move_to(res[l]); }
    }
    res[l].back() = '/';
  }
  CImg<char>::vector(0).move_to(res);
  return res>'x';
}

CImg<char> gmic::callstack2string(const bool is_debug) const {
  return callstack2string(0,is_debug);
}

CImg<char> gmic::callstack2string(const CImg<unsigned int>& callstack_selection, const bool is_debug) const {
  return callstack2string(&callstack_selection,is_debug);
}

// Parse items from a G'MIC command line.
//---------------------------------------
CImgList<char> gmic::commands_line_to_CImgList(const char *const commands_line) {
  if (!commands_line || !*commands_line) return CImgList<char>();
  bool is_dquoted = false;
  const char *ptrs0 = commands_line;
  while (*ptrs0==' ') ++ptrs0;  // Remove leading spaces to first item.
  CImg<char> item((unsigned int)std::strlen(ptrs0) + 1);
  CImgList<char> items;
  char *ptrd = item.data(), c = 0;
  for (const char *ptrs = ptrs0; *ptrs; ++ptrs) {
    c = *ptrs;
    if (c=='\\') { // If escaped character.
      c = *(++ptrs);
      if (!c) { c = '\\'; --ptrs; }
      else if (c=='$') c = gmic_dollar;
      else if (c=='{') c = gmic_lbrace;
      else if (c=='}') c = gmic_rbrace;
      else if (c==',') c = gmic_comma;
      else if (c=='\"') c = gmic_dquote;
      else if (c==' ') c = ' ';
      else *(ptrd++) = '\\';
      *(ptrd++) = c;
    } else if (is_dquoted) { // If non-escaped character inside string.
      if (c=='\"') is_dquoted = false;
      else if (c==1) while (c && c!=' ') c = *(++ptrs); // Discard debug info inside string.
      else *(ptrd++) = (c=='$' && ptrs[1]!='?')?gmic_dollar:c=='{'?gmic_lbrace:c=='}'?gmic_rbrace:
             c==','?gmic_comma:c;
    } else { // Non-escaped character outside string.
      if (c=='\"') is_dquoted = true;
      else if (c==' ') {
        *ptrd = 0; CImg<char>(item.data(),(unsigned int)(ptrd - item.data() + 1)).move_to(items);
        ptrd = item.data();
        ++ptrs; while (*ptrs==' ') ++ptrs; ptrs0 = ptrs--;  // Remove trailing spaces to next item.
      } else *(ptrd++) = c;
    }
  }
  if (is_dquoted) {
    CImg<char> str; CImg<char>::string(commands_line).move_to(str); // Discard debug info inside string.
    char *ptrd = str, c = 0;
    bool _is_debug_info = false;
    cimg_for(str,ptrs,char) {
      c = *ptrs;
      if (c && c!=1) *(ptrd++) = c;
      else { // Try to retrieve first debug line when discarding debug info.
        unsigned int _debug_filename = ~0U, _debug_line = ~0U;
        if (!_is_debug_info && cimg_sscanf(ptrs + 1,"%x,%x",&_debug_line,&(_debug_filename=0))) {
          debug_filename = _debug_filename;
          debug_line = _debug_line;
          _is_debug_info = is_debug_info = true;
        }
        while (c && c!=' ') c = *(++ptrs);
      }
    } *ptrd = 0;
    error("Invalid command line: Double quotes are not closed, in expression '%s'.",
          str.data());
  }
  if (ptrd!=item.data() && c!=' ') {
    *ptrd = 0; CImg<char>(item.data(),(unsigned int)(ptrd - item.data() + 1)).move_to(items);
  }
  if (is_debug) {
    debug("Decompose command line into %u items: ",items.size());
    cimglist_for(items,l) {
      if (items(l,0)==1) {
        if (items(l,1)) debug("  item[%u] = (debug info 0x%s)",l,items[l].data() + 1);
        else debug("  item[%u] = (undefined debug info)",l);
      } else debug("  item[%u] = '%s'",l,items[l].data());
    }
  }
  return items;
}

// Print log message.
//-------------------
gmic& gmic::print(const char *format, ...) {
  if (verbosity<0 && !is_debug) return *this;
  va_list ap;
  va_start(ap,format);
  CImg<char> message(65536);
  message[message.width() - 2] = 0;
  cimg_vsnprintf(message,message.width(),format,ap);
  strreplace_fw(message);
  if (message[message.width() - 2]) cimg::strellipsize(message,message.width() - 2);
  va_end(ap);

  // Display message.
  cimg::mutex(29);
  if (*message!='\r')
    for (unsigned int i = 0; i<nb_carriages; ++i) std::fputc('\n',cimg::output());
  nb_carriages = 1;
  std::fprintf(cimg::output(),
               "[gmic]%s %s",
               callstack2string().data(),message.data());
  std::fflush(cimg::output());
  cimg::mutex(29,0);
  return *this;
}

// Print error message, and quit interpreter.
//-------------------------------------------
gmic& gmic::error(const char *const format, ...) {
  va_list ap;
  va_start(ap,format);
  CImg<char> message(1024);
  message[message.width() - 2] = 0;
  cimg_vsnprintf(message,message.width(),format,ap);
  strreplace_fw(message);
  if (message[message.width() - 2]) cimg::strellipsize(message,message.width() - 2);
  va_end(ap);

  // Display message.
  const CImg<char> s_callstack = callstack2string();
  if (verbosity>=0 || is_debug) {
    cimg::mutex(29);
    if (*message!='\r')
      for (unsigned int i = 0; i<nb_carriages; ++i) std::fputc('\n',cimg::output());
    nb_carriages = 1;
    if (is_debug_info && debug_filename<commands_files.size() && debug_line!=~0U)
      std::fprintf(cimg::output(),"[gmic]%s %s%s*** Error (file '%s', %sline #%u) *** %s%s",
                   s_callstack.data(),cimg::t_red,cimg::t_bold,
                   commands_files[debug_filename].data(),
                   is_debug_info?"":"call from ",debug_line,message.data(),
                   cimg::t_normal);
    else
      std::fprintf(cimg::output(),"[gmic]%s %s%s*** Error *** %s%s",
                   s_callstack.data(),cimg::t_red,cimg::t_bold,
                   message.data(),cimg::t_normal);
    std::fflush(cimg::output());
    cimg::mutex(29,0);
  }

  // Store detailled error message for interpreter.
  CImg<char> full_message(512 + message.width());
  if (debug_filename<commands_files.size() && debug_line!=~0U)
    cimg_snprintf(full_message,full_message.width(),
                  "*** Error in %s (file '%s', %sline #%u) *** %s",
                  s_callstack.data(),
                  commands_files[debug_filename].data(),
                  is_debug_info?"":"call from ",debug_line,message.data());
  else cimg_snprintf(full_message,full_message.width(),
                     "*** Error in %s *** %s",
                     s_callstack.data(),message.data());
  CImg<char>::string(full_message).move_to(status);
  message.assign();
  is_running = false;
  throw gmic_exception(0,status);
}

// Print debug message.
//---------------------
gmic& gmic::debug(const char *format, ...) {
  if (!is_debug) return *this;
  va_list ap;
  va_start(ap,format);
  CImg<char> message(1024);
  message[message.width() - 2] = 0;
  cimg_vsnprintf(message,message.width(),format,ap);
  if (message[message.width() - 2]) cimg::strellipsize(message,message.width() - 2);
  va_end(ap);

  // Display message.
  cimg::mutex(29);
  if (*message!='\r')
    for (unsigned int i = 0; i<nb_carriages; ++i) std::fputc('\n',cimg::output());
  nb_carriages = 1;

  if (is_debug_info && debug_filename<commands_files.size() && debug_line!=~0U)
    std::fprintf(cimg::output(),
                 "%s<gmic>%s#%u ",
                 cimg::t_green,callstack2string(true).data(),debug_line);
  else
    std::fprintf(cimg::output(),
                 "%s<gmic>%s ",
                 cimg::t_green,callstack2string(true).data());

  for (char *s = message; *s; ++s) {
    char c = *s;
    if (c<' ') switch (c) {
      case gmic_dollar : std::fprintf(cimg::output(),"\\$"); break;
      case gmic_lbrace : std::fprintf(cimg::output(),"\\{"); break;
      case gmic_rbrace : std::fprintf(cimg::output(),"\\}"); break;
      case gmic_comma : std::fprintf(cimg::output(),"\\,"); break;
      case gmic_dquote : std::fprintf(cimg::output(),"\\\""); break;
      default : std::fputc(c,cimg::output());
      }
    else std::fputc(c,cimg::output());
  }
  std::fprintf(cimg::output(),
               "%s",
               cimg::t_normal);
  std::fflush(cimg::output());
  cimg::mutex(29,0);
  return *this;
}

// Set variable in the interpreter environment.
//---------------------------------------------
// 'operation' can be { 0 (add new variable), '=' (replace or add),'+','-','*','/','%','&','|','^','<','>' }
// Return the variable value.
inline const char * gmic::set_variable(const char *const name, const char *const value,
                                       const char operation,
                                       const unsigned int *const variables_sizes) {
  if (!name || !value) return "";
  char _operation = operation, end;
  bool is_name_found = false;
  double lvalue, rvalue;
  CImg<char> s_value;
  int ind = 0;
  const bool
    is_global = *name=='_',
    is_thread_global = is_global && name[1]=='_';
  if (is_thread_global) cimg::mutex(30);
  const unsigned int hashcode = gmic::hashcode(name,true);
  const int lind = is_global || !variables_sizes?0:(int)variables_sizes[hashcode];
  CImgList<char>
    &__variables = *variables[hashcode],
    &__variables_names = *variables_names[hashcode];
  if (operation) {
    // Retrieve index of current definition.
    for (int l = __variables.width() - 1; l>=lind; --l) if (!std::strcmp(__variables_names[l],name)) {
        is_name_found = true; ind = l; break;
      }
    if (operation=='=') {
      if (!is_name_found) _operation = 0; // New variable.
      else CImg<char>::string(value).move_to(__variables[ind]);
    } else {
      const char *const s_operation = operation=='+'?"+":operation=='-'?"-":operation=='*'?"*":operation=='/'?"/":
        operation=='%'?"%":operation=='&'?"&":operation=='|'?"|":operation=='^'?"^":
        operation=='<'?"<<":">>";
      if (!is_name_found)
        error("Operation '%s=' requested on undefined variable '%s'.",
              s_operation,name);
      if (std::sscanf(__variables[ind],"%lf%c",&lvalue,&end)!=1)
        error("Operation '%s=' requested on non-numerical variable '%s=%s'.",
              s_operation,name,__variables[ind].data());
      if (std::sscanf(value,"%lf%c",&rvalue,&end)!=1)
        error("Operation '%s=' requested on variable '%s', with non-numerical argument '%s'.",
              s_operation,name,value);
      s_value.assign(24); *s_value = 0;
      cimg_snprintf(s_value,s_value.width(),"%.17g",
                    operation=='+'?lvalue + rvalue:
                    operation=='-'?lvalue - rvalue:
                    operation=='*'?lvalue*rvalue:
                    operation=='/'?lvalue/rvalue:
                    operation=='%'?cimg::mod(lvalue,rvalue):
                    operation=='&'?(double)((cimg_ulong)lvalue & (cimg_ulong)rvalue):
                    operation=='|'?(double)((cimg_ulong)lvalue | (cimg_ulong)rvalue):
                    operation=='^'?std::pow(lvalue,rvalue):
                    operation=='<'?(double)((cimg_long)lvalue << (unsigned int)rvalue):
                    (double)((cimg_long)lvalue >> (unsigned int)rvalue));
      CImg<char>::string(s_value).move_to(__variables[ind]);
    }
  }
  if (!_operation) { // New variable.
    ind = __variables.width();
    CImg<char>::string(name).move_to(__variables_names);
    CImg<char>::string(value).move_to(__variables);
  }
  if (is_thread_global) cimg::mutex(30,0);
  return __variables[ind].data();
}

// Add custom commands from a char* buffer.
//------------------------------------------
gmic& gmic::add_commands(const char *const data_commands,
                         const char *const commands_file) {
  if (!data_commands || !*data_commands) return *this;
  CImg<char> com(256*1024), line(256*1024), mac(256), debug_info(32);
  CImg<unsigned int> pos(512,1,1,1,0);
  unsigned int line_number = 1;
  bool is_last_slash = false, _is_last_slash = false, is_newline = false;
  int ind = -1, l_debug_info = 0;
  char sep = 0;
  if (commands_file) CImg<char>::string(commands_file).move_to(commands_files);

  for (const char *data = data_commands; *data; is_last_slash = _is_last_slash,
         line_number+=is_newline?1:0) {

    // Read new line.
    char *_line = line, *const line_end = line.end();
    while (*data!='\n' && *data && _line<line_end) *(_line++) = *(data++);
    if (_line<line_end) *_line = 0; else *(line_end - 1) = 0;
    if (*data=='\n') { is_newline = true; ++data; } else is_newline = false; // Skip next '\n'.

    // Replace/remove unusual characters.
    char *__line = line;
    for (_line = line; *_line; ++_line) if (*_line!=13) *(__line++) = (unsigned char)*_line<' '?' ':*_line;
    *__line = 0;
    _line = line; if (*_line=='#') *_line = 0; else do { // Remove comments.
        if ((_line=std::strchr(_line,'#')) && *(_line - 1)==' ') { *--_line = 0; break; }
      } while (_line++);

    // Remove useless trailing spaces.
    char *linee = line.data() + std::strlen(line) - 1;
    while (linee>=line && *linee==' ') --linee;
    *(linee + 1) = 0;
    char *lines = line; while (*lines==' ') ++lines; // Remove useless leading spaces.
    if (!*lines) continue; // Empty line.

    // Check if last character is a '\'...
    _is_last_slash = false;
    for (_line = linee; *_line=='\\' && _line>=lines; --_line) _is_last_slash = !_is_last_slash;
    if (_is_last_slash) *(linee--) = 0; // ... and remove it if necessary.
    if (!*lines) continue; // Empty line found.
    *mac = *com = 0;

    if (!is_last_slash && std::strchr(lines,':') && // Check for a command definition.
        cimg_sscanf(lines,"%255[a-zA-Z0-9_] %c %262143[^\n]",mac.data(),&sep,com.data())>=2 &&
        (*lines<'0' || *lines>'9') && sep==':') {
      ind = (int)hashcode(mac,false);
      CImg<char>::string(mac).move_to(commands_names[ind],pos[ind]);
      CImg<char> body = CImg<char>::string(com);
      CImg<char>::vector((char)command_has_arguments(body)).
        move_to(commands_has_arguments[ind],pos[ind]);
      if (commands_file) { // Insert code with debug info.
        if (commands_files.width()<2)
          l_debug_info = cimg_snprintf(debug_info.data() + 1,debug_info.width() - 2,"%x",line_number);
        else
          l_debug_info = cimg_snprintf(debug_info.data() + 1,debug_info.width() - 2,"%x,%x",
                                            line_number,commands_files.width() - 1);
        if (l_debug_info>=debug_info.width() - 1) l_debug_info = debug_info.width() - 2;
        debug_info[0] = 1; debug_info[l_debug_info + 1] = ' ';
        ((CImg<char>(debug_info,l_debug_info + 2,1,1,1,true),body)>'x').
          move_to(commands[ind],pos[ind]++);
      } else body.move_to(commands[ind],pos[ind]++); // Insert code without debug info.
    } else { // Continuation of a previous line.
      if (ind<0) error("Command '-command': Syntax error in expression '%s'.",lines);
      const unsigned int p = pos[ind] - 1;
      if (!is_last_slash) commands[ind][p].back() = ' ';
      else --(commands[ind][p]._width);
      const CImg<char> body = CImg<char>(lines,(unsigned int)(linee - lines + 2));
      commands_has_arguments[ind](p,0) |= (char)command_has_arguments(body);
      if (commands_file && !is_last_slash) { // Insert code with debug info.
        if (commands_files.width()<2)
          l_debug_info = cimg_snprintf(debug_info.data() + 1,debug_info.width() - 2,"%x",line_number);
        else
          l_debug_info = cimg_snprintf(debug_info.data() + 1,debug_info.width() - 2,"%x,%x",
                                       line_number,commands_files.width() - 1);
        if (l_debug_info>=debug_info.width() - 1) l_debug_info = debug_info.width() - 2;
        debug_info[0] = 1; debug_info[l_debug_info + 1] = ' ';
        ((commands[ind][p],CImg<char>(debug_info,l_debug_info + 2,1,1,1,true),body)>'x').
          move_to(commands[ind][p]);
      } else commands[ind][p].append(body,'x'); // Insert code without debug info.
    }
  }

  if (is_debug) {
    CImg<unsigned int> hdist(512);
    unsigned int nb_commands = 0;
    cimg_forX(hdist,i) { hdist[i] = commands[i].size(); nb_commands+=commands[i].size(); }
    const CImg<double> st = hdist.get_stats();
    cimg_snprintf(com,com.width(),
                  "Distribution of command hashes: [ %s ], min = %u, max = %u, mean = %g, std = %g.",
                  hdist.value_string().data(),(unsigned int)st[0],(unsigned int)st[1],st[2],
                  std::sqrt(st[3]));
    cimg::strellipsize(com,512,false);
    debug("%s",com.data());
  }
  return *this;
}

// Add commands from a file.
//---------------------------
gmic& gmic::add_commands(std::FILE *const file,
                         const char *const filename) {
  if (!file) return *this;

  // Try reading it first as a .cimg file.
  try {
    CImg<char> buffer;
    buffer.load_cimg(file).unroll('x');
    buffer.resize(buffer.width() + 1,1,1,1,0);
    add_commands(buffer.data(),filename);
  } catch (...) {
    std::rewind(file);
    std::fseek(file,0,SEEK_END);
    const cimg_long siz = std::ftell(file);
    std::rewind(file);
    if (siz>0) {
      CImg<char> buffer((unsigned int)siz + 1);
      if (std::fread(buffer.data(),sizeof(char),siz,file)) {
        buffer[siz] = 0;
        add_commands(buffer.data(),filename);
      }
    }
  }
  return *this;
}

// Return subset indices from a selection string.
//-----------------------------------------------
CImg<unsigned int> gmic::selection2cimg(const char *const string, const unsigned int indice_max,
                                        const CImgList<char>& names,
                                        const char *const command, const bool is_selection,
                                        CImg<char> *const new_name) {

  // Try to detect common cases to be faster.
  if (string && !*string) return CImg<unsigned int>(); // Empty selection
  if (!string || (*string=='^' && !string[1])) { // Whole selection
    CImg<unsigned int> res(1,indice_max); cimg_forY(res,y) res[y] = (unsigned int)y; return res;
  } else if (*string>='0' && *string<='9' && !string[1]) { // Single positive digit
    const unsigned int ind = *string - '0';
    if (ind<indice_max) return CImg<unsigned int>::vector(ind);
  } else if (*string=='-' && string[1]>='0' && string[2]<='9' && !string[2]) { // Single negative digit
    const unsigned int ind = indice_max - string[1] + '0';
    if (ind<indice_max) return CImg<unsigned int>::vector(ind);
  }

  // Manage remaining cases.
  const char *const stype = is_selection?"selection":"subset";
  const int
    ctypel = is_selection?'[':'\'',
    ctyper = is_selection?']':'\'';

  CImg<bool> is_selected(1,indice_max,1,1,false);
  CImg<char> name, item;
  bool is_inverse = *string=='^';
  const char *it = string + (is_inverse?1:0);
  for (bool stopflag = false; !stopflag; ) {
    float ind0 = 0, ind1 = 0, step = 1;
    int iind0 = 0, iind1 = 0;
    bool is_label = false;
    char sep = 0;
    name.assign(256);

    const char *const it_comma = std::strchr(it,',');
    if (it_comma) { item.assign(it,(unsigned int)(it_comma - it + 1)); item.back() = 0; it = it_comma + 1; }
    else { CImg<char>::string(it).move_to(item); stopflag = true; }

    char end, *const it_colon = std::strchr(item,':');
    if (it_colon) {
      *it_colon = 0;
      if (cimg_sscanf(it_colon + 1,"%f%c",&step,&end)!=1 || step<=0)
        error("Command '%s': Invalid %s %c%s%c (syntax error after colon ':').",
              command,stype,ctypel,string,ctyper);
    }
    if (!*item) { // Particular cases [:N] or [^:N].
      if (is_inverse) { iind0 = 0; iind1 = -1; is_inverse = false; }
      else continue;
    } else if (cimg_sscanf(item,"%f%c",&ind0,&end)==1) { // Single indice
      iind1 = iind0 = (int)cimg::round(ind0);
    } else if (cimg_sscanf(item,"%f-%f%c",&ind0,&ind1,&end)==2) { // Sequence between 2 indices
      iind0 = (int)cimg::round(ind0);
      iind1 = (int)cimg::round(ind1);
    } else if (cimg_sscanf(item,"%255[a-zA-Z0-9_]%c",name.data(),&end)==1 && // Label
               (*name<'0' || *name>'9')) {
      cimglist_for(names,l) if (names[l] && !std::strcmp(names[l],name)) {
        is_selected(l) = true; is_label = true;
      }
      if (!is_label) {
        if (new_name) {
          iind0 = iind1 = -1;
          CImg<char>::string(name).move_to(*new_name);
        } else error("Command '%s': Invalid %s %c%s%c (undefined label '%s').",
                     command,stype,ctypel,string,ctyper,name.data());
      }
    } else if (cimg_sscanf(item,"%f%c%c",&ind0,&sep,&end)==2 && sep=='%') { // Single percent
      iind1 = iind0 = (int)cimg::round(ind0*((int)indice_max - 1)/100) - (ind0<0?1:0);
    } else if (cimg_sscanf(item,"%f%%-%f%c%c",&ind0,&ind1,&sep,&end)==3 && sep=='%') {
      // Sequence between 2 percents.
      iind0 = (int)cimg::round(ind0*((int)indice_max - 1)/100) - (ind0<0?1:0);
      iind1 = (int)cimg::round(ind1*((int)indice_max - 1)/100) - (ind1<0?1:0);
    } else if (cimg_sscanf(item,"%f%%-%f%c",&ind0,&ind1,&end)==2) {
      // Sequence between a percent and an indice.
      iind0 = (int)cimg::round(ind0*((int)indice_max - 1)/100) - (ind0<0?1:0);;
      iind1 = (int)cimg::round(ind1);
    } else if (cimg_sscanf(item,"%f-%f%c%c",&ind0,&ind1,&sep,&end)==3 && sep=='%') {
      // Sequence between an indice and a percent.
      iind0 = (int)cimg::round(ind0);
      iind1 = (int)cimg::round(ind1*((int)indice_max - 1)/100) - (ind1<0?1:0);;
    } else error("Command '%s': Invalid %s %c%s%c.",
                 command,stype,ctypel,string,ctyper);

    if (!indice_max) error("Command '%s': Invalid %s %c%s%c (no data available).",
                           command,stype,ctypel,string,ctyper);
    if (!is_label) {
      int
        uind0 = (int)(iind0<0?iind0 + indice_max:iind0),
        uind1 = (int)(iind1<0?iind1 + indice_max:iind1);
      if (uind0>uind1) { cimg::swap(uind0,uind1); cimg::swap(iind0,iind1); }
      if (uind0<0 || uind0>=(int)indice_max)
        error("Command '%s': Invalid %s %c%s%c (contains indice '%d', "
              "not in range -%u...%u).",
              command,stype,ctypel,string,ctyper,iind0,indice_max,indice_max - 1);
      if (uind1<0 || uind1>=(int)indice_max)
        error("Command '%s': Invalid %s %c%s%c (contains indice '%d', "
              "not in range -%u...%u).",
              command,stype,ctypel,string,ctyper,iind1,indice_max,indice_max - 1);
      const int istep = (int)cimg::round(step);
      for (int l = uind0; l<=uind1; l+=istep) is_selected[l] = true;
    }
  }
  unsigned int indice = 0;
  cimg_for(is_selected,p,bool) if (*p) ++indice;
  CImg<unsigned int> selection(1,is_inverse?indice_max - indice:indice);
  indice = 0;
  if (is_inverse) { cimg_forY(is_selected,l) if (!is_selected[l]) selection[indice++] = (unsigned int)l; }
  else cimg_forY(is_selected,l) if (is_selected[l]) selection[indice++] = (unsigned int)l;
  return selection;
}

// Return selection or filename strings from a set of indices.
//------------------------------------------------------------
// output_type can be { 0=display indices without brackets | 1=display indices with brackets | 2=display image names }
CImg<char>& gmic::selection2string(const CImg<unsigned int>& selection,
                                   const CImgList<char>& images_names,
                                   const unsigned int output_type,
                                   CImg<char>& res) const {
  res.assign(256);
  if (output_type<2) {
    const char *const bl = output_type?"[":"", *const br = output_type?"]":"";
    switch (selection.height()) {
    case 0:
      cimg_snprintf(res.data(),res.width()," %s%s",bl,br);
      break;
    case 1:
      cimg_snprintf(res.data(),res.width()," %s%u%s",
                    bl,selection[0],br);
      break;
    case 2:
      cimg_snprintf(res.data(),res.width(),"s %s%u,%u%s",
                    bl,selection[0],selection[1],br);
      break;
    case 3:
      cimg_snprintf(res.data(),res.width(),"s %s%u,%u,%u%s",
                    bl,selection[0],selection[1],selection[2],br);
      break;
    case 4:
      cimg_snprintf(res.data(),res.width(),"s %s%u,%u,%u,%u%s",
                    bl,selection[0],selection[1],selection[2],selection[3],br);
      break;
    case 5:
      cimg_snprintf(res.data(),res.width(),"s %s%u,%u,%u,%u,%u%s",
                    bl,selection[0],selection[1],selection[2],selection[3],selection[4],br);
      break;
    case 6:
      cimg_snprintf(res.data(),res.width(),"s %s%u,%u,%u,%u,%u,%u%s",
                    bl,selection[0],selection[1],selection[2],
                    selection[3],selection[4],selection[5],br);
      break;
    case 7:
      cimg_snprintf(res.data(),res.width(),"s %s%u,%u,%u,%u,%u,%u,%u%s",
                    bl,selection[0],selection[1],selection[2],selection[3],
                    selection[4],selection[5],selection[6],br);
      break;
    default:
      cimg_snprintf(res.data(),res.width(),"s %s%u,%u,%u,(...),%u,%u,%u%s",
                    bl,selection[0],selection[1],selection[2],
                    selection[selection.height() - 3],
                    selection[selection.height() - 2],
                    selection[selection.height() - 1],br);
    }
    return res;
  }

  switch (selection.height()) {
  case 0:
    *res = 0;
    break;
  case 1:
    cimg_snprintf(res.data(),res.width(),"%s",
                  basename(images_names[selection[0]]));
    break;
  case 2:
    cimg_snprintf(res.data(),res.width(),"%s, %s",
                  basename(images_names[selection[0]]),
                  basename(images_names[selection[1]]));
    break;
  case 3:
    cimg_snprintf(res.data(),res.width(),"%s, %s, %s",
                  basename(images_names[selection[0]]),
                  basename(images_names[selection[1]]),
                  basename(images_names[selection[2]]));
    break;
  case 4:
    cimg_snprintf(res.data(),res.width(),"%s, %s, %s, %s",
                  basename(images_names[selection[0]]),
                  basename(images_names[selection[1]]),
                  basename(images_names[selection[2]]),
                  basename(images_names[selection[3]]));
    break;
  default:
    cimg_snprintf(res.data(),res.width(),"%s, (...), %s",
                  basename(images_names[selection[0]]),
                  basename(images_names[selection.back()]));
  }
  return res;
}

// Print log message.
//-------------------
template<typename T>
gmic& gmic::print(const CImgList<T>& list, const CImg<unsigned int> *const callstack_selection,
                  const char *format, ...) {
  if (verbosity<0 && !is_debug) return *this;
  va_list ap;
  va_start(ap,format);
  CImg<char> message(65536);
  message[message.width() - 2] = 0;
  cimg_vsnprintf(message,message.width(),format,ap);
  strreplace_fw(message);
  if (message[message.width() - 2]) cimg::strellipsize(message,message.width() - 2);
  va_end(ap);

  // Display message.
  cimg::mutex(29);
  if (*message!='\r')
    for (unsigned int i = 0; i<nb_carriages; ++i) std::fputc('\n',cimg::output());
  nb_carriages = 1;
  if (!callstack_selection || *callstack_selection)
    std::fprintf(cimg::output(),
                 "[gmic]-%u%s %s",
                 list.size(),callstack2string(callstack_selection).data(),message.data());
  else std::fprintf(cimg::output(),"%s",message.data());
  std::fflush(cimg::output());
  cimg::mutex(29,0);
  return *this;
}

// Print warning message.
//-----------------------
template<typename T>
gmic& gmic::warn(const CImgList<T>& list, const CImg<unsigned int> *const callstack_selection,
                 const bool force_visible, const char *const format, ...) {
  if (!force_visible && verbosity<0 && !is_debug) return *this;
  va_list ap;
  va_start(ap,format);
  CImg<char> message(1024);
  message[message.width() - 2] = 0;
  cimg_vsnprintf(message,message.width(),format,ap);
  strreplace_fw(message);
  if (message[message.width() - 2]) cimg::strellipsize(message,message.width() - 2);
  va_end(ap);

  // Display message.
  const CImg<char> s_callstack = callstack2string(callstack_selection);
  cimg::mutex(29);
  if (*message!='\r')
    for (unsigned int i = 0; i<nb_carriages; ++i) std::fputc('\n',cimg::output());
  nb_carriages = 1;
  if (!callstack_selection || *callstack_selection) {
    if (debug_filename<commands_files.size() && debug_line!=~0U)
      std::fprintf(cimg::output(),
                   "[gmic]-%u%s %s%s*** Warning (file '%s', %sline #%u) *** %s%s",
                   list.size(),s_callstack.data(),cimg::t_magenta,cimg::t_bold,
                   commands_files[debug_filename].data(),
                   is_debug_info?"":"call from ",debug_line,message.data(),
                   cimg::t_normal);
    else
      std::fprintf(cimg::output(),
                   "[gmic]-%u%s %s%s*** Warning *** %s%s",
                   list.size(),s_callstack.data(),cimg::t_magenta,cimg::t_bold,
                   message.data(),cimg::t_normal);
  } else std::fprintf(cimg::output(),"%s%s%s%s",
                      cimg::t_magenta,cimg::t_bold,message.data(),cimg::t_normal);
  std::fflush(cimg::output());
  cimg::mutex(29,0);
  return *this;
}

// Print error message, and quit interpreter.
//-------------------------------------------
template<typename T>
gmic& gmic::error(const CImgList<T>& list, const CImg<unsigned int> *const callstack_selection,
                  const char *const command, const char *const format, ...) {
  va_list ap;
  va_start(ap,format);
  CImg<char> message(1024);
  message[message.width() - 2] = 0;
  cimg_vsnprintf(message,message.width(),format,ap);

  strreplace_fw(message);
  if (message[message.width() - 2]) cimg::strellipsize(message,message.width() - 2);
  va_end(ap);

  // Display message.
  const CImg<char> s_callstack = callstack2string(callstack_selection);
  if (verbosity>=0 || is_debug) {
    cimg::mutex(29);
    if (*message!='\r')
      for (unsigned int i = 0; i<nb_carriages; ++i) std::fputc('\n',cimg::output());
    nb_carriages = 1;
    if (!callstack_selection || *callstack_selection) {
      if (debug_filename<commands_files.size() && debug_line!=~0U)
        std::fprintf(cimg::output(),
                     "[gmic]-%u%s %s%s*** Error (file '%s', %sline #%u) *** %s%s",
                     list.size(),s_callstack.data(),cimg::t_red,cimg::t_bold,
                     commands_files[debug_filename].data(),
                     is_debug_info?"":"call from ",debug_line,message.data(),
                     cimg::t_normal);
      else
        std::fprintf(cimg::output(),
                     "[gmic]-%u%s %s%s*** Error *** %s%s",
                     list.size(),s_callstack.data(),cimg::t_red,cimg::t_bold,
                     message.data(),cimg::t_normal);
    } else std::fprintf(cimg::output(),"%s",message.data());
    std::fflush(cimg::output());
    cimg::mutex(29,0);
  }

  // Store detailled error message for interpreter.
  CImg<char> full_message(512 + message.width());
  if (debug_filename<commands_files.size() && debug_line!=~0U)
    cimg_snprintf(full_message,full_message.width(),
                  "*** Error in %s (file '%s', %sline #%u) *** %s",
                  s_callstack.data(),
                  commands_files[debug_filename].data(),
                  is_debug_info?"":"call from ",debug_line,message.data());
  else cimg_snprintf(full_message,full_message.width(),
                     "*** Error in %s *** %s",
                     s_callstack.data(),message.data());
  CImg<char>::string(full_message).move_to(status);
  message.assign();
  is_running = false;
  throw gmic_exception(command,status);
}

#define arg_error(command) gmic::error(images,0,command,"Command '-%s': Invalid argument '%s'.",\
                                       command,gmic_argument_text())

// Print debug message.
//---------------------
template<typename T>
gmic& gmic::debug(const CImgList<T>& list, const char *format, ...) {
  if (!is_debug) return *this;
  va_list ap;
  va_start(ap,format);
  CImg<char> message(1024);
  message[message.width() - 2] = 0;
  cimg_vsnprintf(message,message.width(),format,ap);
  if (message[message.width() - 2]) cimg::strellipsize(message,message.width() - 2);
  va_end(ap);

  // Display message.
  cimg::mutex(29);
  if (*message!='\r')
    for (unsigned int i = 0; i<nb_carriages; ++i) std::fputc('\n',cimg::output());
  nb_carriages = 1;
  if (is_debug_info && debug_filename!=~0U && debug_line!=~0U)
    std::fprintf(cimg::output(),
                 "%s<gmic>-%u%s#%u ",
                 cimg::t_green,list.size(),callstack2string(true).data(),debug_line);
  else
    std::fprintf(cimg::output(),
                 "%s<gmic>-%u%s ",
                 cimg::t_green,list.size(),callstack2string(true).data());
  for (char *s = message; *s; ++s) {
    char c = *s;
    if (c<' ') {
      switch (c) {
      case gmic_dollar : std::fprintf(cimg::output(),"\\$"); break;
      case gmic_lbrace : std::fprintf(cimg::output(),"\\{"); break;
      case gmic_rbrace : std::fprintf(cimg::output(),"\\}"); break;
      case gmic_comma : std::fprintf(cimg::output(),"\\,"); break;
      case gmic_dquote : std::fprintf(cimg::output(),"\\\""); break;
      default : std::fputc(c,cimg::output());
      }
    } else std::fputc(c,cimg::output());
  }
  std::fprintf(cimg::output(),
               "%s",
               cimg::t_normal);
  std::fflush(cimg::output());
  cimg::mutex(29,0);
  return *this;
}

// Check if a shared image of the image list is safe or not.
//----------------------------------------------------------
template<typename T>
inline bool gmic_is_valid_pointer(const T *const ptr) {
#if cimg_OS==1
  const int result = access((const char*)ptr,F_OK);
  if (result==-1 && errno==EFAULT) return false;
#elif cimg_OS==2 // #if cimg_OS==1
  return !IsBadReadPtr((void*)ptr,1);
#endif // #if cimg_OS==1
  return true;
}

template<typename T>
CImg<T>& gmic::check_image(const CImgList<T>& list, CImg<T>& img) {
  check_image(list,(const CImg<T>&)img);
  return img;
}

template<typename T>
const CImg<T>& gmic::check_image(const CImgList<T>& list, const CImg<T>& img) {
#ifdef gmic_check_image
  if (!img.is_shared() || gmic_is_valid_pointer(img.data())) return img;
  if (is_debug) error(list,0,0,"Image list contains an invalid shared image (%p,%d,%d,%d,%d) "
                      "(references a deallocated buffer).",
                      img.data(),img.width(),img.height(),img.depth(),img.spectrum());
  else error(list,0,0,"Image list contains an invalid shared image (%d,%d,%d,%d) "
             "(references a deallocated buffer).",
             img.width(),img.height(),img.depth(),img.spectrum());
#else // #ifdef gmic_check_image
  cimg::unused(list);
#endif // #ifdef gmic_check_image
  return img;
}

#define gmic_check(img) check_image(images,img)

// Remove list of images in a selection.
//---------------------------------------
template<typename T>
gmic& gmic::remove_images(CImgList<T> &images, CImgList<char> &images_names,
                          const CImg<unsigned int>& selection,
                          const unsigned int start, const unsigned int end) {
  if (start==0 && end==(unsigned int)selection.height() - 1 && selection.height()==images.width()) {
    images.assign();
    images_names.assign();
  } else for (int l = (int)end; l>=(int)start; ) {
      unsigned int eind = selection[l--], ind = eind;
      while (l>=(int)start && selection[l]==ind - 1) ind = selection[l--];
      images.remove(ind,eind); images_names.remove(ind,eind);
    }
  return *this;
}

// Template constructor.
//----------------------
template<typename T>
gmic::gmic(const char *const commands_line, CImgList<T>& images, CImgList<char>& images_names,
           const char *const custom_commands, const bool include_stdlib,
           float *const p_progress, bool *const p_is_abort):gmic_new_attr {
  _gmic(commands_line,
        images,images_names,
        custom_commands,include_stdlib,
        p_progress,p_is_abort);
}

// This method is shared by all constructors. It initializes all the interpreter environment.
template<typename T>
void gmic::_gmic(const char *const commands_line,
                 CImgList<T>& images, CImgList<char>& images_names,
                 const char *const custom_commands, const bool include_stdlib,
                 float *const p_progress, bool *const p_is_abort) {

  // Initialize class variables and default G'MIC environment.
  setlocale(LC_NUMERIC,"C");
  cimg_exception_mode = cimg::exception_mode();
  cimg::exception_mode(0);
  cimg::srand();
  is_debug = false;
  is_double3d = true;
  nb_carriages = 0;
  verbosity = 0;
  render3d = 4;
  renderd3d = -1;
  focale3d = 700;
  light3d.assign();
  light3d_x = light3d_y = 0;
  light3d_z = -5e8f;
  specular_lightness3d = 0.15f;
  specular_shininess3d = 0.8f;
  starting_commands_line = commands_line;
  reference_time = (unsigned long)cimg::time();
  for (unsigned int l = 0; l<512; ++l) {
    commands_names[l].assign();
    commands[l].assign();
    commands_has_arguments[l].assign();
    _variables[l].assign();
    variables[l] = &_variables[l];
    _variables_names[l].assign();
    variables_names[l] = &_variables_names[l];
  }
  if (include_stdlib) add_commands(gmic::decompress_stdlib().data());
  add_commands(custom_commands);

  // Set pre-defined global variables.
  CImg<char> str(8);
  cimg_snprintf(str,str.width(),"%u",cimg::nb_cpus());
  set_variable("_cpus",str,0);

#if cimg_OS==1
  cimg_snprintf(str,str.width(),"%u",(unsigned int)getpid());
#elif cimg_OS==2 // #if cimg_OS==1
  cimg_snprintf(str,str.width(),"%u",(unsigned int)_getpid());
#else // #if cimg_OS==1
  cimg_snprintf(str,str.width(),"0");
#endif // #if cimg_OS==1
  set_variable("_pid",str,0);

#ifdef gmic_prerelease
  set_variable("_prerelease",gmic_prerelease,0);
#endif // #ifdef gmic_prerelease

  cimg_snprintf(str,str.width(),"%u",gmic_version);
  set_variable("_version",str,0);

  set_variable("_path_rc",gmic::path_rc(),0);
  set_variable("_path_user",gmic::path_user(),0);

#ifdef cimg_use_vt100
  set_variable("_vt100","1",0);
#endif // # if cimg_use_vt100

  // Launch the G'MIC interpreter.
  const CImgList<char> items = commands_line?commands_line_to_CImgList(commands_line):CImgList<char>::empty();
  try {
    _run(items,images,images_names,p_progress,p_is_abort);
  } catch (gmic_exception&) {
    print(images,0,"Abort G'MIC interpreter.\n");
    throw;
  }
}

// Print info on selected images.
//--------------------------------
template<typename T>
gmic& gmic::print_images(const CImgList<T>& images, const CImgList<char>& images_names,
                         const CImg<unsigned int>& selection, const bool is_header) {
  if (!images || !images_names || !selection) {
    if (is_header) print(images,0,"Print image [].");
    return *this;
  }
  const bool is_verbose = verbosity>=0 || is_debug;

  CImg<char> title(256);
  if (is_header) {
    CImg<char> gmic_selection, gmic_names;
    if (is_verbose) {
      selection2string(selection,images_names,1,gmic_selection);
      selection2string(selection,images_names,2,gmic_names);
    }
    cimg::strellipsize(gmic_names,80,false);
    print(images,0,"Print image%s = '%s'.\n",
          gmic_selection.data(),gmic_names.data());
  }
  if (is_verbose) {
    cimg_forY(selection,l) {
      const unsigned int uind = selection[l];
      const CImg<T>& img = images[uind];
      bool is_valid = true;
      int _verbosity = verbosity;
      bool _is_debug = is_debug;
      verbosity = -1; is_debug = false;
      try { gmic_check(img); } catch (gmic_exception&) { is_valid = false; }
      verbosity = _verbosity; is_debug = _is_debug;
      cimg_snprintf(title,title.width(),"[%u] = '%s'",
                    uind,images_names[uind].data());
      cimg::strellipsize(title,80,false);
      img.gmic_print(title,is_debug,is_valid);
    }
    nb_carriages = 0;
  }
  return *this;
}

// Display selected images.
//-------------------------
template<typename T>
gmic& gmic::display_images(const CImgList<T>& images, const CImgList<char>& images_names,
                           const CImg<unsigned int>& selection, unsigned int *const XYZ,
                           const bool exit_on_anykey) {
#if cimg_display!=0
  CImgDisplay *const _display_window = (CImgDisplay*)display_window;
#endif
  if (!images || !images_names || !selection) { print(images,0,"Display image []."); return *this; }
  const bool is_verbose = verbosity>=0 || is_debug;
  CImg<char> gmic_selection;
  if (is_verbose) selection2string(selection,images_names,1,gmic_selection);

  // Check for available display.
#if cimg_display==0
  cimg::unused(exit_on_anykey);
  print(images,0,"Display image%s",gmic_selection.data());
  if (is_verbose) {
    cimg::mutex(29);
    if (XYZ) std::fprintf(cimg::output(),", from point (%u,%u,%u)",XYZ[0],XYZ[1],XYZ[2]);
    std::fprintf(cimg::output()," (console output only, no display support).\n");
    std::fflush(cimg::output());
    cimg::mutex(29,0);
    print_images(images,images_names,selection,false);
  }
#else // #if cimg_display==0
  bool is_available_display = false;
  try {
    is_available_display = (bool)CImgDisplay::screen_width();
  } catch (CImgDisplayException&) {
    print(images,0,"Display image%s",gmic_selection.data());
    if (is_verbose) {
      cimg::mutex(29);
      if (XYZ) std::fprintf(cimg::output(),", from point (%u,%u,%u)",XYZ[0],XYZ[1],XYZ[2]);
      std::fprintf(cimg::output()," (console output only, no display available).\n");
      std::fflush(cimg::output());
      cimg::mutex(29,0);
      print_images(images,images_names,selection,false);
    }
  }
  if (!is_available_display) return *this;

  CImgList<T> visu;
  CImgList<char> t_visu;
  CImg<bool> is_valid(1,selection.height(),1,1,true);
  cimg_forY(selection,l) {
    const CImg<T>& img = images[selection[l]];
    int _verbosity = verbosity;
    bool _is_debug = is_debug;
    verbosity = -1; is_debug = false;
    try { gmic_check(img); } catch (gmic_exception&) { is_valid[l] = false; }
    verbosity = _verbosity; is_debug = _is_debug;
  }

  CImg<char> s_tmp;
  cimg_forY(selection,l) {
    const unsigned int uind = selection[l];
    const CImg<T>& img = images[uind];
    if (img && is_valid[l]) visu.insert(img,~0U,true);
    else visu.insert(1);
    const CImg<char> str = CImg<char>::string(basename(images_names[uind]),true,true);
    s_tmp.assign(str.width() + 16);
    cimg_snprintf(s_tmp,s_tmp.width(),"[%u] %s",uind,str.data());
    s_tmp.move_to(t_visu);
  }

  CImg<char> gmic_names;
  if (visu) selection2string(selection,images_names,2,gmic_names);
  cimg::strellipsize(gmic_names,80,false);

  print(images,0,"Display image%s = '%s'",gmic_selection.data(),gmic_names.data());
  if (is_verbose) {
    cimg::mutex(29);
    if (XYZ) std::fprintf(cimg::output(),", from point (%u,%u,%u).\n",XYZ[0],XYZ[1],XYZ[2]);
    else std::fprintf(cimg::output(),".\n");
    std::fflush(cimg::output());
    nb_carriages = 0;
    cimg::mutex(29,0);
  }
  if (visu) {
    CImgDisplay _disp, &disp = _display_window[0]?_display_window[0]:_disp;
    CImg<char> title(256);
    if (visu.size()==1)
      cimg_snprintf(title,title.width(),"%s (%dx%dx%dx%d)",
                    gmic_names.data(),
                    visu[0].width(),visu[0].height(),visu[0].depth(),visu[0].spectrum());
    else
      cimg_snprintf(title,title.width(),"%s (%u)",
                    gmic_names.data(),visu.size());
    cimg::strellipsize(title,80,false);
    CImg<bool> is_shared(visu.size());
    cimglist_for(visu,l) {
      is_shared[l] = visu[l].is_shared();
      visu[l]._is_shared = images[selection[l]].is_shared();
    }
    print_images(images,images_names,selection,false);

    bool is_exit = false;
    visu._display(disp,0,&t_visu,false,'x',0.5f,XYZ,exit_on_anykey,0,true,is_exit);
    cimglist_for(visu,l) visu[l]._is_shared = is_shared(l);
  }
#endif // #if cimg_display==0
  return *this;
}

// Display plots of selected images.
//----------------------------------
template<typename T>
gmic& gmic::display_plots(const CImgList<T>& images, const CImgList<char>& images_names,
                          const CImg<unsigned int>& selection,
                          const unsigned int plot_type, const unsigned int vertex_type,
                          const double xmin, const double xmax,
                          const double ymin, const double ymax,
                          const bool exit_on_anykey) {
#if cimg_display!=0
  CImgDisplay *const _display_window = (CImgDisplay*)display_window;
#endif
  if (!images || !images_names || !selection) { print(images,0,"Plot image []."); return *this; }
  const bool is_verbose = verbosity>=0 || is_debug;
  CImg<char> gmic_selection;
  if (is_verbose) selection2string(selection,images_names,1,gmic_selection);

#if cimg_display==0
  print(images,0,"Plot image%s (console output only, no display support).\n",gmic_selection.data());
  print_images(images,images_names,selection,false);
  cimg::unused(plot_type,vertex_type,xmin,xmax,ymin,ymax,exit_on_anykey);
#else // #if cimg_display==0
  bool is_available_display = false;
  try {
    is_available_display = (bool)CImgDisplay::screen_width();
  } catch (CImgDisplayException&) {
    print(images,0,"Plot image%s (console output only, no display available).",gmic_selection.data());
    print_images(images,images_names,selection,false);
  }
  if (!is_available_display) return *this;

  CImgList<unsigned int> empty_indices;
  cimg_forY(selection,l) if (!gmic_check(images[selection(l)]))
    CImg<unsigned int>::vector(selection(l)).move_to(empty_indices);
  if (empty_indices && is_verbose) {
    CImg<char> eselec;
    selection2string(empty_indices>'y',images_names,1,eselec);
    warn(images,0,false,
         "Command '-plot': Image%s %s empty.",
         eselec.data(),empty_indices.size()>1?"are":"is");
  }

  CImg<char> gmic_names;
  if (is_verbose) selection2string(selection,images_names,2,gmic_names);
  print(images,0,"Plot image%s = '%s'.",
        gmic_selection.data(),gmic_names.data());

  CImgDisplay _disp, &disp = _display_window[0]?_display_window[0]:_disp;
  bool is_first_line = false;
  cimg_forY(selection,l) {
    const unsigned int uind = selection[l];
    const CImg<T>& img = images[uind];
    if (img) {
      if (is_verbose && !is_first_line) {
        cimg::mutex(29);
        std::fputc('\n',cimg::output());
        std::fflush(cimg::output());
        cimg::mutex(29,0);
        is_first_line = true;
      }
      img.print(images_names[uind].data());
      if (!disp) disp.assign(cimg_fitscreen(CImgDisplay::screen_width()/2,CImgDisplay::screen_height()/2,1),0,0);
      img.display_graph(disp.set_title("%s (%dx%dx%dx%d)",
                                       basename(images_names[uind]),
                                       img.width(),img.height(),img.depth(),img.spectrum()),
                        plot_type,vertex_type,0,xmin,xmax,0,ymin,ymax,exit_on_anykey);
      if (is_verbose) nb_carriages = 0;
    }
  }
#endif // #if cimg_display==0
  return *this;
}

// Display selected 3d objects.
//-----------------------------
template<typename T>
gmic& gmic::display_objects3d(const CImgList<T>& images, const CImgList<char>& images_names,
                              const CImg<unsigned int>& selection,
                              const CImg<unsigned char>& background3d,
                              const bool exit_on_anykey) {
#if cimg_display!=0
  CImgDisplay *const _display_window = (CImgDisplay*)display_window;
#endif
  if (!images || !images_names || !selection) {
    print(images,0,"Display 3d object [].");
    return *this;
  }

  const bool is_verbose = verbosity>=0 || is_debug;
  CImg<char> gmic_selection;
  if (is_verbose) selection2string(selection,images_names,1,gmic_selection);

  CImg<char> error_message(1024);
  cimg_forY(selection,l) if (!gmic_check(images[selection[l]]).is_CImg3d(true,error_message))
    error(images,0,0,
          "Command '-display3d': Invalid 3d object [%d] in selected image%s (%s).",
          selection[l],gmic_selection_err.data(),error_message.data());
#if cimg_display==0
  print(images,0,"Display 3d object%s (skipped, no display support).",gmic_selection.data());
  cimg::unused(background3d,exit_on_anykey);
#else // #if cimg_display==0
  bool is_available_display = false;
  try {
    is_available_display = (bool)CImgDisplay::screen_width();
  } catch (CImgDisplayException&) {
    print(images,0,"Display 3d object%s (skipped, no display available).",gmic_selection.data());
  }
  if (!is_available_display) return *this;

  CImgDisplay _disp, &disp = _display_window[0]?_display_window[0]:_disp;
  cimg_forY(selection,l) {
    const unsigned int uind = selection[l];
    const CImg<T>& img = images[uind];
    if (!disp) {
      if (background3d) disp.assign(cimg_fitscreen(background3d.width(),background3d.height(),1),0,0);
      else disp.assign(cimg_fitscreen(CImgDisplay::screen_width()/2,CImgDisplay::screen_height()/2,1),0,0);
    }

    CImg<unsigned char> background;
    if (background3d) background = background3d.get_resize(disp.width(),disp.height(),1,3);
    else background.assign(1,2,1,3).fill(32,64,32,116,64,96).resize(1,256,1,3,3).
           resize(disp.width(),disp.height(),1,3);
    background.display(disp);

    CImgList<unsigned int> primitives;
    CImgList<unsigned char> colors;
    CImgList<float> opacities;
    CImg<float> vertices(img,false), pose3d(4,4,1,1,0);
    pose3d(0,0) = pose3d(1,1) = pose3d(2,2) = pose3d(3,3) = 1;
    vertices.CImg3dtoobject3d(primitives,colors,opacities,false);
    print(images,0,"Display 3d object [%u] = '%s' (%d vertices, %u primitives).",
          uind,images_names[uind].data(),
          vertices.width(),primitives.size());
    disp.set_title("%s (%d vertices, %u primitives)",
                   basename(images_names[uind]),
                   vertices.width(),primitives.size());
    if (light3d) colors.insert(light3d,~0U,true);
    background.display_object3d(disp,vertices,primitives,colors,opacities,
                                true,render3d,renderd3d,is_double3d,focale3d,
                                light3d_x,light3d_y,light3d_z,
                                specular_lightness3d,specular_shininess3d,
                                true,pose3d,exit_on_anykey);
    print(images,0,"Selected 3d pose = [ %g,%g,%g,%g,%g,%g,%g,%g,%g,%g,%g,%g,%g,%g,%g,%g ].",
          pose3d[0],pose3d[1],pose3d[2],pose3d[3],
          pose3d[4],pose3d[5],pose3d[6],pose3d[7],
          pose3d[8],pose3d[9],pose3d[10],pose3d[11],
          pose3d[12],pose3d[13],pose3d[14],pose3d[15]);
    if (disp.is_closed()) break;
  }
#endif // #if cimg_display==0
  return *this;
}

// Substitute '{}' and '$' expressions in a string.
//--------------------------------------------------
template<typename T>
CImg<char> gmic::substitute_item(const char *const source,
                                 CImgList<T>& images, CImgList<char>& images_names,
                                 CImgList<T>& parent_images, CImgList<char>& parent_images_names,
                                 const unsigned int *const variables_sizes,
                                 const CImg<unsigned int> *const command_selection,
                                 const bool is_image_expr) {
#if cimg_display!=0
  CImgDisplay *const _display_window = (CImgDisplay*)display_window;
#endif
  if (!source) return CImg<char>();
  CImg<char> substituted_items(64), inbraces, substr(40), vs;
  char *ptr_sub = substituted_items.data();
  CImg<unsigned int> _ind;
  const char dot = is_image_expr?'.':0;

  for (const char *nsource = source; *nsource; )
    if (*nsource!='{' && *nsource!='$' && *nsource!=dot) {

      // If not starting with '{', '.' or '$'.
      const char *const nsource0 = nsource;
      do { ++nsource; } while (*nsource && *nsource!='{' && *nsource!='$' && *nsource!=dot);
      CImg<char>(nsource0,(unsigned int)(nsource - nsource0),1,1,1,true).
        append_string_to(substituted_items,ptr_sub);
    } else { // '{...}', '...' or '${...}' expression found.
      bool is_braces = false, is_substituted = false;
      int ind = 0, l_inbraces = 0;
      char sep = 0;
      _ind.assign();
      *substr = 0;
      if (inbraces) *inbraces = 0; else inbraces.assign(1,1,1,1,0);

      // '.' expression ('.', '..' or '...').
      if (*nsource=='.') {
        const char *str = 0;
        unsigned int p = 0, N = 0;
        if (nsource==source || *(nsource - 1)==',') {
          if (!nsource[1] || nsource[1]==',' ||
              (nsource==source && nsource[1]=='x' && nsource[2]>='0' && nsource[2]<='9' &&
               std::sscanf(nsource + 2,"%u%c",&p,&(sep=0))==1)) { str = "[-1]"; N = 1; }
          else if (nsource[1]=='.') {
            if (!nsource[2] || nsource[2]==',' ||
                (nsource==source && nsource[2]=='x' && nsource[3]>='0' && nsource[3]<='9' &&
                 std::sscanf(nsource + 3,"%u%c",&p,&(sep=0))==1)) { str = "[-2]"; N = 2; }
            else if (nsource[2]=='.') {
              if (!nsource[3] || nsource[3]==',' ||
                  (nsource==source && nsource[3]=='x' && nsource[4]>='0' && nsource[4]<='9' &&
                   std::sscanf(nsource + 4,"%u%c",&p,&(sep=0))==1)) { str = "[-3]"; N = 3; }
            }
          }
        }
        if (N) { CImg<char>::string(str,false,true).append_string_to(substituted_items,ptr_sub); nsource+=N; }
        else CImg<char>::append_string_to(*(nsource++),substituted_items,ptr_sub);
        continue;

        // '{...}' expression.
      } else if (*nsource=='{') {
        const char *const ptr_beg = nsource + 1, *ptr_end = ptr_beg;
        unsigned int p = 0;
        for (p = 1; p>0 && *ptr_end; ++ptr_end) { if (*ptr_end=='{') ++p; if (*ptr_end=='}') --p; }
        if (p) {
          CImg<char>::append_string_to(*(nsource++),substituted_items,ptr_sub);
          continue;
        }
        l_inbraces = (int)(ptr_end - ptr_beg - 1);

        if (l_inbraces>0) {
          inbraces.assign(ptr_beg,l_inbraces + 1).back() = 0;
          substitute_item(inbraces,images,images_names,parent_images,parent_images_names,variables_sizes,
                          command_selection,false).move_to(inbraces);
          strreplace_fw(inbraces);
        }
        nsource+=l_inbraces + 2;
        if (!*inbraces)
          error(images,0,0,
                "Item substitution '{}': Empty braces.");

        // Display window features.
        if (!is_substituted && *inbraces=='*' &&
            (!inbraces[1] ||
             (inbraces[1]>='0' && inbraces[1]<='9' && !inbraces[2]) ||
             (inbraces[1]==',' && inbraces[2]) ||
             (inbraces[1]>='0' && inbraces[1]<='9' && inbraces[2]==',' && inbraces[3]))) {
#if cimg_display==0
          *substr = '0'; substr[1] = 0;
          is_substituted = true;
#else // #if cimg_display==0
          unsigned int wind = 0;
          const char *feature = inbraces.data() + 1;
          if (*feature>='0' && *feature<='9') wind = (unsigned int)(*(feature++) - '0');
          CImgDisplay &disp = _display_window[wind];

          if (!*feature) {
            cimg_snprintf(substr,substr.width(),"%d",disp?(disp.is_closed()?0:1):0);
            is_substituted = true;
          } else if (*feature==',') {
            bool flush_request = false;
            if (*(++feature)=='-' &&
                feature[1]!='w' && feature[1]!='h' && feature[1]!='d' && feature[1]!='e' &&
                feature[1]!='u' && feature[1]!='v' && feature[1]!='n' && feature[1]!='t') {
              flush_request = true; ++feature;
            }
            if (!feature[1]) switch (*feature) { // Single-char features.
              case 'w' : // Display width.
                cimg_snprintf(substr,substr.width(),"%d",disp.width());
                is_substituted = true;
                break;
              case 'h' : // Display height.
                cimg_snprintf(substr,substr.width(),"%d",disp.height());
                is_substituted = true;
                break;
              case 'd' : // Window width.
                cimg_snprintf(substr,substr.width(),"%d",disp.window_width());
                is_substituted = true;
                break;
              case 'e' : // Window height.
                cimg_snprintf(substr,substr.width(),"%d",disp.window_height());
                is_substituted = true;
                break;
              case 'u' : // Screen width.
                try {
                  cimg_snprintf(substr,substr.width(),"%d",CImgDisplay::screen_width());
                } catch (CImgDisplayException&) {
                  *substr = '0'; substr[1] = 0;
                }
                is_substituted = true;
                break;
              case 'v' : // Screen height.
                try {
                  cimg_snprintf(substr,substr.width(),"%d",CImgDisplay::screen_height());
                } catch (CImgDisplayException&) {
                  *substr = '0'; substr[1] = 0;
                }
                is_substituted = true;
                break;
              case 'n' : // Normalization type.
                cimg_snprintf(substr,substr.width(),"%d",disp.normalization());
                is_substituted = true;
                break;
              case 't' : // Window title.
                cimg_snprintf(substr,substr.width(),"%s",disp.title());
                is_substituted = true;
                break;
              case 'x' : // X-coordinate of mouse pointer.
                cimg_snprintf(substr,substr.width(),"%d",disp.mouse_x());
                is_substituted = true;
                if (flush_request) { disp._mouse_x = -1; disp._mouse_y = -1; }
                break;
              case 'y' : // Y-coordinate of mouse pointer.
                cimg_snprintf(substr,substr.width(),"%d",disp.mouse_y());
                is_substituted = true;
                if (flush_request) { disp._mouse_x = -1; disp._mouse_y = -1; }
                break;
              case 'b' : // State of mouse buttons.
                cimg_snprintf(substr,substr.width(),"%d",disp.button());
                is_substituted = true;
                if (flush_request) disp._button = 0;
                break;
              case 'o' : // State of mouse wheel.
                cimg_snprintf(substr,substr.width(),"%d",disp.wheel());
                is_substituted = true;
                if (flush_request) disp._wheel = 0;
                break;
              case 'c' : // Closed state of display window.
                cimg_snprintf(substr,substr.width(),"%d",(int)disp.is_closed());
                is_substituted = true;
                if (flush_request) disp._is_closed = false;
                break;
              case 'r' : // Resize event.
                cimg_snprintf(substr,substr.width(),"%d",(int)disp.is_resized());
                is_substituted = true;
                if (flush_request) disp._is_resized = false;
                break;
              case 'm' : // Move event.
                cimg_snprintf(substr,substr.width(),"%d",(int)disp.is_moved());
                is_substituted = true;
                if (flush_request) disp._is_moved = false;
                break;
              case 'k' : // Key event.
                cimg_snprintf(substr,substr.width(),"%u",disp.key());
                is_substituted = true;
                if (flush_request) disp._keys[0] = 0;
                break;
              } else if (*feature=='w' && feature[1]=='h' && !feature[2]) { // Display width*height.
              cimg_snprintf(substr,substr.width(),"%ld",
                            (long)disp.width()*disp.height());
              is_substituted = true;
            } else if (*feature=='d' && feature[1]=='e' && !feature[2]) { // Window width*height.
              cimg_snprintf(substr,substr.width(),"%ld",
                            (long)disp.window_width()*disp.window_height());
              is_substituted = true;
            } else if (*feature=='u' && feature[1]=='v' && !feature[2]) { // Screen width*height.
              try {
                cimg_snprintf(substr,substr.width(),"%ld",
                              (long)CImgDisplay::screen_width()*CImgDisplay::screen_height());
              } catch (CImgDisplayException&) {
                *substr = '0'; substr[1] = 0;
              }
              is_substituted = true;
            }
            if (!is_substituted) { // Pressed state of specified key.
              bool &ik = disp.is_key(feature);
              cimg_snprintf(substr,substr.width(),"%d",(int)ik);
              is_substituted = true;
              if (flush_request) ik = false;
            }
          }
#endif // #if cimg_display==0
        }

        // Double-quoted string.
        if (!is_substituted && inbraces.width()>=3 && *inbraces=='`' && inbraces[1]=='`') {
          strreplace_bw(inbraces.data() + 2);
          CImg<char>(inbraces.data() + 2,inbraces.width() - 3,1,1,1,true).
            append_string_to(substituted_items,ptr_sub);
          *substr = 0; is_substituted = true;
        }

        // Escaped string.
        if (!is_substituted && inbraces.width()>=2 && *inbraces=='/') {
          const char *s = inbraces.data() + 1;
          vs.assign(inbraces.width()*4);
          const unsigned int l = strescape(s,vs);
          CImg<char>(vs,l,1,1,1,true).
            append_string_to(substituted_items,ptr_sub);
          *substr = 0; is_substituted = true;
        }

        // Sequence of ascii characters.
        if (!is_substituted && inbraces.width()>=3 && *inbraces=='\'' &&
            inbraces[inbraces.width() - 2]=='\'') {
          const char *s = inbraces.data() + 1;
          if (inbraces.width()>3) {
            inbraces[inbraces.width() - 2] = 0;
            cimg::strunescape(inbraces);
            for (*substr = 0; *s; ++s) {
              cimg_snprintf(substr,substr.width(),"%d,",(int)(unsigned char)*s);
              CImg<char>(substr.data(),(unsigned int)std::strlen(substr),1,1,1,true).
                append_string_to(substituted_items,ptr_sub);
            }
            if (*substr) --ptr_sub;
          }
          *substr = 0; is_substituted = true;
        }

        // Image feature.
        if (!is_substituted) {
          const char *feature = inbraces;
          if (l_inbraces<=2) ind = images.width() - 1; // Single-char case.
          else if (cimg_sscanf(inbraces,"%d%c",&ind,&(sep=0))==2 && sep==',') {
            if (ind<0) ind+=images.width();
            if (ind<0 || ind>=images.width()) {
              if (images.width())
                error(images,0,0,
                      "Item substitution '{%s}': Invalid selection [%d] (not in range -%u...%u).",
                      cimg::strellipsize(inbraces,64,false),ind,images.size(),images.size() - 1);
              else
                error(images,0,0,
                      "Item substitution '{%s}': Invalid selection [%d] (no image data available).",
                      cimg::strellipsize(inbraces,64,false),ind);
            }
            while (*feature!=',') ++feature;
            ++feature;
          } else if (cimg_sscanf(inbraces,"%255[a-zA-Z0-9_]%c",substr.assign(256).data(),&(sep=0))==2 && sep==',') {
            selection2cimg(substr,images.size(),images_names,"Item substitution '{name,feature}'").move_to(_ind);
            if (_ind.height()!=1)
              error(images,0,0,
                    "Item substitution '{%s}': Invalid selection [%s], specifies multiple images.",
                    cimg::strellipsize(inbraces,64,false),substr.data());
            ind = (int)*_ind;
            while (*feature!=',') ++feature;
            ++feature;
          } else ind = images.width() - 1;

          CImg<T> &img = ind>=0?gmic_check(images[ind]):CImg<T>::empty();
          *substr = 0;
          if (!*feature)
            error(images,0,0,
                  "Item substitution '{%s}': Request for empty feature.",
                  cimg::strellipsize(inbraces,64,false));

          if (!feature[1]) switch (*feature) { // Single-char feature.
            case 'b' : { // Image basename.
              if (ind>=0) {
                substr.assign(std::max(substr.width(),images_names[ind].width()));
                cimg::split_filename(images_names[ind].data(),substr);
                const char *const basename = gmic::basename(substr);
                std::memmove(substr,basename,std::strlen(basename) + 1);
                strreplace_bw(substr);
              }
              is_substituted = true;
            } break;
            case 'd' : // Image depth.
              cimg_snprintf(substr,substr.width(),"%d",img.depth());
              is_substituted = true;
              break;
            case 'f' : { // Image folder name.
              if (ind>=0) {
                substr.assign(std::max(substr.width(),images_names[ind].width()));
                std::strcpy(substr,images_names[ind]);
                const char *const basename = gmic::basename(substr);
                substr[basename - substr.data()] = 0;
                strreplace_bw(substr);
              }
              is_substituted = true;
            } break;
            case 'h' : // Image height.
              cimg_snprintf(substr,substr.width(),"%d",img.height());
              is_substituted = true;
              break;
            case 'n' : // Image name.
              if (ind>=0) {
                substr.assign(std::max(substr.width(),images_names[ind].width()));
                cimg_snprintf(substr,substr.width(),"%s",images_names[ind].data());
                strreplace_bw(substr);
              }
              is_substituted = true;
              break;
            case 's' : // Number of image channels.
              cimg_snprintf(substr,substr.width(),"%d",img.spectrum());
              is_substituted = true;
              break;
            case 't' : { // Ascii string from image values.
              const unsigned int siz = (unsigned int)img.size();
              if (siz) {
                unsigned int strsiz = 0;
                cimg_for(img,ptr,T) if ((unsigned char)*ptr) ++strsiz; else break;
                if (strsiz) {
                  CImg<char> text(strsiz + 1), _text = text.get_shared_points(0,strsiz - 1,0,0,0);
                  _text = CImg<T>(img.data(),strsiz,1,1,1,true);
                  text.back() = 0;
                  strreplace_bw(text);
                  _text.append_string_to(substituted_items,ptr_sub);
                }
              }
              *substr = 0; is_substituted = true;
            } break;
            case 'x' : // Image extension.
              if (ind>=0) {
                substr.assign(std::max(substr.width(),images_names[ind].width()));
                cimg_snprintf(substr,substr.width(),"%s",
                              cimg::split_filename(images_names[ind].data()));
                strreplace_bw(substr);
              }
              is_substituted = true;
              break;
            case 'w' : // Image width.
              cimg_snprintf(substr,substr.width(),"%d",img.width());
              is_substituted = true;
              break;
            case '^' : { // Sequence of all pixel values.
              img.value_string(',').move_to(vs);
              if (vs && *vs) { --vs._width; vs.append_string_to(substituted_items,ptr_sub); }
              *substr = 0; is_substituted = true;
            } break;
            }

          const unsigned int l_feature = (unsigned int)std::strlen(feature);
          if (!is_substituted && *feature=='@') { // Subset of values.
            if (l_feature>=2) {
              if (feature[1]=='^' && !feature[2]) { // All pixel values
                img.value_string(',').move_to(vs);
                if (vs && *vs) { --vs._width; vs.append_string_to(substituted_items,ptr_sub); }
                *substr = 0; is_substituted = true;
              } else {
                CImg<char> subset(feature + 1,l_feature);
                subset.back() = 0;
                CImg<T> values;
                ++feature;
                int _verbosity = verbosity;
                bool _is_debug = is_debug;
                verbosity = -1; is_debug = false;
                CImg<char> _status;
                status.move_to(_status); // Save status because 'selection2cimg' may change it.
                try {
                  const CImg<unsigned int> inds = selection2cimg(subset,img.size(),CImgList<char>::empty(),"",false);
                  values.assign(1,inds.height());
                  cimg_foroff(inds,p) values[p] = img[inds[p]];
                } catch (gmic_exception &e) {
                  const char *const e_ptr = std::strstr(e.what(),": ");
                  error(images,0,0,
                        "Item substitution '{%s}': %s",
                        cimg::strellipsize(inbraces,64,false),e_ptr?e_ptr + 2:e.what());
                }
                _status.move_to(status);
                verbosity = _verbosity; is_debug = _is_debug;
                cimg_foroff(values,p) {
                  cimg_snprintf(substr,substr.width(),"%.17g",(double)values[p]);
                  CImg<char>::string(substr,true,true).
                    append_string_to(substituted_items,ptr_sub);
                  *(ptr_sub - 1) = ',';
                }
                if (values) --ptr_sub;
              }
            }
            *substr = 0; is_substituted = true;
          }

          if (!is_substituted && l_feature==2 && *feature=='\'' && feature[1]=='\'') { // Empty string.
            *substr = 0; is_substituted = true;
          }

          if (!is_substituted) { // Other mathematical expression.
            const bool is_string = l_feature>=3 && *feature=='`' && inbraces[inbraces.width() - 2]=='`';
            if (is_string) { ++feature; inbraces[inbraces.width() - 2] = 0; }
            const bool is_rounded = *feature=='_';
            if (is_rounded) ++feature;

            try {
              CImg<double> output;
              img.eval(output,feature,0,0,0,0,&images,&images);
              if (is_string) {
                vs.assign(output.height() + 1,1,1,1).fill(output).back() = 0;
                CImg<char>::string(vs,false,true).
                  append_string_to(substituted_items,ptr_sub);
              } else {
                if (output.height()>1) { // Vector-valued result
                  output.value_string(',',0,is_rounded?"%g":"%.17g").move_to(vs);
                  if (vs && *vs) { --vs._width; vs.append_string_to(substituted_items,ptr_sub); }
                } else { // Scalar result
                  if (is_rounded) cimg_snprintf(substr,substr.width(),"%g",*output);
                  else cimg_snprintf(substr,substr.width(),"%.17g",*output);
                  is_substituted = true;
                }
              }
            } catch (CImgException& e) {
              const char *const e_ptr = std::strstr(e.what(),": ");
              if (is_string) inbraces[inbraces.width() - 2] = '`';
              error(images,0,0,
                    "Item substitution '{%s}': %s",
                    cimg::strellipsize(inbraces,64,false),e_ptr?e_ptr + 2:e.what());
            }
          }
        }
        if (is_substituted && *substr)
          CImg<char>(substr.data(),(unsigned int)std::strlen(substr),1,1,1,true).
            append_string_to(substituted_items,ptr_sub);
        continue;

        //  '${...}' expressions.
      } else if (nsource[1]=='{') {
        const char *const ptr_beg = nsource + 2, *ptr_end = ptr_beg; unsigned int p = 0;
        for (p = 1; p>0 && *ptr_end; ++ptr_end) { if (*ptr_end=='{') ++p; if (*ptr_end=='}') --p; }
        if (p) {
          CImg<char>::append_string_to(*(nsource++),substituted_items,ptr_sub);
          continue;
        }
        l_inbraces = (int)(ptr_end - ptr_beg - 1);
        if (l_inbraces>0) {
          inbraces.assign(ptr_beg,l_inbraces + 1).back() = 0;
          substitute_item(inbraces,images,images_names,parent_images,parent_images_names,variables_sizes,
                          command_selection,false).move_to(inbraces);
        }
        is_braces = true;
      }

      // Substitute '$?' -> String that describes the current command selection.
      if (nsource[1]=='?') {
        if (command_selection) {
          const unsigned int substr_width = (unsigned int)substr.width();
          selection2string(*command_selection,images_names,1,substr);
          CImg<char>(substr.data(),(unsigned int)std::strlen(substr),1,1,1,true).
            append_string_to(substituted_items,ptr_sub);
          substr.assign(substr_width);
          nsource+=2;
        } else CImg<char>::append_string_to(*(nsource++),substituted_items,ptr_sub);

        // Substitute '$!' -> Number of images in the list.
      } else if (nsource[1]=='!') {
        cimg_snprintf(substr,substr.width(),"%u",images.size());
        CImg<char>(substr.data(),(unsigned int)std::strlen(substr),1,1,1,true).
          append_string_to(substituted_items,ptr_sub);
        nsource+=2;

        // Substitute '$^' -> Verbosity level.
      } else if (nsource[1]=='^') {
        cimg_snprintf(substr,substr.width(),"%d",verbosity);
        CImg<char>(substr.data(),(unsigned int)std::strlen(substr),1,1,1,true).
          append_string_to(substituted_items,ptr_sub);
        nsource+=2;

        // Substitute '$|' -> Timer value.
      } else if (nsource[1]=='|') {
        cimg_snprintf(substr,substr.width(),"%g",(cimg::time() - reference_time)/1000.);
        CImg<char>(substr.data(),(unsigned int)std::strlen(substr),1,1,1,true).
          append_string_to(substituted_items,ptr_sub);
        nsource+=2;

        // Substitute '$/' -> Current call stack.
      } else if (nsource[1]=='/') {
        cimglist_for(callstack,i) {
          callstack[i].append_string_to(substituted_items,ptr_sub);
          *(ptr_sub - 1) = '/';
        }
        nsource+=2;

        // Substitute '$>' and '$<' -> Forward/backward indice of current loop.
      } else if (nsource[1]=='>' || nsource[1]=='<') {
        if (!repeatdones)
          error(images,0,0,
                "Item substitution '$%c': There is no loop currently running.",
                nsource[1]);
        const CImg<unsigned int> &rd = repeatdones.back();
        cimg_snprintf(substr,substr.width(),"%u",nsource[1]=='>'?rd[2]:rd[1] - 1);
        CImg<char>(substr.data(),(unsigned int)std::strlen(substr),1,1,1,true).
          append_string_to(substituted_items,ptr_sub);
        nsource+=2;

        // Substitute '$name' and '${name}' -> Variable, image indice or environment variable.
      } else if ((((is_braces && cimg_sscanf(inbraces,"%255[a-zA-Z0-9_]",
                                             substr.assign(256).data())==1) &&
                   !inbraces[std::strlen(substr)]) ||
                  (cimg_sscanf(nsource + 1,"%255[a-zA-Z0-9_]",substr.assign(256).data())==1)) &&
                 (*substr<'0' || *substr>'9')) {
        const CImg<char>& name = is_braces?inbraces:substr;
        const unsigned int
          hashcode = gmic::hashcode(name,true),
          l_name = is_braces?l_inbraces + 3:(unsigned int)std::strlen(name) + 1;
        const bool
          is_global = *name=='_',
          is_thread_global = is_global && name[1]=='_';
        const int lind = is_global?0:(int)variables_sizes[hashcode];
        if (is_thread_global) cimg::mutex(30);
        const CImgList<char>
          &__variables = *variables[hashcode],
          &__variables_names = *variables_names[hashcode];
        bool is_name_found = false;
        for (int l = __variables.width() - 1; l>=lind; --l)
          if (!std::strcmp(__variables_names[l],name)) {
            is_name_found = true; ind = l; break;
          }
        if (is_name_found) {
          if (__variables[ind].size()>1)
            CImg<char>(__variables[ind].data(),(unsigned int)(__variables[ind].size() - 1)).
              append_string_to(substituted_items,ptr_sub);
        } else {
          for (int l = images.width() - 1; l>=0; --l)
            if (images_names[l] && !std::strcmp(images_names[l],name)) {
              is_name_found = true; ind = l; break;
            }
          if (is_name_found) {
            cimg_snprintf(substr,substr.width(),"%d",ind);
            CImg<char>(substr.data(),(unsigned int)std::strlen(substr),1,1,1,true).
              append_string_to(substituted_items,ptr_sub);
          } else {
            const char *const s_env = std::getenv(name);
            if (s_env) CImg<char>(s_env,(unsigned int)std::strlen(s_env),1,1,1,true).
                         append_string_to(substituted_items,ptr_sub);
          }
        }
        if (is_thread_global) cimg::mutex(30,0);
        nsource+=l_name;

        // Substitute '${"-command"}' -> Status value after command execution.
      } else if (is_braces) {
        nsource+=l_inbraces + 3;
        if (l_inbraces>0) {
          const CImgList<char>
            ncommands_line = commands_line_to_CImgList(strreplace_fw(inbraces));
          unsigned int nposition = 0;
          CImg<char>::string("*substitute").move_to(callstack);
          CImg<unsigned int> nvariables_sizes(512);
          cimg_forX(nvariables_sizes,l) nvariables_sizes[l] = variables[l]->size();
          _run(ncommands_line,nposition,images,images_names,parent_images,parent_images_names,
               nvariables_sizes,0,inbraces,command_selection);
          for (unsigned int l = 0; l<nvariables_sizes._width - 2; ++l) if (variables[l]->size()>nvariables_sizes[l]) {
              variables_names[l]->remove(nvariables_sizes[l],variables[l]->size() - 1);
              variables[l]->remove(nvariables_sizes[l],variables[l]->size() - 1);
            }
          callstack.remove();
          is_return = false;
        }
        if (status.width()>1)
          CImg<char>(status.data(),(unsigned int)std::strlen(status),1,1,1,true).
            append_string_to(substituted_items,ptr_sub);

        // Replace '$' by itself.
      } else CImg<char>::append_string_to(*(nsource++),substituted_items,ptr_sub);
    }
  *ptr_sub = 0;
  return CImg<char>(substituted_items.data(),(unsigned int)(ptr_sub - substituted_items.data() + 1));
}

// Main parsing procedures.
//-------------------------
gmic& gmic::run(const char *const commands_line,
                float *const p_progress, bool *const p_is_abort) {
  gmic_list<gmic_pixel_type> images;
  gmic_list<char> images_names;
  return run(commands_line,images,images_names,
             p_progress,p_is_abort);
}

template<typename T>
gmic& gmic::run(const char *const commands_line,
                gmic_list<T> &images, gmic_list<char> &images_names,
                float *const p_progress, bool *const p_is_abort) {
  cimg::mutex(26);
  if (is_running)
    error(images,0,0,
          "An instance of G'MIC interpreter %p is already running.",
          (void*)this);
  is_running = true;
  cimg::mutex(26,0);
  starting_commands_line = commands_line;
  is_debug = false;
  _run(commands_line_to_CImgList(commands_line),
       images,images_names,p_progress,p_is_abort);
  is_running = false;
  return *this;
}

template<typename T>
gmic& gmic::_run(const gmic_list<char>& commands_line,
                 gmic_list<T> &images, gmic_list<char> &images_names,
                 float *const p_progress, bool *const p_is_abort) {
  CImg<unsigned int> variables_sizes(512,1,1,1,0);
  unsigned int position = 0;
  setlocale(LC_NUMERIC,"C");
  callstack.assign(1U);
  callstack._data[0].assign(2,1,1,1);
  callstack._data[0]._data[0] = '.';
  callstack._data[0]._data[1] = 0;
  dowhiles.assign(0U);
  repeatdones.assign(0U);
  status.assign(0U);
  nb_carriages = 0;
  debug_filename = ~0U;
  debug_line = ~0U;
  is_released = true;
  is_debug_info = false;
  is_debug = false;
  is_start = true;
  is_quit = false;
  is_return = false;
  check_elif = false;
  if (p_progress) progress = p_progress; else { _progress = -1; progress = &_progress; }
  if (p_is_abort) is_abort = p_is_abort; else { _is_abort = false; is_abort = &_is_abort; }
  is_abort_thread = false;
  *progress = -1;
  cimglist_for(commands_line,l) if (!std::strcmp("-debug",commands_line[l].data())) { is_debug = true; break; }
  return _run(commands_line,position,images,images_names,images,images_names,variables_sizes,0,0,0);
}

#if defined(_MSC_VER) && !defined(_WIN64)
#pragma optimize("y", off)
#endif // #if defined(_MSC_VER) && !defined(_WIN64)

template<typename T>
gmic& gmic::_run(const CImgList<char>& commands_line, unsigned int& position,
                 CImgList<T>& images, CImgList<char>& images_names,
                 CImgList<T>& parent_images, CImgList<char>& parent_images_names,
                 const unsigned int *const variables_sizes,
                 bool *const is_noarg, const char *const parent_arguments,
                 const CImg<unsigned int> *const command_selection) {

#if cimg_display!=0
  CImgDisplay *const _display_window = (CImgDisplay*)display_window;
#endif
  if (!commands_line || position>=commands_line._width) {
    if (is_debug) debug(images,"Return from empty function '%s/'.",
                        callstack.back().data());
    return *this;
  }
  typedef typename cimg::superset<T,float>::type Tfloat;
  typedef typename cimg::superset<T,cimg_long>::type Tlong;
  typedef typename cimg::last<T,cimg_ulong>::type ulongT;
  typedef typename cimg::last<T,cimg_long>::type longT;
  typedef typename cimg::last<T,cimg_uint64>::type uint64T;
  typedef typename cimg::last<T,cimg_int64>::type int64T;
  const unsigned int initial_callstack_size = callstack.size(), initial_debug_line = debug_line;

  CImgList<st_gmic_parallel<T> > threads_data;
  CImgList<unsigned int> primitives;
  CImgList<unsigned char> g_list_uc;
  CImgList<float> g_list_f;
  CImgList<char> g_list_c;
  CImgList<T> g_list;

  CImg<unsigned int> ind, ind0, ind1;
  CImg<unsigned char> g_img_uc;
  CImg<float> vertices;
  CImg<char> name;
  CImg<T> g_img;

  unsigned int next_debug_line = ~0U, next_debug_filename = ~0U, _debug_line, _debug_filename,
    is_high_connectivity, __ind = 0, boundary = 0, pattern = 0, exit_on_anykey = 0, wind = 0;
  char end, sep = 0, sep0 = 0, sep1 = 0, sepx = 0, sepy = 0, sepz = 0, sepc = 0, axis = 0;
  double vmin = 0, vmax = 0, value, value0, value1, nvalue, nvalue0, nvalue1;
  bool is_endlocal = false;
  float opacity = 0;
  int err;

  // Allocate string variables, widely used afterwards
  // (prevents stack overflow on recursive calls while remaining thread-safe).
  CImg<char> _formula(4096), _color(4096), message(1024), _title(256), _indices(256),
    _argx(256), _argy(256), _argz(256), _argc(256), _current_command(256), argument_text(81),
    _command(256), _restriction(256);

  char
    *const formula = _formula.data(),
    *const color = _color.data(),
    *const title = _title.data(),
    *const indices = _indices.data(),
    *const argx = _argx.data(),
    *const argy = _argy.data(),
    *const argz = _argz.data(),
    *const argc = _argc.data(),
    *const current_command = _current_command.data(),
    *const command = _command.data(),
    *const restriction = _restriction.data();
  *formula = *color = *title = *indices = *argx = *argy = *argz = *argc =
    *current_command = *command = *restriction = 0;

  try {

    // Init interpreter environment.
    if (images.size()<images_names.size())
      images_names.remove(images.size(),images_names.size() - 1);
    else if (images.size()>images_names.size())
      images_names.insert(images.size() - images_names.size(),CImg<char>::string("[unnamed]"));

    if (is_debug) {
      if (is_start) {
        print(images,0,"Start G'MIC interpreter (in debug mode).");
        debug(images,"Initial command line: '%s'.",starting_commands_line);
        commands_line_to_CImgList(starting_commands_line); // Do it twice, when debug enabled.
      }
      nb_carriages = 2;
      debug(images,"%sEnter scope '%s/'.%s",
            cimg::t_bold,callstack.back().data(),cimg::t_normal);
      is_start = false;
    }

    // Begin command line parsing.
    if (!commands_line && is_start) { print(images,0,"Start G'MIC interpreter."); is_start = false; }
    while (position<commands_line.size() && !is_quit && !is_return) {

#ifdef cimg_use_abort
      _cimg_is_abort.ptr = is_abort;
#endif // #ifdef cimg_use_abort
      const bool is_first_item = !position;

      // Process debug info.
      if (next_debug_line!=~0U) { debug_line = next_debug_line; next_debug_line = ~0U; }
      if (next_debug_filename!=~0U) { debug_filename = next_debug_filename; next_debug_filename = ~0U; }
      while (position<commands_line.size() && *commands_line[position]==1) {
        if (cimg_sscanf(commands_line[position].data() + 1,"%x,%x",&_debug_line,&(_debug_filename=0))>0) {
          is_debug_info = true; debug_line = _debug_line; debug_filename = _debug_filename;
        }
        ++position;
      }
      if (position>=commands_line.size()) break;

      // Check consistency of the interpreter environment.
      if (images_names.size()!=images.size())
        error("G'MIC encountered a fatal error (images (%u) and images names (%u) have different size). "
               "Please submit a bug report, at: https://github.com/dtschump/gmic-community/issues",
              images_names.size(),images.size());
      if (!callstack)
        error("G'MIC encountered a fatal error (empty call stack). "
              "Please submit a bug report, at: https://github.com/dtschump/gmic-community/issues");
      if (callstack.size()>=64)
        error("Call stack overflow (infinite recursion?).");

      // Substitute expressions in current item.
      const char
        *const initial_item = commands_line[position].data(),
        *const empty_argument = "",
        *initial_argument = empty_argument;

      unsigned int position_argument = position + 1;
      while (position_argument<commands_line.size() && *(commands_line[position_argument])==1) {
        if (cimg_sscanf(commands_line[position_argument].data() + 1,"%x,%x",&_debug_line,&(_debug_filename=0))>0) {
          is_debug_info = true; next_debug_line = _debug_line; next_debug_filename = _debug_filename;
        }
        ++position_argument;
      }
      if (position_argument<commands_line.size()) initial_argument = commands_line[position_argument];

      CImg<char> _item, _argument;
      substitute_item(initial_item,images,images_names,parent_images,parent_images_names,
                      variables_sizes,command_selection,false).move_to(_item);
      char *item = _item;
      const char *argument = initial_argument;

      // Split command/restriction, if necessary.
      *command = *restriction = 0;

      bool is_double_hyphen = false, is_restriction = false;
      const unsigned int siz = images._width;
      CImg<unsigned int> selection;
      CImg<char> new_name;
      if (*item=='-' && item[1] && item[1]!='.') {
        sep0 = sep1 = 0;
        if (item[1]=='-' && item[2] && item[2]!='[' && item[2]!='.' && (item[2]!='3' || item[3]!='d')) {
          ++item; is_double_hyphen = true;
        }
        strreplace_fw(item);
        err = cimg_sscanf(item,"%255[^[]%c%255[a-zA-Z_0-9.eE%^,:+-]%c%c",
                          command,&sep0,restriction,&sep1,&end);

        const unsigned int l_command = err==1?(unsigned int)std::strlen(command):0;
        if (err==1 && l_command>=2 && command[l_command - 1]=='.') { // Selection shortcut
          err = 4; sep0 = '['; sep1 = ']'; *restriction = '-';
          if (command[l_command - 2]!='.') { restriction[1] = '1'; command[l_command - 1] = 0; }
          else if (l_command>=3 && command[l_command - 3]!='.') { restriction[1] = '2'; command[l_command - 2] = 0; }
          else if (l_command>=4 && command[l_command - 4]!='.') { restriction[1] = '3'; command[l_command - 3] = 0; }
          restriction[2] = 0;
        }
        if (err==1) { // No selection -> all images
          selection.assign(1,siz);
          cimg_forY(selection,y) selection[y] = (unsigned int)y;
        } else if (err==2 && sep0=='[' && item[std::strlen(command) + 1]==']') { // Empty selection
          selection.assign(); is_restriction = true;
        } else if (err==4 && sep1==']') { // Other selections
          is_restriction = true;
          if (!is_double_hyphen && (!std::strcmp("-wait",command) ||
                                    !std::strcmp("-cursor",command)))
            selection2cimg(restriction,10,CImgList<char>::empty(),command).move_to(selection);
          else if (!is_double_hyphen && command[1]=='i' && (!command[2] || !std::strcmp("-input",command)))
            selection2cimg(restriction,siz + 1,images_names,command,true,&new_name).move_to(selection);
          else if (!is_double_hyphen &&
                   ((command[1]=='e' && (!command[2] ||
                                         !std::strcmp("-echo",command) ||
                                         !std::strcmp("-error",command))) ||
                    !std::strcmp("-warn",command)))
            selection2cimg(restriction,callstack.size(),CImgList<char>::empty(),command).move_to(selection);
          else if (!is_double_hyphen && !std::strcmp("-pass",command))
            selection2cimg(restriction,parent_images.size(),parent_images_names,command).move_to(selection);
          else
            selection2cimg(restriction,siz,images_names,command).move_to(selection);
        } else {
          std::strncpy(command,item,_command.width() - 1);
          command[_command.width() - 1] = *restriction = 0;
        }
        if (is_double_hyphen) --item;
      } else {
        std::strncpy(command,item,_command.width() - 1);
        command[_command.width() - 1] = *restriction = 0;
      }
      position = position_argument;

      if (*command=='-') {
        std::strncpy(current_command,command,_current_command.width() - 1);
        current_command[_current_command.width() - 1] = 0;
      } else *current_command = 0;

      const bool
        is_verbose_command = *item=='-' && item[1]=='v' && (!item[2] || !std::strcmp(item,"-verbose")),
        is_echo_command = is_double_hyphen || is_verbose_command?false:
        *command=='-' && command[1]=='e' && (!command[2] || !std::strcmp(command,"-echo")),
        is_input_command = is_double_hyphen || is_verbose_command || is_echo_command?false:
        *command=='-' && command[1]=='i' && (!command[2] || !std::strcmp(command,"-input")),
        is_check_command = is_verbose_command || is_echo_command || is_input_command?false:!std::strcmp(item,"-check"),
        is_skip_command = is_verbose_command || is_echo_command || is_input_command || is_check_command?false:
        !std::strcmp(item,"-skip");

      // Check for verbosity command, prior to the first output of a log message.
      bool is_verbose = verbosity>=0 || is_debug, is_verbose_argument = false;
      const int old_verbosity = verbosity;
      if (is_verbose_command) {
        // Do a first fast check.
        if (*argument=='-' && !argument[1]) { --verbosity; is_verbose_argument = true; }
        else if (*argument=='+' && !argument[1]) { ++verbosity; is_verbose_argument = true; }
        else {
          gmic_substitute_args(false);
          if (*argument=='-' && !argument[1]) { --verbosity; is_verbose_argument = true; }
          else if (*argument=='+' && !argument[1]) { ++verbosity; is_verbose_argument = true; }
          else {
            float level = 0;
            if (cimg_sscanf(argument,"%f%c",&level,&end)==1) {
              verbosity = (int)cimg::round(level);
              is_verbose_argument = true;
            }
            else arg_error("verbose");
          }
        }
      }
      is_verbose = verbosity>=0 || is_debug;
      const bool is_very_verbose = verbosity>0 || is_debug;

      // Generate strings for displaying image selections when verbosity>=0.
      CImg<char> gmic_selection;
      if (is_debug ||
          (verbosity>=0 && !is_check_command && !is_skip_command && !is_echo_command && !is_verbose_command))
        selection2string(selection,images_names,1,gmic_selection);

      if (is_debug) {
        if (std::strcmp(item,initial_item))
          debug(images,"Item '%s' -> '%s', selection%s.",
                initial_item,item,gmic_selection.data());
        else
          debug(images,"Item '%s', selection%s.",
                initial_item,gmic_selection.data());
      }

      // Display starting message.
      if (is_start) {
        print(images,0,"Start G'MIC interpreter.");
        is_start = false;
      }

      // Cancellation point.
      if (*is_abort || is_abort_thread) {
        if (is_very_verbose) print(images,0,"Abort G'MIC interpreter.\n");
        dowhiles.assign();
        repeatdones.assign();
        position = commands_line.size();
        is_released = is_quit = true;
        break;
      }

      // Begin command interpretation.
      if (*item=='-' && item[1]) {

        // Manage command shortcuts.
        char command1 = command[1];
        const char
          command2 = command1?command[2]:0, command3 = command2?command[3]:0,
          command4 = command3?command[4]:0, command5 = command4?command[5]:0;

        static const char* onechar_shortcuts[] = {
          0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, // 0-31
          0,0,0,0,0,"-mod","-and",0,0,0,"-mul","-add",0,"-sub",0,"-div",0,0,0,0,0,0,0,0,0,0,0,0, // 32-59
          "-lt","-set","-gt",0, // 60-63
          0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,"-pow",0, // 64-95
          0,"-append","-blur","-cut","-display","-echo","-fill","-gradient",0,"-input","-image","-keep", // 96-107
          "-local","-command","-normalize","-output","-print","-quit","-resize","-split","-text","-status", // 108-117
          "-verbose","-window","-exec","-unroll","-crop",0,"-or",0,0,0 // 118-127
        };

        if (!command2) { // Single-char shortcut.
          const bool
            is_mquvx = command1=='m' || command1=='q' || command1=='u' || command1=='v' || command1=='x',
            is_deiopwx = command1=='d' || command1=='e' || command1=='i' || command1=='o' || command1=='p' ||
                         command1=='w' || command1=='x';
          if ((unsigned int)command1<128 && onechar_shortcuts[(unsigned int)command1] &&
              (!is_mquvx || (!is_double_hyphen && !is_restriction)) &&
              (!is_deiopwx || !is_double_hyphen)) {
            std::strcpy(command,onechar_shortcuts[(unsigned int)command1]);
            if (is_mquvx) { CImg<char>::string(command).move_to(_item); *command = 0; }
            else *item = 0;
          }

        } else if (!command3) { // Two-chars shortcuts.
          if (command1=='s' && command2=='h' && !is_double_hyphen) std::strcpy(command,"-shared");
          else if (command1=='m' && command2=='v') std::strcpy(command,"-move");
          else if (command1=='n' && command2=='m' && !is_double_hyphen) std::strcpy(command,"-name");
          else if (command1=='r' && command2=='m') std::strcpy(command,"-remove");
          else if (command1=='r' && command2=='v') std::strcpy(command,"-reverse");
          else if (command1=='<' && command2=='<') std::strcpy(command,"-bsl");
          else if (command1=='>' && command2=='>') std::strcpy(command,"-bsr");
          else if (command1=='=' && command2=='=') std::strcpy(command,"-eq");
          else if (command1=='>' && command2=='=') std::strcpy(command,"-ge");
          else if (command1=='<' && command2=='=') std::strcpy(command,"-le");
          else if (command1=='/' && command2=='/') std::strcpy(command,"-mdiv");
          else if (command1=='*' && command2=='*') std::strcpy(command,"-mmul");
          else if (command1=='!' && command2=='=') std::strcpy(command,"-neq");

        } else if (!command4 && command2=='3' && command3=='d') switch (command1) {
            // Three-chars shortcuts (ending with '3d').
          case 'd' : if (!is_double_hyphen) std::strcpy(command,"-display3d"); break;
          case 'j' : std::strcpy(command,"-object3d"); break;
          case '+' : std::strcpy(command,"-add3d"); break;
          case '/' : std::strcpy(command,"-div3d"); break;
          case 'f' : if (!is_double_hyphen && !is_restriction)
              CImg<char>::string("-focale3d").move_to(_item);
            break;
          case 'l' : if (!is_double_hyphen && !is_restriction)
              CImg<char>::string("-light3d").move_to(_item);
            break;
          case 'm' : if (!is_double_hyphen && !is_restriction)
              CImg<char>::string("-mode3d").move_to(_item);
          case '*' : std::strcpy(command,"-mul3d"); break;
          case 'o' : std::strcpy(command,"-opacity3d"); break;
          case 'p' : std::strcpy(command,"-primitives3d"); break;
          case 'r' : std::strcpy(command,"-rotate3d"); break;
          case 's' : std::strcpy(command,"-split3d"); break;
          case '-' : std::strcpy(command,"-sub3d"); break;
          case 't' : std::strcpy(command,"-texturize3d"); break;
          } else if (!command5 && command3=='3' && command4=='d') {
          // Four-chars shortcuts (ending with '3d').
          if (command1=='d' && command2=='b') {
            if (!is_double_hyphen && !is_restriction) CImg<char>::string("-double3d").move_to(_item);
          } else if (command1=='m' && command2=='d') {
            if (!is_double_hyphen && !is_restriction) CImg<char>::string("-moded3d").move_to(_item);
          }
          else if (command1=='r' && command2=='v') std::strcpy(command,"-reverse3d");
          else if (command1=='s' && command2=='l') {
            if (!is_double_hyphen && !is_restriction) CImg<char>::string("-specl3d").move_to(_item);
          }
          else if (command1=='s' && command2=='s') {
            if (!is_double_hyphen && !is_restriction) CImg<char>::string("-specs3d").move_to(_item);
          }
        }
        item = _item;
        command1 = *command?command[1]:item[1];

        // Check if a new name has been requested for a command that does not allow that.
        if (new_name && !is_double_hyphen && !is_input_command)
          error(images,0,0,
                "Item '%s %s': Unknow name '%s'.",
                initial_item,initial_argument,new_name.data());

        // Dispatch to dedicated parsing code, regarding the first character of the command.
        // We rely on the compiler to optimize this using an associative array (verified with g++).
        switch (command1) {
        case 'a' : goto gmic_commands_a;
        case 'b' : goto gmic_commands_b;
        case 'c' : goto gmic_commands_c;
        case 'd' : goto gmic_commands_d;
        case 'e' : goto gmic_commands_e;
        case 'f' : goto gmic_commands_f;
        case 'g' : goto gmic_commands_g;
        case 'h' : goto gmic_commands_h;
        case 'i' :
          if (command[2]=='f' && !command[3]) goto gmic_commands_others; // (Skip for '-if').
          goto gmic_commands_i;
        case 'k' : goto gmic_commands_k;
        case 'l' : goto gmic_commands_l;
        case 'm' : goto gmic_commands_m;
        case 'n' : goto gmic_commands_n;
        case 'o' : goto gmic_commands_o;
        case 'p' : goto gmic_commands_p;
        case 'q' : goto gmic_commands_q;
        case 'r' : goto gmic_commands_r;
        case 's' : goto gmic_commands_s;
        case 't' : goto gmic_commands_t;
        case 'u' : goto gmic_commands_u;
        case 'v' : goto gmic_commands_v;
        case 'w' : goto gmic_commands_w;
        case 'x' : goto gmic_commands_x;
        default : goto gmic_commands_others;
        }

        //-----------------------------
        // Commands starting by '-a...'
        //-----------------------------
      gmic_commands_a :

        // Append.
        if (!std::strcmp("-append",command)) {
          gmic_substitute_args(true);
          float align = 0;
          axis = sep = 0;
          if ((cimg_sscanf(argument,"%c%c",
                           &axis,&end)==1 ||
               cimg_sscanf(argument,"%c,%f%c",
                           &axis,&align,&end)==2) &&
              (axis=='x' || axis=='y' || axis=='z' || axis=='c')) {
            print(images,0,"Append image%s along the '%c'-axis, with alignment %g.",
                  gmic_selection.data(),
                  axis,align);
            if (selection) {
              cimg_forY(selection,l) if (gmic_check(images[selection[l]]))
                g_list.insert(gmic_check(images[selection[l]]),~0U,true);
              CImg<T> img = g_list.get_append(axis,align);
              name = images_names[selection[0]];
              if (is_double_hyphen) {
                img.move_to(images);
                images_names.insert(name.copymark());
              } else if (selection.height()>=2) {
                remove_images(images,images_names,selection,1,selection.height() - 1);
                img.move_to(images[selection[0]].assign());
                name.move_to(images_names[selection[0]]);
              }
              g_list.assign();
            }
          } else if ((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c,%c%c",
                                  indices,&sep,&axis,&end)==3 ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c,%c,%f%c",
                                  indices,&sep,&axis,&(align=0),&end)==4) &&
                     (axis=='x' || axis=='y' || axis=='z' || axis=='c') &&
                     sep==']' &&
                     (ind=selection2cimg(indices,images.size(),images_names,"-append")).height()==1) {
            print(images,0,"Append image [%u] to image%s, along the '%c'-axis, with alignment %g.",
                  *ind,gmic_selection.data(),axis,align);
            const CImg<T> img0 = gmic_image_arg(*ind);
            cimg_forY(selection,l) gmic_apply(append(img0,axis,align));
          } else arg_error("append");
          is_released = false; ++position; continue;
        }

        // Autocrop.
        if (!std::strcmp("-autocrop",command)) {
          gmic_substitute_args(false);
          if (*argument && cimg_sscanf(argument,"%4095[0-9.,eEinfa+-]%c",formula,&end)==1)
            try { CImg<T>(1).fill(argument,true,false).move_to(g_img); }
            catch (CImgException&) { g_img.assign(); }
          if (g_img) {
            print(images,0,"Auto-crop image%s by vector '%s'.",
                  gmic_selection.data(),
                  gmic_argument_text_printed());
            ++position;
          } else print(images,0,"Auto-crop image%s.",
                       gmic_selection.data());
          cimg_forY(selection,l) {
            if (g_img) {
              CImg<T>& img = images[selection[l]];
              g_img.assign(img.spectrum()).fill(argument,true,false);
              gmic_apply(gmic_autocrop(g_img));
            } else gmic_apply(gmic_autocrop());
          }
          g_img.assign();
          is_released = false; continue;
        }

        // Add.
        gmic_arithmetic_command("-add",
                                operator+=,
                                "Add %g%s to image%s",
                                value,ssep,gmic_selection.data(),Tfloat,
                                operator+=,
                                "Add image [%d] to image%s",
                                ind[0],gmic_selection.data(),
                                operator_pluseq,
                                "Add expression %s to image%s",
                                gmic_argument_text_printed(),gmic_selection.data(),
                                "Add image%s");

        // Add 3d objects together, or shift a 3d object.
        if (!std::strcmp("-add3d",command)) {
          gmic_substitute_args(true);
          float tx = 0, ty = 0, tz = 0;
          sep = *indices = 0;
          if (cimg_sscanf(argument,"%f%c",
                          &tx,&end)==1 ||
              cimg_sscanf(argument,"%f,%f%c",
                          &tx,&ty,&end)==2 ||
              cimg_sscanf(argument,"%f,%f,%f%c",
                          &tx,&ty,&tz,&end)==3) {
            print(images,0,"Shift 3d object%s by displacement (%g,%g,%g).",
                  gmic_selection.data(),
                  tx,ty,tz);
            cimg_forY(selection,l) {
              const unsigned int uind = selection[l];
              CImg<T>& img = images[uind];
              try { gmic_apply(shift_CImg3d(tx,ty,tz)); }
              catch (CImgException&) {
                if (!img.is_CImg3d(true,&(*message=0)))
                  error(images,0,0,
                        "Command '-add3d': Invalid 3d object [%d], in selected image%s (%s).",
                        uind,gmic_selection_err.data(),message.data());
                else throw;
              }
            }
            ++position;
          } else if (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep,&end)==2 &&
                     sep==']' &&
                     (ind=selection2cimg(indices,images.size(),images_names,"-add3d")).height()==1) {
            const CImg<T> img0 = gmic_image_arg(*ind);
            print(images,0,"Merge 3d object%s with 3d object [%u].",
                  gmic_selection.data(),*ind);
            cimg_forY(selection,l) {
              const unsigned int _ind = selection[l];
              CImg<T>& img = gmic_check(images[_ind]);
              g_list.assign(2);
              g_list[0].assign(img,true);
              g_list[1].assign(img0,true);
              CImg<T> res;
              try { CImg<T>::append_CImg3d(g_list).move_to(res); }
              catch (CImgException&) {
                if (!img0.is_CImg3d(true,&(*message=0)))
                  error(images,0,0,
                        "Command '-add3d': Invalid 3d object [%u], in specified "
                        "argument '%s' (%s).",
                        *ind,gmic_argument_text(),message.data());
                else if (!img.is_CImg3d(true,message))
                  error(images,0,0,
                        "Command '-add3d': Invalid 3d object [%d], in selected image%s (%s).",
                        _ind,gmic_selection_err.data(),message.data());
                else throw;
              }
              if (is_double_hyphen) {
                res.move_to(images);
                images_names[_ind].get_copymark().move_to(images_names);
              } else res.move_to(images[_ind].assign());
            }
            g_list.assign();
            ++position;
          } else {
            print(images,0,"Merge 3d object%s.",
                  gmic_selection.data());
            if (selection) {
              g_list.assign(selection.height());
              cimg_forY(selection,l) g_list[l].assign(gmic_check(images[selection[l]]),true);
              CImg<T> img;
              try { CImg<T>::append_CImg3d(g_list).move_to(img); }
              catch (CImgException&) {
                cimg_forY(selection,l) {
                  const unsigned int uind = selection[l];
                  if (!images[uind].is_CImg3d(true,&(*message=0)))
                    error(images,0,0,
                          "Command '-add3d': Invalid 3d object [%d], in selected image%s (%s).",
                          uind,gmic_selection_err.data(),message.data());
                }
                throw;
              }
              name = images_names[selection[0]];
              if (is_double_hyphen) {
                img.move_to(images);
                images_names.insert(name.copymark());
              } else if (selection.height()>=2) {
                remove_images(images,images_names,selection,1,selection.height() - 1);
                img.move_to(images[selection[0]].assign());
                name.move_to(images_names[selection[0]]);
              }
              g_list.assign();
            }
          }
          is_released = false; continue;
        }

        // Absolute value.
        gmic_simple_command("-abs",abs,"Compute pointwise absolute value of image%s.");

        // Bitwise and.
        gmic_arithmetic_command("-and",
                                operator&=,
                                "Compute bitwise AND of image%s by %g%s",
                                gmic_selection.data(),value,ssep,Tlong,
                                operator&=,
                                "Compute bitwise AND of image%s by image [%d]",
                                gmic_selection.data(),ind[0],
                                operator_andeq,
                                "Compute bitwise AND of image%s by expression %s",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Compute sequential bitwise AND of image%s");

        // Arc-tangent (two arguments).
        if (!std::strcmp("-atan2",command)) {
          gmic_substitute_args(true);
          sep = 0;
          if (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",
                          indices,&sep,&end)==2 && sep==']' &&
              (ind=selection2cimg(indices,images.size(),images_names,"-atan2")).height()==1) {
            print(images,0,"Compute pointwise oriented arc-tangent of image%s, "
                  "with x-argument [%u].",
                  gmic_selection.data(),
                  *ind);
            const CImg<T> img0 = gmic_image_arg(*ind);
            cimg_forY(selection,l) gmic_apply(atan2(img0));
          } else arg_error("atan2");
          is_released = false; ++position; continue;
        }

        // Arc-cosine.
        gmic_simple_command("-acos",acos,"Compute pointwise arc-cosine of image%s.");

        // Arc-sine.
        gmic_simple_command("-asin",asin,"Compute pointwise arc-sine of image%s.");

        // Arc-tangent.
        gmic_simple_command("-atan",atan,"Compute pointwise arc-tangent of image%s.");

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-b...'
        //-----------------------------
      gmic_commands_b :

        // Blur.
        if (!std::strcmp("-blur",command)) {
          gmic_substitute_args(false);
          unsigned int is_gaussian = 0;
          float sigma = -1;
          sep = *argx = 0;
          boundary = 1;

          const char *_argument = argument;
          if (cimg_sscanf(argument,"%255[xyzc]%c",argx,&sep)==2 && sep==',') {
            _argument+=1 + std::strlen(argx);
          } else sep = *argx = 0;

          if ((cimg_sscanf(_argument,"%f%c",
                           &sigma,&end)==1 ||
               (cimg_sscanf(_argument,"%f%c%c",
                            &sigma,&sep,&end)==2 && sep=='%') ||
               cimg_sscanf(_argument,"%f,%u%c",
                           &sigma,&boundary,&end)==2 ||
               (cimg_sscanf(_argument,"%f%c,%u%c",
                            &sigma,&sep,&boundary,&end)==3 && sep=='%') ||
               cimg_sscanf(_argument,"%f,%u,%u%c",
                           &sigma,&boundary,&is_gaussian,&end)==3 ||
               (cimg_sscanf(_argument,"%f%c,%u,%u%c",
                            &sigma,&sep,&boundary,&is_gaussian,&end)==4 && sep=='%')) &&
              sigma>=0 && boundary<=1 && is_gaussian<=1) {
            print(images,0,"Blur image%s%s%s%s with standard deviation %g%s, %s boundary conditions "
                  "and %s kernel.",
                  gmic_selection.data(),
                  *argx?" along the '":"",
                  *argx?argx:"",
                  *argx?std::strlen(argx)==1?"'-axis,":"'-axes,":"",
                  sigma,sep=='%'?"%":"",
                  boundary?"neumann":"dirichlet",
                  is_gaussian?"gaussian":"quasi-gaussian");
            if (sep=='%') sigma = -sigma;
            if (*argx) {
              g_img.assign(4,1,1,1,(T)0);
              for (const char *s = argx; *s; ++s) g_img[*s>='x'?*s - 'x':3]+=sigma;
              cimg_forY(selection,l) gmic_apply(gmic_blur(g_img[0],g_img[1],g_img[2],g_img[3],
                                                          (bool)boundary,(bool)is_gaussian));
              g_img.assign();
            } else cimg_forY(selection,l) gmic_apply(blur(sigma,(bool)boundary,(bool)is_gaussian));
          } else arg_error("blur");
          is_released = false; ++position; continue;
        }

        // Box filter.
        if (!std::strcmp("-boxfilter",command)) {
          unsigned int order = 0;
          gmic_substitute_args(false);
          float sigma = -1;
          sep = *argx = 0;
          boundary = 1;
          const char *_argument = argument;
          if (cimg_sscanf(argument,"%255[xyzc]%c",argx,&sep)==2 && sep==',') {
            _argument+=1 + std::strlen(argx);
          } else sep = *argx = 0;
          if ((cimg_sscanf(_argument,"%f%c",
                           &sigma,&end)==1 ||
               (cimg_sscanf(_argument,"%f%c%c",
                            &sigma,&sep,&end)==2 && sep=='%') ||
               cimg_sscanf(_argument,"%f,%u%c",
                           &sigma,&order,&end)==2 ||
               (cimg_sscanf(_argument,"%f%c,%u%c",
                            &sigma,&sep,&order,&end)==3 && sep=='%') ||
               cimg_sscanf(_argument,"%f,%u,%u%c",
                           &sigma,&order,&boundary,&end)==3 ||
               (cimg_sscanf(_argument,"%f%c,%u,%u%c",
                            &sigma,&sep,&order,&boundary,&end)==4 && sep=='%')) &&
              sigma>=0 && boundary<=1 && order<=2) {
            print(images,0,"Blur image%s%s%s%s with normalized box filter of size %g%s, order %u and "
                  "%s boundary conditions.",
                  gmic_selection.data(),
                  *argx?" along the '":"",
                  *argx?argx:"",
                  *argx?std::strlen(argx)==1?"'-axis,":"'-axes,":"",
                  sigma,sep=='%'?"%":"",
                  order,
                  boundary?"neumann":"dirichlet");
            if (sep=='%') sigma = -sigma;
            if (*argx) {
              g_img.assign(4,1,1,1,(T)0);
              for (const char *s = argx; *s; ++s) g_img[*s>='x'?*s - 'x':3]+=sigma;
              cimg_forY(selection,l) gmic_apply(gmic_blur_box(g_img[0],g_img[1],g_img[2],g_img[3],
                                                              order,(bool)boundary));
              g_img.assign();
            } else cimg_forY(selection,l) gmic_apply(gmic_blur_box(sigma,order,(bool)boundary));
          } else arg_error("boxfilter");
          is_released = false; ++position; continue;
        }

        // Bitwise right shift.
        gmic_arithmetic_command("-bsr",
                                operator>>=,
                                "Compute bitwise right shift of image%s by %g%s",
                                gmic_selection.data(),value,ssep,Tlong,
                                operator>>=,
                                "Compute bitwise right shift of image%s by image [%d]",
                                gmic_selection.data(),ind[0],
                                operator_brseq,
                                "Compute bitwise right shift of image%s by expression %s",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Compute sequential bitwise right shift of image%s");

        // Bitwise left shift.
        gmic_arithmetic_command("-bsl",
                                operator<<=,
                                "Compute bitwise left shift of image%s by %g%s",
                                gmic_selection.data(),value,ssep,Tlong,
                                operator<<=,
                                "Compute bitwise left shift of image%s by image [%d]",
                                gmic_selection.data(),ind[0],
                                operator_blseq,
                                "Compute bitwise left shift of image%s by expression %s",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Compute sequential bitwise left shift of image%s");

        // Bilateral filter.
        if (!std::strcmp("-bilateral",command)) {
          gmic_substitute_args(true);
          float sigma_s = 0, sigma_r = 0, sampling_s = 0, sampling_r = 0;
          sep0 = sep1 = *argz = *argc = 0;
          if ((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                           indices,argx,argy,&end)==3 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-],%255[0-9.eE%+-],%f,%f%c",
                           indices,argx,argy,&sampling_s,&sampling_r,&end)==5) &&
              (cimg_sscanf(argx,"%f%c",&sigma_s,&end)==1 ||
               (cimg_sscanf(argx,"%f%c%c",&sigma_s,&sep0,&end)==2 && sep0=='%')) &&
              (cimg_sscanf(argy,"%f%c",&sigma_r,&end)==1 ||
               (cimg_sscanf(argy,"%f%c%c",&sigma_r,&sep1,&end)==2 && sep1=='%')) &&
              (ind=selection2cimg(indices,images.size(),images_names,"-bilateral")).height()==1 &&
              sigma_s>=0 && sigma_r>=0 && sampling_s>=0 && sampling_r>=0) {
            print(images,0,"Apply joint bilateral filter on image%s, with guide image [%u], "
                  " standard deviations (%g%s,%g%s) and sampling (%g,%g).",
                  gmic_selection.data(),
                  *ind,
                  sigma_s,sep0=='%'?"%":"",
                  sigma_r,sep1=='%'?"%":"",
                  sampling_s,sampling_r);
            const CImg<T> guide = gmic_image_arg(*ind);
            if (sep0=='%') sigma_s = -sigma_s;
            if (sep1=='%') sigma_r = -sigma_r;
            cimg_forY(selection,l) gmic_apply(blur_bilateral(guide,sigma_s,sigma_r,sampling_s,sampling_r));
          } else if ((cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                                  argx,argy,&end)==2 ||
                      cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%f,%f%c",
                                  argx,argy,&sampling_s,&sampling_r,&end)==4) &&
                     (cimg_sscanf(argx,"%f%c",&sigma_s,&end)==1 ||
                      (cimg_sscanf(argx,"%f%c%c",&sigma_s,&sep0,&end)==2 && sep0=='%')) &&
                     (cimg_sscanf(argy,"%f%c",&sigma_r,&end)==1 ||
                      (cimg_sscanf(argy,"%f%c%c",&sigma_r,&sep1,&end)==2 && sep1=='%')) &&
                     sigma_s>=0 && sigma_r>=0 && sampling_s>=0 && sampling_r>=0) {
            print(images,0,"Apply bilateral filter on image%s, with standard deviations (%g%s,%g%s) and "
                  "sampling (%g,%g).",
                  gmic_selection.data(),
                  sigma_s,sep0=='%'?"%":"",
                  sigma_r,sep1=='%'?"%":"",
                  sampling_s,sampling_r);
            if (sep0=='%') sigma_s = -sigma_s;
            if (sep1=='%') sigma_r = -sigma_r;
            cimg_forY(selection,l)
              gmic_apply(blur_bilateral(images[selection[l]],sigma_s,sigma_r,sampling_s,sampling_r));
          } else arg_error("bilateral");
          is_released = false; ++position; continue;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-c...'
        //-----------------------------
      gmic_commands_c :

        // Check expression or filename.
        if (is_check_command) {
          gmic_substitute_args(false);
          name.assign(argument,(unsigned int)std::strlen(argument) + 1);
          strreplace_fw(name);
          bool is_cond = false, is_filename = false;
          const CImg<T> &img = images.size()?images.back():CImg<T>::empty();
          try { if (img.eval(name,0,0,0,0,&images,&images)) is_cond = true; }
          catch (CImgException&) {
            is_filename = true;
            is_cond = check_filename(name);
          }
          if (is_very_verbose)
            print(images,0,"Check %s '%s' -> %s.",
                  is_filename?"file":"expression",
                  gmic_argument_text_printed(),
                  is_filename?(is_cond?"found":"not found"):(is_cond?"true":"false"));
          if (!is_cond) {
            if (is_first_item && callstack.size()>1 && callstack.back()[0]!='*')
              gmic::error(images,0,callstack.back(),"Command '-%s': Invalid argument '%s'.",
                          callstack.back().data(),_gmic_argument_text(parent_arguments,argument_text,true));
            else error(images,0,0,
                       "Command '-check': Expression '%s' is false (and no file with this name exists).",
                       gmic_argument_text());
          }
          ++position; continue;
        }

        // Crop.
        if (!std::strcmp("-crop",command)) {
          gmic_substitute_args(false);
          name.assign(64,8);
          char
            *const st0 = name.data(0,0), *const st1 = name.data(0,1), *const st2 = name.data(0,2),
            *const st3 = name.data(0,3), *const st4 = name.data(0,4), *const st5 = name.data(0,5),
            *const st6 = name.data(0,6), *const st7 = name.data(0,7);
          char sep2 = sep0 = sep1 = 0, sep3 = 0, sep4 = 0, sep5 = 0, sep6 = 0, sep7 = 0;
          float a0 = 0, a1 = 0, a2 = 0, a3 = 0, a4 = 0, a5 = 0, a6 = 0, a7 = 0;
          *st0 = *st1 = *st2 = *st3 = *st4 = *st5 = *st6 = *st7 = 0;
          boundary = 0;
          if ((boundary=0,cimg_sscanf(argument,"%63[0-9.eE%+-],%63[0-9.eE%+-]%c",
                                      st0,
                                      st1,&end)==2 ||
               cimg_sscanf(argument,"%63[0-9.eE%+-],%63[0-9.eE%+-],%u%c",
                           st0,
                           st1,&boundary,&end)==3) &&
              (cimg_sscanf(st0,"%f%c",&a0,&end)==1 ||
               (cimg_sscanf(st0,"%f%c%c",&a0,&sep0,&end)==2 && sep0=='%')) &&
              (cimg_sscanf(st1,"%f%c",&a1,&end)==1 ||
               (cimg_sscanf(st1,"%f%c%c",&a1,&sep1,&end)==2 && sep1=='%')) &&
              boundary<=1) {
            print(images,0,"Crop image%s with coordinates (%g%s) - (%g%s) and "
                  "%s boundary conditions.",
                  gmic_selection.data(),
                  a0,sep0=='%'?"%":"",
                  a1,sep1=='%'?"%":"",
                  boundary?"neumann":"dirichlet");
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              const int
                x0 = (int)cimg::round(sep0=='%'?a0*(img.width() - 1)/100:a0),
                x1 = (int)cimg::round(sep1=='%'?a1*(img.width() - 1)/100:a1);
              gmic_apply(crop(x0,x1,(bool)boundary));
            }
            ++position;
          } else if ((boundary=0,cimg_sscanf(argument,
                                             "%63[0-9.eE%+-],%63[0-9.eE%+-],"
                                             "%63[0-9.eE%+-],%63[0-9.eE%+-]%c",
                                             st0,st1,st2,st3,&end)==4 ||
                      cimg_sscanf(argument,
                                  "%63[0-9.eE%+-],%63[0-9.eE%+-],"
                                  "%63[0-9.eE%+-],%63[0-9.eE%+-],%u%c",
                                  st0,st1,st2,st3,&boundary,&end)==5) &&
                     (cimg_sscanf(st0,"%f%c",&a0,&end)==1 ||
                      (cimg_sscanf(st0,"%f%c%c",&a0,&sep0,&end)==2 && sep0=='%')) &&
                     (cimg_sscanf(st1,"%f%c",&a1,&end)==1 ||
                      (cimg_sscanf(st1,"%f%c%c",&a1,&sep1,&end)==2 && sep1=='%')) &&
                     (cimg_sscanf(st2,"%f%c",&a2,&end)==1 ||
                      (cimg_sscanf(st2,"%f%c%c",&a2,&sep2,&end)==2 && sep2=='%')) &&
                     (cimg_sscanf(st3,"%f%c",&a3,&end)==1 ||
                      (cimg_sscanf(st3,"%f%c%c",&a3,&sep3,&end)==2 && sep3=='%')) &&
                     boundary<=1) {
            print(images,0,
                  "Crop image%s with coordinates (%g%s,%g%s) - (%g%s,%g%s) and "
                  "%s boundary conditions.",
                  gmic_selection.data(),
                  a0,sep0=='%'?"%":"",
                  a1,sep1=='%'?"%":"",
                  a2,sep2=='%'?"%":"",
                  a3,sep3=='%'?"%":"",
                  boundary?"neumann":"dirichlet");
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              const int
                x0 = (int)cimg::round(sep0=='%'?a0*(img.width() - 1)/100:a0),
                y0 = (int)cimg::round(sep1=='%'?a1*(img.height() - 1)/100:a1),
                x1 = (int)cimg::round(sep2=='%'?a2*(img.width() - 1)/100:a2),
                y1 = (int)cimg::round(sep3=='%'?a3*(img.height() - 1)/100:a3);
              gmic_apply(crop(x0,y0,x1,y1,(bool)boundary));
            }
            ++position;
          } else if ((boundary=0,cimg_sscanf(argument,
                                             "%63[0-9.eE%+-],%63[0-9.eE%+-],%63[0-9.eE%+-],"
                                             "%63[0-9.eE%+-],%63[0-9.eE%+-],%63[0-9.eE%+-]%c",
                                             st0,st1,st2,st3,st4,st5,&end)==6 ||
                      cimg_sscanf(argument,"%63[0-9.eE%+-],%63[0-9.eE%+-],%63[0-9.eE%+-],"
                                  "%63[0-9.eE%+-],%63[0-9.eE%+-],%63[0-9.eE%+-],%u%c",
                                  st0,st1,st2,st3,st4,st5,&boundary,&end)==7) &&
                     (cimg_sscanf(st0,"%f%c",&a0,&end)==1 ||
                      (cimg_sscanf(st0,"%f%c%c",&a0,&sep0,&end)==2 && sep0=='%')) &&
                     (cimg_sscanf(st1,"%f%c",&a1,&end)==1 ||
                      (cimg_sscanf(st1,"%f%c%c",&a1,&sep1,&end)==2 && sep1=='%')) &&
                     (cimg_sscanf(st2,"%f%c",&a2,&end)==1 ||
                      (cimg_sscanf(st2,"%f%c%c",&a2,&sep2,&end)==2 && sep2=='%')) &&
                     (cimg_sscanf(st3,"%f%c",&a3,&end)==1 ||
                      (cimg_sscanf(st3,"%f%c%c",&a3,&sep3,&end)==2 && sep3=='%')) &&
                     (cimg_sscanf(st4,"%f%c",&a4,&end)==1 ||
                      (cimg_sscanf(st4,"%f%c%c",&a4,&sep4,&end)==2 && sep4=='%')) &&
                     (cimg_sscanf(st5,"%f%c",&a5,&end)==1 ||
                      (cimg_sscanf(st5,"%f%c%c",&a5,&sep5,&end)==2 && sep5=='%')) &&
                     boundary<=1) {
            print(images,0,"Crop image%s with coordinates (%g%s,%g%s,%g%s) - (%g%s,%g%s,%g%s) "
                  "and %s boundary conditions.",
                  gmic_selection.data(),
                  a0,sep0=='%'?"%":"",
                  a1,sep1=='%'?"%":"",
                  a2,sep2=='%'?"%":"",
                  a3,sep3=='%'?"%":"",
                  a4,sep4=='%'?"%":"",
                  a5,sep5=='%'?"%":"",
                  boundary?"neumann":"dirichlet");
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              const int
                x0 = (int)cimg::round(sep0=='%'?a0*(img.width() - 1)/100:a0),
                y0 = (int)cimg::round(sep1=='%'?a1*(img.height() - 1)/100:a1),
                z0 = (int)cimg::round(sep2=='%'?a2*(img.depth() - 1)/100:a2),
                x1 = (int)cimg::round(sep3=='%'?a3*(img.width() - 1)/100:a3),
                y1 = (int)cimg::round(sep4=='%'?a4*(img.height() - 1)/100:a4),
                z1 = (int)cimg::round(sep5=='%'?a5*(img.depth() - 1)/100:a5);
              gmic_apply(crop(x0,y0,z0,x1,y1,z1,(bool)boundary));
            }
            ++position;
          } else if ((boundary=0,cimg_sscanf(argument,
                                             "%63[0-9.eE%+-],%63[0-9.eE%+-],%63[0-9.eE%+-],"
                                             "%63[0-9.eE%+-],%63[0-9.eE%+-],%63[0-9.eE%+-],"
                                             "%63[0-9.eE%+-],%63[0-9.eE%+-]%c",
                                             st0,st1,st2,st3,st4,st5,st6,st7,&end)==8 ||
                      cimg_sscanf(argument,"%63[0-9.eE%+-],%63[0-9.eE%+-],%63[0-9.eE%+-],"
                                  "%63[0-9.eE%+-],%63[0-9.eE%+-],%63[0-9.eE%+-],"
                                  "%63[0-9.eE%+-],%63[0-9.eE%+-],%u%c",
                                  st0,st1,st2,st3,st4,st5,st6,st7,&boundary,&end)==9) &&
                     (cimg_sscanf(st0,"%f%c",&a0,&end)==1 ||
                      (cimg_sscanf(st0,"%f%c%c",&a0,&sep0,&end)==2 && sep0=='%')) &&
                     (cimg_sscanf(st1,"%f%c",&a1,&end)==1 ||
                      (cimg_sscanf(st1,"%f%c%c",&a1,&sep1,&end)==2 && sep1=='%')) &&
                     (cimg_sscanf(st2,"%f%c",&a2,&end)==1 ||
                      (cimg_sscanf(st2,"%f%c%c",&a2,&sep2,&end)==2 && sep2=='%')) &&
                     (cimg_sscanf(st3,"%f%c",&a3,&end)==1 ||
                      (cimg_sscanf(st3,"%f%c%c",&a3,&sep3,&end)==2 && sep3=='%')) &&
                     (cimg_sscanf(st4,"%f%c",&a4,&end)==1 ||
                      (cimg_sscanf(st4,"%f%c%c",&a4,&sep4,&end)==2 && sep4=='%')) &&
                     (cimg_sscanf(st5,"%f%c",&a5,&end)==1 ||
                      (cimg_sscanf(st5,"%f%c%c",&a5,&sep5,&end)==2 && sep5=='%')) &&
                     (cimg_sscanf(st6,"%f%c",&a6,&end)==1 ||
                      (cimg_sscanf(st6,"%f%c%c",&a6,&sep6,&end)==2 && sep6=='%')) &&
                     (cimg_sscanf(st7,"%f%c",&a7,&end)==1 ||
                      (cimg_sscanf(st7,"%f%c%c",&a7,&sep7,&end)==2 && sep7=='%')) &&
                     boundary<=1) {
            print(images,0,
                  "Crop image%s with coordinates (%g%s,%g%s,%g%s,%g%s) - (%g%s,%g%s,%g%s,%g%s) "
                  "and %s boundary conditions.",
                  gmic_selection.data(),
                  a0,sep0=='%'?"%":"",
                  a1,sep1=='%'?"%":"",
                  a2,sep2=='%'?"%":"",
                  a3,sep3=='%'?"%":"",
                  a4,sep4=='%'?"%":"",
                  a5,sep5=='%'?"%":"",
                  a6,sep6=='%'?"%":"",
                  a7,sep7=='%'?"%":"",
                  boundary?"neumann":"dirichlet");
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              const int
                x0 = (int)cimg::round(sep0=='%'?a0*(img.width() - 1)/100:a0),
                y0 = (int)cimg::round(sep1=='%'?a1*(img.height() - 1)/100:a1),
                z0 = (int)cimg::round(sep2=='%'?a2*(img.depth() - 1)/100:a2),
                v0 = (int)cimg::round(sep3=='%'?a3*(img.spectrum() - 1)/100:a3),
                x1 = (int)cimg::round(sep4=='%'?a4*(img.width() - 1)/100:a4),
                y1 = (int)cimg::round(sep5=='%'?a5*(img.height() - 1)/100:a5),
                z1 = (int)cimg::round(sep6=='%'?a6*(img.depth() - 1)/100:a6),
                v1 = (int)cimg::round(sep7=='%'?a7*(img.spectrum() - 1)/100:a7);
              gmic_apply(crop(x0,y0,z0,v0,x1,y1,z1,v1,(bool)boundary));
            }
            ++position;
          } else {
#if cimg_display==0
            print(images,0,"Crop image%s in interactive mode (skipped, no display support).",
                  gmic_selection.data());
#else // #if cimg_display==0
            bool is_available_display = false;
            try {
              is_available_display = (bool)CImgDisplay::screen_width();
            } catch (CImgDisplayException&) {
              print(images,0,"Crop image%s in interactive mode (skipped, no display available).",
                    gmic_selection.data());
            }
            if (is_available_display) {
              print(images,0,"Crop image%s in interactive mode.",
                    gmic_selection.data());
              CImgDisplay _disp, &disp = _display_window[0]?_display_window[0]:_disp;
              cimg_forY(selection,l) {
                CImg<T>& img = gmic_check(images[selection[l]]);
                if (disp) disp.resize(cimg_fitscreen(img.width(),img.height(),1),false);
                else disp.assign(cimg_fitscreen(img.width(),img.height(),1),0,1);
                disp.set_title("%s: crop",basename(images_names[selection[l]]));
                const CImg<int> s = img.get_select(disp,2);
                print(images,0,"Crop image [%d] with coordinates (%d,%d,%d) - (%d,%d,%d).",
                      selection[l],
                      s[0],s[1],s[2],
                      s[3],s[4],s[5]);
                gmic_apply(crop(s[0],s[1],s[2],s[3],s[4],s[5]));
              }
            }
#endif // #if cimg_display==0
          }
          is_released = false; continue;
        }

        // Cut.
        if (!std::strcmp("-cut",command)) {
          gmic_substitute_args(true);
          ind0.assign(); ind1.assign();
          sep0 = sep1 = *argx = *argy = *indices = 0;
          value0 = value1 = 0;
          if (cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-]%c",
                          argx,argy,&end)==2 &&
              ((cimg_sscanf(argx,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep0,&end)==2 &&
                sep0==']' &&
                (ind0=selection2cimg(indices,images.size(),images_names,"-cut")).height()==1) ||
               (cimg_sscanf(argx,"%lf%c%c",&value0,&sep0,&end)==2 && sep0=='%') ||
               cimg_sscanf(argx,"%lf%c",&value0,&end)==1) &&
              ((cimg_sscanf(argy,"[%255[a-zA-Z0-9_.%+-]%c%c",formula,&sep1,&end)==2 &&
                sep1==']' &&
                (ind1=selection2cimg(formula,images.size(),images_names,"-cut")).height()==1) ||
               (cimg_sscanf(argy,"%lf%c%c",&value1,&sep1,&end)==2 && sep1=='%') ||
               cimg_sscanf(argy,"%lf%c",&value1,&end)==1)) {
            if (ind0) { value0 = images[*ind0].min(); sep0 = 0; }
            if (ind1) { value1 = images[*ind1].max(); sep1 = 0; }
            print(images,0,"Cut image%s in range [%g%s,%g%s].",
                  gmic_selection.data(),
                  value0,sep0=='%'?"%":"",
                  value1,sep1=='%'?"%":"");
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              nvalue0 = value0; nvalue1 = value1;
              vmin = vmax = 0;
              if (sep0=='%' || sep1=='%') {
                if (img) vmax = (double)img.max_min(vmin);
                if (sep0=='%') nvalue0 = vmin + (vmax - vmin)*value0/100;
                if (sep1=='%') nvalue1 = vmin + (vmax - vmin)*value1/100;
              }
              gmic_apply(cut((T)nvalue0,(T)nvalue1));
            }
            ++position;
          } else if (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep0,&end)==2 &&
                     sep0==']' &&
                     (ind0=selection2cimg(indices,images.size(),images_names,"-cut")).height()==1) {
            if (images[*ind0]) value1 = (double)images[*ind0].max_min(value0);
            print(images,0,"Cut image%s in range [%g,%g].",
                  gmic_selection.data(),
                  value0,
                  value1);
            cimg_forY(selection,l) gmic_apply(cut((T)value0,(T)value1));
            ++position;
          } else {
            g_img.assign(2,selection.height()).fill((T)0);
#if cimg_display==0
            print(images,0,"Cut image%s in interactive mode (skipped, no display support).",
                  gmic_selection.data());
#else // #if cimg_display==0
            bool is_available_display = false;
            try {
              is_available_display = (bool)CImgDisplay::screen_width();
            } catch (CImgDisplayException&) {
              print(images,0,"Cut image%s in interactive mode (skipped, no display available).",
                    gmic_selection.data());
            }
            if (is_available_display) {
              print(images,0,"Cut image%s in interactive mode.",
                    gmic_selection.data());
              CImgDisplay _disp, &disp = _display_window[0]?_display_window[0]:_disp;
              cimg_forY(selection,l) {
                CImg<T> &img = gmic_check(images[selection[l]]);
                value0 = value1 = 0;
                if (img) {
                  CImg<T> visu = img.depth()>1?img.get_projections2d(img.width()/2,
                                                                     img.height()/2,
                                                                     img.depth()/2).
                    channels(0,std::min(3,img.spectrum()) - 1):
                    img.get_channels(0,std::min(3,img.spectrum() - 1));
                  const unsigned int
                    w = CImgDisplay::_fitscreen(visu.width(),visu.height(),1,256,-85,false),
                    h = CImgDisplay::_fitscreen(visu.width(),visu.height(),1,256,-85,true);
                  if (disp) disp.resize(w,h,false); else disp.assign(w,h,0,0);
                  double percent0 = 0, percent1 = 100;
                  vmin = 0, vmax = (double)img.max_min(vmin);
                  bool stopflag = false, is_clicked = false;
                  int omx = -1, omy = -1;
                  g_img_uc.assign();
                  for (disp.show().flush(); !stopflag; ) {
                    static const unsigned char white[] = { 255,255,255 }, black[] = { 0,0,0 };
                    const unsigned int key = disp.key();
                    if (!g_img_uc) {
                      value0 = vmin + percent0*(vmax - vmin)/100;
                      value1 = vmin + percent1*(vmax - vmin)/100;
                      disp.display((g_img_uc=visu.get_cut((T)value0,(T)value1).normalize((T)0,(T)255).resize(disp)).
                                   draw_text(0,0,"Cut [%g,%g] = [%.3g%%,%.3g%%]",
                                             white,black,0.7f,13,value0,value1,percent0,percent1)).
                        set_title("%s (%dx%dx%dx%d)",
                                  basename(images_names[selection[l]]),
                                  img.width(),img.height(),img.depth(),img.spectrum()).wait();
                    }
                    const int mx = disp.mouse_x(), my = disp.mouse_y();
                    if (disp.button()) {
                      if (mx>=0 && my>=0 && (mx!=omx || my!=omy)) {
                        percent0 = (my - 16)*100.0/(disp.height() - 32);
                        percent1 = (mx - 16)*100.0/(disp.width() - 32);
                        if (percent0<0) percent0 = 0; else if (percent0>101) percent0 = 101;
                        if (percent1<0) percent1 = 0; else if (percent1>101) percent1 = 101;
                        if (percent0>percent1) cimg::swap(percent0,percent1);
                        omx = mx; omy = my; g_img_uc.assign();
                      }
                      is_clicked = true;
                    } else if (is_clicked) break;
                    if (disp.is_closed() || (key && key!=cimg::keyCTRLLEFT)) stopflag = true;
                    if (key==cimg::keyD && disp.is_keyCTRLLEFT()) {
                      disp.resize(cimg_fitscreen(3*disp.width()/2,3*disp.height()/2,1),
                                  stopflag=false).set_key(cimg::keyD,false);
                      g_img_uc.assign();
                    }
                    if (key==cimg::keyC && disp.is_keyCTRLLEFT()) {
                      disp.resize(cimg_fitscreen(2*disp.width()/3,2*disp.height()/3,1),
                                  stopflag=false).set_key(cimg::keyC,false);
                      g_img_uc.assign();
                    }
                    if (disp.is_resized()) { disp.resize(false); g_img_uc.assign(); }
                  }
                  value0 = vmin + percent0*(vmax - vmin)/100;
                  value1 = vmin + percent1*(vmax - vmin)/100;
                  print(images,0,"Cut image [%d] in range [%g,%g] = [%.3g%%,%.3g%%].",
                        selection[l],value0,value1,percent0,percent1);
                  gmic_apply(cut((T)value0,(T)value1));
                } else gmic_apply(replace(img));
                g_img(0,l) = (T)value0; g_img(1,l) = (T)value1;
              }
              g_img_uc.assign();
            }
#endif // #if cimg_display==0
            g_img.value_string().move_to(status);
            g_img.assign();
          }
          is_released = false; continue;
        }

        // Keep channels.
        if (!std::strcmp("-channels",command)) {
          gmic_substitute_args(true);
          ind0.assign(); ind1.assign();
          sep0 = sep1 = *argx = *argy = *indices = 0;
          value0 = value1 = 0;
          if (cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-]%c",
                          argx,&end)==1 &&
              ((cimg_sscanf(argx,"[%255[a-zA-Z0-9_.%+-]%c%c]",indices,&sep0,&end)==2 &&
                sep0==']' &&
                (ind0=selection2cimg(indices,images.size(),images_names,"-channels")).height()==1) ||
               cimg_sscanf(argx,"%lf%c",&value0,&end)==1 ||
               (cimg_sscanf(argx,"%lf%c%c",&value0,&sep0,&end)==2 && sep0=='%'))) {
            if (ind0) { value0 = images[*ind0].spectrum() - 1.; sep0 = 0; }
            print(images,0,"Keep channel %g%s of image%s.",
                  value0,sep0=='%'?"%":"",
                  gmic_selection.data());
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              nvalue0 = cimg::round(sep0=='%'?value0*(img.spectrum() - 1)/100:value0);
              gmic_apply(channel((int)nvalue0));
            }
          } else if (cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-]%c",
                                 argx,argy,&end)==2 &&
                     ((cimg_sscanf(argx,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep0,&end)==2 &&
                       sep0==']' &&
                       (ind0=selection2cimg(indices,images.size(),images_names,"-channels")).height()==1) ||
                      cimg_sscanf(argx,"%lf%c",&value0,&end)==1 ||
                      (cimg_sscanf(argx,"%lf%c%c",&value0,&sep0,&end)==2 && sep0=='%')) &&
                     ((cimg_sscanf(argx,"[%255[a-zA-Z0-9_.%+-]%c%c",formula,&sep0,&end)==2 &&
                       sep0==']' &&
                       (ind1=selection2cimg(formula,images.size(),images_names,"-channels")).height()==1) ||
                      cimg_sscanf(argy,"%lf%c",&value1,&end)==1 ||
                      (cimg_sscanf(argy,"%lf%c%c",&value1,&sep1,&end)==2 && sep1=='%'))) {
            if (ind0) { value0 = images[*ind0].spectrum() - 1.; sep0 = 0; }
            if (ind1) { value1 = images[*ind1].spectrum() - 1.; sep1 = 0; }
            print(images,0,"Keep channels %g%s...%g%s of image%s.",
                  value0,sep0=='%'?"%":"",
                  value1,sep1=='%'?"%":"",
                  gmic_selection.data());
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              nvalue0 = cimg::round(sep0=='%'?value0*(img.spectrum() - 1)/100:value0);
              nvalue1 = cimg::round(sep1=='%'?value1*(img.spectrum() - 1)/100:value1);
              gmic_apply(channels((int)nvalue0,(int)nvalue1));
            }
          } else arg_error("channels");
          is_released = false; ++position; continue;
        }

        // Keep columns.
        if (!std::strcmp("-columns",command)) {
          gmic_substitute_args(true);
          ind0.assign(); ind1.assign();
          sep0 = sep1 = *argx = *argy = *indices = 0;
          value0 = value1 = 0;
          if (cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-]%c",
                          argx,&end)==1 &&
              ((cimg_sscanf(argx,"[%255[a-zA-Z0-9_.%+-]%c%c]",indices,&sep0,&end)==2 &&
                sep0==']' &&
                (ind0=selection2cimg(indices,images.size(),images_names,"-columns")).height()==1) ||
               cimg_sscanf(argx,"%lf%c",&value0,&end)==1 ||
               (cimg_sscanf(argx,"%lf%c%c",&value0,&sep0,&end)==2 && sep0=='%'))) {
            if (ind0) { value0 = images[*ind0].width() - 1.; sep0 = 0; }
            print(images,0,"Keep column %g%s of image%s.",
                  value0,sep0=='%'?"%":"",
                  gmic_selection.data());
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              nvalue0 = cimg::round(sep0=='%'?value0*(img.width() - 1)/100:value0);
              gmic_apply(column((int)nvalue0));
            }
          } else if (cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-]%c",
                                 argx,argy,&end)==2 &&
                     ((cimg_sscanf(argx,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep0,&end)==2 &&
                       sep0==']' &&
                       (ind0=selection2cimg(indices,images.size(),images_names,"-columns")).height()==1) ||
                      cimg_sscanf(argx,"%lf%c",&value0,&end)==1 ||
                      (cimg_sscanf(argx,"%lf%c%c",&value0,&sep0,&end)==2 && sep0=='%')) &&
                     ((cimg_sscanf(argx,"[%255[a-zA-Z0-9_.%+-]%c%c",formula,&sep0,&end)==2 &&
                       sep0==']' &&
                       (ind1=selection2cimg(formula,images.size(),images_names,"-columns")).height()==1) ||
                      cimg_sscanf(argy,"%lf%c",&value1,&end)==1 ||
                      (cimg_sscanf(argy,"%lf%c%c",&value1,&sep1,&end)==2 && sep1=='%'))) {
            if (ind0) { value0 = images[*ind0].width() - 1.; sep0 = 0; }
            if (ind1) { value1 = images[*ind1].width() - 1.; sep1 = 0; }
            print(images,0,"Keep columns %g%s...%g%s of image%s.",
                  value0,sep0=='%'?"%":"",
                  value1,sep1=='%'?"%":"",
                  gmic_selection.data());
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              nvalue0 = cimg::round(sep0=='%'?value0*(img.width() - 1)/100:value0);
              nvalue1 = cimg::round(sep1=='%'?value1*(img.width() - 1)/100:value1);
              gmic_apply(columns((int)nvalue0,(int)nvalue1));
            }
          } else arg_error("columns");
          is_released = false; ++position; continue;
        }

        // Import custom commands.
        if (!std::strcmp("-command",item)) {
          gmic_substitute_args(false);
          name.assign(argument,(unsigned int)std::strlen(argument) + 1);
          const char *arg_command_text = gmic_argument_text_printed();
          unsigned int offset_argument_text = 0;
          char *arg_command = name;
          strreplace_fw(arg_command);

          unsigned int siz = 0;
          for (unsigned int l = 0; l<512; ++l) siz+=commands[l].size();

          bool add_debug_info = true;
          if ((*arg_command=='0' || *arg_command=='1') && arg_command[1]==',') {
            add_debug_info = (*arg_command=='1');
            arg_command+=2; arg_command_text+=2; offset_argument_text = 2;
          }

          std::FILE *file = std::fopen(arg_command,"rb");
          if (file) {
            print(images,0,"Import custom commands from file '%s'%s",
                  arg_command_text,
                  !add_debug_info?" without debug info":"");
            add_commands(file,add_debug_info?arg_command:0);
            std::fclose(file);
          } else if (!cimg::strncasecmp(arg_command,"http://",7) ||
                     !cimg::strncasecmp(arg_command,"https://",8)) { // Try to read from network.
            print(images,0,"Import custom commands from URL '%s'%s",
                  arg_command_text,
                  !add_debug_info?" without debug info":"");
            try {
              file = std::fopen(cimg::load_network(arg_command,argx),"r");
            } catch (...) {
              file = 0;
            }
            if (file) {
              CImg<char> _status;
              status.move_to(_status); // Save status because 'add_commands' can change it.
              const int _verbosity = verbosity;
              const bool _is_debug = is_debug;
              verbosity = -1; is_debug = false;
              try {
                add_commands(file,add_debug_info?arg_command:0);
                std::fclose(file);
              } catch (...) {
                std::fclose(file);
                file = 0;
              }
              verbosity = _verbosity; is_debug = _is_debug;
              _status.move_to(status);
            }
            if (!file)
              error(images,0,0,
                    "Command '-command': Unable to load custom command file '%s' "
                    "from network.",
                    gmic_argument_text() + offset_argument_text);
            std::remove(argx);
          } else {
            print(images,0,"Import custom commands from expression '%s'",
                  arg_command_text);
            add_commands(arg_command);
          }
          if (is_verbose) {
            unsigned int nb_added = 0;
            for (unsigned int l = 0; l<512; ++l) nb_added+=commands[l].size();
            nb_added-=siz;
            cimg::mutex(29);
            std::fprintf(cimg::output()," (added %u command%s, total %u).",
                         nb_added,nb_added>1?"s":"",siz + nb_added);
            std::fflush(cimg::output());
            cimg::mutex(29,0);
          }
          ++position; continue;
        }

        // Check validity of 3d object.
        if (!is_double_hyphen && !std::strcmp("-check3d",command)) {
          gmic_substitute_args(false);
          bool is_full_check = true;
          if (!argument[1] && (*argument=='0' || *argument=='1')) {
            is_full_check = (*argument=='1');
            ++position;
          } else is_full_check = true;
          if (is_very_verbose)
            print(images,0,"Check validity of 3d object%s (%s check)",
                  gmic_selection.data(),
                  is_full_check?"full":"fast");
          cimg_forY(selection,l) {
            const unsigned int uind = selection[l];
            CImg<T>& img = gmic_check(images[uind]);
            if (!img.is_CImg3d(is_full_check,&(*message=0))) {
              if (is_very_verbose) {
                cimg::mutex(29);
                std::fprintf(cimg::output()," -> invalid.");
                std::fflush(cimg::output());
                cimg::mutex(29,0);
              }
              error(images,0,0,
                    "Command '-check3d': Invalid 3d object [%d], in selected image%s (%s).",
                    uind,gmic_selection_err.data(),message.data());
            }
          }
          if (is_very_verbose) {
            cimg::mutex(29);
            std::fprintf(cimg::output()," -> valid.");
            std::fflush(cimg::output());
            cimg::mutex(29,0);
          }
          continue;
        }

        // Cosine.
        gmic_simple_command("-cos",cos,"Compute pointwise cosine of image%s.");

        // Convolve.
        if (!std::strcmp("-convolve",command)) {
          gmic_substitute_args(true);
          unsigned int is_normalized = 0;
          boundary = 1;
          sep = 0;
          if (((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",
                            indices,&sep,&end)==2 && sep==']') ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u%c",
                           indices,&boundary,&end)==2 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u,%u%c",
                           indices,&boundary,&is_normalized,&end)==3) &&
              (ind=selection2cimg(indices,images.size(),images_names,"-convolve")).height()==1 &&
              boundary<=1) {
            print(images,0,
                  "Convolve image%s with kernel [%u] and %s boundary conditions, "
                  "with%s normalization.",
                  gmic_selection.data(),
                  *ind,
                  boundary?"neumann":"dirichlet",
                  is_normalized?"":"out");
            const CImg<T> kernel = gmic_image_arg(*ind);
            cimg_forY(selection,l) gmic_apply(convolve(kernel,boundary,(bool)is_normalized));
          } else arg_error("convolve");
          is_released = false; ++position; continue;
        }

        // Correlate.
        if (!std::strcmp("-correlate",command)) {
          gmic_substitute_args(true);
          unsigned int is_normalized = 0;
          boundary = 1;
          sep = 0;
          if (((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",
                            indices,&sep,&end)==2 && sep==']') ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u%c",
                           indices,&boundary,&end)==2 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u,%u%c",
                           indices,&boundary,&is_normalized,&end)==3) &&
              (ind=selection2cimg(indices,images.size(),images_names,"-correlate")).height()==1 &&
              boundary<=1) {
            print(images,0,
                  "Correlate image%s with kernel [%u] and %s boundary conditions, "
                  "with%s normalization.",
                  gmic_selection.data(),
                  *ind,
                  boundary?"neumann":"dirichlet",
                  is_normalized?"":"out");
            const CImg<T> kernel = gmic_image_arg(*ind);
            cimg_forY(selection,l) gmic_apply(correlate(kernel,boundary,(bool)is_normalized));
          } else arg_error("correlate");
          is_released = false; ++position; continue;
        }

        // Set 3d object color.
        if (!std::strcmp("-color3d",command) || !std::strcmp("-col3d",command)) {
          gmic_substitute_args(false);
          float R = 200, G = 200, B = 200;
          opacity = -1;
          if ((cimg_sscanf(argument,"%f%c",
                           &R,&end)==1 && ((B=G=R),1)) ||
              (cimg_sscanf(argument,"%f,%f%c",
                           &R,&G,&end)==2 && ((B=0),1)) ||
              cimg_sscanf(argument,"%f,%f,%f%c",
                          &R,&G,&B,&end)==3 ||
              cimg_sscanf(argument,"%f,%f,%f,%f%c",
                          &R,&G,&B,&opacity,&end)==4) {
            const bool set_opacity = (opacity>=0);
            if (set_opacity)
              print(images,0,"Set colors of 3d object%s to (%g,%g,%g), with opacity %g.",
                    gmic_selection.data(),
                    R,G,B,
                    opacity);
            else
              print(images,0,"Set color of 3d object%s to (%g,%g,%g).",
                    gmic_selection.data(),
                    R,G,B);
            cimg_forY(selection,l) {
              const unsigned int uind = selection[l];
              CImg<T>& img = gmic_check(images[uind]);
              try { gmic_apply(color_CImg3d(R,G,B,opacity,true,set_opacity)); }
              catch (CImgException&) {
                if (!img.is_CImg3d(true,&(*message=0)))
                  error(images,0,0,
                        "Command '-color3d': Invalid 3d object [%d], "
                        "in selected image%s (%s).",
                        uind,gmic_selection_err.data(),message.data());
                else throw;
              }
            }
          } else arg_error("color3d");
          is_released = false; ++position; continue;
        }

        // Cumulate.
        if (!std::strcmp("-cumulate",command)) {
          gmic_substitute_args(false);
          bool is_axes_argument = true;
          for (const char *s = argument; *s; ++s) {
            const char _s = *s;
            if (_s!='x' && _s!='y' && _s!='z' && _s!='c') { is_axes_argument = false; break; }
          }
          if (*argument && is_axes_argument) {
            print(images,0,"Cumulate values of image%s along the '%s'-ax%cs.",
                  gmic_selection.data(),
                  gmic_argument_text_printed(),
                  std::strlen(argument)>1?'e':'i');
            cimg_forY(selection,l) gmic_apply(cumulate(argument));
            ++position;
          } else {
            print(images,0,"Cumulate values of image%s.",
                  gmic_selection.data());
            cimg_forY(selection,l) gmic_apply(cumulate());
          }
          is_released = false; continue;
        }

        // Hyperbolic cosine.
        gmic_simple_command("-cosh",cosh,"Compute pointwise hyperbolic cosine of image%s.");

        // Camera input.
        if (!std::strcmp("-camera",item)) {
          gmic_substitute_args(false);
          float
            cam_index = 0, nb_frames = 1, skip_frames = 0,
            capture_width = 0, capture_height = 0;
          if ((cimg_sscanf(argument,"%f%c",
                           &cam_index,&end)==1 ||
               cimg_sscanf(argument,"%f,%f%c",
                           &cam_index,&nb_frames,&end)==2 ||
               cimg_sscanf(argument,"%f,%f,%f%c",
                           &cam_index,&nb_frames,&skip_frames,&end)==3 ||
               cimg_sscanf(argument,"%f,%f,%f,%f,%f%c",
                           &cam_index,&nb_frames,&skip_frames,
                           &capture_width,&capture_height,&end)==5) &&
              cam_index>=0 && nb_frames>=0 && skip_frames>=0 &&
              ((!capture_width && !capture_height) || (capture_width>0 && capture_height>0)))
            ++position;
          cam_index = cimg::round(cam_index);
          nb_frames = cimg::round(nb_frames);
          skip_frames = cimg::round(skip_frames);
          capture_width = cimg::round(capture_width);
          capture_height = cimg::round(capture_height);
          if (!nb_frames) {
            print(images,0,"Release camera #%g.",cam_index);
            CImg<T>::get_load_camera((unsigned int)cam_index,0,true);
          } else {
            if (capture_width)
              print(images,0,"Insert %g image%s from camera #%g, with %g frames skipping "
                    "and resolution %gx%g.",
                    cam_index,nb_frames,nb_frames>1?"s":"",skip_frames,
                    capture_width,capture_height);
            else print(images,0,"Insert %g image%s from camera #%g, with %g frames skipping.",
                       cam_index,nb_frames,nb_frames>1?"s":"",skip_frames);
            cimg_snprintf(title,_title.width(),"[Camera #%g]",cam_index);
            CImg<char>::string(title).move_to(name);
            if (nb_frames>1) {
              cimg::mutex(29);
              std::fputc('\n',cimg::output());
              std::fflush(cimg::output());
              cimg::mutex(29,0);
            }
            for (unsigned int k = 0; k<(unsigned int)nb_frames; ++k) {
              if (nb_frames>1 && is_verbose) {
                cimg::mutex(29);
                std::fprintf(cimg::output(),"\r  > Image %u/%u        ",
                             k + 1,(unsigned int)nb_frames);
                std::fflush(cimg::output());
                cimg::mutex(29,0);
              }
              CImg<T>::get_load_camera((unsigned int)cam_index,(unsigned int)skip_frames,false,
                                       (unsigned int)capture_width,(unsigned int)capture_height).
                move_to(images);
              images_names.insert(name);
            }
          }
          is_released = false; continue;
        }

        // Show/hide mouse cursor.
        if (!is_double_hyphen && !std::strcmp("-cursor",command)) {
          gmic_substitute_args(false);
          if (!is_restriction)
            CImg<unsigned int>::vector(0,1,2,3,4,5,6,7,8,9).move_to(selection);
          bool state = true;
          if (!argument[1] && (*argument=='0' || *argument=='1')) {
            state = (*argument=='1'); ++position;
          } else state = true;

#if cimg_display==0
          print(images,0,"%s mouse cursor for display window%s (skipped, no display support).",
                state?"Show":"Hide",
                gmic_selection.data());
#else // #if cimg_display==0
          try {
            if (state) cimg_forY(selection,l) {
                if (!_display_window[l].is_closed()) _display_window[selection[l]].show_mouse();
              }
            else cimg_forY(selection,l) {
                if (!_display_window[l].is_closed()) _display_window[selection[l]].hide_mouse();
              }
            print(images,0,"%s mouse cursor for display window%s.",
                  state?"Show":"Hide",
                  gmic_selection.data());
          } catch (CImgDisplayException&) {
            print(images,0,"%s mouse cursor for display window%s (skipped, no display available).",
                  state?"Show":"Hide",
                  gmic_selection.data());
          }
#endif // #if cimg_display==0
          continue;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-d...'
        //-----------------------------
      gmic_commands_d :

        // Done.
        if (!std::strcmp("-done",item)) {
          const CImg<char> &s = callstack.back();
          if (s[0]!='*' || s[1]!='r')
            error(images,0,0,
                  "Command '-done': Not associated to a '-repeat' command "
                  "within the same scope.");
          *title = 0;
          CImg<unsigned int> &rd = repeatdones.back();
          const unsigned int counter = ++rd[2];
          unsigned int hashcode = ~0U, pos = ~0U;
          if (rd.height()>3) { hashcode = (unsigned int)rd[3]; pos = (unsigned int)rd[4]; }
          if ((rd[2]==~0U && --rd[2]) || --rd[1]) {
            position = rd[0];
            if (hashcode!=~0U) {
              cimg_snprintf(argx,_argx.width(),"%u",counter);
              CImg<char>::string(argx).move_to((*variables[hashcode])[pos]);
            }
            next_debug_line = debug_line; next_debug_filename = debug_filename;
          } else {
            if (is_very_verbose) print(images,0,"End 'repeat...done' block.");
            if (hashcode!=~0U) {
              variables[hashcode]->remove(pos);
              variables_names[hashcode]->remove(pos);
            }
            repeatdones.remove();
            callstack.remove();
          }
          continue;
        }

        // Do...while.
        if (!std::strcmp("-do",item)) {
          if (is_debug_info && debug_line!=~0U) {
            cimg_snprintf(argx,_argx.width(),"*do#%u",debug_line);
            CImg<char>::string(argx).move_to(callstack);
          } else CImg<char>::string("*do").move_to(callstack);
          if (is_very_verbose) print(images,0,"Start '-do...-while' block.");
          CImg<unsigned int>::vector(position).move_to(dowhiles);
          continue;
        }

        // Discard value.
        if (!std::strcmp("-discard",command)) {
          gmic_substitute_args(false);
          CImg<T> values;
          *argx = 0;

          if (cimg_sscanf(argument,"%255[xyzc]%c",argx,&end)==1) {

            // Discard neighboring duplicate values along axes.
            print(images,0,"Discard neighboring duplicate values along '%s'-ax%cs, in image%s.",
                  argx,
                  std::strlen(argx)>1?'e':'i',
                  gmic_selection.data());
            cimg_forY(selection,l) gmic_apply(gmic_discard(argx));
            ++position;

          } else if (cimg_sscanf(argument,"%255[xyzc]%c",argx,&end)==2 && end==',') {

            // Discard sequence of values along axes.
            unsigned int nb_values = 1, s_argx = (unsigned int)std::strlen(argx) + 1;
            for (const char *s = argument + s_argx; *s; ++s) if (*s==',') ++nb_values;
            try { values.assign(nb_values,1,1,1).fill(argument + s_argx,true,false); }
            catch (CImgException&) { arg_error("discard"); }
            print(images,0,"Discard sequence of values '%s' along '%s'-ax%cs, in image%s.",
                  gmic_argument_text_printed() + s_argx,
                  argx,
                  std::strlen(argx)>1?'e':'i',
                  gmic_selection.data());
            cimg_forY(selection,l) gmic_apply(gmic_discard(values,argx));
            ++position;

          } else { // Discard sequence of values or neighboring duplicate values.
            unsigned int nb_values = *argument?1U:0U;
            for (const char *s = argument; *s; ++s) if (*s==',') ++nb_values;
            try { values.assign(nb_values,1,1,1).fill(argument,true,false); }
            catch (CImgException&) { values.assign(); }
            if (values) {
              print(images,0,"Discard sequence of values '%s' in image%s.",
                    gmic_argument_text_printed(),
                    gmic_selection.data());
              cimg_forY(selection,l) gmic_apply(discard(values));
              ++position;

            } else {
              print(images,0,"Discard neighboring duplicate values in image%s.",
                    gmic_selection.data());
              cimg_forY(selection,l) gmic_apply(discard());
            }
          }
          is_released = false; continue;
        }

        // Enable debug mode (useful when '-debug' is invoked from a custom command).
        if (!std::strcmp("-debug",item)) {
          is_debug = true;
          continue;
        }

        // Divide.
        gmic_arithmetic_command("-div",
                                operator/=,
                                "Divide image%s by %g%s",
                                gmic_selection.data(),value,ssep,Tfloat,
                                div,
                                "Divide image%s by image [%d]",
                                gmic_selection.data(),ind[0],
                                operator_diveq,
                                "Divide image%s by expression %s",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Divide image%s");

        // Distance function.
        if (!std::strcmp("-distance",command)) {
          gmic_substitute_args(true);
          unsigned int algorithm = 0, off = 0;
          int metric = 2;
          sep0 = sep1 = *indices = 0;
          value = 0;
          if ((cimg_sscanf(argument,"%lf%c",
                           &value,&end)==1 ||
               (cimg_sscanf(argument,"%lf%c%c",
                            &value,&sep0,&end)==2 && sep0=='%') ||
               cimg_sscanf(argument,"%lf,%d%c",
                           &value,&metric,&end)==2 ||
               (cimg_sscanf(argument,"%lf%c,%d%c",
                            &value,&sep0,&metric,&end)==3 && sep0=='%')) &&
              metric>=0 && metric<=3) {
            print(images,0,"Compute distance map to isovalue %g%s in image%s, "
                  "with %s metric.",
                  value,sep0=='%'?"%":"",
                  gmic_selection.data(),
                  metric==0?"chebyshev":metric==1?"manhattan":metric==2?"euclidean":
                  "squared-euclidean");
            cimg_forY(selection,l) {
              CImg<T> &img = gmic_check(images[selection[l]]);
              nvalue = value;
              if (sep0=='%' && img) {
                vmax = (double)img.max_min(vmin);
                nvalue = vmin + value*(vmax - vmin)/100;
              }
              gmic_apply(distance((T)nvalue,metric));
            }
          } else if ((((cimg_sscanf(argument,"%lf,[%255[a-zA-Z0-9_.%+-]%c%c",
                                    &value,indices,&sep1,&end)==3 ||
                        (cimg_sscanf(argument,"%lf%c,[%255[a-zA-Z0-9_.%+-]%c%c",
                                     &value,&sep0,indices,&sep1,&end)==4 && sep0=='%')) &&
                       sep1==']') ||
                      ((cimg_sscanf(argument,"%lf,[%255[a-zA-Z0-9_.%+-]],%u%c",
                                    &value,indices,&algorithm,&end)==3 ||
                        (cimg_sscanf(argument,"%lf%c,[%255[a-zA-Z0-9_.%+-]],%u%c",
                                     &value,&sep0,indices,&algorithm,&end)==4 && sep0=='%')) &&
                       algorithm<=4)) &&
                     (ind=selection2cimg(indices,images.size(),images_names,"-distance")).height()==1) {
            print(images,0,"Compute distance map%s to isovalue %g%s in image%s, "
                  "using %s algorithm, with metric [%u].",
                  selection.height()>1?(algorithm>=3?"s and return paths":"s"):
                  (algorithm>=3?" and return path":""),
                  value,sep0=='%'?"%":"",
                  gmic_selection.data(),
                  algorithm==0?"fast-marching":algorithm==1||algorithm==3?
                  "low-connectivity dijkstra":"high-connectivity dijkstra",
                  *ind);
            const CImg<T> custom_metric = gmic_image_arg(*ind);
            if (algorithm<3) cimg_forY(selection,l) {
                CImg<T> &img = gmic_check(images[selection[l]]);
                nvalue = value;
                if (sep0=='%' && img) {
                  vmax = (double)img.max_min(vmin);
                  nvalue = vmin + value*(vmax - vmin)/100;
                }
                if (!algorithm) { gmic_apply(distance_eikonal((T)nvalue,custom_metric)); }
                else gmic_apply(distance_dijkstra((T)nvalue,custom_metric,algorithm==2));
              }
            else cimg_forY(selection,l) {
                const unsigned int uind = selection[l] + off;
                CImg<T>& img = gmic_check(images[uind]);
                nvalue = value;
                if (sep0=='%' && img) {
                  vmax = (double)img.max_min(vmin);
                  nvalue = vmin + value*(vmax - vmin)/100;
                }
                name = images_names[uind];
                CImg<T> path(1),
                  dist = img.get_distance_dijkstra((T)nvalue,custom_metric,algorithm==4,path);
                if (is_double_hyphen) {
                  images_names.insert(2,name.copymark());
                  dist.move_to(images,~0U);
                  path.move_to(images,~0U);
                } else {
                  off+=1;
                  dist.move_to(images[uind].assign());
                  path.move_to(images,uind + 1);
                  images_names[uind] = name;
                  images_names.insert(name.copymark(),uind + 1);
                }
              }
          } else arg_error("distance");
          is_released = false; ++position; continue;
        }

        // Dilate.
        if (!std::strcmp("-dilate",command)) {
          gmic_substitute_args(true);
          float sx = 3, sy = 3, sz = 1;
          unsigned int is_real = 0;
          boundary = 1;
          sep = 0;
          if (((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",
                            indices,&sep,&end)==2 && sep==']') ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u%c",
                           indices,&boundary,&end)==2 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u,%u%c",
                           indices,&boundary,&is_real,&end)==3) &&
              (ind=selection2cimg(indices,images.size(),images_names,"-dilate")).height()==1 &&
              boundary<=1) {
            print(images,0,"Dilate image%s with kernel [%u] and %s boundary conditions, "
                  "in %s mode.",
                  gmic_selection.data(),
                  *ind,
                  boundary?"neumann":"dirichlet",
                  is_real?"real":"binary");
            const CImg<T> kernel = gmic_image_arg(*ind);
            cimg_forY(selection,l) gmic_apply(dilate(kernel,boundary,(bool)is_real));
          } else if ((cimg_sscanf(argument,"%f%c",
                                  &sx,&end)==1) &&
                     sx>=0) {
            sx = cimg::round(sx);
            print(images,0,"Dilate image%s with kernel of size %g and neumann boundary conditions.",
                  gmic_selection.data(),
                  sx);
            cimg_forY(selection,l) gmic_apply(dilate((unsigned int)sx));
          } else if ((cimg_sscanf(argument,"%f,%f%c",
                                  &sx,&sy,&end)==2 ||
                      cimg_sscanf(argument,"%f,%f,%f%c",
                                  &sx,&sy,&sz,&end)==3) &&
                     sx>=0 && sy>=0 && sz>=0) {
            sx = cimg::round(sx);
            sy = cimg::round(sy);
            sz = cimg::round(sz);
            print(images,0,"Dilate image%s with %gx%gx%g kenrel and neumann boundary conditions.",
                  gmic_selection.data(),
                  sx,sy,sz);
            cimg_forY(selection,l) gmic_apply(dilate((unsigned int)sx,(unsigned int)sy,(unsigned int)sz));
          } else arg_error("dilate");
          is_released = false; ++position; continue;
        }

        // Set double-sided mode for 3d rendering.
        if (!std::strcmp("-double3d",item)) {
          gmic_substitute_args(false);
          bool state = true;
          if (!argument[1] && (*argument=='0' || *argument=='1')) {
            state = (*argument=='1');
            ++position;
          } else state = true;
          is_double3d = state;
          print(images,0,"%s double-sided mode for 3d rendering.",
                is_double3d?"Enable":"Disable");
          continue;
        }

        // Patch-based smoothing.
        if (!std::strcmp("-denoise",command)) {
          gmic_substitute_args(false);
          float sigma_s = 10, sigma_r = 10, smoothness = 1;
          unsigned int is_fast_approximation = 0;
          float psize = 5, rsize = 6;
          if ((cimg_sscanf(argument,"%f%c",
                           &sigma_s,&end)==1 ||
               cimg_sscanf(argument,"%f,%f%c",
                           &sigma_s,&sigma_r,&end)==2 ||
               cimg_sscanf(argument,"%f,%f,%f%c",
                           &sigma_s,&sigma_r,&psize,&end)==3 ||
               cimg_sscanf(argument,"%f,%f,%f,%f%c",
                           &sigma_s,&sigma_r,&psize,&rsize,&end)==4 ||
               cimg_sscanf(argument,"%f,%f,%f,%f,%f%c",
                           &sigma_s,&sigma_r,&psize,&rsize,&smoothness,&end)==5 ||
               cimg_sscanf(argument,"%f,%f,%f,%f,%f,%u%c",
                           &sigma_s,&sigma_r,&psize,&rsize,&smoothness,
                           &is_fast_approximation,&end)==6) &&
              sigma_s>=0 && sigma_r>=0 && psize>=0 && rsize>=0 && is_fast_approximation<=1) {
            psize = cimg::round(psize);
            rsize = cimg::round(rsize);
            print(images,0,"Denoise image%s using %gx%g patchs, with standard deviations %lg,%g, "
                  "lookup size %g and smoothness %g.",
                  gmic_selection.data(),
                  psize,
                  psize,
                  sigma_s,
                  sigma_r,
                  rsize,
                  smoothness);
            cimg_forY(selection,l)
              gmic_apply(blur_patch(sigma_s,sigma_r,(unsigned int)psize,(unsigned int)rsize,smoothness,
                                    (bool)is_fast_approximation));
          } else arg_error("denoise");
          is_released = false; ++position; continue;
        }

        // Deriche filter.
        if (!std::strcmp("-deriche",command)) {
          gmic_substitute_args(false);
          unsigned int order = 0;
          float sigma = 0;
          axis = sep = 0;
          boundary = 1;
          if ((cimg_sscanf(argument,"%f,%u,%c%c",&sigma,&order,&axis,&end)==3 ||
               (cimg_sscanf(argument,"%f%c,%u,%c%c",&sigma,&sep,&order,&axis,&end)==4 &&
                sep=='%') ||
               cimg_sscanf(argument,"%f,%u,%c,%u%c",&sigma,&order,&axis,&boundary,&end)==4 ||
               (cimg_sscanf(argument,"%f%c,%u,%c,%u%c",
                            &sigma,&sep,&order,&axis,&boundary,&end)==5 && sep=='%')) &&
              sigma>=0 && order<=2 && (axis=='x' || axis=='y' || axis=='z' || axis=='c') &&
              boundary<=1) {
            print(images,0,"Apply %u-order Deriche filter on image%s, along axis '%c' with standard "
                  "deviation %g%s and %s boundary conditions.",
                  order,gmic_selection.data(),axis,
                  sigma,sep=='%'?"%":"",
                  boundary?"neumann":"dirichlet");
            if (sep=='%') sigma = -sigma;
            cimg_forY(selection,l) gmic_apply(deriche(sigma,order,axis,(bool)boundary));
          } else arg_error("deriche");
          is_released = false; ++position; continue;
        }

        // Dijkstra algorithm.
        if (!std::strcmp("-dijkstra",command)) {
          gmic_substitute_args(false);
          float snode = 0, enode = 0;
          if (cimg_sscanf(argument,"%f,%f%c",&snode,&enode,&end)==2 &&
              snode>=0 && enode>=0) {
            snode = cimg::round(snode);
            enode = cimg::round(enode);
            print(images,0,"Compute minimal path from adjacency matri%s%s with the "
                  "Dijkstra algorithm.",
                  selection.height()>1?"ce":"x",gmic_selection.data());
            unsigned int off = 0;
            cimg_forY(selection,l) {
              const unsigned int uind = selection[l] + off;
              name = images_names[uind];
              if (is_double_hyphen) {
                CImg<T> path, dist = gmic_check(images[uind]).get_dijkstra((unsigned int)snode,
                                                                           (unsigned int)enode,
                                                                           path);
                images_names.insert(name.copymark());
                name.move_to(images_names);
                dist.move_to(images);
                path.move_to(images);
              } else {
                CImg<T> path;
                gmic_check(images[uind]).dijkstra((unsigned int)snode,(unsigned int)enode,path);
                images_names.insert(name.get_copymark(),uind + 1);
                name.move_to(images_names[uind]);
                images.insert(path,uind + 1);
                ++off;
              }
            }
          } else arg_error("dijkstra");
          is_released = false; ++position; continue;
        }

        // Estimate displacement field.
        if (!std::strcmp("-displacement",command)) {
          gmic_substitute_args(true);
          float nb_scales = 0, nb_iterations = 10000, smoothness = 0.1f, precision = 5.0f;
          unsigned int is_backward = 1;
          sep = *argx = 0;
          ind0.assign();
          if (((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",
                            indices,&sep,&end)==2 && sep==']') ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f%c",
                           indices,&smoothness,&end)==2 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f%c",
                           indices,&smoothness,&precision,&end)==3 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f%c",
                           indices,&smoothness,&precision,&nb_scales,&end)==4 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f,%f%c",
                           indices,&smoothness,&precision,&nb_scales,&nb_iterations,&end)==5 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f,%f,%u%c",
                           indices,&smoothness,&precision,&nb_scales,&nb_iterations,
                           &is_backward,&end)==6 ||
               (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f,%f,%u,[%255[a-zA-Z0-9_.%+-]%c%c",
                            indices,&smoothness,&precision,&nb_scales,&nb_iterations,
                            &is_backward,argx,&sep,&end)==8 && sep==']')) &&
              (ind=selection2cimg(indices,images.size(),images_names,"-displacement")).height()==1 &&
              precision>=0 && nb_scales>=0 && nb_iterations>=0 && is_backward<=1 &&
              (!*argx || (ind0=selection2cimg(argx,images.size(),images_names,"-displacement")).height()==1)) {
            nb_scales = cimg::round(nb_scales);
            nb_iterations = cimg::round(nb_iterations);
            if (nb_scales) cimg_snprintf(argx,_argx.width(),"%g ",nb_scales); else std::strcpy(argx,"auto-");
            if (ind0) cimg_snprintf(argy,_argy.width()," with guide [%u]",*ind0); else *_argy = 0;

            print(images,0,"Estimate displacement field from source [%u] to image%s, with "
                  "%s smoothness %g, precision %g, %sscales, %g iteration%s, in %s direction%s.",
                  *ind,
                  gmic_selection.data(),
                  smoothness>=0?"isotropic":"anisotropic",cimg::abs(smoothness),
                  precision,
                  argx,
                  nb_iterations,nb_iterations!=1?"s":"",
                  is_backward?"backward":"forward",
                  argy);
            const CImg<T> source = gmic_image_arg(*ind);
            const CImg<T> constraints = ind0?gmic_image_arg(*ind0):CImg<T>::empty();
            cimg_forY(selection,l) gmic_apply(displacement(source,smoothness,precision,(unsigned int)nb_scales,
                                                           (unsigned int)nb_iterations,(bool)is_backward,
                                                           constraints));
          } else arg_error("displacement");
          is_released = false; ++position; continue;
        }

        // Display.
        if (!is_double_hyphen && !std::strcmp("-display",command)) {
          gmic_substitute_args(false);
          unsigned int XYZ[3];
          bool is_args = false;
          exit_on_anykey = 0;
          if ((cimg_sscanf(argument,"%lf,%lf,%lf%c",&value,&value0,&value1,&end)==3 ||
               cimg_sscanf(argument,"%lf,%lf,%lf,%u%c",&value,&value0,&value1,&exit_on_anykey,&end)==4) &&
              value>=0 && value0>=0 && value1>=0 && exit_on_anykey<=1) {
            is_args = true;
            XYZ[0] = (unsigned int)cimg::round(value);
            XYZ[1] = (unsigned int)cimg::round(value0);
            XYZ[2] = (unsigned int)cimg::round(value1);
            ++position;
          }
          display_images(images,images_names,selection,is_args?XYZ:0,exit_on_anykey);
          is_released = true; continue;
        }

        // Display 3d object.
        if (!is_double_hyphen && !std::strcmp("-display3d",command)) {
          gmic_substitute_args(true);
          exit_on_anykey = 0;
          sep = *indices = 0;
          ind.assign();
          if ((cimg_sscanf(argument,"%u%c",
                           &exit_on_anykey,&end)==1 ||
               (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",
                            indices,&sep,&end)==2 && sep==']') ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u%c",
                           indices,&exit_on_anykey,&end)==2) &&
              exit_on_anykey<=1 &&
              (*argument!='[' ||
               (ind=selection2cimg(indices,images.size(),images_names,"-display3d")).height()==1)) ++position;
          if (ind.height()==1) g_img_uc = gmic_image_arg(*ind);
          display_objects3d(images,images_names,selection,g_img_uc,exit_on_anykey);
          g_img_uc.assign();
          is_released = true; continue;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-e...'
        //-----------------------------
      gmic_commands_e :

        // Endif.
        if (!std::strcmp("-endif",item)) {
          const CImg<char> &s = callstack.back();
          if (s[0]!='*' || s[1]!='i')
            error(images,0,0,
                  "Command '-endif': Not associated to a '-if' command within the same scope.");
          if (is_very_verbose) print(images,0,"End 'if...endif' block.");
          check_elif = false;
          callstack.remove();
          continue;
        }

        // Else and elif.
        if (!std::strcmp("-else",item) || (!std::strcmp("-elif",item) && !check_elif)) {
          const CImg<char> &s = callstack.back();
          if (s[0]!='*' || s[1]!='i')
            error(images,0,0,
                  "Command '%s': Not associated to a '-if' command within the same scope.",
                  item);
          check_elif = false;
          if (is_very_verbose) print(images,0,"Reach '-else' block.");
          for (int nb_ifs = 1; nb_ifs && position<commands_line.size(); ++position) {
            const char *const it = commands_line[position].data();
            if (*it==1 &&
                cimg_sscanf(commands_line[position].data() + 1,"%x,%x",&_debug_line,&(_debug_filename=0))>0) {
              is_debug_info = true; next_debug_line = _debug_line; next_debug_filename = _debug_filename;
            } else if (!std::strcmp("-if",it)) ++nb_ifs;
            else if (!std::strcmp("-endif",it)) { if (!--nb_ifs) --position; }
          }
          continue;
        }

        // End local environment.
        if (!std::strcmp("-endlocal",item) || !std::strcmp("-endl",item)) {
          const CImg<char> &s = callstack.back();
          if (s[0]!='*' || s[1]!='l')
            error(images,0,0,
                  "Command '-endlocal': Not associated to a '-local' command within "
                  "the same scope.");
          if (is_very_verbose) print(images,0,"End 'local...endlocal' block.");
          is_endlocal = true;
          break;
        }

        // Echo.
        if (!is_double_hyphen && is_echo_command) {
          if (is_verbose) {
            gmic_substitute_args(false);
            name.assign(argument,(unsigned int)std::strlen(argument) + 1);
            cimg::strunescape(name);
            if (is_restriction) print(images,&selection,"%s",name.data());
            else print(images,0,"%s",name.data());
          }
          ++position; continue;
        }

        // Exec.
        if (!std::strcmp("-exec",item)) {
          gmic_substitute_args(false);
#ifdef gmic_noexec
          print(images,0,"Execute external command '%s' (skipped, no exec allowed).",
                gmic_argument_text_printed());
#else // #ifdef gmic_noexec
          print(images,0,"Execute external command '%s'\n",
                gmic_argument_text_printed());
          name.assign(argument,(unsigned int)std::strlen(argument) + 1);
          cimg::strunescape(name);
          strreplace_fw(name);
          cimg::mutex(31);
          const int errcode = cimg::system(name);
          cimg::mutex(31,0);
          cimg_snprintf(title,_title.width(),"%d",errcode);
          CImg<char>::string(title).move_to(status);
          if (errcode) print(images,0,"Command '-exec' returned error code '%d'.",
                             errcode);
#endif // #ifdef gmic_noexec
          ++position; continue;
        }

        // Error.
        if (!is_double_hyphen && !std::strcmp("-error",command)) {
          gmic_substitute_args(false);
          name.assign(argument,(unsigned int)std::strlen(argument) + 1);
          cimg::strunescape(name);
          if (is_restriction) error(images,&selection,0,"%s",name.data());
          else error(images,0,0,"%s",name.data());
        }

        // Invert endianness.
        if (!std::strcmp("-endian",item)) {
          gmic_substitute_args(false);
          if (!std::strcmp(argument,"uchar") ||
              !std::strcmp(argument,"unsigned char") || !std::strcmp(argument,"char") ||
              !std::strcmp(argument,"ushort") || !std::strcmp(argument,"unsigned short") ||
              !std::strcmp(argument,"short") || !std::strcmp(argument,"uint") ||
              !std::strcmp(argument,"unsigned int") || !std::strcmp(argument,"int") ||
              !std::strcmp(argument,"uint64") || !std::strcmp(argument,"unsigned int64") ||
              !std::strcmp(argument,"int64") || !std::strcmp(argument,"float") ||
              !std::strcmp(argument,"double")) {
            print(images,0,"Invert data endianness of image%s, with assumed pixel type '%s'.",
                  gmic_selection.data(),argument);
            ++position;
          } else print(images,0,"Invert data endianness of image%s.",
                       gmic_selection.data());
          cimg_forY(selection,l) gmic_apply(gmic_invert_endianness(argument));
          is_released = false; continue;
        }

        // Exponential.
        gmic_simple_command("-exp",exp,"Compute pointwise exponential of image%s.");

        // Test equality.
        gmic_arithmetic_command("-eq",
                                operator_eq,
                                "Compute boolean equality between image%s and %g%s",
                                gmic_selection.data(),value,ssep,T,
                                operator_eq,
                                "Compute boolean equality between image%s and image [%d]",
                                gmic_selection.data(),ind[0],
                                operator_eq,
                                "Compute boolean equality between image%s and expression %s'",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Compute boolean equality between image%s");

        // Draw ellipse.
        if (!std::strcmp("-ellipse",command)) {
          gmic_substitute_args(false);
          float x = 0, y = 0, R = 0, r = 0, angle = 0;
          sep = sepx = sepy = sepz = sepc = *argx = *argy = *argz = *argc = *color = 0;
          pattern = ~0U; opacity = 1;
          if ((cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                           argx,argy,argz,&end)==3 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%255[0-9.eE%+-]%c",
                           argx,argy,argz,argc,&end)==4 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%255[0-9.eE%+-],%f%c",
                           argx,argy,argz,argc,&angle,&end)==5 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%255[0-9.eE%+-],%f,%f%c",
                           argx,argy,argz,argc,&angle,&opacity,&end)==6 ||
               (cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                            "%255[0-9.eE%+-],%f,%f,0%c%x%c",
                            argx,argy,argz,argc,&angle,&opacity,&sep,&pattern,
                            &end)==8 &&
                sep=='x') ||
               (cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                            "%255[0-9.eE%+-],%f,%f,0%c%x,%4095[0-9.eEinfa,+-]%c",
                            argx,argy,argz,argc,&angle,&opacity,&sep,
                            &pattern,color,&end)==9 &&
                sep=='x') ||
               (cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                            "%255[0-9.eE%+-],%f,%f,%4095[0-9.eEinfa,+-]%c",
                            argx,argy,argz,argc,&angle,&opacity,color,&end)==7)) &&
              (cimg_sscanf(argx,"%f%c",&x,&end)==1 ||
               (cimg_sscanf(argx,"%f%c%c",&x,&sepx,&end)==2 && sepx=='%')) &&
              (cimg_sscanf(argy,"%f%c",&y,&end)==1 ||
               (cimg_sscanf(argy,"%f%c%c",&y,&sepy,&end)==2 && sepy=='%')) &&
              (cimg_sscanf(argz,"%f%c",&R,&end)==1 ||
               (cimg_sscanf(argz,"%f%c%c",&R,&sepz,&end)==2 && sepz=='%')) &&
              (!*argc ||
               cimg_sscanf(argc,"%f%c",&r,&end)==1 ||
               (cimg_sscanf(argc,"%f%c%c",&r,&sepc,&end)==2 && sepc=='%'))) {
            if (!*argc) r = R;
            print(images,0,"Draw %s ellipse at (%g%s,%g%s) with radii (%g%s,%g%s) on image%s, "
                  "with orientation %g deg., opacity %g and color (%s).",
                  sep=='x'?"outlined":"filled",
                  x,sepx=='%'?"%":"",
                  y,sepy=='%'?"%":"",
                  R,sepz=='%'?"%":"",
                  r,sepc=='%'?"%":"",
                  gmic_selection.data(),
                  angle,
                  opacity,
                  *color?color:"default");
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              g_img.assign(img.spectrum(),1,1,1,(T)0).fill(color,true,false);
              const float rmax = std::sqrt((float)cimg::sqr(img.width()) +
                                           cimg::sqr(img.height()));
              const int
                nx = (int)cimg::round(sepx=='%'?x*(img.width() - 1)/100:x),
                ny = (int)cimg::round(sepy=='%'?y*(img.height() - 1)/100:y);
              const float
                nR = cimg::round(sepz=='%'?R*rmax/100:R),
                nr = cimg::round(sepc=='%'?r*rmax/100:r);
              if (sep=='x') {
                if (nR==nr) { gmic_apply(draw_circle(nx,ny,(int)nR,g_img.data(),opacity,~0U)); }
                else gmic_apply(draw_ellipse(nx,ny,nR,nr,angle,g_img.data(),opacity,~0U));
              } else {
                if (nR==nr) { gmic_apply(draw_circle(nx,ny,(int)nR,g_img.data(),opacity)); }
                else gmic_apply(draw_ellipse(nx,ny,nR,nr,angle,g_img.data(),opacity));
              }
            }
          } else arg_error("ellipse");
          g_img.assign();
          is_released = false; ++position; continue;
        }

        // Equalize.
        if (!std::strcmp("-equalize",command)) {
          gmic_substitute_args(false);
          float nb_levels = 256;
          bool no_min_max = false;
          sep = sep0 = sep1 = 0;
          value0 = value1 = 0;
          if (((cimg_sscanf(argument,"%f%c",
                            &nb_levels,&end)==1 && (no_min_max=true)) ||
               ((cimg_sscanf(argument,"%f%c%c",
                             &nb_levels,&sep,&end)==2 && sep=='%') && (no_min_max=true)) ||
               cimg_sscanf(argument,"%f,%lf,%lf%c",
                           &nb_levels,&value0,&value1,&end)==3 ||
               (cimg_sscanf(argument,"%f%c,%lf,%lf%c",
                            &nb_levels,&sep,&value0,&value1,&end)==4 && sep=='%') ||
               (cimg_sscanf(argument,"%f,%lf%c,%lf%c",
                            &nb_levels,&value0,&sep0,&value1,&end)==4 && sep0=='%') ||
               (cimg_sscanf(argument,"%f%c,%lf%c,%lf%c",
                            &nb_levels,&sep,&value0,&sep0,&value1,&end)==5 && sep=='%' &&
                sep0=='%') ||
               (cimg_sscanf(argument,"%f,%lf,%lf%c%c",
                            &nb_levels,&value0,&value1,&sep1,&end)==4 && sep1=='%') ||
               (cimg_sscanf(argument,"%f%c,%lf,%lf%c%c",
                            &nb_levels,&sep,&value0,&value1,&sep1,&end)==5 && sep=='%' &&
                sep1=='%') ||
               (cimg_sscanf(argument,"%f,%lf%c,%lf%c%c",
                            &nb_levels,&value0,&sep0,&value1,&sep1,&end)==5 && sep0=='%' &&
                sep1=='%') ||
               (cimg_sscanf(argument,"%f%c,%lf%c,%lf%c%c",
                            &nb_levels,&sep,&value0,&sep0,&value1,&sep1,&end)==6 && sep=='%' &&
                sep0=='%' && sep1=='%')) &&
              nb_levels>=0.5) { nb_levels = cimg::round(nb_levels); ++position; }
          else { nb_levels = 256; value0 = 0; value1 = 100; sep = 0; sep0 = sep1 = '%'; }
          if (no_min_max) { value0 = 0; value1 = 100; sep0 = sep1 = '%'; }
          print(images,0,"Equalize histogram of image%s, with %g%s levels in range [%g%s,%g%s].",
                gmic_selection.data(),
                nb_levels,sep=='%'?"%":"",
                value0,sep0=='%'?"%":"",
                value1,sep1=='%'?"%":"");
          cimg_forY(selection,l) {
            CImg<T>& img = gmic_check(images[selection[l]]);
            nvalue0 = value0; nvalue1 = value1;
            vmin = vmax = 0;
            if (sep0=='%' || sep1=='%') {
              if (img) vmax = (double)img.max_min(vmin);
              if (sep0=='%') nvalue0 = vmin + (vmax - vmin)*value0/100;
              if (sep1=='%') nvalue1 = vmin + (vmax - vmin)*value1/100;
            }
            const unsigned int
              _nb_levels = std::max(1U,
                                    (unsigned int)cimg::round(sep=='%'?
                                                              nb_levels*(1 + nvalue1 - nvalue0)/100:
                                                              nb_levels));
            gmic_apply(equalize(_nb_levels,(T)nvalue0,(T)nvalue1));
          }
          is_released = false; continue;
        }

        // Erode.
        if (!std::strcmp("-erode",command)) {
          gmic_substitute_args(true);
          unsigned int is_real = 0;
          float sx = 3, sy = 3, sz = 1;
          boundary = 1;
          sep = 0;
          if (((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",
                            indices,&sep,&end)==2 && sep==']') ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u%c",
                           indices,&boundary,&end)==2 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u,%u%c",
                           indices,&boundary,&is_real,&end)==3) &&
              (ind=selection2cimg(indices,images.size(),images_names,"-erode")).height()==1 &&
              boundary<=1) {
            print(images,0,"Erode image%s with kernel [%u] and %s boundary conditions, "
                  "in %s mode.",
                  gmic_selection.data(),
                  *ind,
                  boundary?"neumann":"dirichlet",
                  is_real?"real":"binary");
            const CImg<T> kernel = gmic_image_arg(*ind);
            cimg_forY(selection,l) gmic_apply(erode(kernel,boundary,(bool)is_real));
          } else if ((cimg_sscanf(argument,"%f%c",
                                  &sx,&end)==1) &&
                     sx>=0) {
            sx = cimg::round(sx);
            print(images,0,"Erode image%s with kernel of size %g and neumann boundary conditions.",
                  gmic_selection.data(),
                  sx);
            cimg_forY(selection,l) gmic_apply(erode((unsigned int)sx));
          } else if ((cimg_sscanf(argument,"%f,%f%c",
                                  &sx,&sy,&end)==2 ||
                      cimg_sscanf(argument,"%f,%f,%f%c",
                                  &sx,&sy,&sz,&end)==3) &&
                     sx>=0 && sy>=0 && sz>=0) {
            sx = cimg::round(sx);
            sy = cimg::round(sy);
            sz = cimg::round(sz);
            print(images,0,"Erode image%s with %gx%gx%g kernel and neumann boundary conditions.",
                  gmic_selection.data(),
                  sx,sy,sz);
            cimg_forY(selection,l) gmic_apply(erode((unsigned int)sx,(unsigned int)sy,(unsigned int)sz));
          } else arg_error("erode");
          is_released = false; ++position; continue;
        }

        // Build 3d elevation.
        if (!std::strcmp("-elevation3d",command)) {
          gmic_substitute_args(true);
          sep = *formula = *indices = 0;
          float fact = 1;
          if (cimg_sscanf(argument,"'%4095[^']'%c",formula,&end)==1) {
            print(images,0,"Build 3d elevation of image%s, with elevation formula '%s'.",
                  gmic_selection.data(),
                  formula);
            cimg_forY(selection,l) {
              CImg<T>& img = gmic_check(images[selection[l]]);
              CImg<typename CImg<T>::Tfloat> elev(img.width(),img.height(),1,1,formula,true);
              img.get_elevation3d(primitives,g_list_f,elev).move_to(vertices);
              vertices.object3dtoCImg3d(primitives,g_list_f,false);
              gmic_apply(replace(vertices));
              primitives.assign();
            }
            ++position;
          } else if (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep,&end)==2 &&
                     sep==']' &&
                     (ind=selection2cimg(indices,images.size(),images_names,"-elevation3d")).height()==1) {
            print(images,0,"Build 3d elevation of image%s, with elevation map [%u].",
                  gmic_selection.data(),
                  *ind);
            CImg<typename CImg<T>::Tfloat> elev;
            if (images[*ind].spectrum()>1) images[*ind].get_norm().move_to(elev);
            else elev = gmic_image_arg(*ind);
            cimg_forY(selection,l) {
              CImg<T>& img = gmic_check(images[selection[l]]);
              img.get_elevation3d(primitives,g_list_f,elev).move_to(vertices);
              vertices.object3dtoCImg3d(primitives,g_list_f,false);
              gmic_apply(replace(vertices));
              primitives.assign();
            }
            ++position;
          } else {
            if (cimg_sscanf(argument,"%f%c",
                            &fact,&end)==1) {
              print(images,0,"Build 3d elevation of image%s, with elevation factor %g.",
                    gmic_selection.data(),
                    fact);
              ++position;
            } else
              print(images,0,"Build 3d elevation of image%s.",
                    gmic_selection.data());
            cimg_forY(selection,l) {
              CImg<T>& img = gmic_check(images[selection[l]]);
              CImg<typename CImg<T>::Tfloat> elev;
              if (fact==1 && img.spectrum()==1) elev = img.get_shared();
              else if (img.spectrum()>1) (img.get_norm().move_to(elev))*=fact;
              else (elev = img)*=fact;
              img.get_elevation3d(primitives,g_list_f,elev).move_to(vertices);
              vertices.object3dtoCImg3d(primitives,g_list_f,false);
              gmic_apply(replace(vertices));
              primitives.assign();
            }
          }
          g_list_f.assign();
          is_released = false; continue;
        }

        // Eigenvalues/eigenvectors.
        if (!std::strcmp("-eigen",command)) {
          print(images,0,"Compute eigen-values/vectors of symmetric matri%s or matrix field%s.",
                selection.height()>1?"ce":"x",gmic_selection.data());
          unsigned int off = 0;
          cimg_forY(selection,l) {
            const unsigned int uind = selection[l] + off;
            name = images_names[uind];
            CImg<float> val, vec;
            gmic_check(images[uind]).gmic_symmetric_eigen(val,vec);
            if (is_double_hyphen) {
              images_names.insert(name.copymark());
              name.move_to(images_names);
              val.move_to(images);
              vec.move_to(images);
            } else {
              images_names.insert(name.get_copymark(),uind + 1); name.move_to(images_names[uind]);
              val.move_to(images[uind].assign()); images.insert(vec,uind + 1);
              ++off;
            }
          }
          is_released = false; continue;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-f...'
        //-----------------------------
      gmic_commands_f :

        // Fill.
        if (!std::strcmp("-fill",command)) {
          gmic_substitute_args(true);
          sep = *indices = 0;
          value = 0;
          if (cimg_sscanf(argument,"%lf%c",
                          &value,&end)==1) {
            print(images,0,"Fill image%s with %g.",
                  gmic_selection.data(),
                  value);
            cimg_forY(selection,l) gmic_apply(fill((T)value));
          } else if (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep,&end)==2 &&
                     sep==']' &&
                     (ind=selection2cimg(indices,images.size(),images_names,"-fill")).height()==1) {
            print(images,0,"Fill image%s with values from image [%u].",
                  gmic_selection.data(),
                  *ind);
            const CImg<T> values = gmic_image_arg(*ind);
            cimg_forY(selection,l) gmic_apply(fill(values));
          } else {
            gmic_argument_text_printed();
            if (*argument_text=='\'') cimg::strpare(argument_text,'\'',true,false);
            print(images,0,"Fill image%s with expression '%s'.",
                  gmic_selection.data(),
                  argument_text.data());
            name.assign(argument,(unsigned int)std::strlen(argument) + 1);
            cimg::strpare(name,'\'',true,false);
            strreplace_fw(name);
            cimg_forY(selection,l) gmic_apply(fill(name.data(),true,true,&images,&images));
          }
          is_released = false; ++position; continue;
        }

        // Flood fill.
        if (!std::strcmp("-flood",command)) {
          gmic_substitute_args(false);
          float x = 0, y = 0, z = 0, tolerance = 0;
          sepx = sepy = sepz = *argx = *argy = *argz = *color = 0;
          is_high_connectivity = 0;
          opacity = 1;
          if ((cimg_sscanf(argument,"%255[0-9.eE%+-]%c",
                           argx,&end)==1 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                           argx,argy,&end)==2 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                           argx,argy,argz,&end)==3 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eEinfa%+-],%f%c",
                           argx,argy,argz,&tolerance,&end)==4 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eEinfa%+-],%f,%u%c",
                           argx,argy,argz,&tolerance,&is_high_connectivity,&end)==5 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eEinfa%+-],%f,%u,%f%c",
                           argx,argy,argz,&tolerance,&is_high_connectivity,&opacity,&end)==6 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eEinfa%+-],%f,%u,%f,"
                           "%4095[0-9.eEinfa,+-]%c",
                           argx,argy,argz,&tolerance,&is_high_connectivity,
                           &opacity,color,&end)==7) &&
              (cimg_sscanf(argx,"%f%c",&x,&end)==1 ||
               (cimg_sscanf(argx,"%f%c%c",&x,&sepx,&end)==2 && sepx=='%')) &&
              (!*argy ||
               cimg_sscanf(argy,"%f%c",&y,&end)==1 ||
               (cimg_sscanf(argy,"%f%c%c",&y,&sepy,&end)==2 && sepy=='%')) &&
              (!*argz ||
               cimg_sscanf(argz,"%f%c",&z,&end)==1 ||
               (cimg_sscanf(argz,"%f%c%c",&z,&sepz,&end)==2 && sepz=='%')) &&
              tolerance>=0) {
            print(images,0,
                  "Flood fill image%s from (%g%s,%g%s,%g%s), with tolerance %g, %s connectivity,"
                  "opacity %g and color (%s).",
                  gmic_selection.data(),
                  x,sepx=='%'?"%":"",
                  y,sepy=='%'?"%":"",
                  z,sepz=='%'?"%":"",
                  tolerance,
                  is_high_connectivity?"high":"low",
                  opacity,
                  *color?color:"default");
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              g_img.assign(img.spectrum(),1,1,1,(T)0).fill(color,true,false);
              const int
                nx = (int)cimg::round(sepx=='%'?x*(img.width() - 1)/100:x),
                ny = (int)cimg::round(sepy=='%'?y*(img.height() - 1)/100:y),
                nz = (int)cimg::round(sepz=='%'?z*(img.depth() - 1)/100:z);
              gmic_apply(draw_fill(nx,ny,nz,g_img.data(),opacity,tolerance,(bool)is_high_connectivity));
            }
          } else arg_error("flood");
          g_img.assign();
          is_released = false; ++position; continue;
        }

        // List of directory files.
        if (!std::strcmp("-files",item)) {
          gmic_substitute_args(false);
          unsigned int mode = 5;
          if ((*argument>='0' && *argument<='5') &&
              argument[1]==',' && argument[2]) {
            mode = (unsigned int)(*argument - '0');
            argument+=2;
          }
          const unsigned int _mode = mode%3;
          print(images,0,"Get list of %s from location '%s'.",
                _mode==0?"files":_mode==1?"folders":"files and folders",
                argument);
          g_list_c = cimg::files(argument,true,_mode,mode>=3);
          cimglist_for(g_list_c,l) {
            strreplace_bw(g_list_c[l]);
            g_list_c[l].back() = ',';
          }
          if (g_list_c) {
            g_list_c.back().back() = 0;
            (g_list_c>'x').move_to(status);
          } else status.assign();
          g_list_c.assign();
          ++position; continue;
        }

        // Set 3d focale.
        if (!std::strcmp("-focale3d",item)) {
          gmic_substitute_args(false);
          value = 700;
          if (cimg_sscanf(argument,"%lf%c",&value,&end)==1) ++position;
          else value = 700;
          focale3d = (float)value;
          print(images,0,"Set 3d focale to %g.",
                focale3d);
          continue;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-g...'
        //-----------------------------
      gmic_commands_g :

        // Greater or equal.
        gmic_arithmetic_command("-ge",
                                operator_ge,
                                "Compute boolean 'greater or equal than' between image%s and %g%s",
                                gmic_selection.data(),value,ssep,T,
                                operator_ge,
                                "Compute boolean 'greater or equal than' between image%s "
                                "and image [%d]",
                                gmic_selection.data(),ind[0],
                                operator_ge,
                                "Compute boolean 'greater or equal than' between image%s "
                                "and expression %s'",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Compute boolean 'greater or equal than' between image%s");

        // Greater than.
        gmic_arithmetic_command("-gt",
                                operator_gt,
                                "Compute boolean 'greater than' between image%s and %g%s",
                                gmic_selection.data(),value,ssep,T,
                                operator_gt,
                                "Compute boolean 'greater than' between image%s and image [%d]",
                                gmic_selection.data(),ind[0],
                                operator_gt,
                                "Compute boolean 'greater than' between image%s and expression %s'",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Compute boolean 'greater than' between image%s");

        // Compute gradient.
        if (!std::strcmp("-gradient",command)) {
          gmic_substitute_args(false);
          int scheme = 3;
          *argx = 0;
          if ((cimg_sscanf(argument,"%15[xyz]%c",
                           argx,&end)==1 ||
               cimg_sscanf(argument,"%15[xyz],%d%c",
                           argx,&scheme,&end)==2) &&
              scheme>=-1 && scheme<=5) {
            ++position;
            print(images,0,"Compute gradient of image%s along axes '%s', with %s scheme.",
                  gmic_selection.data(),
                  argx,
                  scheme==-1?"backward differences":scheme==4?"deriche":scheme==5?"vanvliet":
                  scheme==1?"forward differences":scheme==2?"sobel":
                  scheme==3?"rotation invariant":"centered differences");
          } else print(images,0,"Compute gradient of image%s, with rotation invariant scheme.",
                       gmic_selection.data());
          unsigned int off = 0;
          cimg_forY(selection,l) {
            const unsigned int uind = selection[l] + off;
            CImg<T>& img = gmic_check(images[uind]);
            g_list = img.get_gradient(*argx?argx:0,scheme);
            name = images_names[uind];
            if (is_double_hyphen) {
              images_names.insert(g_list.size(),name.copymark());
              g_list.move_to(images,~0U);
            } else {
              off+=g_list.size() - 1;
              g_list[0].move_to(images[uind].assign());
              for (unsigned int i = 1; i<g_list.size(); ++i) g_list[i].move_to(images,uind + i);
              images_names[uind] = name;
              if (g_list.size()>1)
                images_names.insert(g_list.size() - 1,name.copymark(),uind + 1);
            }
          }
          g_list.assign();
          is_released = false; continue;
        }

        // Guided filter.
        if (!std::strcmp("-guided",command)) {
          gmic_substitute_args(true);
          float radius = 0, regularization = 0;
          *argz = *argc = 0;
          sep0 = sep1 = 0;
          if (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                          indices,argx,argy,&end)==3 &&
              (cimg_sscanf(argx,"%f%c",&radius,&end)==1 ||
               (cimg_sscanf(argx,"%f%c%c",&radius,&sep0,&end)==2 && sep0=='%')) &&
              (cimg_sscanf(argy,"%f%c",&regularization,&end)==1 ||
               (cimg_sscanf(argy,"%f%c%c",&regularization,&sep1,&end)==2 && sep1=='%')) &&
              (ind=selection2cimg(indices,images.size(),images_names,"-guided")).height()==1 &&
              radius>=0 && regularization>=0) {
            print(images,0,"Apply guided filter on image%s, with guide image [%u], "
                  "radius %g%s and regularization %g%s.",
                  gmic_selection.data(),
                  *ind,
                  radius,sep0=='%'?"%":"",
                  regularization,sep1=='%'?"%":"");
            const CImg<T> guide = gmic_image_arg(*ind);
            if (sep0=='%') radius = -radius;
            if (sep1=='%') regularization = -regularization;
            cimg_forY(selection,l) gmic_apply(blur_guided(guide,radius,regularization));
          } else if (cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                                 argx,argy,&end)==2 &&
                     (cimg_sscanf(argx,"%f%c",&radius,&end)==1 ||
                      (cimg_sscanf(argx,"%f%c%c",&radius,&sep0,&end)==2 && sep0=='%')) &&
                     (cimg_sscanf(argy,"%f%c",&regularization,&end)==1 ||
                      (cimg_sscanf(argy,"%f%c%c",&regularization,&sep1,&end)==2 && sep1=='%')) &&
                     radius>=0 && regularization>=0) {
            print(images,0,"Apply guided filter on image%s, with radius %g%s and regularization %g%s.",
                  gmic_selection.data(),
                  radius,sep0=='%'?"%":"",
                  regularization,sep1=='%'?"%":"");
            if (sep0=='%') radius = -radius;
            if (sep1=='%') regularization = -regularization;
            cimg_forY(selection,l) gmic_apply(blur_guided(images[selection[l]],radius,regularization));
          } else arg_error("guided");
          is_released = false; ++position; continue;
        }

        // Draw graph.
        if (!std::strcmp("-graph",command)) {
          gmic_substitute_args(true);
          double ymin = 0, ymax = 0, xmin = 0, xmax = 0;
          unsigned int plot_type = 1, vertex_type = 1;
          float resolution = 65536;
          *formula = *color = sep = sep1 = 0;
          pattern = ~0U; opacity = 1;
          if (((cimg_sscanf(argument,"'%1023[^']%c%c",
                            formula,&sep,&end)==2 && sep=='\'') ||
               cimg_sscanf(argument,"'%1023[^']',%f%c",
                           formula,&resolution,&end)==2 ||
               cimg_sscanf(argument,"'%1023[^']',%f,%u%c",
                           formula,&resolution,&plot_type,&end)==3 ||
               cimg_sscanf(argument,"'%1023[^']',%f,%u,%u%c",
                           formula,&resolution,&plot_type,&vertex_type,&end)==4 ||
               cimg_sscanf(argument,"'%1023[^']',%f,%u,%u,%lf,%lf%c",
                           formula,&resolution,&plot_type,&vertex_type,&xmin,&xmax,&end)==6 ||
               cimg_sscanf(argument,"'%1023[^']',%f,%u,%u,%lf,%lf,%lf,%lf%c",
                           formula,&resolution,&plot_type,&vertex_type,&xmin,&xmax,
                           &ymin,&ymax,&end)==8 ||
               cimg_sscanf(argument,"'%1023[^']',%f,%u,%u,%lf,%lf,%lf,%lf,%f%c",
                           formula,&resolution,&plot_type,&vertex_type,
                           &xmin,&xmax,&ymin,&ymax,&opacity,&end)==9 ||
               (cimg_sscanf(argument,"'%1023[^']',%f,%u,%u,%lf,%lf,%lf,%lf,%f,0%c%x%c",
                            formula,&resolution,&plot_type,&vertex_type,&xmin,&xmax,
                            &ymin,&ymax,&opacity,&sep1,&pattern,&end)==11 && sep1=='x') ||
               (cimg_sscanf(argument,"'%1023[^']',%f,%u,%u,%lf,%lf,%lf,%lf,%f,%4095[0-9.eEinfa,+-]%c",
                            formula,&resolution,&plot_type,&vertex_type,&xmin,&xmax,&ymin,&ymax,
                            &opacity,color,&end)==10 && (bool)(pattern=~0U)) ||
               (*color=0,cimg_sscanf(argument,"'%1023[^']',%f,%u,%u,%lf,%lf,%lf,%lf,%f,0%c%x,"
                                     "%4095[0-9.eEinfa,+-]%c",
                                     formula,&resolution,&plot_type,&vertex_type,&xmin,&xmax,
                                     &ymin,&ymax,&opacity,&sep1,&pattern,color,&end)==12 &&
                sep1=='x')) &&
              resolution>0 && plot_type<=3 && vertex_type<=7) {
            resolution = cimg::round(resolution);
            strreplace_fw(formula);
            print(images,0,
                  "Draw graph of formula '%s' on image%s, with resolution %g, %s contours, "
                  "%s vertices, x-range = (%g,%g), y-range = (%g,%g), opacity %g, "
                  "pattern 0x%x and color (%s).",
                  formula,
                  gmic_selection.data(),
                  resolution,
                  plot_type==0?"no":plot_type==1?"linear":plot_type==2?"spline":"bar",
                  vertex_type==0?"no":vertex_type==1?"dot":vertex_type==2?"straight cross":
                  vertex_type==3?"diagonal cross":vertex_type==4?"filled circle":
                  vertex_type==5?"outlined circle":vertex_type==6?"square":"diamond",
                  xmin,xmax,
                  ymin,ymax,
                  opacity,pattern,
                  *color?color:"default");
            if (xmin==0 && xmax==0) { xmin = -4; xmax = 4; }
            if (!plot_type && !vertex_type) plot_type = 1;
            if (resolution<1) resolution = 65536;

            CImg<double> values(4,(unsigned int)resolution--,1,1,0);
            const double dx = xmax - xmin;
            cimg_forY(values,X) values(0,X) = xmin + X*dx/resolution;
            cimg::eval(formula,values).move_to(values);

            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              g_img.assign(img.spectrum(),1,1,1,(T)0).fill(color,true,false);
              gmic_apply(draw_graph(values,g_img.data(),opacity,plot_type,vertex_type,ymin,ymax,pattern));
            }
          } else if (((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",
                                   indices,&sep,&end)==2 && sep==']') ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u%c",
                                  indices,&plot_type,&end)==2 ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u,%u%c",
                                  indices,&plot_type,&vertex_type,&end)==3 ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u,%u,%lf,%lf%c",
                                  indices,&plot_type,&vertex_type,&ymin,&ymax,&end)==5 ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u,%u,%lf,%lf,%f%c",
                                  indices,&plot_type,&vertex_type,&ymin,&ymax,&opacity,&end)==6||
                      (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u,%u,%lf,%lf,%f,0%c%x%c",
                                   indices,&plot_type,&vertex_type,&ymin,&ymax,&opacity,&sep1,
                                   &pattern,&end)==8 &&
                       sep1=='x') ||
                      (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u,%u,%lf,%lf,%f,"
                                   "%4095[0-9.eEinfa,+-]%c",
                                   indices,&plot_type,&vertex_type,&ymin,&ymax,&opacity,
                                   color,&end)==7 &&
                       (bool)(pattern=~0U)) ||
                      (*color=0,cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u,%u,%lf,%lf,"
                                            "%f,0%c%x,%4095[0-9.eEinfa,+-]%c",
                                            indices,&plot_type,&vertex_type,&ymin,&ymax,
                                            &opacity,&sep1,&pattern,color,&end)==9 &&
                       sep1=='x')) &&
                     (ind=selection2cimg(indices,images.size(),images_names,"-graph")).height()==1 &&
                     plot_type<=3 && vertex_type<=7) {
            if (!plot_type && !vertex_type) plot_type = 1;
            print(images,0,"Draw graph of dataset [%u] on image%s, with %s contours, %s vertices, "
                  "y-range = (%g,%g), opacity %g, pattern 0x%x and color (%s).",
                  *ind,
                  gmic_selection.data(),
                  plot_type==0?"no":plot_type==1?"linear":plot_type==2?"spline":"bar",
                  vertex_type==0?"no":vertex_type==1?"dot":vertex_type==2?"straight cross":
                  vertex_type==3?"diagonal cross":vertex_type==4?"filled circle":
                  vertex_type==5?"outlined circle":vertex_type==6?"square":"diamond",
                  ymin,ymax,
                  opacity,pattern,
                  *color?color:"default");
            const CImg<T> values = gmic_image_arg(*ind);
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              g_img.assign(img.spectrum(),1,1,1,(T)0).fill(color,true,false);
              gmic_apply(draw_graph(values,g_img.data(),opacity,plot_type,vertex_type,ymin,ymax,pattern));
            }
          } else arg_error("graph");
          g_img.assign();
          is_released = false; ++position; continue;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-h...'
        //-----------------------------
      gmic_commands_h :

        // Histogram.
        if (!std::strcmp("-histogram",command)) {
          gmic_substitute_args(false);
          float nb_levels = 256;
          bool no_min_max = false;
          sep = sep0 = sep1 = 0;
          value0 = value1 = 0;
          if (((cimg_sscanf(argument,"%f%c",
                            &nb_levels,&end)==1 && (no_min_max=true)) ||
               ((cimg_sscanf(argument,"%f%c%c",
                             &nb_levels,&sep,&end)==2 && sep=='%') && (no_min_max=true)) ||
               cimg_sscanf(argument,"%f,%lf,%lf%c",
                           &nb_levels,&value0,&value1,&end)==3 ||
               (cimg_sscanf(argument,"%f%c,%lf,%lf%c",
                            &nb_levels,&sep,&value0,&value1,&end)==4 && sep=='%') ||
               (cimg_sscanf(argument,"%f,%lf%c,%lf%c",
                            &nb_levels,&value0,&sep0,&value1,&end)==4 && sep0=='%') ||
               (cimg_sscanf(argument,"%f%c,%lf%c,%lf%c",
                            &nb_levels,&sep,&value0,&sep0,&value1,&end)==5 && sep=='%' &&
                sep0=='%') ||
               (cimg_sscanf(argument,"%f,%lf,%lf%c%c",
                            &nb_levels,&value0,&value1,&sep1,&end)==4 && sep1=='%') ||
               (cimg_sscanf(argument,"%f%c,%lf,%lf%c%c",
                            &nb_levels,&sep,&value0,&value1,&sep1,&end)==5 && sep=='%' &&
                sep1=='%') ||
               (cimg_sscanf(argument,"%f,%lf%c,%lf%c%c",
                            &nb_levels,&value0,&sep0,&value1,&sep1,&end)==5 && sep0=='%' &&
                sep1=='%') ||
               (cimg_sscanf(argument,"%f%c,%lf%c,%lf%c%c",
                            &nb_levels,&sep,&value0,&sep0,&value1,&sep1,&end)==6 && sep=='%' &&
                sep0=='%' && sep1=='%')) &&
              nb_levels>=0.5) { nb_levels = cimg::round(nb_levels); ++position; }
          else { nb_levels = 256; value0 = 0; value1 = 100; sep = 0; sep0 = sep1 = '%'; }
          if (no_min_max) { value0 = 0; value1 = 100; sep0 = sep1 = '%'; }
          print(images,0,"Compute histogram of image%s, using %g%s level%s in range [%g%s,%g%s].",
                gmic_selection.data(),
                nb_levels,sep=='%'?"%":"",
                nb_levels>1?"s":"",
                value0,sep0=='%'?"%":"",
                value1,sep1=='%'?"%":"");
          cimg_forY(selection,l) {
            CImg<T> &img = gmic_check(images[selection[l]]);
            nvalue0 = value0; nvalue1 = value1;
            vmin = vmax = 0;
            if (sep0=='%' || sep1=='%') {
              if (img) vmax = (double)img.max_min(vmin);
              if (sep0=='%') nvalue0 = vmin + (vmax - vmin)*value0/100;
              if (sep1=='%') nvalue1 = vmin + (vmax - vmin)*value1/100;
            }
            const unsigned int
              _nb_levels = std::max(1U,
                                    (unsigned int)cimg::round(sep=='%'?
                                                              nb_levels*(1 + nvalue1 - nvalue0)/100:
                                                              nb_levels));
            gmic_apply(histogram(_nb_levels,(T)nvalue0,(T)nvalue1));
          }
          is_released = false; continue;
        }

        // HSI to RGB.
        gmic_simple_command("-hsi2rgb",HSItoRGB,"Convert image%s from HSI to RGB color bases.");

        // HSL to RGB.
        gmic_simple_command("-hsl2rgb",HSLtoRGB,"Convert image%s from HSL to RGB color bases.");

        // HSV to RGB.
        gmic_simple_command("-hsv2rgb",HSVtoRGB,"Convert image%s from HSV to RGB color bases.");

        // Compute Hessian.
        if (!std::strcmp("-hessian",command)) {
          gmic_substitute_args(false);
          *argx = 0;
          if (cimg_sscanf(argument,"%255[xyz]%c",
                          argx,&end)==1) {
            ++position;
            print(images,0,"Compute Hessian of image%s along axes '%s'.",
                  gmic_selection.data(),
                  argx);
          } else
            print(images,0,"Compute Hessian of image%s.",
                  gmic_selection.data());
          unsigned int off = 0;
          cimg_forY(selection,l) {
            const unsigned int uind = selection[l] + off;
            CImg<T>& img = gmic_check(images[uind]);
            g_list = img.get_hessian(*argx?argx:0);
            name = images_names[uind];
            if (is_double_hyphen) {
              images_names.insert(g_list.size(),name.copymark());
              g_list.move_to(images,~0U);
            } else {
              off+=g_list.size() - 1;
              g_list[0].move_to(images[uind].assign());
              for (unsigned int i = 1; i<g_list.size(); ++i) g_list[i].move_to(images,uind + i);
              images_names[uind] = name;
              if (g_list.size()>1) images_names.insert(g_list.size() - 1,name.copymark(),uind + 1);
            }
          }
          g_list.assign();
          is_released = false; continue;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-i...'
        //-----------------------------
      gmic_commands_i :

        // Draw image.
        if (!std::strcmp("-image",command)) {
          gmic_substitute_args(true);
          name.assign(256);
          float x = 0, y = 0, z = 0, c = 0, max_opacity_mask = 1;
          *indices = *name = *argx = *argy = *argz = *argc = sep = sepx = sepy = sepz = sepc = 0;
          ind0.assign();
          opacity = 1;
          if (((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",
                            indices,&sep,&end)==2 && sep==']') ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-]%c",
                           indices,argx,&end)==2 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                           indices,argx,argy,&end)==3 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%255[0-9.eE%+-]%c",
                           indices,argx,argy,argz,&end)==4 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%255[0-9.eE%+-],"
                           "%255[0-9.eE%+-]%c",
                           indices,argx,argy,argz,argc,&end)==5 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%255[0-9.eE%+-],%255[0-9.eE%+-],%f%c",
                           indices,argx,argy,argz,argc,&opacity,&end)==6 ||
               (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                            "%255[0-9.eE%+-],%255[0-9.eE%+-],%f,[%255[a-zA-Z0-9_.%+-]%c%c",
                            indices,argx,argy,argz,argc,&opacity,name.data(),&sep,&end)==8 &&
                sep==']') ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%255[0-9.eE%+-],%255[0-9.eE%+-],%f,[%255[a-zA-Z0-9_.%+-]],%f%c",
                           indices,argx,argy,argz,argc,&opacity,name.data(),
                           &max_opacity_mask,&end)==8) &&
              (ind=selection2cimg(indices,images.size(),images_names,"-image")).height()==1 &&
              (!*name ||
               (ind0=selection2cimg(name,images.size(),images_names,"-image")).height()==1) &&
              (!*argx ||
               cimg_sscanf(argx,"%f%c",&x,&end)==1 ||
               (cimg_sscanf(argx,"%f%c%c",&x,&sepx,&end)==2 && sepx=='%')) &&
              (!*argy ||
               cimg_sscanf(argy,"%f%c",&y,&end)==1 ||
               (cimg_sscanf(argy,"%f%c%c",&y,&sepy,&end)==2 && sepy=='%')) &&
              (!*argz ||
               cimg_sscanf(argz,"%f%c",&z,&end)==1 ||
               (cimg_sscanf(argz,"%f%c%c",&z,&sepz,&end)==2 && sepz=='%')) &&
              (!*argc ||
               cimg_sscanf(argc,"%f%c",&c,&end)==1 ||
               (cimg_sscanf(argc,"%f%c%c",&c,&sepc,&end)==2 && sepc=='%'))) {
            const CImg<T> sprite = gmic_image_arg(*ind);
            CImg<T> mask;
            if (ind0) {
              mask = gmic_image_arg(*ind0);
              print(images,0,"Draw image [%u] at (%g%s,%g%s,%g%s,%g%s) on image%s, "
                    "with opacity %g and mask [%u].",
                    *ind,
                    x,sepx=='%'?"%":"",
                    y,sepy=='%'?"%":"",
                    z,sepz=='%'?"%":"",
                    c,sepc=='%'?"%":"",
                    gmic_selection.data(),
                    opacity,
                    *ind0);
            } else print(images,0,"Draw image [%u] at (%g%s,%g%s,%g%s,%g%s) on image%s, "
                         "with opacity %g.",
                         *ind,
                         x,sepx=='%'?"%":"",
                         y,sepy=='%'?"%":"",
                         z,sepz=='%'?"%":"",
                         c,sepc=='%'?"%":"",
                         gmic_selection.data(),
                         opacity);
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              const int
                nx = (int)cimg::round(sepx=='%'?x*(img.width() - 1)/100:x),
                ny = (int)cimg::round(sepy=='%'?y*(img.height() - 1)/100:y),
                nz = (int)cimg::round(sepz=='%'?z*(img.depth() - 1)/100:z),
                nc = (int)cimg::round(sepc=='%'?c*(img.spectrum() - 1)/100:c);
              if (ind0) { gmic_apply(draw_image(nx,ny,nz,nc,sprite,mask,opacity,max_opacity_mask)); }
              else gmic_apply(draw_image(nx,ny,nz,nc,sprite,opacity));
            }
          } else arg_error("image");
          is_released = false; ++position; continue;
        }

        // Index image with a LUT.
        if (!std::strcmp("-index",command)) {
          gmic_substitute_args(true);
          unsigned int lut_type = 0, map_indexes = 0;
          float dithering = 0;
          sep = 0;
          if (((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",
                            indices,&sep,&end)==2 && sep==']') ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f%c",
                           indices,&dithering,&end)==2 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%u%c",
                           indices,&dithering,&map_indexes,&end)==3) &&
              (ind=selection2cimg(indices,images.size(),images_names,"-index")).height()==1) {
            const float ndithering = dithering<0?0:dithering>1?1:dithering;
            print(images,0,"Index values in image%s by LUT [%u], with dithering level %g%s.",
                  gmic_selection.data(),
                  *ind,
                  ndithering,
                  map_indexes?" and index mapping":"");
            const CImg<T> palette = gmic_image_arg(*ind);
            cimg_forY(selection,l) gmic_apply(index(palette,ndithering,(bool)map_indexes));
          } else if ((cimg_sscanf(argument,"%u%c",&lut_type,&end)==1 ||
                      cimg_sscanf(argument,"%u,%f%c",&lut_type,&dithering,&end)==2 ||
                      cimg_sscanf(argument,"%u,%f,%u%c",
                                  &lut_type,&dithering,&map_indexes,&end)==3) &&
                     lut_type<=7) {
            const float ndithering = dithering<0?0:dithering>1?1:dithering;
            print(images,0,"Index values in image%s by %s color LUT, with dithering level %g%s.",
                  gmic_selection.data(),
                  lut_type==0?"default":lut_type==1?"HSV":lut_type==2?"lines":lut_type==3?"hot":
                  lut_type==4?"cool":lut_type==5?"jet":lut_type==6?"flag":"cube",
                  ndithering,map_indexes?" and index mapping":"");
            const CImg<T>
              palette = lut_type==0?CImg<T>::default_LUT256():lut_type==1?CImg<T>::HSV_LUT256():
              lut_type==2?CImg<T>::lines_LUT256():lut_type==3?CImg<T>::hot_LUT256():
              lut_type==4?CImg<T>::cool_LUT256():lut_type==5?CImg<T>::jet_LUT256():
              lut_type==6?CImg<T>::flag_LUT256():CImg<T>::cube_LUT256();
            cimg_forY(selection,l) gmic_apply(index(palette,ndithering,(bool)map_indexes));
          } else arg_error("index");
          is_released = false; ++position; continue;
        }

        // Matrix inverse.
        gmic_simple_command("-invert",invert,"Invert matrix image%s.");

        // Extract 3d isoline.
        if (!std::strcmp("-isoline3d",command)) {
          gmic_substitute_args(false);
          float x0 = -3, y0 = -3, x1 = 3, y1 = 3, dx = 256, dy = 256;
          sep = sepx = sepy = *formula = 0;
          value = 0;
          if (cimg_sscanf(argument,"%lf%c",
                          &value,&end)==1 ||
              cimg_sscanf(argument,"%lf%c%c",
                          &value,&sep,&end)==2) {
            print(images,0,"Extract 3d isolines from image%s, using isovalue %g%s.",
                  gmic_selection.data(),
                  value,sep=='%'?"%":"");
            cimg_forY(selection,l) {
              const unsigned int uind = selection[l];
              CImg<T>& img = gmic_check(images[uind]);
              if (img) {
                vertices.assign();
                primitives.assign();
                g_list_uc.assign();
                g_img_uc.assign(3,img.spectrum(),1,1,220).noise(35,1);
                if (img.spectrum()==1) g_img_uc(0) = g_img_uc(1) = g_img_uc(2) = 200;
                else {
                  g_img_uc(0,0) = 255; g_img_uc(1,0) = g_img_uc(2,0) = 30;
                  g_img_uc(0,1) = g_img_uc(2,1) = 30; g_img_uc(1,1) = 255;
                  if (img.spectrum()>=3) { g_img_uc(0,2) = g_img_uc(1,2) = 30; g_img_uc(2,2) = 255; }
                }
                cimg_forC(img,k) {
                  const CImg<T> channel = img.get_shared_channel(k);
                  nvalue = value;
                  if (sep=='%') {
                    vmax = (double)channel.max_min(vmin);
                    nvalue = vmin + (vmax - vmin)*value/100;
                  }
                  CImgList<unsigned int> prims;
                  const CImg<float> pts = img.get_shared_channel(k).get_isoline3d(prims,(float)nvalue);
                  vertices.append_object3d(primitives,pts,prims);
                  g_list_uc.insert(prims.size(),CImg<unsigned char>::vector(g_img_uc(0,k),
                                                                            g_img_uc(1,k),
                                                                            g_img_uc(2,k)));
                }
                if (!vertices)
                  warn(images,0,false,
                       "Command '-isoline3d': Isovalue %g%s not found in image [%u].",
                       value,sep=='%'?"%":"",uind);
                vertices.object3dtoCImg3d(primitives,g_list_uc,false);
                gmic_apply(replace(vertices));
                primitives.assign();
                g_list_uc.assign();
                g_img_uc.assign();
              } else gmic_apply(replace(img));
            }
          } else if ((cimg_sscanf(argument,"'%4095[^']',%lf%c",
                                  formula,&value,&end)==2 ||
                      cimg_sscanf(argument,"'%4095[^']',%lf,%f,%f,%f,%f%c",
                                  formula,&value,&x0,&y0,&x1,&y1,&end)==6 ||
                      cimg_sscanf(argument,"'%4095[^']',%lf,%f,%f,%f,%f,%f,%f%c",
                                  formula,&value,&x0,&y0,&x1,&y1,&dx,&dy,&end)==8 ||
                      (cimg_sscanf(argument,"'%4095[^']',%lf,%f,%f,%f,%f,%f%c,%f%c",
                                   formula,&value,&x0,&y0,&x1,&y1,&dx,&sepx,&dy,&end)==9 &&
                       sepx=='%') ||
                      (cimg_sscanf(argument,"'%4095[^']',%lf,%f,%f,%f,%f,%f,%f%c%c",
                                   formula,&value,&x0,&y0,&x1,&y1,&dx,&dy,&sepy,&end)==9 &&
                       sepy=='%') ||
                      (cimg_sscanf(argument,"'%4095[^']',%lf,%f,%f,%f,%f,%f%c,%f%c%c",
                                   formula,&value,&x0,&y0,&x1,&y1,&dx,&sepx,&dy,&sepy,&end)==10&&
                       sepx=='%' && sepy=='%')) &&
                     dx>0 && dy>0) {
            dx = cimg::round(dx);
            dy = cimg::round(dy);
            strreplace_fw(formula);
            print(images,0,"Extract 3d isoline %g from formula '%s', in range (%g,%g)-(%g,%g) "
                  "with size %g%sx%g%s.",
                  value,
                  formula,
                  x0,y0,
                  x1,y1,
                  dx,sepx=='%'?"%":"",
                  dy,sepy=='%'?"%":"");
            if (sepx=='%') dx = -dx;
            if (sepy=='%') dy = -dy;
            CImg<T>::isoline3d(primitives,(const char*)formula,(float)value,
                               x0,y0,x1,y1,(int)dx,(int)dy).move_to(vertices);
            vertices.object3dtoCImg3d(primitives,false).move_to(images);
            primitives.assign();
            cimg_snprintf(title,_title.width(),"[3d isoline %g of '%s']",value,formula);
            CImg<char>::string(title).move_to(images_names);
          } else arg_error("isoline3d");
          is_released = false; ++position; continue;
        }

        // Extract 3d isosurface.
        if (!std::strcmp("-isosurface3d",command)) {
          gmic_substitute_args(false);
          float x0 = -3, y0 = -3, z0 = -3, x1 = 3, y1 = 3, z1 = 3,
            dx = 32, dy = 32, dz = 32;
          sep = sepx = sepy = sepz = *formula = 0;
          value = 0;
          if (cimg_sscanf(argument,"%lf%c",
                          &value,&end)==1 ||
              cimg_sscanf(argument,"%lf%c%c",
                          &value,&sep,&end)==2) {
            print(images,0,"Extract 3d isosurface from image%s, using isovalue %g%s.",
                  gmic_selection.data(),
                  value,sep=='%'?"%":"");
            cimg_forY(selection,l) {
              const unsigned int uind = selection[l];
              CImg<T>& img = gmic_check(images[uind]);
              if (img) {
                vertices.assign();
                primitives.assign();
                g_list_uc.assign();
                g_img_uc.assign(3,img.spectrum(),1,1,220).noise(35,1);
                if (img.spectrum()==1) g_img_uc(0) = g_img_uc(1) = g_img_uc(2) = 200;
                else {
                  g_img_uc(0,0) = 255; g_img_uc(1,0) = g_img_uc(2,0) = 30;
                  g_img_uc(0,1) = g_img_uc(2,1) = 30; g_img_uc(1,1) = 255;
                  if (img.spectrum()>=3) { g_img_uc(0,2) = g_img_uc(1,2) = 30; g_img_uc(2,2) = 255; }
                }
                cimg_forC(img,k) {
                  const CImg<T> channel = img.get_shared_channel(k);
                  nvalue = value;
                  if (sep=='%') {
                    vmax = (double)channel.max_min(vmin);
                    nvalue = vmin + (vmax - vmin)*value/100;
                  }
                  CImgList<unsigned int> prims;
                  const CImg<float> pts = channel.get_isosurface3d(prims,(float)nvalue);
                  vertices.append_object3d(primitives,pts,prims);
                  g_list_uc.insert(prims.size(),CImg<unsigned char>::vector(g_img_uc(0,k),
                                                                            g_img_uc(1,k),
                                                                            g_img_uc(2,k)));
                }
                if (!vertices) {
                  if (img.depth()>1)
                    warn(images,0,false,
                         "Command '-isosurface3d': Isovalue %g%s not found in image [%u].",
                         value,sep=='%'?"%":"",uind);
                  else
                    warn(images,0,false,
                         "Command '-isosurface3d': Image [%u] has a single slice, "
                         "isovalue %g%s not found.",
                         uind,value,sep=='%'?"%":"");
                }
                vertices.object3dtoCImg3d(primitives,g_list_uc,false);
                gmic_apply(replace(vertices));
                primitives.assign(); g_list_uc.assign(); g_img_uc.assign();
              } else gmic_apply(replace(img));
            }
          } else if ((cimg_sscanf(argument,"'%4095[^']',%lf%c",
                                  formula,&value,&end)==2 ||
                      cimg_sscanf(argument,"'%4095[^']',%lf,%f,%f,%f,%f,%f,%f%c",
                                  formula,&value,&x0,&y0,&z0,&x1,&y1,&z1,&end)==8 ||
                      cimg_sscanf(argument,"'%4095[^']',%lf,%f,%f,%f,%f,%f,%f,%f,%f,%f%c",
                                  formula,&value,&x0,&y0,&z0,&x1,&y1,&z1,&dx,&dy,&dz,&end)==11 ||
                      (cimg_sscanf(argument,"'%4095[^']',%lf,%f,%f,%f,%f,%f,%f,%f%c,%f,%f%c",
                                   formula,&value,&x0,&y0,&z0,&x1,&y1,&z1,
                                   &dx,&sepx,&dy,&dz,&end)==12 &&
                       sepx=='%') ||
                      (cimg_sscanf(argument,"'%4095[^']',%lf,%f,%f,%f,%f,%f,%f,%f,%f%c,%f%c",
                                   formula,&value,&x0,&y0,&z0,&x1,&y1,&z1,
                                   &dx,&dy,&sepy,&dz,&end)==12 &&
                       sepy=='%') ||
                      (cimg_sscanf(argument,"'%4095[^']',%lf,%f,%f,%f,%f,%f,%f,%f,%f,%f%c%c",
                                   formula,&value,&x0,&y0,&z0,&x1,&y1,&z1,
                                   &dx,&dy,&dz,&sepz,&end)==12 &&
                       sepz=='%') ||
                      (cimg_sscanf(argument,"'%4095[^']',%lf,%f,%f,%f,%f,%f,%f,%f%c,%f%c,%f%c",
                                   formula,&value,&x0,&y0,&z0,&x1,&y1,&z1,
                                   &dx,&sepx,&dy,&sepy,&dz,&end)==13 &&
                       sepx=='%' && sepy=='%') ||
                      (cimg_sscanf(argument,"'%4095[^']',%lf,%f,%f,%f,%f,%f,%f,%f%c,%f,%f%c%c",
                                   formula,&value,&x0,&y0,&z0,&x1,&y1,&z1,
                                   &dx,&sepx,&dy,&dz,&sepz,&end)==13 &&
                       sepx=='%' && sepz=='%') ||
                      (cimg_sscanf(argument,"'%4095[^']',%lf,%f,%f,%f,%f,%f,%f,%f,%f%c,%f%c%c",
                                   formula,&value,&x0,&y0,&z0,&x1,&y1,&z1,
                                   &dx,&dy,&sepy,&dz,&sepz,&end)==13 &&
                       sepy=='%' && sepz=='%') ||
                      (cimg_sscanf(argument,"'%4095[^']',%lf,%f,%f,%f,%f,%f,%f,%f%c,%f%c,%f%c%c",
                                   formula,&value,&x0,&y0,&z0,&x1,&y1,&z1,
                                   &dx,&sepx,&dy,&sepy,&dz,&sepz,&end)==14 &&
                       sepx=='%' && sepy=='%' && sepz=='%')) &&
                     dx>0 && dy>0 && dz>0) {
            dx = cimg::round(dx);
            dy = cimg::round(dy);
            dz = cimg::round(dz);
            strreplace_fw(formula);
            print(images,0,"Extract 3d isosurface %g from formula '%s', "
                  "in range (%g,%g,%g)-(%g,%g,%g) with size %g%sx%g%sx%g%s.",
                  value,
                  formula,
                  x0,y0,z0,
                  x1,y1,z1,
                  dx,sepx=='%'?"%":"",
                  dy,sepy=='%'?"%":"",
                  dz,sepz=='%'?"%":"");
            if (sepx=='%') dx = -dx;
            if (sepy=='%') dy = -dy;
            if (sepz=='%') dz = -dz;
            CImg<T>::isosurface3d(primitives,(const char*)formula,(float)value,
                                  x0,y0,z0,x1,y1,z1,(int)dx,(int)dy,(int)dz).move_to(vertices);
            vertices.object3dtoCImg3d(primitives,false).move_to(images);
            primitives.assign();
            cimg_snprintf(title,_title.width(),"[3d isosurface %g of '%s']",value,formula);
            CImg<char>::string(title).move_to(images_names);
          } else arg_error("isosurface3d");
          is_released = false; ++position; continue;
        }

        // Inpaint.
        if (!std::strcmp("-inpaint",command)) {
          gmic_substitute_args(true);
          float patch_size = 11, lookup_size = 22, lookup_factor = 0.5, lookup_increment = 1,
            blend_size = 0, blend_threshold = 0, blend_decay = 0.05f, blend_scales = 10;
          unsigned int is_blend_outer = 1, method = 1;
          sep = *indices = 0;
          if (((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep,&end)==2 &&
                sep==']') ||
               (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%c%c",indices,&sep,&end)==2 &&
                sep=='0') ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],0,%u%c",indices,&method,&end)==2) &&
              (ind=selection2cimg(indices,images.size(),images_names,"-inpaint")).height()==1 &&
              method<=3) {
            print(images,0,"Inpaint image%s masked by image [%u], with %s algorithm.",
                  gmic_selection.data(),
                  *ind,
                  method==0?"low-connectivity average":method==1?"high-connectivity average":
                  method==2?"low-connectivity median":"high-connectivity median");
            const CImg<T> mask = gmic_image_arg(*ind);
            cimg_forY(selection,l) gmic_apply(inpaint(mask,method));
          } else if (((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",
                                   indices,&sep,&end)==2 && sep==']') ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f%c",
                                  indices,&patch_size,&end)==2 ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f%c",
                                  indices,&patch_size,&lookup_size,&end)==3 ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f%c",
                                  indices,&patch_size,&lookup_size,&lookup_factor,&end)==4 ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f,%f%c",
                                  indices,&patch_size,&lookup_size,&lookup_factor,
                                  &lookup_increment,&end)==5 ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f,%f,%f%c",
                                  indices,&patch_size,&lookup_size,&lookup_factor,
                                  &lookup_increment,&blend_size,&end)==6 ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f,%f,%f,%f%c",
                                  indices,&patch_size,&lookup_size,&lookup_factor,
                                  &lookup_increment,&blend_size,&blend_threshold,&end)==7 ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f,%f,%f,%f,%f%c",
                                  indices,&patch_size,&lookup_size,&lookup_factor,
                                  &lookup_increment,&blend_size,&blend_threshold,&blend_decay,
                                  &end)==8 ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f,%f,%f,%f,%f,%f%c",
                                  indices,&patch_size,&lookup_size,&lookup_factor,
                                  &lookup_increment,&blend_size,&blend_threshold,&blend_decay,
                                  &blend_scales,&end)==9 ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f,%f,%f,%f,%f,%f,%u%c",
                                  indices,&patch_size,&lookup_size,&lookup_factor,
                                  &lookup_increment,&blend_size,&blend_threshold,&blend_decay,
                                  &blend_scales,&is_blend_outer,&end)==10) &&
                     (ind=selection2cimg(indices,images.size(),images_names,"-inpaint")).height()==1 &&
                     patch_size>=0.5 && lookup_size>=0.5 && lookup_factor>=0 &&
                     blend_size>=0 && blend_threshold>=0 && blend_threshold<=1 &&
                     blend_decay>=0 && blend_scales>=0.5 && is_blend_outer<=1) {
            const CImg<T> mask = gmic_image_arg(*ind);
            patch_size = cimg::round(patch_size);
            lookup_size = cimg::round(lookup_size);
            lookup_increment = cimg::round(lookup_increment);
            blend_size = cimg::round(blend_size);
            blend_scales = cimg::round(blend_scales);
            print(images,0,"Inpaint image%s masked by image [%d], with patch size %g, "
                  "lookup size %g, lookup factor %g, lookup_increment %g, blend size %g, "
                  "blend threshold %g, blend decay %g, %g blend scale%s and outer blending %s.",
                  gmic_selection.data(),*ind,
                  patch_size,lookup_size,lookup_factor,lookup_increment,
                  blend_size,blend_threshold,blend_decay,blend_scales,blend_scales!=1?"s":"",
                  is_blend_outer?"enabled":"disabled");
            cimg_forY(selection,l)
              gmic_apply(inpaint_patch(mask,
                                       (unsigned int)patch_size,(unsigned int)lookup_size,
                                       lookup_factor,
                                       (int)lookup_increment,
                                       (unsigned int)blend_size,blend_threshold,blend_decay,
                                       (unsigned int)blend_scales,(bool)is_blend_outer));
          } else arg_error("inpaint");
          is_released = false; ++position; continue;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-k...'
        //-----------------------------
      gmic_commands_k :

        // Keep images.
        if (!std::strcmp("-keep",command)) {
          print(images,0,"Keep image%s",
                gmic_selection.data());
          g_list.assign(selection.height());
          g_list_c.assign(selection.height());
          if (is_double_hyphen) {
            cimg_forY(selection,l) {
              const unsigned int uind = selection[l];
              g_list[l].assign(images[uind]);
              g_list_c[l].assign(images_names[uind]).copymark();
            }
            g_list.move_to(images,~0U);
            g_list_c.move_to(images_names,~0U);
          } else {
            cimg_forY(selection,l) {
              const unsigned int uind = selection[l];
              g_list[l].swap(images[uind]);
              g_list_c[l].swap(images_names[uind]);
            }
            g_list.swap(images);
            g_list_c.swap(images_names);
          }
          if (is_verbose) {
            cimg::mutex(29);
            std::fprintf(cimg::output()," (%u image%s left).",
                         images.size(),images.size()==1?"":"s");
            std::fflush(cimg::output());
            cimg::mutex(29,0);
          }
          g_list.assign(); g_list_c.assign();
          is_released = false; continue;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-l...'
        //-----------------------------
      gmic_commands_l :

        // Start local environnement.
        if (!std::strcmp("-local",command)) {
          if (is_debug_info && debug_line!=~0U) {
            cimg_snprintf(argx,_argx.width(),"*local#%u",debug_line);
            CImg<char>::string(argx).move_to(callstack);
          } else CImg<char>::string("*local").move_to(callstack);
          if (is_very_verbose)
            print(images,0,"Start '-local...-endlocal' block, with selected image%s.",
                  gmic_selection.data());
          g_list.assign(selection.height());
          g_list_c.assign(selection.height());
          gmic_exception exception;

          if (is_double_hyphen) cimg_forY(selection,l) {
              const unsigned int uind = selection[l];
              g_list[l].assign(images[uind]);
              g_list_c[l].assign(images_names[uind]).copymark();
            } else {
            cimg::mutex(27);
            cimg_forY(selection,l) {
              const unsigned int uind = selection[l];
              if (images[uind].is_shared())
                g_list[l].assign(images[uind],false);
              else {
                if ((images[uind].width() || images[uind].height()) && !images[uind]._spectrum) {
                  selection2string(selection,images_names,1,name);
                  error(images,0,0,
                        "Command '-local': Invalid selection%s "
                        "(image [%u] is already used in another thread).",
                        name.data() + (*name=='s'?1:0),uind);
                }
                g_list[l].swap(images[uind]);
                // Small hack to be able to track images of the selection passed to the new environment.
                std::memcpy(&images[uind]._width,&g_list[l]._data,sizeof(void*));
                images[uind]._spectrum = 0;
              }
              g_list_c[l] = images_names[uind];   // Make a copy to be still able to recognize '-pass[label]'.
            }
            cimg::mutex(27,0);
          }
          const unsigned int local_callstack_size = callstack.size();
          try {
            if (next_debug_line!=~0U) { debug_line = next_debug_line; next_debug_line = ~0U; }
            if (next_debug_filename!=~0U) { debug_filename = next_debug_filename; next_debug_filename = ~0U; }
            _run(commands_line,position,g_list,g_list_c,images,images_names,variables_sizes,is_noarg,0,
                 command_selection);
          } catch (gmic_exception &e) {
            int nb_locals = 0;
            for (nb_locals = 1; nb_locals && position<commands_line.size(); ++position) {
              const char *const it = commands_line[position].data();
              if (*it==1 &&
                  cimg_sscanf(commands_line[position].data() + 1,"%x,%x",&_debug_line,&(_debug_filename=0))>0) {
                is_debug_info = true; next_debug_line = _debug_line; next_debug_filename = _debug_filename;
              } else if (!std::strcmp("-local",it) || !std::strcmp("-l",it) ||
                         !std::strcmp("--local",it) || !std::strcmp("--l",it) ||
                         !std::strncmp("-local[",it,7) || !std::strncmp("-l[",it,3) ||
                         !std::strncmp("--local[",it,8) || !std::strncmp("--l[",it,4)) ++nb_locals;
              else if (!std::strcmp("-endlocal",it) || !std::strcmp("-endl",it)) --nb_locals;
              else if (nb_locals==1 && !std::strcmp("-onfail",it)) break;
            }
            if (callstack.size()>local_callstack_size) callstack.remove(local_callstack_size,callstack.size() - 1);
            if (nb_locals==1 && position<commands_line.size()) { // Onfail block found.
              if (is_very_verbose) print(images,0,"Reach '-onfail' block.");
              try {
                _run(commands_line,++position,g_list,g_list_c,
                     parent_images,parent_images_names,variables_sizes,is_noarg,0,0);
              } catch (gmic_exception &e) {
                cimg::swap(exception._command_help,e._command_help);
                cimg::swap(exception._message,e._message);
              }
            } else {
              cimg::swap(exception._command_help,e._command_help);
              cimg::swap(exception._message,e._message);
            }
          }
          callstack.remove();
          if (is_double_hyphen) {
            g_list.move_to(images,~0U);
            g_list_c.move_to(images_names,~0U);
          } else {
            const unsigned int nb = std::min((unsigned int)selection.height(),g_list.size());
            if (nb>0) {
              for (unsigned int i = 0; i<nb; ++i) {
                const unsigned int uind = selection[i];
                if (images[uind].is_shared()) {
                  images[uind] = g_list[i];
                  g_list[i].assign();
                } else images[uind].swap(g_list[i]);
                images_names[uind].swap(g_list_c[i]);
              }
              g_list.remove(0,nb - 1);
              g_list_c.remove(0,nb - 1);
            }
            if (nb<(unsigned int)selection.height())
              remove_images(images,images_names,selection,nb,selection.height() - 1);
            else if (g_list) {
              const unsigned int uind0 = selection?selection.back() + 1:images.size();
              images.insert(g_list,uind0);
              g_list_c.move_to(images_names,uind0);
            }
          }
          if (exception._message) throw exception;
          g_list.assign(); g_list_c.assign();
          continue;
        }

        // Less or equal.
        gmic_arithmetic_command("-le",
                                operator_le,
                                "Compute boolean 'less or equal than' between image%s and %g%s",
                                gmic_selection.data(),value,ssep,T,
                                operator_le,
                                "Compute boolean 'less or equal than' between image%s and image [%d]",
                                gmic_selection.data(),ind[0],
                                operator_le,
                                "Compute boolean 'less or equal than' between image%s and "
                                "expression %s'",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Compute boolean 'less or equal than' between image%s");

        // Less than.
        gmic_arithmetic_command("-lt",
                                operator_lt,
                                "Compute boolean 'less than' between image%s and %g%s",
                                gmic_selection.data(),value,ssep,T,
                                operator_lt,
                                "Compute boolean 'less than' between image%s and image [%d]",
                                gmic_selection.data(),ind[0],
                                operator_lt,
                                "Compute boolean 'less than' between image%s and expression %s'",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Compute boolean 'less than' between image%s");

        // Logarithm, base-e.
        gmic_simple_command("-log",log,"Compute pointwise base-e logarithm of image%s.");

        // Logarithm, base-2.
        gmic_simple_command("-log2",log2,"Compute pointwise base-2 logarithm of image%s.");

        // Logarithm, base-10.
        gmic_simple_command("-log10",log10,"Compute pointwise base-10 logarithm of image%s.");

        // Draw line.
        if (!std::strcmp("-line",command)) {
          gmic_substitute_args(false);
          *argx = *argy = *argz = *argc = *color = 0;
          float x0 = 0, y0 = 0, x1 = 0, y1 = 0;
          char sepx0 = 0, sepy0 = 0, sepx1 = 0, sepy1 = 0, sep1 = 0;
          pattern = ~0U; opacity = 1;
          if ((cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%255[0-9.eE%+-]%c",
                           argx,argy,argz,argc,&end)==4 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%255[0-9.eE%+-],%f%c",
                           argx,argy,argz,argc,&opacity,&end)==5 ||
               (cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                            "%255[0-9.eE%+-],%f,0%c%x%c",
                            argx,argy,argz,argc,&opacity,&sep1,&pattern,&end)==7 &&
                sep1=='x') ||
               (cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                            "%255[0-9.eE%+-],%f,%4095[0-9.eEinfa,+-]%c",
                            argx,argy,argz,argc,&opacity,color,&end)==6 && (bool)(pattern=~0U)) ||
               (*color=0,cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                                     "%255[0-9.eE%+-],%f,0%c%x,%4095[0-9.eEinfa,+-]%c",
                                     argx,argy,argz,argc,&opacity,&sep1,
                                     &pattern,color,&end)==8 && sep1=='x')) &&
              (cimg_sscanf(argx,"%f%c",&x0,&end)==1 ||
               (cimg_sscanf(argx,"%f%c%c",&x0,&sepx0,&end)==2 && sepx0=='%')) &&
              (cimg_sscanf(argy,"%f%c",&y0,&end)==1 ||
               (cimg_sscanf(argy,"%f%c%c",&y0,&sepy0,&end)==2 && sepy0=='%')) &&
              (cimg_sscanf(argz,"%f%c",&x1,&end)==1 ||
               (cimg_sscanf(argz,"%f%c%c",&x1,&sepx1,&end)==2 && sepx1=='%')) &&
              (cimg_sscanf(argc,"%f%c",&y1,&end)==1 ||
               (cimg_sscanf(argc,"%f%c%c",&y1,&sepy1,&end)==2 && sepy1=='%'))) {
            print(images,0,"Draw line (%g%s,%g%s) - (%g%s,%g%s) on image%s, with opacity %g, "
                  "pattern 0x%x and color (%s).",
                  x0,sepx0=='%'?"%":"",
                  y0,sepy0=='%'?"%":"",
                  x1,sepx1=='%'?"%":"",
                  y1,sepy1=='%'?"%":"",
                  gmic_selection.data(),
                  opacity,pattern,
                  *color?color:"default");
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              g_img.assign(img.spectrum(),1,1,1,(T)0).fill(color,true,false);
              const int
                nx0 = (int)cimg::round(sepx0=='%'?x0*(img.width() - 1)/100:x0),
                ny0 = (int)cimg::round(sepy0=='%'?y0*(img.height() - 1)/100:y0),
                nx1 = (int)cimg::round(sepx1=='%'?x1*(img.width() - 1)/100:x1),
                ny1 = (int)cimg::round(sepy1=='%'?y1*(img.height() - 1)/100:y1);
              gmic_apply(draw_line(nx0,ny0,nx1,ny1,g_img.data(),opacity,pattern));
            }
          } else arg_error("line");
          g_img.assign();
          is_released = false; ++position; continue;
        }

        // Lab to RGB
        if (!std::strcmp("-lab2rgb",command)) {
          gmic_substitute_args(false);
          bool use_D65 = true;
          if ((*argument=='0' || *argument=='1') && !argument[1]) {
            use_D65 = *argument=='1';
            ++position;
          }
          print(images,0,"Convert image%s from Lab to RGB color bases, with D%u illuminant.",
                gmic_selection.data(),use_D65?65:50);
          cimg_forY(selection,l) gmic_apply(LabtoRGB(use_D65));
          is_released = false; continue;
        }

        // Label connected components.
        if (!std::strcmp("-label",command)) {
          gmic_substitute_args(false);
          float tolerance = 0;
          is_high_connectivity = 0;
          if ((cimg_sscanf(argument,"%f%c",&tolerance,&end)==1 ||
               cimg_sscanf(argument,"%f,%u%c",&tolerance,&is_high_connectivity,&end)==2) &&
              tolerance>=0) ++position;
          else { tolerance = 0; is_high_connectivity = 0; }
          print(images,0,
                "Label connected components on image%s, with tolerance %g and "
                "%s connectivity.",
                gmic_selection.data(),tolerance,is_high_connectivity?"high":"low");
          cimg_forY(selection,l) gmic_apply(label((bool)is_high_connectivity,tolerance));
          is_released = false; continue;
        }

        // Set 3d light position.
        if (!std::strcmp("-light3d",item)) {
          gmic_substitute_args(true);
          float lx = 0, ly = 0, lz = -5e8f;
          sep = *indices = 0;
          if (cimg_sscanf(argument,"%f,%f,%f%c",
                          &lx,&ly,&lz,&end)==3) {
            print(images,0,"Set 3d light position to (%g,%g,%g).",
                  lx,ly,lz);
            light3d_x = lx;
            light3d_y = ly;
            light3d_z = lz;
            ++position;
          } else if (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep,&end)==2 &&
                     sep==']' &&
                     (ind=selection2cimg(indices,images.size(),images_names,"-light3d")).height()==1) {
            print(images,0,"Set 3d light texture from image [%u].",*ind);
            light3d.assign(images[*ind],false);
            ++position;
          } else {
            print(images,0,"Reset 3d light to default.");
            light3d.assign();
            light3d_x = light3d_y = 0; light3d_z = -5e8f;
          }
          continue;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-m...'
        //-----------------------------
      gmic_commands_m :

        // Move images.
        if (!std::strcmp("-move",command)) {
          gmic_substitute_args(false);
          float pos = 0;
          sep = 0;
          if (cimg_sscanf(argument,"%f%c",&pos,&end)==1 ||
              (cimg_sscanf(argument,"%f%c%c",&pos,&sep,&end)==2 && sep=='%')) {
            const int
              _iind0 = (int)cimg::round(sep=='%'?pos*images.size()/100:pos),
              iind0 = _iind0<0?_iind0 + (int)images.size():_iind0;
            if (iind0<0 || iind0>(int)images.size())
              error(images,0,0,
                    "Command '-move': Invalid position '%d' (not in range -%u...%u).",
                    _iind0,images.size(),images.size() - 1);
            print(images,0,"Move image%s to position %d.",
                  gmic_selection.data(),
                  iind0);
            CImgList<T> _images, nimages;
            CImgList<char> _images_names, nimages_names;
            if (is_double_hyphen) {
              _images.insert(images.size());
              // Copy original list while preserving shared state of each item.
              cimglist_for(_images,l) _images[l].assign(images[l],images[l].is_shared());
              _images_names.assign(images_names);
            }
            nimages.insert(selection.height());
            cimg_forY(selection,l) {
              const unsigned int uind = selection[l];
              if (is_double_hyphen) images[uind].move_to(nimages[l]);
              else images[uind].swap(nimages[l]);
              // Empty shared image as a special item to be removed later.
              images[uind]._is_shared = true;
              images_names[uind].move_to(nimages_names);
            }
            images.insert(nimages.size(),iind0);
            cimglist_for(nimages,l) nimages[l].swap(images[iind0 + l]);
            nimages_names.move_to(images_names,iind0);
            cimglist_for(images,l) if (!images[l] && images[l].is_shared()) {
              images.remove(l); images_names.remove(l--); // Remove special items.
            }
            if (is_double_hyphen) {
              cimglist_for(images,l) // Replace shared items by non-shared one for a get version.
                if (images[l].is_shared()) {
                  CImg<T> tmp; (images[l].move_to(tmp)).swap(images[l]);
                }
              images.insert(_images.size(),0);
              cimglist_for(_images,l) images[l].swap(_images[l]);
              _images_names.move_to(images_names,0);
            }
          } else arg_error("move");
          is_released = false; ++position; continue;
        }

        // Mirror.
        if (!std::strcmp("-mirror",command)) {
          gmic_substitute_args(false);
          bool is_valid_argument = *argument!=0;
          if (is_valid_argument) for (const char *s = argument; *s; ++s) {
              const char _s = *s;
              if (_s!='x' && _s!='y' && _s!='z' && _s!='c') { is_valid_argument = false; break; }
            }
          if (is_valid_argument) {
            print(images,0,"Mirror image%s along the '%s'-ax%cs.",
                  gmic_selection.data(),
                  gmic_argument_text_printed(),
                  std::strlen(argument)>1?'e':'i');
            cimg_forY(selection,l) gmic_apply(mirror(argument));
          } else arg_error("mirror");
          is_released = false; ++position; continue;
        }

        // Manage mutexes.
        if (!std::strcmp("-mutex",item)) {
          gmic_substitute_args(false);
          unsigned int number, is_lock = 1;
          if ((cimg_sscanf(argument,"%u%c",
                           &number,&end)==1 ||
               cimg_sscanf(argument,"%u,%u%c",
                           &number,&is_lock,&end)==2) &&
              number<256 && is_lock<=1) {
            print(images,0,"%s mutex #%u.",
                  is_lock?"Lock":"Unlock",number);
            if (is_lock) gmic_mutex().lock(number);
            else gmic_mutex().unlock(number);
          } else arg_error("mutex");
          ++position; continue;
        }

        // Multiplication.
        gmic_arithmetic_command("-mul",
                                operator*=,
                                "Multiply image%s by %g%s",
                                gmic_selection.data(),value,ssep,Tfloat,
                                mul,
                                "Multiply image%s by image [%d]",
                                gmic_selection.data(),ind[0],
                                operator_muleq,
                                "Multiply image%s by expression %s",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Multiply image%s");
        // Modulo.
        gmic_arithmetic_command("-mod",
                                operator%=,
                                "Compute pointwise modulo of image%s by %g%s",
                                gmic_selection.data(),value,ssep,T,
                                operator%=,
                                "Compute pointwise modulo of image%s by image [%d]",
                                gmic_selection.data(),ind[0],
                                operator_modeq,
                                "Compute pointwise modulo of image%s by expression %s",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Compute sequential pointwise modulo of image%s");

        // Max.
        gmic_arithmetic_command("-max",
                                max,
                                "Compute pointwise maximum between image%s and %g%s",
                                gmic_selection.data(),value,ssep,T,
                                max,
                                "Compute pointwise maximum between image%s and image [%d]",
                                gmic_selection.data(),ind[0],
                                max,
                                "Compute pointwise maximum between image%s and expression %s",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Compute pointwise maximum of all image%s together");
        // Min.
        gmic_arithmetic_command("-min",
                                min,
                                "Compute pointwise minimum between image%s and %g%s",
                                gmic_selection.data(),value,ssep,T,
                                min,
                                "Compute pointwise minimum between image%s and image [%d]",
                                gmic_selection.data(),ind[0],
                                min,
                                "Compute pointwise minimum between image%s and expression %s",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Compute pointwise minimum of image%s");

        // Matrix multiplication.
        gmic_arithmetic_command("-mmul",
                                operator*=,
                                "Multiply matrix/vector%s by %g%s",
                                gmic_selection.data(),value,ssep,Tfloat,
                                operator*=,
                                "Multiply matrix/vector%s by matrix/vector image [%d]",
                                gmic_selection.data(),ind[0],
                                operator_muleq,
                                "Multiply matrix/vector%s by expression %s",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Multiply matrix/vector%s");

        // Set 3d rendering modes.
        if (!std::strcmp("-mode3d",item)) {
          gmic_substitute_args(false);
          float mode = 4;
          if (cimg_sscanf(argument,"%f%c",
                          &mode,&end)==1 &&
              (mode=cimg::round(mode))>=-1 && mode<=5) ++position;
          else mode = 4;
          render3d = (int)mode;
          print(images,0,"Set static 3d rendering mode to %s.",
                render3d==-1?"bounding-box":
                render3d==0?"pointwise":render3d==1?"linear":render3d==2?"flat":
                render3d==3?"flat-shaded":render3d==4?"Gouraud-shaded":
                render3d==5?"Phong-shaded":"none");
          continue;
        }

        if (!std::strcmp("-moded3d",item)) {
          gmic_substitute_args(false);
          float mode = -1;
          if (cimg_sscanf(argument,"%f%c",
                          &mode,&end)==1 &&
              (mode=cimg::round(mode))>=-1 && mode<=5) ++position;
          else mode = -1;
          renderd3d = (int)mode;
          print(images,0,"Set dynamic 3d rendering mode to %s.",
                renderd3d==-1?"bounding-box":
                renderd3d==0?"pointwise":renderd3d==1?"linear":renderd3d==2?"flat":
                renderd3d==3?"flat-shaded":renderd3d==4?"Gouraud-shaded":
                renderd3d==5?"Phong-shaded":"none");
          continue;
        }

        // Map LUT.
        if (!std::strcmp("-map",command)) {
          gmic_substitute_args(true);
          unsigned int lut_type = 0;
          sep = *indices = 0;
          boundary = 0;
          if (((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep,&end)==2 && sep==']') ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u%c",indices,&boundary,&end)==2) &&
              (ind=selection2cimg(indices,images.size(),images_names,"-map")).height()==1 &&
              boundary<=2) {
            print(images,0,"Map LUT [%u] on image%s, with %s boundary conditions.",
                  *ind,
                  gmic_selection.data(),
                  boundary==0?"dirichlet":boundary==1?"neumann":"periodic");
            const CImg<T> palette = gmic_image_arg(*ind);
            cimg_forY(selection,l) gmic_apply(map(palette,boundary));
          } else if ((cimg_sscanf(argument,"%u%c",&lut_type,&end)==1 ||
                      cimg_sscanf(argument,"%u,%u%c",&lut_type,&boundary,&end)==2) &&
                     lut_type<=7 && boundary<=2) {
            print(images,0,"Map %s color LUT on image%s, with %s boundary conditions.",
                  lut_type==0?"default":lut_type==1?"HSV":lut_type==2?"lines":lut_type==3?"hot":
                  lut_type==4?"cool":lut_type==5?"jet":lut_type==6?"flag":"cube",
                  gmic_selection.data(),
                  boundary==0?"dirichlet":boundary==1?"neumann":"periodic");
            const CImg<T>
              palette = lut_type==0?CImg<T>::default_LUT256():lut_type==1?CImg<T>::HSV_LUT256():
              lut_type==2?CImg<T>::lines_LUT256():lut_type==3?CImg<T>::hot_LUT256():
              lut_type==4?CImg<T>::cool_LUT256():lut_type==5?CImg<T>::jet_LUT256():
              lut_type==6?CImg<T>::flag_LUT256():CImg<T>::cube_LUT256();
            cimg_forY(selection,l) gmic_apply(map(palette,boundary));
          } else arg_error("map");
          is_released = false; ++position; continue;
        }

        // Median filter.
        if (!std::strcmp("-median",command)) {
          gmic_substitute_args(false);
          float siz = 3, threshold = 0;
          if ((cimg_sscanf(argument,"%f%c",
                           &siz,&end)==1 ||
               cimg_sscanf(argument,"%f,%f%c",
                           &siz,&threshold,&end)==2) &&
              siz>=0 && threshold>=0) {
            siz = cimg::round(siz);
            if (threshold)
              print(images,0,"Apply median filter of size %g with threshold %g, on image%s.",
                    siz,threshold,
                    gmic_selection.data());
            else
              print(images,0,"Apply median filter of size %g, on image%s.",
                    siz,
                    gmic_selection.data());
            cimg_forY(selection,l) gmic_apply(blur_median((unsigned int)siz,threshold));
          } else arg_error("median");
          is_released = false; ++position; continue;
        }

        // Matrix division.
        gmic_arithmetic_command("-mdiv",
                                operator/=,
                                "Divide matrix/vector%s by %g%s",
                                gmic_selection.data(),value,ssep,Tfloat,
                                operator/=,
                                "Divide matrix/vector%s by matrix/vector image [%d]",
                                gmic_selection.data(),ind[0],
                                operator_diveq,
                                "Divide matrix/vector%s by expression %s",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Divide matrix/vector%s");

        // MSE.
        if (!std::strcmp("-mse",command)) {
          print(images,0,"Compute the %dx%d matrix of MSE values, from image%s.",
                selection.height(),selection.height(),
                gmic_selection.data());
          if (selection) {
            g_list.assign(selection.height());
            cimg_forY(selection,l) g_list[l].assign(gmic_check(images[selection[l]]),true);
            CImg<T> img(g_list.size(),g_list.size(),1,1,(T)0);
            cimg_forXY(img,x,y) if (x>y) img(x,y) = img(y,x) = (T)g_list[x].MSE(g_list[y]);
            CImg<char>::string("[MSE]").move_to(name);
            if (is_double_hyphen) {
              img.move_to(images);
              name.move_to(images_names);
            } else {
              remove_images(images,images_names,selection,1,selection.height() - 1);
              img.move_to(images[selection[0]].assign());
              name.move_to(images_names[selection[0]]);
            }
            g_list.assign();
          }
          is_released = false; continue;
        }

        // Draw mandelbrot/julia fractal.
        if (!std::strcmp("-mandelbrot",command)) {
          gmic_substitute_args(false);
          double z0r = -2, z0i = -2, z1r = 2, z1i = 2, paramr = 0, parami = 0;
          unsigned int is_julia = 0;
          float itermax = 100;
          opacity = 1;
          if ((cimg_sscanf(argument,"%lf,%lf,%lf,%lf%c",
                           &z0r,&z0i,&z1r,&z1i,&end)==4 ||
               cimg_sscanf(argument,"%lf,%lf,%lf,%lf,%f%c",
                           &z0r,&z0i,&z1r,&z1i,&itermax,&end)==5 ||
               cimg_sscanf(argument,"%lf,%lf,%lf,%lf,%f,%u%c",
                           &z0r,&z0i,&z1r,&z1i,&itermax,&is_julia,&end)==6 ||
               cimg_sscanf(argument,"%lf,%lf,%lf,%lf,%f,%u,%lf,%lf%c",
                           &z0r,&z0i,&z1r,&z1i,&itermax,&is_julia,&paramr,
                           &parami,&end)==8 ||
               cimg_sscanf(argument,"%lf,%lf,%lf,%lf,%f,%u,%lf,%lf,%f%c",
                           &z0r,&z0i,&z1r,&z1i,&itermax,&is_julia,
                           &paramr,&parami,&opacity,&end)==9) &&
              itermax>=0 && is_julia<=1) {
            itermax = cimg::round(itermax);
            print(images,0,"Draw %s fractal on image%s, from complex area (%g,%g)-(%g,%g) "
                  "with c0 = (%g,%g) and %g iterations.",
                  is_julia?"julia":"mandelbrot",
                  gmic_selection.data(),
                  z0r,z0i,
                  z1r,z1i,
                  paramr,parami,
                  itermax);
            cimg_forY(selection,l) gmic_apply(draw_mandelbrot(CImg<T>(),opacity,z0r,z0i,z1r,z1i,(unsigned int)itermax,
                                                              true,(bool)is_julia,paramr,parami));
          } else arg_error("mandelbrot");
          is_released = false; ++position; continue;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-n...'
        //-----------------------------
      gmic_commands_n :

        // Set image name.
        if (!is_double_hyphen && !std::strcmp("-name",command)) {
          gmic_substitute_args(false);
          print(images,0,"Set name of image%s to '%s'.",
                gmic_selection.data(),gmic_argument_text_printed());
          CImg<char>::string(argument).move_to(name);
          strreplace_fw(name);
          cimg_forY(selection,l) images_names[selection[l]].assign(name);
          ++position; continue;
        }

        // Normalize.
        if (!std::strcmp("-normalize",command)) {
          gmic_substitute_args(true);
          ind0.assign(); ind1.assign();
          sep0 = sep1 = *argx = *argy = *indices = 0;
          value0 = value1 = 0;
          if (cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-]%c",
                          argx,argy,&end)==2 &&
              ((cimg_sscanf(argx,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep0,&end)==2 &&
                sep0==']' &&
                (ind0=selection2cimg(indices,images.size(),images_names,"-normalize")).height()==1) ||
               (cimg_sscanf(argx,"%lf%c%c",&value0,&sep0,&end)==2 && sep0=='%') ||
               cimg_sscanf(argx,"%lf%c",&value0,&end)==1) &&
              ((cimg_sscanf(argy,"[%255[a-zA-Z0-9_.%+-]%c%c",formula,&sep1,&end)==2 &&
                sep1==']' &&
                (ind1=selection2cimg(formula,images.size(),images_names,"-normalize")).height()==1) ||
               (cimg_sscanf(argy,"%lf%c%c",&value1,&sep1,&end)==2 && sep1=='%') ||
               cimg_sscanf(argy,"%lf%c",&value1,&end)==1)) {
            if (ind0) { value0 = images[*ind0].min(); sep0 = 0; }
            if (ind1) { value1 = images[*ind1].max(); sep1 = 0; }
            print(images,0,"Normalize image%s in range [%g%s,%g%s].",
                  gmic_selection.data(),
                  value0,sep0=='%'?"%":"",
                  value1,sep1=='%'?"%":"");
            cimg_forY(selection,l) {
              CImg<T>& img = gmic_check(images[selection[l]]);
              nvalue0 = value0; nvalue1 = value1;
              vmin = vmax = 0;
              if (sep0=='%' || sep1=='%') {
                if (img) vmax = (double)img.max_min(vmin);
                if (sep0=='%') nvalue0 = vmin + (vmax - vmin)*value0/100;
                if (sep1=='%') nvalue1 = vmin + (vmax - vmin)*value1/100;
              }
              gmic_apply(normalize((T)nvalue0,(T)nvalue1));
            }
          } else if (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep0,&end)==2 &&
                     sep0==']' &&
                     (ind0=selection2cimg(indices,images.size(),images_names,"-normalize")).height()==1) {
            if (images[*ind0]) value1 = (double)images[*ind0].max_min(value0);
            print(images,0,"Normalize image%s in range [%g,%g].",
                  gmic_selection.data(),
                  value0,
                  value1);
            cimg_forY(selection,l) gmic_apply(normalize((T)value0,(T)value1));
          } else arg_error("normalize");
          is_released = false; ++position; continue;
        }

        // Test difference.
        gmic_arithmetic_command("-neq",
                                operator_neq,
                                "Compute boolean inequality between image%s and %g%s",
                                gmic_selection.data(),value,ssep,T,
                                operator_neq,
                                "Compute boolean inequality between image%s and image [%d]",
                                gmic_selection.data(),ind[0],
                                operator_neq,
                                "Compute boolean inequality between image%s and expression %s'",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Compute boolean inequality between image%s");

        // Discard custom command arguments.
        if (!std::strcmp("-noarg",item)) {
          print(images,0,"Discard command arguments.");
          if (is_noarg) *is_noarg = true;
          continue;
        }

        // Add noise.
        if (!std::strcmp("-noise",command)) {
          gmic_substitute_args(false);
          int noise_type = 0;
          float sigma = 0;
          sep = 0;
          if ((cimg_sscanf(argument,"%f%c",
                           &sigma,&end)==1 ||
               (cimg_sscanf(argument,"%f%c%c",
                            &sigma,&sep,&end)==2 && sep=='%') ||
               cimg_sscanf(argument,"%f,%d%c",
                           &sigma,&noise_type,&end)==2 ||
               (cimg_sscanf(argument,"%f%c,%d%c",
                            &sigma,&sep,&noise_type,&end)==3 && sep=='%')) &&
              sigma>=0 && noise_type>=0 && noise_type<=4) {
            const char *s_type = noise_type==0?"gaussian":
              noise_type==1?"uniform":
              noise_type==2?"salt&pepper":
              noise_type==3?"poisson":"rice";
            if (sep=='%') sigma = -sigma;
            print(images,0,"Add %s noise to image%s, with standard deviation %g%s.",
                  s_type,
                  gmic_selection.data(),
                  cimg::abs(sigma),sep=='%'?"%":"");
            cimg_forY(selection,l) gmic_apply(noise(sigma,noise_type));
          } else arg_error("noise");
          is_released = false; ++position; continue;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-o...'
        //-----------------------------
      gmic_commands_o :

        // Exception handling in local environments.
        if (!std::strcmp("-onfail",item)) {
          const CImg<char> &s = callstack.back();
          if (s[0]!='*' || s[1]!='l')
            error(images,0,0,
                  "Command '-onfail': Not associated to a '-local' command within "
                  "the same scope.");
          for (int nb_locals = 1; nb_locals && position<commands_line.size(); ++position) {
            const char *const it = commands_line[position].data();
            if (*it==1 &&
                cimg_sscanf(commands_line[position].data() + 1,"%x,%x",&_debug_line,&(_debug_filename=0))>0) {
              is_debug_info = true; next_debug_line = _debug_line; next_debug_filename = _debug_filename;
            } else if (!std::strcmp("-local",it) || !std::strcmp("-l",it) ||
                       !std::strcmp("--local",it) || !std::strcmp("--l",it) ||
                       !std::strncmp("-local[",it,7) || !std::strncmp("-l[",it,3) ||
                       !std::strncmp("--local[",it,8) || !std::strncmp("--l[",it,4)) ++nb_locals;
            else if (!std::strcmp("-endlocal",it) || !std::strcmp("-endl",it)) {
              --nb_locals; if (!nb_locals) --position;
            }
          }
          continue;
        }

        // Draw 3d object.
        if (!std::strcmp("-object3d",command)) {
          gmic_substitute_args(true);
          float x = 0, y = 0, z = 0;
          unsigned int
            is_zbuffer = 1,
            _render3d = (unsigned int)std::max(0,render3d),
            _is_double3d = is_double3d?1U:0U;
          float
            _focale3d = focale3d,
            _light3d_x = light3d_x,
            _light3d_y = light3d_y,
            _light3d_z = light3d_z,
            _specular_lightness3d = specular_lightness3d,
            _specular_shininess3d = specular_shininess3d;
          sep = sepx = sepy = *argx = *argy = 0;
          opacity = 1;
          if (((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",
                            indices,&sep,&end)==2 && sep==']') ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-]%c",
                           indices,argx,&end)==2 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                           indices,argx,argy,&end)==3 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%f%c",
                           indices,argx,argy,&z,&end)==4 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%f,%f%c",
                           indices,argx,argy,&z,&opacity,&end)==5 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%f,%f,%u%c",
                           indices,argx,argy,&z,&opacity,&_render3d,&end)==6 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%f,%f,%u,%u%c",
                           indices,argx,argy,&z,&opacity,&_render3d,&_is_double3d,&end)==7 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%f,%f,%u,%u,%u%c",
                           indices,argx,argy,&z,&opacity,&_render3d,&_is_double3d,&is_zbuffer,
                           &end)==8 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%f,%f,%u,%u,%u,%f%c",
                           indices,argx,argy,&z,&opacity,&_render3d,&_is_double3d,&is_zbuffer,
                           &_focale3d,&end)==9 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%f,%f,%u,%u,%u,%f,%f,%f,%f%c",
                           indices,argx,argy,&z,&opacity,&_render3d,&_is_double3d,&is_zbuffer,
                           &_focale3d,&_light3d_x,&_light3d_y,&_light3d_z,&end)==12 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%f,%f,%u,%u,%u,%f,%f,%f,%f,%f,%f%c",
                           indices,argx,argy,&z,&opacity,&_render3d,&_is_double3d,&is_zbuffer,
                           &_focale3d,&_light3d_x,&_light3d_y,&_light3d_z,
                           &_specular_lightness3d,&_specular_shininess3d,&end)==14) &&
              (ind=selection2cimg(indices,images.size(),images_names,"-object3d")).height()==1 &&
              (!*argx ||
               cimg_sscanf(argx,"%f%c",&x,&end)==1 ||
               (cimg_sscanf(argx,"%f%c%c",&x,&sepx,&end)==2 && sepx=='%')) &&
              (!*argy ||
               cimg_sscanf(argy,"%f%c",&y,&end)==1 ||
               (cimg_sscanf(argy,"%f%c%c",&y,&sepy,&end)==2 && sepy=='%')) &&
              _render3d<=5 && is_zbuffer<=1 && _is_double3d<=1) {
            const CImg<T> img0 = gmic_image_arg(*ind);

            print(images,0,"Draw 3d object [%u] at (%g%s,%g%s,%g) on image%s, with opacity %g, "
                  "%s rendering, %s-sided mode, %sz-buffer, focale %g, 3d light at (%g,%g,%g) "
                  "and specular properties (%g,%g)",
                  *ind,
                  x,sepx=='%'?"%":"",
                  y,sepy=='%'?"%":"",
                  z,
                  gmic_selection.data(),
                  opacity,
                  _render3d==0?"dot":_render3d==1?"wireframe":_render3d==2?"flat":
                  _render3d==3?"flat-shaded":_render3d==4?"gouraud-shaded":"phong-shaded",
                  _is_double3d?"double":"simple",
                  is_zbuffer?"":"no ",
                  _focale3d,_light3d_x,_light3d_y,_light3d_z,
                  _specular_lightness3d,_specular_shininess3d);
            CImgList<float> opacities;
            vertices.assign(img0,false);
            try {
              if (_render3d>=3) {
                vertices.CImg3dtoobject3d(primitives,g_list_uc,opacities,false);
                if (light3d) g_list_uc.insert(light3d,~0U,true);
              } else vertices.CImg3dtoobject3d(primitives,g_list_f,opacities,false);
            } catch (CImgException&) {
              if (!vertices.is_CImg3d(true,&(*message=0)))
                error(images,0,0,
                      "Command '-object3d': Invalid 3d object [%u], specified "
                      "in argument '%s' (%s).",
                      *ind,gmic_argument_text(),message.data());
              else throw;
            }

            cimglist_for(opacities,o) if (!opacities[o].is_shared()) opacities[o]*=opacity;
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              const float
                nx = sepx=='%'?x*(img.width() - 1)/100:x,
                ny = sepy=='%'?y*(img.height() - 1)/100:y;
              CImg<float> zbuffer(is_zbuffer?img.width():0,is_zbuffer?img.height():0,1,1,0);
              if (g_list_f) {
                gmic_apply(draw_object3d(nx,ny,z,vertices,primitives,g_list_f,opacities,
                                         _render3d,_is_double3d,_focale3d,
                                         _light3d_x,_light3d_y,_light3d_z,
                                         _specular_lightness3d,_specular_shininess3d,
                                         zbuffer));
                g_list_f.assign();
              } else {
                gmic_apply(draw_object3d(nx,ny,z,vertices,primitives,g_list_uc,opacities,
                                         _render3d,_is_double3d,_focale3d,
                                         _light3d_x,_light3d_y,_light3d_z,
                                         _specular_lightness3d,_specular_shininess3d,
                                         zbuffer));
                g_list_uc.assign();
              }
            }
          } else arg_error("object3d");
          vertices.assign();
          primitives.assign();
          is_released = false; ++position; continue;
        }

        // Bitwise or.
        gmic_arithmetic_command("-or",
                                operator|=,
                                "Compute bitwise OR of image%s by %g%s",
                                gmic_selection.data(),value,ssep,Tlong,
                                operator|=,
                                "Compute bitwise OR of image%s by image [%d]",
                                gmic_selection.data(),ind[0],
                                operator_oreq,
                                "Compute bitwise OR of image%s by expression %s",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Compute sequential bitwise OR of image%s");

        // Set 3d object opacity.
        if (!std::strcmp("-opacity3d",command)) {
          gmic_substitute_args(true);
          value = 1;
          if (cimg_sscanf(argument,"%lf%c",
                          &value,&end)==1) ++position;
          else value = 1;
          print(images,0,"Set opacity of 3d object%s to %g.",
                gmic_selection.data(),
                value);
          cimg_forY(selection,l) {
            const unsigned int uind = selection[l];
            CImg<T>& img = images[uind];
            try { gmic_apply(color_CImg3d(0,0,0,(float)value,false,true)); }
            catch (CImgException&) {
              if (!img.is_CImg3d(true,&(*message=0)))
                error(images,0,0,
                      "Command '-opacity3d': Invalid 3d object [%d], "
                      "in selected image%s (%s).",
                      uind,gmic_selection.data(),message.data());
              else throw;
            }
          }
          is_released = false; continue;
        }

        // Output.
        if (!is_double_hyphen && !std::strcmp("-output",command)) {
          gmic_substitute_args(false);

          // Set good alias for shared variables.
          CImg<char> &_filename = _color, &filename_tmp = _title, &options = _argc;
          char cext[12];
          *cext = *_filename = *filename_tmp = *options = 0;
          CImgList<unsigned int> empty_indices;
          CImg<char> eselec;

          if (cimg_sscanf(argument,"%11[a-zA-Z]:%4095[^,],%255s",  // Detect forced file format.
                          cext,_filename.data(),options.data())<2 ||
              !cext[1]) {  // length of preprend 'ext' must be >=2 (avoid case 'C:\\...' on Windows).
            *cext = *_filename = *options = 0;
            if (cimg_sscanf(argument,"%4095[^,],%255s",_filename.data(),options.data())!=2) {
              std::strncpy(_filename,argument,_filename.width() - 1);
              _filename[_filename.width() - 1] = 0;
            }
          }
          strreplace_fw(_filename);
          strreplace_fw(options);

          if (*cext) { // Force output to be written as a '.ext' file : generate random filename.
            if (*_filename=='-' && (!_filename[1] || _filename[1]=='.')) {
              // Simplify filename 'ext:-.foo' as '-.ext'.
              cimg_snprintf(_filename,_filename.width(),"-.%s",cext);
              *cext = 0;
            } else {
              std::FILE *file = 0;
              do {
                cimg_snprintf(filename_tmp,filename_tmp.width(),"%s%c%s.%s",
                              cimg::temporary_path(),cimg_file_separator,
                              cimg::filenamerand(),cext);
                if ((file=std::fopen(filename_tmp,"rb"))!=0) std::fclose(file);
              } while (file);
            }
          }
          const char
            *const filename = *cext?filename_tmp:_filename,
            *const ext = cimg::split_filename(filename);
          CImg<char> uext = CImg<char>::string(ext);
          cimg::lowercase(uext);

          if (!cimg::strcasecmp(ext,"off")) {
            *formula = 0;
            std::strncpy(formula,filename,_formula.width() - 1);
            formula[_formula.width() - 1] = 0;

            if (*options)
              error(images,0,0,
                    "Command '-output': File '%s', format does not take any output options (options '%s' specified).",
                    formula,options.data());

            print(images,0,"Output 3d object%s as %s file '%s'.",
                  gmic_selection.data(),uext.data(),formula);

            cimg_forY(selection,l) {
              const unsigned int uind = selection[l];
              const CImg<T>& img = gmic_check(images[uind]);
              if (selection.height()!=1) cimg::number_filename(filename,l,6,formula);
              CImgList<float> opacities;
              vertices.assign(img,false);
              try {
                vertices.CImg3dtoobject3d(primitives,g_list_f,opacities,false).
                  save_off(primitives,g_list_f,formula);
              } catch (CImgException&) {
                if (!vertices.is_CImg3d(true,&(*message=0)))
                  error(images,0,0,
                        "Command '-output': 3d object file '%s', invalid 3d object [%u] "
                        "in selected image%s (%s).",
                        formula,uind,gmic_selection.data(),message.data());
                else throw;
              }
            }
            vertices.assign();
            primitives.assign();
            g_list_f.assign();
          } else if (!cimg::strcasecmp(ext,"cpp") || !cimg::strcasecmp(ext,"c") ||
                     !cimg::strcasecmp(ext,"hpp") || !cimg::strcasecmp(ext,"h") ||
                     !cimg::strcasecmp(ext,"pan")) {
            const char *const
              stype = (cimg_sscanf(options,"%255[a-z64]%c",&(*argx=0),&(end=0))==1 ||
                       (cimg_sscanf(options,"%255[a-z64]%c",&(*argx=0),&end)==2 && end==','))?
              argx:cimg::type<T>::string();
            g_list.assign(selection.height());
            cimg_forY(selection,l) if (!gmic_check(images[selection(l)]))
              CImg<unsigned int>::vector(selection(l)).move_to(empty_indices);
            if (empty_indices && is_verbose) {
              selection2string(empty_indices>'y',images_names,1,eselec);
              warn(images,0,false,
                   "Command '-output': Image%s %s empty.",
                   eselec.data(),empty_indices.size()>1?"are":"is");
            }
            cimg_forY(selection,l)
              g_list[l].assign(images[selection[l]],images[selection[l]]?true:false);
            if (g_list.size()==1)
              print(images,0,
                    "Output image%s as %s file '%s', with pixel type '%s' (1 image %dx%dx%dx%d).",
                    gmic_selection.data(),
                    uext.data(),_filename.data(),
                    stype,
                    g_list[0].width(),g_list[0].height(),
                    g_list[0].depth(),g_list[0].spectrum());
            else print(images,0,"Output image%s as %s file '%s', with pixel type '%s'.",
                       gmic_selection.data(),
                       uext.data(),_filename.data(),
                       stype);
            if (!g_list)
              error(images,0,0,
                    "Command '-output': File '%s', instance list (%u,%p) is empty.",
                    _filename.data(),g_list.size(),g_list.data());

#define gmic_save_multitype(value_type,svalue_type) \
              if (!std::strcmp(stype,svalue_type)) { \
                if (g_list.size()==1) \
                  CImg<value_type>(g_list[0], \
                                   cimg::type<T>::string()==cimg::type<value_type>::string()). \
                    save(filename); \
                else { \
                  cimglist_for(g_list,l) { \
                    cimg::number_filename(filename,l,6,formula); \
                    CImg<value_type>(g_list[l], \
                                     cimg::type<T>::string()==cimg::type<value_type>::string()). \
                                     save(formula); \
                  } \
                } \
              }
            gmic_save_multitype(unsigned char,"uchar")
            else gmic_save_multitype(unsigned char,"unsigned char")
              else gmic_save_multitype(char,"char")
                else gmic_save_multitype(unsigned short,"ushort")
                  else gmic_save_multitype(unsigned short,"unsigned short")
                    else gmic_save_multitype(short,"short")
                      else gmic_save_multitype(unsigned int,"uint")
                        else gmic_save_multitype(unsigned int,"unsigned int")
                          else gmic_save_multitype(int,"int")
                            else gmic_save_multitype(uint64T,"uint64")
                              else gmic_save_multitype(uint64T,"unsigned int64")
                                else gmic_save_multitype(int64T,"int64")
                                  else gmic_save_multitype(float,"float")
                                    else gmic_save_multitype(double,"double")
                                      else error(images,0,0,
                                                 "Command '-output': File '%s', invalid "
                                                 "specified pixel type '%s'.",
                                                 _filename.data(),stype);
          } else if (!cimg::strcasecmp(ext,"tiff") || !cimg::strcasecmp(ext,"tif")) {
            const char *const
              stype = (cimg_sscanf(options,"%255[a-z64]%c",&(*argx=0),&(end=0))==1 ||
                       (cimg_sscanf(options,"%255[a-z64]%c",&(*argx=0),&end)==2 && end==','))?
              argx:cimg::type<T>::string();
            const unsigned int l_stype = (unsigned int)std::strlen(stype);
            const char *const _options = options.data() + (stype!=argx?0:l_stype + (end==','?1:0));
            float _is_multipage = 0;
            *argy = 0; opacity = 1;
            if (cimg_sscanf(_options,"%255[a-z],%f,%f",argy,&_is_multipage,&opacity)<1)
              cimg_sscanf(_options,"%f,%f",&_is_multipage,&opacity);
            const unsigned int compression_type =
              !cimg::strcasecmp(argy,"jpeg") ||
              !cimg::strcasecmp(argy,"jpg")?2:
              !cimg::strcasecmp(argy,"lzw")?1U:0U;
            const bool is_multipage = (bool)cimg::round(_is_multipage);
            const bool use_bigtiff = (bool)cimg::round(opacity);

            g_list.assign(selection.height());
            cimg_forY(selection,l) if (!gmic_check(images[selection(l)]))
              CImg<unsigned int>::vector(selection(l)).move_to(empty_indices);
            if (empty_indices && is_verbose) {
              selection2string(empty_indices>'y',images_names,1,eselec);
              warn(images,0,false,
                   "Command '-output': Image%s %s empty.",
                   eselec.data(),empty_indices.size()>1?"are":"is");
            }
            cimg_forY(selection,l)
              g_list[l].assign(images[selection[l]],g_list[l]?true:false);
            if (g_list.size()==1)
              print(images,0,"Output image%s as %s file '%s', with pixel type '%s', %s compression "
                    "and %sbigtiff support (1 image %dx%dx%dx%d).",
                    gmic_selection.data(),
                    uext.data(),_filename.data(),stype,
                    compression_type==2?"JPEG":compression_type==1?"LZW":"no",
                    use_bigtiff?"":"no ",
                    g_list[0].width(),g_list[0].height(),
                    g_list[0].depth(),g_list[0].spectrum());
            else print(images,0,"Output image%s as %s file '%s', with pixel type '%s', "
                       "%s compression, %s-page mode and %s bigtiff support.",
                       gmic_selection.data(),
                       uext.data(),_filename.data(),stype,
                       compression_type==2?"JPEG":compression_type==1?"LZW":"no",
                       is_multipage?"multi":"single",
                       use_bigtiff?"":"no ");
            if (!g_list)
              error(images,0,0,
                    "Command '-output': File '%s', instance list (%u,%p) is empty.",
                    _filename.data(),g_list.size(),g_list.data());

#define gmic_save_tiff(value_type,svalue_type) \
              if (!std::strcmp(stype,svalue_type)) { \
                if (g_list.size()==1 || is_multipage) \
                  CImgList<value_type>(g_list, \
                                   cimg::type<T>::string()==cimg::type<value_type>::string()). \
                    save_tiff(filename,compression_type,0,0,use_bigtiff); \
                else { \
                  cimglist_for(g_list,l) { \
                    cimg::number_filename(filename,l,6,formula); \
                    CImg<value_type>(g_list[l], \
                                   cimg::type<T>::string()==cimg::type<value_type>::string()). \
                      save_tiff(formula,compression_type,0,0,use_bigtiff); \
                  } \
                } \
              }
            gmic_save_tiff(unsigned char,"uchar")
            else gmic_save_tiff(unsigned char,"unsigned char")
              else gmic_save_tiff(char,"char")
                else gmic_save_tiff(unsigned short,"ushort")
                  else gmic_save_tiff(unsigned short,"unsigned short")
                    else gmic_save_tiff(short,"short")
                      else gmic_save_tiff(unsigned int,"uint")
                        else gmic_save_tiff(unsigned int,"unsigned int")
                          else gmic_save_tiff(int,"int")
                            else gmic_save_tiff(uint64T,"uint64")
                              else gmic_save_tiff(uint64T,"unsigned int64")
                                else gmic_save_tiff(int64T,"int64")
                                  else gmic_save_tiff(float,"float")
                                    else gmic_save_tiff(double,"double")
                                      else error(images,0,0,
                                                 "Command '-output': File '%s', invalid "
                                                 "specified pixel type '%s'.",
                                                 _filename.data(),stype);

          } else if (!cimg::strcasecmp(ext,"gif")) {
            float fps = 0, _nb_loops = 0;
            g_list.assign(selection.height());
            cimg_forY(selection,l) if (!gmic_check(images[selection(l)]))
              CImg<unsigned int>::vector(selection(l)).move_to(empty_indices);
            if (empty_indices && is_verbose) {
              selection2string(empty_indices>'y',images_names,1,eselec);
              warn(images,0,false,
                   "Command '-output': Image%s %s empty.",
                   eselec.data(),empty_indices.size()>1?"are":"is");
            }
            cimg_forY(selection,l)
              g_list[l].assign(images[selection[l]],g_list[l]?true:false);
            if (g_list.size()>1 && cimg_sscanf(options,"%f,%f",&fps,&_nb_loops)>=1 && fps>0) {
              // Save animated .gif file.
              const unsigned int nb_loops = (unsigned int)cimg::round(_nb_loops);
              if (nb_loops)
                print(images,0,
                      "Output image%s as animated %s file '%s', with %g fps and %u loops.",
                      gmic_selection.data(),uext.data(),_filename.data(),fps,nb_loops);
              else
                print(images,0,
                      "Output image%s as animated %s file '%s', with %g fps.",
                      gmic_selection.data(),uext.data(),_filename.data(),fps);
              g_list.save_gif_external(filename,fps,nb_loops);
            } else {
              if (g_list.size()==1)
                print(images,0,"Output image%s as %s file '%s' (1 image %dx%dx%dx%d).",
                      gmic_selection.data(),
                      uext.data(),_filename.data(),
                      g_list[0].width(),g_list[0].height(),
                      g_list[0].depth(),g_list[0].spectrum());
              else print(images,0,"Output image%s as %s file '%s'.",
                         gmic_selection.data(),uext.data(),_filename.data());
              g_list.save(filename); // Save distinct .gif files.
            }
          } else if (!cimg::strcasecmp(ext,"jpeg") || !cimg::strcasecmp(ext,"jpg")) {
            float quality = 100;
            if (cimg_sscanf(options,"%f%c",&quality,&end)!=1) quality = 100;
            if (quality<0) quality = 0; else if (quality>100) quality = 100;
            g_list.assign(selection.height());
            cimg_forY(selection,l) if (!gmic_check(images[selection(l)]))
              CImg<unsigned int>::vector(selection(l)).move_to(empty_indices);
            if (empty_indices && is_verbose) {
              selection2string(empty_indices>'y',images_names,1,eselec);
              warn(images,0,false,
                   "Command '-output': Image%s %s empty.",
                   eselec.data(),empty_indices.size()>1?"are":"is");
            }
            cimg_forY(selection,l)
              g_list[l].assign(images[selection[l]],g_list[l]?true:false);
            if (g_list.size()==1)
              print(images,0,
                    "Output image%s as %s file '%s', with quality %g%% (1 image %dx%dx%dx%d).",
                    gmic_selection.data(),
                    uext.data(),_filename.data(),
                    quality,
                    g_list[0].width(),g_list[0].height(),
                    g_list[0].depth(),g_list[0].spectrum());
            else print(images,0,"Output image%s as %s file '%s', with quality %g%%.",
                       gmic_selection.data(),
                       uext.data(),_filename.data(),
                       quality);
            if (!g_list)
              error(images,0,0,
                    "Command '-output': File '%s', instance list (%u,%p) is empty.",
                    _filename.data(),g_list.size(),g_list.data());
            if (g_list.size()==1)
              g_list[0].save_jpeg(filename,(unsigned int)cimg::round(quality));
            else {
              cimglist_for(g_list,l) {
                cimg::number_filename(filename,l,6,formula);
                g_list[l].save_jpeg(formula,(unsigned int)cimg::round(quality));
              }
            }
          } else if (!cimg::strcasecmp(ext,"mnc") && *options) {
            g_list.assign(selection.height());
            cimg_forY(selection,l) if (!gmic_check(images[selection(l)]))
              CImg<unsigned int>::vector(selection(l)).move_to(empty_indices);
            if (empty_indices && is_verbose) {
              selection2string(empty_indices>'y',images_names,1,eselec);
              warn(images,0,false,
                   "Command '-output': Image%s %s empty.",
                   eselec.data(),empty_indices.size()>1?"are":"is");
            }
            cimg_forY(selection,l)
              g_list[l].assign(images[selection[l]],g_list[l]?true:false);
            if (g_list.size()==1)
              print(images,0,
                    "Output image%s as %s file '%s', with header get from file '%s' "
                    "(1 image %dx%dx%dx%d).",
                    gmic_selection.data(),
                    uext.data(),_filename.data(),
                    options.data(),
                    g_list[0].width(),g_list[0].height(),
                    g_list[0].depth(),g_list[0].spectrum());
            else
              print(images,0,
                    "Output image%s as %s file '%s', with header get from file '%s'.",
                    gmic_selection.data(),
                    uext.data(),_filename.data(),
                    options.data());
            if (g_list.size()==1)
              g_list[0].save_minc2(filename,options);
            else {
              cimglist_for(g_list,l) {
                cimg::number_filename(filename,l,6,formula);
                g_list[l].save_minc2(formula,options);
              }
            }
          } else if (!cimg::strcasecmp(ext,"raw")) {
            const char *const stype = cimg_sscanf(options,"%255[a-z64]%c",argx,&end)==1?argx:
              cimg::type<T>::string();
            g_list.assign(selection.height());
            cimg_forY(selection,l) if (!gmic_check(images[selection(l)]))
              CImg<unsigned int>::vector(selection(l)).move_to(empty_indices);
            if (empty_indices && is_verbose) {
              selection2string(empty_indices>'y',images_names,1,eselec);
              warn(images,0,false,
                   "Command '-output': Image%s %s empty.",
                   eselec.data(),empty_indices.size()>1?"are":"is");
            }
            cimg_forY(selection,l)
              g_list[l].assign(images[selection[l]],images[selection[l]]?true:false);
            if (g_list.size()==1)
              print(images,0,
                    "Output image%s as %s file '%s', with pixel type '%s' (1 image %dx%dx%dx%d).",
                    gmic_selection.data(),
                    uext.data(),_filename.data(),
                    stype,
                    g_list[0].width(),g_list[0].height(),
                    g_list[0].depth(),g_list[0].spectrum());
            else print(images,0,"Output image%s as %s file '%s', with pixel type '%s'.",
                       gmic_selection.data(),
                       uext.data(),_filename.data(),
                       stype);
            if (!g_list)
              error(images,0,0,
                    "Command '-output': File '%s', instance list (%u,%p) is empty.",
                    _filename.data(),g_list.size(),g_list.data());

#define gmic_save_raw(value_type,svalue_type) \
              if (!std::strcmp(stype,svalue_type)) { \
                if (g_list.size()==1) \
                  CImg<value_type>(g_list[0], \
                                   cimg::type<T>::string()==cimg::type<value_type>::string()). \
                    save_raw(filename); \
                else { \
                  cimglist_for(g_list,l) { \
                    cimg::number_filename(filename,l,6,formula); \
                    CImg<value_type>(g_list[l], \
                                     cimg::type<T>::string()==cimg::type<value_type>::string()). \
                                     save_raw(formula); \
                  } \
                } \
              }
            gmic_save_raw(unsigned char,"uchar")
            else gmic_save_raw(unsigned char,"unsigned char")
              else gmic_save_raw(char,"char")
                else gmic_save_raw(unsigned short,"ushort")
                  else gmic_save_raw(unsigned short,"unsigned short")
                    else gmic_save_raw(short,"short")
                      else gmic_save_raw(unsigned int,"uint")
                        else gmic_save_raw(unsigned int,"unsigned int")
                          else gmic_save_raw(int,"int")
                            else gmic_save_raw(uint64T,"uint64")
                              else gmic_save_raw(uint64T,"unsigned int64")
                                else gmic_save_raw(int64T,"int64")
                                  else gmic_save_raw(float,"float")
                                    else gmic_save_raw(double,"double")
                                      else error(images,0,0,
                                                 "Command '-output': File '%s', invalid "
                                                 "specified pixel type '%s'.",
                                                 _filename.data(),stype);
          } else if (!cimg::strcasecmp(ext,"cimg") || !cimg::strcasecmp(ext,"cimgz")) {
            const char *const stype = cimg_sscanf(options,"%255[a-z64]%c",argx,&end)==1?argx:
              cimg::type<T>::string();
            g_list.assign(selection.height());
            cimg_forY(selection,l)
              g_list[l].assign(images[selection[l]],images[selection[l]]?true:false);
            print(images,0,"Output image%s as %s file '%s', with pixel type '%s'.",
                  gmic_selection.data(),
                  uext.data(),_filename.data(),
                  stype);

#define gmic_save_cimg(value_type,svalue_type) \
              if (!std::strcmp(stype,svalue_type)) \
                CImgList<value_type>(g_list, \
                                     cimg::type<T>::string()==cimg::type<value_type>::string()). \
                                     save(filename);
            gmic_save_cimg(unsigned char,"uchar")
            else gmic_save_cimg(unsigned char,"unsigned char")
              else gmic_save_cimg(char,"char")
                else gmic_save_cimg(unsigned short,"ushort")
                  else gmic_save_cimg(unsigned short,"unsigned short")
                    else gmic_save_cimg(short,"short")
                      else gmic_save_cimg(unsigned int,"uint")
                        else gmic_save_cimg(unsigned int,"unsigned int")
                          else gmic_save_cimg(int,"int")
                            else gmic_save_cimg(uint64T,"uint64")
                              else gmic_save_cimg(uint64T,"unsigned int64")
                                else gmic_save_cimg(int64T,"int64")
                                  else gmic_save_cimg(float,"float")
                                    else gmic_save_cimg(double,"double")
                                      else error(images,0,0,
                                                 "Command '-output': File '%s', invalid "
                                                 "specified pixel type '%s'.",
                                                 _filename.data(),stype);
          } else if (!cimg::strcasecmp(ext,"gmz") || !*ext) {
            const char *const stype = cimg_sscanf(options,"%255[a-z64]%c",argx,&end)==1?argx:
              cimg::type<T>::string();
            g_list.assign(selection.height());
            CImgList<char> gmz_info(1 + selection.height());
            CImg<char>::string("GMZ").move_to(gmz_info[0]);
            cimg_forY(selection,l) {
              const unsigned int uind = selection[l];
              g_list[l].assign(images[uind],images[uind]?true:false);
              CImg<char>::string(images_names[uind]).move_to(gmz_info[1 + l]);
            }
            (gmz_info>'x').unroll('y').move_to(g_list);
            print(images,0,"Output image%s as %s file '%s', with pixel type '%s'.",
                  gmic_selection.data(),
                  uext.data(),_filename.data(),
                  stype);

#define gmic_save_gmz(value_type,svalue_type) \
              if (!std::strcmp(stype,svalue_type)) \
                CImgList<value_type>(g_list, \
                                     cimg::type<T>::string()==cimg::type<value_type>::string()). \
                                     save_cimg(filename,true);
            gmic_save_gmz(unsigned char,"uchar")
            else gmic_save_gmz(unsigned char,"unsigned char")
              else gmic_save_gmz(char,"char")
                else gmic_save_gmz(unsigned short,"ushort")
                  else gmic_save_gmz(unsigned short,"unsigned short")
                    else gmic_save_gmz(short,"short")
                      else gmic_save_gmz(unsigned int,"uint")
                        else gmic_save_gmz(unsigned int,"unsigned int")
                          else gmic_save_gmz(int,"int")
                            else gmic_save_gmz(uint64T,"uint64")
                              else gmic_save_gmz(uint64T,"unsigned int64")
                                else gmic_save_gmz(int64T,"int64")
                                  else gmic_save_gmz(float,"float")
                                    else gmic_save_gmz(double,"double")
                                      else error(images,0,0,
                                                 "Command '-output': File '%s', invalid "
                                                 "specified pixel type '%s'.",
                                                 _filename.data(),stype);
          } else if (!cimg::strcasecmp(ext,"avi") ||
                     !cimg::strcasecmp(ext,"mov") ||
                     !cimg::strcasecmp(ext,"asf") ||
                     !cimg::strcasecmp(ext,"divx") ||
                     !cimg::strcasecmp(ext,"flv") ||
                     !cimg::strcasecmp(ext,"mpg") ||
                     !cimg::strcasecmp(ext,"m1v") ||
                     !cimg::strcasecmp(ext,"m2v") ||
                     !cimg::strcasecmp(ext,"m4v") ||
                     !cimg::strcasecmp(ext,"mjp") ||
                     !cimg::strcasecmp(ext,"mp4") ||
                     !cimg::strcasecmp(ext,"mkv") ||
                     !cimg::strcasecmp(ext,"mpe") ||
                     !cimg::strcasecmp(ext,"movie") ||
                     !cimg::strcasecmp(ext,"ogm") ||
                     !cimg::strcasecmp(ext,"ogg") ||
                     !cimg::strcasecmp(ext,"ogv") ||
                     !cimg::strcasecmp(ext,"qt") ||
                     !cimg::strcasecmp(ext,"rm") ||
                     !cimg::strcasecmp(ext,"vob") ||
                     !cimg::strcasecmp(ext,"wmv") ||
                     !cimg::strcasecmp(ext,"xvid") ||
                     !cimg::strcasecmp(ext,"mpeg")) {
            float fps = 0, keep_open = 0;
            name.assign(8); *name = 0; // codec
            cimg_sscanf(options,"%f,%7[a-zA-Z0-9],%f",&fps,name.data(),&keep_open);
            fps = cimg::round(fps);
            if (!fps) fps = 25;
            if (*name=='0' && !name[1]) *name = 0;
            g_list.assign(selection.height());
            cimg_forY(selection,l) if (!gmic_check(images[selection(l)]))
              CImg<unsigned int>::vector(selection(l)).move_to(empty_indices);
            if (empty_indices && is_verbose) {
              selection2string(empty_indices>'y',images_names,1,eselec);
              warn(images,0,false,
                   "Command '-output': Image%s %s empty.",
                   eselec.data(),empty_indices.size()>1?"are":"is");
            }
            cimg_forY(selection,l)
              g_list[l].assign(images[selection[l]],g_list[l]?true:false);
            print(images,0,"Output image%s as %s file '%s', with %g fps and %s codec.",
                  gmic_selection.data(),
                  uext.data(),_filename.data(),
                  fps,*name?name.data():"(default)");
            try {
              g_list.save_video(filename,(unsigned int)fps,name,(bool)keep_open);
            } catch (CImgException &e) {
              warn(images,0,false,
                   "Command '-output': Cannot encode file '%s' natively (%s). Trying fallback function.",
                   filename,e.what());
              g_list.save_ffmpeg_external(filename,(unsigned int)fps);
            }
          } else {
            g_list.assign(selection.height());
            cimg_forY(selection,l) if (!gmic_check(images[selection(l)]))
              CImg<unsigned int>::vector(selection(l)).move_to(empty_indices);
            if (empty_indices && is_verbose) {
              selection2string(empty_indices>'y',images_names,1,eselec);
              warn(images,0,false,
                   "Command '-output': Image%s %s empty.",
                   eselec.data(),empty_indices.size()>1?"are":"is");
            }
            cimg_forY(selection,l)
              g_list[l].assign(images[selection[l]],g_list[l]?true:false);
            if (g_list.size()==1)
              print(images,0,"Output image%s as %s file '%s' (1 image %dx%dx%dx%d).",
                    gmic_selection.data(),
                    uext.data(),_filename.data(),
                    g_list[0].width(),g_list[0].height(),
                    g_list[0].depth(),g_list[0].spectrum());
            else print(images,0,"Output image%s as %s file '%s'.",
                       gmic_selection.data(),uext.data(),_filename.data());

            if (*options)
              error(images,0,0,
                    "Command '-output': File '%s', format '%s' does not take any output options "
                    "(options '%s' specified).",
                    _filename.data(),ext,options.data());

            g_list.save(filename);
          }

          if (*cext) { // When output forced to 'ext' : copy final file to specified location.
            try {
              CImg<unsigned char>::get_load_raw(filename_tmp).save_raw(_filename);
              std::remove(filename_tmp);
            } catch (...) { // Failed, maybe 'filename_tmp' consists of several numbered images.
              bool save_failure = false;
              *message = 0;
              for (unsigned int i = 0; i!=~0U; ++i) {
                cimg::number_filename(filename_tmp,i,6,formula);
                cimg::number_filename(_filename,i,6,message);
                try { CImg<unsigned char>::get_load_raw(formula).save_raw(message); }
                catch (...) { i = ~0U - 1; if (!i) save_failure = true; }
              }
              if (save_failure)
                error(images,0,0,
                      "Command '-output': Invalid write of file '%s' from temporary file '%s'.",
                      _filename.data(),filename_tmp.data());
            }
          }
          g_list.assign();
          is_released = true; ++position; continue;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-p...'
        //-----------------------------
      gmic_commands_p :

        // Pass image from parent context.
        if (!is_double_hyphen && !std::strcmp("-pass",command)) {
          gmic_substitute_args(false);
          unsigned int shared_state = 2;
          if (cimg_sscanf(argument,"%u%c",&shared_state,&end)==1 && shared_state<=2) ++position;
          else shared_state = 2;
          print(images,0,"Insert image%s from parent context %s%s.",
                gmic_selection.data(),
                shared_state==0?"in non-shared state":
                shared_state==1?"in shared state":"using adaptive state",
                selection.height()>1?"s":"");

          cimg_forY(selection,l) {
            CImg<T> &img = parent_images[selection[l]];
            const T *p = 0;
            std::memcpy(&p,&img._width,sizeof(void*));

            if (p && !img.data()) {
              // Parent image is in the current selection -> must search the current list.
              bool found_image = false;
              cimglist_for(images,i) {
                if (images[i].data()==p) { // Found it !
                  images.insert(images[i],~0U,shared_state==1);
                  images_names.insert(images_names[i].get_copymark());
                  found_image = true;
                  break;
                }
              }
              if (!found_image) error(images,0,0,
                                      "Command '-pass': Unreferenced image [%d] from parent context "
                                      "(has been re-allocated in current context or reserved by another thread).",
                                      selection[l]);
            } else { // Easy case, parent image not in the current selection.
              images.insert(img,~0U,(bool)shared_state);
              images_names.insert(parent_images_names[selection[l]].get_copymark());
            }
          }
          is_released = false; continue;
        }

        // Run multiple commands in parallel.
        if (!std::strcmp("-parallel",item)) {
          gmic_substitute_args(false);
          const char *_arg = argument, *_arg_text = gmic_argument_text_printed();
          bool wait_mode = true;
          if ((*_arg=='0' || *_arg=='1') && (_arg[1]==',' || !_arg[1])) {
            wait_mode = (bool)(*_arg - '0'); _arg+=2; _arg_text+=2;
          }
          CImgList<char> arguments = CImg<char>::string(_arg).get_split(CImg<char>::vector(','),0,false);
          CImg<st_gmic_parallel<T> >(1,arguments.width()).move_to(threads_data);
          CImg<st_gmic_parallel<T> > &_threads_data = threads_data.back();

#ifdef gmic_is_parallel
          print(images,0,"Execute %d command%s '%s' in parallel%s.",
                arguments.width(),arguments.width()>1?"s":"",_arg_text,
                wait_mode?" and wait thread termination immediately":
                " and wait thread termination when current environment ends");
#else // #ifdef gmic_is_parallel
          print(images,0,"Execute %d commands '%s' (run sequentially, "
                "parallel computing disabled).",
                arguments.width(),_arg_text);
#endif // #ifdef gmic_is_parallel

          // Prepare thread structures.
          cimg_forY(_threads_data,l) {
            gmic &gi = _threads_data[l].gmic_instance;
            for (unsigned int i = 0; i<512; ++i) {
              gi.commands[i].assign(commands[i],true);
              gi.commands_names[i].assign(commands_names[i],true);
              gi.commands_has_arguments[i].assign(commands_has_arguments[i],true);

              if (i==511) { // Share inter-thread global variables.
                gi.variables[i] = variables[i];
                gi.variables_names[i] = variables_names[i];
              } else {
                if (i==510) { // Make a copy of single-thread global variables.
                  gi._variables[i].assign(_variables[i]);
                  gi._variables_names[i].assign(_variables_names[i]);
                  _threads_data[l].variables_sizes[i] = variables_sizes[i];
                } else _threads_data[l].variables_sizes[i] = 0;
                gi.variables[i] = &gi._variables[i];
                gi.variables_names[i] = &gi._variables_names[i];
              }
            }

            gi.callstack.assign(callstack);
            gi.commands_files.assign(commands_files,true);
            cimg_snprintf(title,_title.width(),"*thread%d",l);
            CImg<char>::string(title).move_to(gi.callstack);
            gi.light3d.assign(light3d);
            gi.status.assign(status);
            gi.debug_filename = debug_filename;
            gi.debug_line = debug_line;
            gi.focale3d = focale3d;
            gi.light3d_x = light3d_x;
            gi.light3d_y = light3d_y;
            gi.light3d_z = light3d_z;
            gi.specular_lightness3d = specular_lightness3d;
            gi.specular_shininess3d = specular_shininess3d;
            gi._progress = 0;
            gi.progress = &gi._progress;
            gi.is_released = is_released;
            gi.is_debug = is_debug;
            gi.is_start = false;
            gi.is_quit = false;
            gi.is_return = false;
            gi.is_double3d = is_double3d;
            gi.check_elif = false;
            gi.verbosity = verbosity;
            gi.render3d = render3d;
            gi.renderd3d = renderd3d;
            gi._is_abort = _is_abort;
            gi.is_abort = is_abort;
            gi.is_abort_thread = false;
            gi.nb_carriages = nb_carriages;
            gi.reference_time = reference_time;
            _threads_data[l].images = &images;
            _threads_data[l].images_names = &images_names;
            _threads_data[l].parent_images = &parent_images;
            _threads_data[l].parent_images_names = &parent_images_names;
            _threads_data[l].threads_data = &threads_data;
            _threads_data[l].command_selection = command_selection;
            _threads_data[l].is_thread_running = true;

            // Substitute special characters codes appearing outside strings.
            arguments[l].resize(1,arguments[l].height() + 1,1,1,0);
            bool is_dquoted = false;
            for (char *s = arguments[l].data(); *s; ++s) {
              const char c = *s;
              if (c=='\"') is_dquoted = !is_dquoted;
              if (!is_dquoted) *s = c<' '?(c==gmic_dollar?'$':c==gmic_lbrace?'{':c==gmic_rbrace?'}':
                                           c==gmic_comma?',':c==gmic_dquote?'\"':c):c;
            }
            gi.commands_line_to_CImgList(arguments[l].data()).
              move_to(_threads_data[l].commands_line);
          }

          // Run threads.
          cimg_forY(_threads_data,l) {
#ifdef gmic_is_parallel
#if cimg_OS!=2

#if defined(__MACOSX__) || defined(__APPLE__)
            const ulongT stacksize = (ulongT)8*1024*1024;
            pthread_attr_t thread_attr;
            if (!pthread_attr_init(&thread_attr) && !pthread_attr_setstacksize(&thread_attr,stacksize))
              // Reserve enough stack size for the new thread.
              pthread_create(&_threads_data[l].thread_id,&thread_attr,gmic_parallel<T>,(void*)&_threads_data[l]);
            else
#endif // #if defined(__MACOSX__) || defined(__APPLE__)
              pthread_create(&_threads_data[l].thread_id,0,gmic_parallel<T>,(void*)&_threads_data[l]);

#else // #if cimg_OS!=2
            _threads_data[l].thread_id = CreateThread(0,0,gmic_parallel<T>,
                                                      (void*)&_threads_data[l],0,0);
#endif // #if cimg_OS!=2
#else // #ifdef gmic_is_parallel
            gmic_parallel<T>((void*)&_threads_data[l]);
#endif // #ifdef gmic_is_parallel
          }

          // Wait threads if immediate waiting mode selected.
          if (wait_mode) {
            cimg_forY(_threads_data,l) if (_threads_data[l].is_thread_running) {
#ifdef gmic_is_parallel
#if cimg_OS!=2
              pthread_join(_threads_data[l].thread_id,0);
#else // #if cimg_OS!=2
              WaitForSingleObject(_threads_data[l].thread_id,INFINITE);
              CloseHandle(_threads_data[l].thread_id);
#endif // #if cimg_OS!=2
              _threads_data[l].is_thread_running = false;
#endif // #ifdef gmic_is_parallel
            }

            // Get 'released' state of the image list.
            cimg_forY(_threads_data,l) is_released&=_threads_data[l].gmic_instance.is_released;

            // Get status modified by first thread.
            _threads_data[0].gmic_instance.status.move_to(status);

            // Check for possible exceptions thrown by threads.
            cimg_forY(_threads_data,l) if (_threads_data[l].exception._message)
              throw _threads_data[l].exception;

            threads_data.remove();
          }

          ++position; continue;
        }

        // Permute axes.
        if (!std::strcmp("-permute",command)) {
          gmic_substitute_args(false);
          print(images,0,"Permute axes of image%s, with permutation '%s'.",
                gmic_selection.data(),gmic_argument_text_printed());
          cimg_forY(selection,l) gmic_apply(permute_axes(argument));
          is_released = false; ++position; continue;
        }

        // Set progress indice.
        if (!std::strcmp("-progress",item)) {
          gmic_substitute_args(false);
          value = -1;
          if (cimg_sscanf(argument,"%lf%c",
                          &value,&end)==1) {
            if (value<0) value = -1; else if (value>100) value = 100;
            if (value>=0)
              print(images,0,"Set progress indice to %g%%.",
                    value);
            else
              print(images,0,"Disable progress indice.");
            *progress = (float)value;
          } else arg_error("progress");
          ++position; continue;
        }

        // Print.
        if (!is_double_hyphen && !std::strcmp("-print",command)) {
          print_images(images,images_names,selection);
          is_released = true; continue;
        }

        // Power.
        gmic_arithmetic_command("-pow",
                                pow,
                                "Compute image%s to the power of %g%s",
                                gmic_selection.data(),value,ssep,Tfloat,
                                pow,
                                "Compute image%s to the power of image [%d]",
                                gmic_selection.data(),ind[0],
                                pow,
                                "Compute image%s to the power of expression %s",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Compute sequential power of image%s");

        // Draw point.
        if (!std::strcmp("-point",command)) {
          gmic_substitute_args(false);
          float x = 0, y = 0, z = 0;
          sepx = sepy = sepz = *argx = *argy = *argz = *color = 0;
          opacity = 1;
          if ((cimg_sscanf(argument,"%255[0-9.eE%+-]%c",
                           argx,&end)==1 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                           argx,argy,&end)==2 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                           argx,argy,argz,&end)==3 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],%f%c",
                           argx,argy,argz,&opacity,&end)==4 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],%f,"
                           "%4095[0-9.eEinfa,+-]%c",
                           argx,argy,argz,&opacity,color,&end)==5) &&
              (cimg_sscanf(argx,"%f%c",&x,&end)==1 ||
               (cimg_sscanf(argx,"%f%c%c",&x,&sepx,&end)==2 && sepx=='%')) &&
              (!*argy ||
               cimg_sscanf(argy,"%f%c",&y,&end)==1 ||
               (cimg_sscanf(argy,"%f%c%c",&y,&sepy,&end)==2 && sepy=='%')) &&
              (!*argz ||
               cimg_sscanf(argz,"%f%c",&z,&end)==1 ||
               (cimg_sscanf(argz,"%f%c%c",&z,&sepz,&end)==2 && sepz=='%'))) {
            print(images,0,
                  "Draw point (%g%s,%g%s,%g%s) on image%s, with opacity %g and color (%s).",
                  x,sepx=='%'?"%":"",
                  y,sepy=='%'?"%":"",
                  z,sepz=='%'?"%":"",
                  gmic_selection.data(),
                  opacity,
                  *color?color:"default");
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              g_img.assign(img.spectrum(),1,1,1,(T)0).fill(color,true,false);
              const int
                nx = (int)cimg::round(sepx=='%'?x*(img.width() - 1)/100:x),
                ny = (int)cimg::round(sepy=='%'?y*(img.height() - 1)/100:y),
                nz = (int)cimg::round(sepz=='%'?z*(img.depth() - 1)/100:z);
              gmic_apply(draw_point(nx,ny,nz,g_img.data(),opacity));
            }
          } else arg_error("point");
          g_img.assign();
          is_released = false; ++position; continue;
        }

        // Draw polygon.
        if (!std::strcmp("-polygon",command)) {
          gmic_substitute_args(false);
          name.assign(256);
          float N = 0, x0 = 0, y0 = 0;
          sep1 = sepx = sepy = *name = *color = 0;
          pattern = ~0U; opacity = 1;
          if (cimg_sscanf(argument,"%f%c",
                          &N,&end)==2 && N>=1) {
            N = cimg::round(N);
            const char
              *nargument = argument + cimg_snprintf(name,name.width(),"%u",
                                                    (unsigned int)N) + 1,
              *const eargument = argument + std::strlen(argument);
            vertices.assign((unsigned int)N,2,1,1,0);
            CImg<bool> percents((unsigned int)N,2,1,1,0);
            for (unsigned int n = 0; n<(unsigned int)N; ++n) if (nargument<eargument) {
                sepx = sepy = 0;
                if (cimg_sscanf(nargument,"%255[0-9.eE%+-],%255[0-9.eE%+-]",
                                argx,argy)==2 &&
                    (cimg_sscanf(argx,"%f%c",&x0,&end)==1 ||
                     (cimg_sscanf(argx,"%f%c%c",&x0,&sepx,&end)==2 && sepx=='%')) &&
                    (cimg_sscanf(argy,"%f%c",&y0,&end)==1 ||
                     (cimg_sscanf(argy,"%f%c%c",&y0,&sepy,&end)==2 && sepy=='%'))) {
                  vertices(n,0) = x0; percents(n,0) = (sepx=='%');
                  vertices(n,1) = y0; percents(n,1) = (sepy=='%');
                  nargument+=std::strlen(argx) + std::strlen(argy) + 2;
                } else arg_error("polygon");
              } else arg_error("polygon");
            if (nargument<eargument &&
                cimg_sscanf(nargument,"%4095[0-9.eEinfa+-]",color)==1 &&
                cimg_sscanf(color,"%f",&opacity)==1) {
              nargument+=std::strlen(color) + 1;
              *color = 0;
            }
            if (nargument<eargument &&
                cimg_sscanf(nargument,"0%c%4095[0-9a-fA-F]",&sep1,color)==2 && sep1=='x' &&
                cimg_sscanf(color,"%x%c",&pattern,&end)==1) {
              nargument+=std::strlen(color) + 3;
              *color = 0;
            }
            const char *const _color = nargument<eargument?nargument:&(end=0);
            if (sep1=='x')
              print(images,0,"Draw %g-vertices outlined polygon on image%s, with opacity %g, "
                    "pattern 0x%x and color (%s).",
                    N,
                    gmic_selection.data(),
                    opacity,pattern,
                    *_color?_color:"default");
            else
              print(images,0,"Draw %g-vertices filled polygon on image%s, with opacity %g "
                    "and color (%s).",
                    N,
                    gmic_selection.data(),
                    opacity,
                    *_color?_color:"default");
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              CImg<int> coords(vertices.width(),2,1,1,0);
              cimg_forX(coords,p) {
                if (percents(p,0))
                  coords(p,0) = (int)cimg::round(vertices(p,0)*(img.width() - 1)/100);
                else coords(p,0) = (int)cimg::round(vertices(p,0));
                if (percents(p,1))
                  coords(p,1) = (int)cimg::round(vertices(p,1)*(img.height() - 1)/100);
                else coords(p,1) = (int)cimg::round(vertices(p,1));
              }
              g_img.assign(img.spectrum(),1,1,1,(T)0).fill(_color,true,false);
              if (sep1=='x') { gmic_apply(draw_polygon(coords,g_img.data(),opacity,pattern)); }
              else gmic_apply(draw_polygon(coords,g_img.data(),opacity));
            }
          } else arg_error("polygon");
          vertices.assign(); g_img.assign();
          is_released = false; ++position; continue;
        }

        // Draw plasma fractal.
        if (!std::strcmp("-plasma",command)) {
          gmic_substitute_args(false);
          float alpha = 1, beta = 1, scale = 8;
          if ((cimg_sscanf(argument,"%f%c",
                           &alpha,&end)==1 ||
               cimg_sscanf(argument,"%f,%f%c",
                           &alpha,&beta,&end)==2 ||
               cimg_sscanf(argument,"%f,%f,%f%c",
                           &alpha,&beta,&scale,&end)==3) &&
              scale>=0) ++position;
          else { alpha = beta = 1; scale = 8; }
          const unsigned int _scale = (unsigned int)cimg::round(scale);
          print(images,0,"Draw plasma fractal on image%s, with alpha %g, beta %g and scale %u.",
                gmic_selection.data(),
                alpha,
                beta,
                _scale);
          cimg_forY(selection,l) gmic_apply(draw_plasma(alpha,beta,_scale));
          is_released = false; continue;
        }

        // Convert 3d object primitives.
        if (!std::strcmp("-primitives3d",command)) {
          gmic_substitute_args(false);
          unsigned int mode = 0;
          if (cimg_sscanf(argument,"%u%c",
                          &mode,&end)==1 &&
              mode<=2) {
            print(images,0,"Convert primitives of 3d object%s to %s.",
                  gmic_selection.data(),
                  mode==0?"points":mode==1?"segments":"no-textures");
            cimg_forY(selection,l) {
              const unsigned int uind = selection[l];
              CImg<T> &img = images[uind];
              try { gmic_apply(convert_primitives_CImg3d(mode)); }
              catch (CImgException&) {
                if (!img.is_CImg3d(true,&(*message=0)))
                  error(images,0,0,
                        "Command '-primitives3d': Invalid 3d object [%d], "
                        "in selected image%s (%s).",
                        uind,gmic_selection_err.data(),message.data());
                else throw;
              }
            }
          } else arg_error("primitives3d");
          is_released = false; ++position; continue;
        }

        // Get patch-match correspondence map.
        if (!std::strcmp("-patchmatch",command)) {
          gmic_substitute_args(true);
          float patch_width, patch_height, patch_depth = 1, nb_iterations = 5, nb_randoms = 5;
          const CImg<T> *initialization = 0;
          unsigned int is_score = 0;
          *argx = 0; ind0.assign();
          if (((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%c",
                            indices,&patch_width,&end)==2 && (patch_height=patch_width)) ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%c",
                           indices,&patch_width,&patch_height,&end)==3 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f%c",
                           indices,&patch_width,&patch_height,&patch_depth,&end)==4 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f,%f%c",
                           indices,&patch_width,&patch_height,&patch_depth,&nb_iterations,&end)==5 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f,%f,%f%c",
                           indices,&patch_width,&patch_height,&patch_depth,&nb_iterations,&nb_randoms,&end)==6 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f,%f,%f,%u%c",
                           indices,&patch_width,&patch_height,&patch_depth,&nb_iterations,&nb_randoms,
                           &is_score,&end)==7 ||
               (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f,%f,%f,%u,[%255[a-zA-Z0-9_.%+-]%c%c",
                            indices,&patch_width,&patch_height,&patch_depth,&nb_iterations,&nb_randoms,
                            &is_score,argx,&sep,&end)==9 && sep==']')) &&
              (ind=selection2cimg(indices,images.size(),images_names,"-patchmatch")).height()==1 &&
              (!*argx ||
               (ind0=selection2cimg(argx,images.size(),images_names,"-patchmatch")).height()==1) &&
              patch_width>=1 && patch_height>=1 && patch_depth>=1 &&
              nb_iterations>=0 && nb_randoms>=0 && is_score<=1) {
            patch_width = cimg::round(patch_width);
            patch_height = cimg::round(patch_height);
            patch_depth = cimg::round(patch_depth);
            nb_iterations = cimg::round(nb_iterations);
            nb_randoms = cimg::round(nb_randoms);
            if (ind0) initialization = &images[*ind0];
            print(images,0,"Estimate correspondence map between image%s and patch image [%u], "
                  "using %gx%gx%g patches, %g iteration%s, and %g randomization%s "
                  "(%sscore returned).",
                  gmic_selection.data(),
                  *ind,
                  patch_width,patch_height,patch_depth,
                  nb_iterations,nb_iterations!=1?"s":"",
                  nb_randoms,nb_randoms!=1?"s":"",
                  is_score?"":"no ");
            const CImg<T> patch_image = gmic_image_arg(*ind);
            cimg_forY(selection,l) gmic_apply(gmic_patchmatch(patch_image,
                                                              (unsigned int)patch_width,
                                                              (unsigned int)patch_height,
                                                              (unsigned int)patch_depth,
                                                              (unsigned int)nb_iterations,
                                                              (unsigned int)nb_randoms,
                                                              (bool)is_score,
                                                              initialization));
          } else arg_error("patchmatch");
          is_released = false; ++position; continue;
        }

        // Display as a graph plot.
        if (!is_double_hyphen && !std::strcmp("-plot",command)) {
          gmic_substitute_args(false);
          double ymin = 0, ymax = 0, xmin = 0, xmax = 0;
          unsigned int plot_type = 1, vertex_type = 1;
          float resolution = 65536;
          *formula = sep = 0;
          exit_on_anykey = 0;
          if (((cimg_sscanf(argument,"'%1023[^']%c%c",
                            formula,&sep,&end)==2 && sep=='\'') ||
               cimg_sscanf(argument,"'%1023[^']',%f%c",
                           formula,&resolution,&end)==2 ||
               cimg_sscanf(argument,"'%1023[^']',%f,%u%c",
                           formula,&resolution,&plot_type,&end)==3 ||
               cimg_sscanf(argument,"'%1023[^']',%f,%u,%u%c",
                           formula,&resolution,&plot_type,&vertex_type,&end)==4 ||
               cimg_sscanf(argument,"'%1023[^']',%f,%u,%u,%lf,%lf%c",
                           formula,&resolution,&plot_type,&vertex_type,&xmin,&xmax,&end)==6 ||
               cimg_sscanf(argument,"'%1023[^']',%f,%u,%u,%lf,%lf,%lf,%lf%c",
                           formula,&resolution,&plot_type,&vertex_type,
                           &xmin,&xmax,&ymin,&ymax,&end)==8 ||
               cimg_sscanf(argument,"'%1023[^']',%f,%u,%u,%lf,%lf,%lf,%lf,%u%c",
                           formula,&resolution,&plot_type,&vertex_type,
                           &xmin,&xmax,&ymin,&ymax,&exit_on_anykey,&end)==9) &&
              resolution>0 && plot_type<=3 && vertex_type<=7 && exit_on_anykey<=1) {
            resolution = cimg::round(resolution);
            strreplace_fw(formula);
            if (xmin==0 && xmax==0) { xmin = -4; xmax = 4; }
            if (!plot_type && !vertex_type) plot_type = 1;
            if (resolution<1) resolution = 65536;
            CImgList<double> tmp_img(1);
            CImg<double> &values = tmp_img[0];

            values.assign(4,(unsigned int)resolution--,1,1,0);
            const double dx = xmax - xmin;
            cimg_forY(values,X) values(0,X) = xmin + X*dx/resolution;
            cimg::eval(formula,values).move_to(values);

            cimg_snprintf(title,_title.width(),"[Plot of '%s']",formula);
            CImg<char>::string(title).move_to(g_list_c);
            display_plots(tmp_img,g_list_c,CImg<unsigned int>::vector(0),
                          plot_type,vertex_type,xmin,xmax,ymin,ymax,exit_on_anykey);
            g_list_c.assign();
            ++position;
          } else {
            plot_type = 1; vertex_type = 0; ymin = ymax = xmin = xmax = 0;
            if ((cimg_sscanf(argument,"%u%c",
                             &plot_type,&end)==1 ||
                 cimg_sscanf(argument,"%u,%u%c",
                             &plot_type,&vertex_type,&end)==2 ||
                 cimg_sscanf(argument,"%u,%u,%lf,%lf%c",
                             &plot_type,&vertex_type,&xmin,&xmax,&end)==4 ||
                 cimg_sscanf(argument,"%u,%u,%lf,%lf,%lf,%lf%c",
                             &plot_type,&vertex_type,&xmin,&xmax,&ymin,&ymax,&end)==6 ||
                 cimg_sscanf(argument,"%u,%u,%lf,%lf,%lf,%lf,%u%c",
                             &plot_type,&vertex_type,&xmin,&xmax,&ymin,&ymax,&exit_on_anykey,&end)==7) &&
                plot_type<=3 && vertex_type<=7 && exit_on_anykey<=1) ++position;
            if (!plot_type && !vertex_type) plot_type = 1;
            display_plots(images,images_names,selection,plot_type,vertex_type,
                          xmin,xmax,ymin,ymax,exit_on_anykey);
          }
          is_released = true; continue;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-q...'
        //-----------------------------
      gmic_commands_q :

        // Quit.
        if (!std::strcmp("-quit",item)) {
          print(images,0,"Quit G'MIC interpreter.");
          dowhiles.assign();
          repeatdones.assign();
          position = commands_line.size();
          is_released = is_quit = true;
          *is_abort = true;
          break;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-r...'
        //-----------------------------
      gmic_commands_r :

        // Remove images.
        if (!std::strcmp("-remove",command)) {
          print(images,0,"Remove image%s",
                gmic_selection.data());
          if (is_double_hyphen) { g_list.assign(images); g_list_c.assign(images_names); }
          remove_images(images,images_names,selection,0,selection.height() - 1);
          if (is_double_hyphen) {
            g_list.move_to(images,0);
            g_list_c.move_to(images_names,0);
          }
          if (is_verbose) {
            cimg::mutex(29);
            std::fprintf(cimg::output()," (%u image%s left).",
                         images.size(),images.size()==1?"":"s");
            std::fflush(cimg::output());
            cimg::mutex(29,0);
          }
          g_list.assign(); g_list_c.assign();
          is_released = false; continue;
        }

        // Repeat.
        if (!std::strcmp("-repeat",item)) {
          gmic_substitute_args(false);
          float number = 0;
          *title  = 0;
          if (cimg_sscanf(argument,"%f%c",&number,&end)==1 ||
              (cimg_sscanf(argument,"%f,%255[a-zA-Z0-9_]%c",&number,title,&sep)==2 &&
               (*title<'0' || *title>'9'))) {
            const unsigned int nb = number<=0?0U:
              cimg::type<float>::is_inf(number)?~0U:(unsigned int)cimg::round(number);
            if (nb) {
              if (is_debug_info && debug_line!=~0U) {
                cimg_snprintf(argx,_argx.width(),"*repeat#%u",debug_line);
                CImg<char>::string(argx).move_to(callstack);
              } else CImg<char>::string("*repeat").move_to(callstack);
              if (is_very_verbose) {
                if (*title) print(images,0,"Start '-repeat...-done' block with variable '%s' (%u iteration%s).",
                                  title,nb,nb>1?"s":"");
                else print(images,0,"Start '-repeat...-done' block (%u iteration%s).",
                           nb,nb>1?"s":"");
              }
              const unsigned int l = (unsigned int)std::strlen(title);
              CImg<unsigned int> rd(1,3 + (l?2:0));
              rd[0] = position + 1; rd[1] = nb; rd[2] = 0;
              if (l) {
                const unsigned int hashcode = gmic::hashcode(title,true);
                rd[3] = hashcode;
                rd[4] = variables[hashcode]->_width;
                CImg<char>::string(title).move_to(*variables_names[hashcode]);
                CImg<char>::string("0").move_to(*variables[hashcode]);
              }
              rd.move_to(repeatdones);
            } else {
              if (is_very_verbose) {
                if (*title) print(images,0,"Skip 'repeat...done' block with variable '%s' (0 iteration).",
                                  title);
                else print(images,0,"Skip 'repeat...done' block (0 iteration).");
              }
              int nb_repeats = 0;
              for (nb_repeats = 1; nb_repeats && position<commands_line.size(); ++position) {
                const char *it = commands_line[position].data();
                if (!std::strcmp("-repeat",it)) ++nb_repeats;
                else if (!std::strcmp("-done",it)) --nb_repeats;
              }
              if (nb_repeats && position>=commands_line.size())
                error(images,0,0,
                      "Command '-repeat': Missing associated '-done' command.");
              continue;
            }
          } else arg_error("repeat");
          ++position; continue;
        }

        // Resize.
        if (!std::strcmp("-resize",command)) {
          gmic_substitute_args(true);
          float valx = 100, valy = 100, valz = 100, valc = 100, cx = 0, cy = 0, cz = 0, cc = 0;
          CImg<char> indicesy(256), indicesz(256), indicesc(256);
          CImg<unsigned int> ind, indx, indy, indz, indc;
          int interpolation = 1;
          *indices = *indicesy = *indicesz = *indicesc = *argx = *argy = *argz = *argc = sep = 0;
          sepx = sepy = sepz = sepc = '%';
          boundary = 0;

          if (((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",
                            indices,&sep,&end)==2 && sep==']') ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%d%c",
                           indices,&interpolation,&end)==2 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%d,%u%c",
                           indices,&interpolation,&boundary,&end)==3 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%d,%u,%f%c",
                           indices,&interpolation,&boundary,&cx,&end)==4 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%d,%u,%f,%f%c",
                           indices,&interpolation,&boundary,&cx,&cy,&end)==5 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%d,%u,%f,%f,%f%c",
                           indices,&interpolation,&boundary,&cx,&cy,&cz,&end)==6 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%d,%u,%f,%f,%f,%f%c",
                           indices,&interpolation,&boundary,&cx,&cy,&cz,&cc,&end)==7) &&
              (ind=selection2cimg(indices,images.size(),images_names,"-resize")).height()==1 &&
              interpolation>=-1 && interpolation<=6 && boundary<=2 &&
              cx>=0 && cx<=1 && cy>=0 && cy<=1 && cz>=0 && cz<=1 && cc>=0 && cc<=1) {
            const int
              nvalx = images[*ind].width(),
              nvaly = images[*ind].height(),
              nvalz = images[*ind].depth(),
              nvalc = images[*ind].spectrum();
            print(images,0,"Resize image%s to %dx%dx%dx%d, with %s interpolation, "
                  "%s boundary conditions and alignment (%g,%g,%g,%g).",
                  gmic_selection.data(),
                  nvalx,nvaly,nvalz,nvalc,
                  interpolation<=0?"no":interpolation==1?"nearest-neighbor":
                  interpolation==2?"moving average":interpolation==3?"linear":
                  interpolation==4?"grid":interpolation==5?"cubic":"lanczos",
                  boundary<=0?"dirichlet":boundary==1?"neumann":"periodic",
                  cx,cy,cz,cc);
            cimg_forY(selection,l) gmic_apply(resize(nvalx,nvaly,nvalz,nvalc,interpolation,boundary,cx,cy,cz,cc));
            ++position;
          } else if ((cx=cy=cz=cc=0, interpolation=1, boundary=0, true) &&
                     (cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-]%c",
                                  argx,&end)==1 ||
                      cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-]%c",
                                  argx,argy,&end)==2 ||
                      cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-],"
                                  "%255[][a-zA-Z0-9_.eE%+-]%c",
                                  argx,argy,argz,&end)==3 ||
                      cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-],"
                                  "%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-]%c",
                                  argx,argy,argz,argc,&end)==4 ||
                      cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-],"
                                  "%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-],%d%c",
                                  argx,argy,argz,argc,&interpolation,&end)==5 ||
                      cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-],"
                                  "%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-],%d,%u%c",
                                  argx,argy,argz,argc,&interpolation,&boundary,&end)==6 ||
                      cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-],"
                                  "%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-],%d,%u,%f%c",
                                  argx,argy,argz,argc,&interpolation,&boundary,&cx,&end)==7 ||
                      cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-],"
                                  "%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-],%d,%u,%f,"
                                  "%f%c",
                                  argx,argy,argz,argc,&interpolation,&boundary,&cx,&cy,&end)==8||
                      cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-],"
                                  "%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-],%d,%u,%f,"
                                  "%f,%f%c",
                                  argx,argy,argz,argc,&interpolation,&boundary,
                                  &cx,&cy,&cz,&end)==9 ||
                      cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-],"
                                  "%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-],%d,%u,%f,"
                                  "%f,%f,%f%c",
                                  argx,argy,argz,argc,&interpolation,&boundary,
                                  &cx,&cy,&cz,&cc,&end)==10) &&
                     ((cimg_sscanf(argx,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sepx,&end)==2 &&
                       sepx==']' &&
                       (indx=selection2cimg(indices,images.size(),images_names,"-resize")).height()==1) ||
                      (sepx=0,cimg_sscanf(argx,"%f%c",&valx,&sepx)==1 && valx>=1) ||
                      (cimg_sscanf(argx,"%f%c%c",&valx,&sepx,&end)==2 && sepx=='%')) &&
                     (!*argy ||
                      (cimg_sscanf(argy,"[%255[a-zA-Z0-9_.%+-]%c%c",indicesy.data(),&sepy,
                                   &end)==2 &&
                       sepy==']' &&
                       (indy=selection2cimg(indicesy,images.size(),images_names,"-resize")).height()==1) ||
                      (sepy=0,cimg_sscanf(argy,"%f%c",&valy,&sepy)==1 && valy>=1) ||
                      (cimg_sscanf(argy,"%f%c%c",&valy,&sepy,&end)==2 && sepy=='%')) &&
                     (!*argz ||
                      (cimg_sscanf(argz,"[%255[a-zA-Z0-9_.%+-]%c%c",indicesz.data(),&sepz,
                                   &end)==2 &&
                       sepz==']' &&
                       (indz=selection2cimg(indicesz,images.size(),images_names,"-resize")).height()==1) ||
                      (sepz=0,cimg_sscanf(argz,"%f%c",&valz,&sepz)==1 && valz>=1) ||
                      (cimg_sscanf(argz,"%f%c%c",&valz,&sepz,&end)==2 && sepz=='%')) &&
                     (!*argc ||
                      (cimg_sscanf(argc,"[%255[a-zA-Z0-9_.%+-]%c%c",indicesc.data(),&sepc,
                                   &end)==2 &&
                       sepc==']' &&
                       (indc=selection2cimg(indicesc,images.size(),images_names,"-resize")).height()==1) ||
                      (sepc=0,cimg_sscanf(argc,"%f%c",&valc,&sepc)==1 && valc>=1) ||
                      (cimg_sscanf(argc,"%f%c%c",&valc,&sepc,&end)==2 && sepc=='%')) &&
                     valx>0 && valy>0 && valz>0 && valc>0 &&
                     interpolation>=-1 && interpolation<=6 && boundary<=2 &&
                     cx>=0 && cx<=1 && cy>=0 && cy<=1 && cz>=0 && cz<=1 && cc>=0 && cc<=1) {
            if (indx) { valx = (float)images[*indx].width(); sepx = 0; }
            if (indy) { valy = (float)images[*indy].height(); sepy = 0; }
            if (indz) { valz = (float)images[*indz].depth(); sepz = 0; }
            if (indc) { valc = (float)images[*indc].spectrum(); sepc = 0; }
            print(images,0,
                  "Resize image%s to %g%s%g%s%g%s%g%s, with %s interpolation, "
                  "%s boundary conditions and alignment (%g,%g,%g,%g).",
                  gmic_selection.data(),
                  valx,sepx=='%'?"%x":"x",
                  valy,sepy=='%'?"%x":"x",
                  valz,sepz=='%'?"%x":"x",
                  valc,sepc=='%'?"% ":"",
                  interpolation<=0?"no":interpolation==1?"nearest neighbor":
                  interpolation==2?"moving average":interpolation==3?"linear":
                  interpolation==4?"grid":interpolation==5?"cubic":"lanczos",
                  boundary<=0?"dirichlet":boundary==1?"neumann":"periodic",
                  cx,cy,cz,cc);
            cimg_forY(selection,l) {
              CImg<T>& img = images[selection[l]];
              const int
                _nvalx = (int)cimg::round(sepx=='%'?valx*img.width()/100:valx),
                _nvaly = (int)cimg::round(sepy=='%'?valy*img.height()/100:valy),
                _nvalz = (int)cimg::round(sepz=='%'?valz*img.depth()/100:valz),
                _nvalc = (int)cimg::round(sepc=='%'?valc*img.spectrum()/100:valc),
                nvalx = _nvalx?_nvalx:1,
                nvaly = _nvaly?_nvaly:1,
                nvalz = _nvalz?_nvalz:1,
                nvalc = _nvalc?_nvalc:1;
              gmic_apply(resize(nvalx,nvaly,nvalz,nvalc,interpolation,boundary,cx,cy,cz,cc));
            }
            ++position;
          } else {
#if cimg_display==0
            print(images,0,"Resize image%s in interactive mode (skipped, no display support).",
                  gmic_selection.data());
#else // #if cimg_display==0
            bool is_available_display = false;
            try {
              is_available_display = (bool)CImgDisplay::screen_width();
            } catch (CImgDisplayException&) {
              print(images,0,"Resize image%s in interactive mode (skipped, no display available).",
                    gmic_selection.data());
            }
            if (is_available_display) {
              print(images,0,"Resize image%s in interactive mode.",
                    gmic_selection.data());
              CImgDisplay _disp, &disp = _display_window[0]?_display_window[0]:_disp;
              cimg_forY(selection,l) {
                CImg<T>& img = gmic_check(images[selection[l]]);
                if (img) {
                  if (disp) disp.resize(cimg_fitscreen(img.width(),img.height(),1),false);
                  else disp.assign(cimg_fitscreen(img.width(),img.height(),1),0,1);
                  disp.set_title("%s: resize",basename(images_names[selection[l]]));
                  img.get_select(disp,0);
                  print(images,0,
                        "Resize image [%d] to %dx%d, with nearest-neighbor interpolation.",
                        selection[l],
                        disp.width(),
                        disp.height());
                  gmic_apply(resize(disp));
                } else gmic_apply(replace(img));
              }
            }
#endif // #if cimg_display==0
          }
          is_released = false; continue;
        }

        // Reverse positions.
        if (!std::strcmp("-reverse",command)) {
          print(images,0,"Reverse positions of image%s.",
                gmic_selection.data());
          if (is_double_hyphen) cimg_forY(selection,l) {
              const unsigned int i = selection[selection.height() - 1 - l];
              images.insert(images[i]);
              images_names.insert(images_names[i]);
            } else for (unsigned int l = 0; l<selection._height/2; ++l) {
              const unsigned int i0 = selection[l], i1 = selection[selection.height() - 1 - l];
              images[i0].swap(images[i1]);
              images_names[i0].swap(images_names[i1]);
            }
          is_released = false; continue;
        }

        // Return.
        if (!std::strcmp("-return",item)) {
          if (is_very_verbose) print(images,0,"Return.");
          position = commands_line.size();
          while (callstack && callstack.back()[0]=='*') {
            const char c = callstack.back()[1];
            if (c=='d') dowhiles.remove();
            else if (c=='r') repeatdones.remove();
            else if (c=='l' || c=='>' || c=='s') break;
            callstack.remove();
          }
          is_return = true;
          break;
        }

        // Keep rows.
        if (!std::strcmp("-rows",command)) {
          gmic_substitute_args(true);
          ind0.assign(); ind1.assign();
          sep0 = sep1 = *argx = *argy = *indices = 0;
          value0 = value1 = 0;
          if (cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-]%c",
                          argx,&end)==1 &&
              ((cimg_sscanf(argx,"[%255[a-zA-Z0-9_.%+-]%c%c]",indices,&sep0,&end)==2 &&
                sep0==']' &&
                (ind0=selection2cimg(indices,images.size(),images_names,"-rows")).height()==1) ||
               cimg_sscanf(argx,"%lf%c",&value0,&end)==1 ||
               (cimg_sscanf(argx,"%lf%c%c",&value0,&sep0,&end)==2 && sep0=='%'))) {
            if (ind0) { value0 = images[*ind0].height() - 1.; sep0 = 0; }
            print(images,0,"Keep rows %g%s of image%s.",
                  value0,sep0=='%'?"%":"",
                  gmic_selection.data());
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              nvalue0 = cimg::round(sep0=='%'?value0*(img.height() - 1)/100:value0);
              gmic_apply(row((int)nvalue0));
            }
          } else if (cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-]%c",
                                 argx,argy,&end)==2 &&
                     ((cimg_sscanf(argx,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep0,&end)==2 &&
                       sep0==']' &&
                       (ind0=selection2cimg(indices,images.size(),images_names,"-rows")).height()==1) ||
                      cimg_sscanf(argx,"%lf%c",&value0,&end)==1 ||
                      (cimg_sscanf(argx,"%lf%c%c",&value0,&sep0,&end)==2 && sep0=='%')) &&
                     ((cimg_sscanf(argx,"[%255[a-zA-Z0-9_.%+-]%c%c",formula,&sep0,&end)==2 &&
                       sep0==']' &&
                       (ind1=selection2cimg(formula,images.size(),images_names,"-rows")).height()==1) ||
                      cimg_sscanf(argy,"%lf%c",&value1,&end)==1 ||
                      (cimg_sscanf(argy,"%lf%c%c",&value1,&sep1,&end)==2 && sep1=='%'))) {
            if (ind0) { value0 = images[*ind0].height() - 1.; sep0 = 0; }
            if (ind1) { value1 = images[*ind1].height() - 1.; sep1 = 0; }
            print(images,0,"Keep rows %g%s...%g%s of image%s.",
                  value0,sep0=='%'?"%":"",
                  value1,sep1=='%'?"%":"",
                  gmic_selection.data());
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              nvalue0 = cimg::round(sep0=='%'?value0*(img.height() - 1)/100:value0);
              nvalue1 = cimg::round(sep1=='%'?value1*(img.height() - 1)/100:value1);
              gmic_apply(rows((int)nvalue0,(int)nvalue1));
            }
          } else arg_error("rows");
          is_released = false; ++position; continue;
        }

        // Rotate.
        if (!std::strcmp("-rotate",command)) {
          gmic_substitute_args(false);
          float angle = 0, u = 0, v = 0, w = 0, cx = 0, cy = 0, cz = 0;
          unsigned int interpolation = 1;
          char sep2 = sep1 = sep0 = *argx = *argy = *argz = 0;
          boundary = 0;
          if ((cimg_sscanf(argument,"%f%c",
                           &angle,&end)==1 ||
               cimg_sscanf(argument,"%f,%u%c",
                           &angle,&interpolation,&end)==2 ||
               cimg_sscanf(argument,"%f,%u,%u%c",
                           &angle,&interpolation,&boundary,&end)==3 ||
               cimg_sscanf(argument,"%f,%u,%u,%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                           &angle,&interpolation,&boundary,argx,argy,&end)==5) &&
              (!*argx ||
               cimg_sscanf(argx,"%f%c",&cx,&end)==1 ||
               (cimg_sscanf(argx,"%f%c%c",&cx,&sep0,&end)==2 && sep0=='%')) &&
              (!*argy ||
               cimg_sscanf(argy,"%f%c",&cy,&end)==1 ||
               (cimg_sscanf(argy,"%f%c%c",&cy,&sep1,&end)==2 && sep1=='%')) &&
              interpolation<=2 && boundary<=2) { // 2d rotation
            if (*argx) {
              print(images,0,"Rotate image%s of %g deg., with %s interpolation, %s boundary conditions "
                    "and center at (%g%s,%g%s).",
                    gmic_selection.data(),angle,
                    interpolation==0?"nearest-neighbor":interpolation==1?"linear":"cubic",
                    boundary==0?"dirichlet":boundary==1?"neumann":"periodic",
                    cx,sep0=='%'?"%":"",cy,sep1=='%'?"%":"");
              cimg_forY(selection,l) {
                CImg<T> &img = images[selection[l]];
                const float
                  ncx = sep0=='%'?cx*(img.width() - 1)/100:cx,
                  ncy = sep1=='%'?cy*(img.height() - 1)/100:cy;
                gmic_apply(rotate(angle,ncx,ncy,interpolation,boundary));
              }
            } else {
              print(images,0,"Rotate image%s of %g deg., with %s interpolation and %s boundary conditions.",
                    gmic_selection.data(),angle,
                    interpolation==0?"nearest-neighbor":interpolation==1?"linear":"cubic",
                    boundary==0?"dirichlet":boundary==1?"neumann":"periodic");
              cimg_forY(selection,l) gmic_apply(rotate(angle,interpolation,boundary));
            }
          } else if ((cimg_sscanf(argument,"%f,%f,%f,%f,%u,%u,%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                                  &u,&v,&w,&angle,&interpolation,&boundary,&(*argx=0),&(*argy=0),argz,&end)==9 ||
                      cimg_sscanf(argument,"%f,%f,%f,%f,%u,%u%c",
                                  &u,&v,&w,&angle,&interpolation,&boundary,&end)==6) &&
                     (!*argx ||
                      cimg_sscanf(argx,"%f%c",&cx,&end)==1 ||
                      (cimg_sscanf(argx,"%f%c%c",&cx,&sep0,&end)==2 && sep0=='%')) &&
                     (!*argy ||
                      cimg_sscanf(argy,"%f%c",&cy,&end)==1 ||
                      (cimg_sscanf(argy,"%f%c%c",&cy,&sep1,&end)==2 && sep1=='%')) &&
                     (!*argz ||
                      cimg_sscanf(argz,"%f%c",&cz,&end)==1 ||
                      (cimg_sscanf(argz,"%f%c%c",&cz,&sep1,&end)==2 && sep2=='%')) &&
                     interpolation<=2 && boundary<=2) { // 3d rotation
            if (*argx) {
              print(images,0,"Rotate image%s around axis (%g,%g,%g) with angle %g deg., %s interpolation, "
                    "%s boundary conditions and center at (%g%s,%g%s,%g%s).",
                    gmic_selection.data(),u,v,w,angle,
                    interpolation==0?"nearest-neighbor":interpolation==1?"linear":"cubic",
                    boundary==0?"dirichlet":boundary==1?"neumann":"periodic",
                    cx,sep0=='%'?"%":"",cy,sep1=='%'?"%":"",cz,sep2=='%'?"%":"");
              cimg_forY(selection,l) {
                CImg<T> &img = images[selection[l]];
                const float
                  ncx = sep0=='%'?cx*(img.width() - 1)/100:cx,
                  ncy = sep1=='%'?cy*(img.height() - 1)/100:cy,
                  ncz = sep2=='%'?cy*(img.depth() - 1)/100:cz;
                gmic_apply(rotate(u,v,w,angle,ncx,ncy,ncz,interpolation,boundary));
              }
            } else {
              print(images,0,"Rotate image%s around axis (%g,%g,%g) with angle %g deg., %s interpolation "
                    "and %s boundary conditions.",
                    gmic_selection.data(),u,v,w,angle,
                    interpolation==0?"nearest-neighbor":interpolation==1?"linear":"cubic",
                    boundary==0?"dirichlet":boundary==1?"neumann":"periodic");
              cimg_forY(selection,l) gmic_apply(rotate(u,v,w,angle,interpolation,boundary));
            }
          } else arg_error("rotate");
          is_released = false; ++position; continue;
        }

        // Round.
        if (!std::strcmp("-round",command)) {
          gmic_substitute_args(false);
          int rounding_type = 0;
          value = 1;
          if ((cimg_sscanf(argument,"%lf%c",
                           &value,&end)==1 ||
               cimg_sscanf(argument,"%lf,%d%c",
                           &value,&rounding_type,&end)==2) &&
              value>=0 && rounding_type>=-1 && rounding_type<=1) ++position;
          else { value = 1; rounding_type = 0; }
          print(images,0,"Round values of image%s by %g and %s rounding.",
                gmic_selection.data(),
                value,
                rounding_type<0?"backward":rounding_type>0?"forward":"nearest");
          cimg_forY(selection,l) gmic_apply(round(value,rounding_type));
          is_released = false; continue;
        }

        // Fill with random values.
        if (!std::strcmp("-rand",command)) {
          gmic_substitute_args(true);
          ind0.assign(); ind1.assign();
          sep0 = sep1 = *argx = *argy = *indices = 0;
          value0 = value1 = 0;
          if (cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-]%c",
                          argx,argy,&end)==2 &&
              ((cimg_sscanf(argx,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep0,&end)==2 &&
                sep0==']' &&
                (ind0=selection2cimg(indices,images.size(),images_names,"-rand")).height()==1) ||
               (cimg_sscanf(argx,"%lf%c%c",&value0,&sep0,&end)==2 && sep0=='%') ||
               cimg_sscanf(argx,"%lf%c",&value0,&end)==1) &&
              ((cimg_sscanf(argy,"[%255[a-zA-Z0-9_.%+-]%c%c",formula,&sep1,&end)==2 &&
                sep1==']' &&
                (ind1=selection2cimg(formula,images.size(),images_names,"-rand")).height()==1) ||
               (cimg_sscanf(argy,"%lf%c%c",&value1,&sep1,&end)==2 && sep1=='%') ||
               cimg_sscanf(argy,"%lf%c",&value1,&end)==1)) {
            if (ind0) { value0 = images[*ind0].min(); sep0 = 0; }
            if (ind1) { value1 = images[*ind1].max(); sep1 = 0; }
            print(images,0,"Fill image%s with random values, in range [%g%s,%g%s].",
                  gmic_selection.data(),
                  value0,sep0=='%'?"%":"",
                  value1,sep1=='%'?"%":"");
            cimg_forY(selection,l) {
              CImg<T>& img = gmic_check(images[selection[l]]);
              nvalue0 = value0; nvalue1 = value1;
              vmin = vmax = 0;
              if (sep0=='%' || sep1=='%') {
                if (img) vmax = (double)img.max_min(vmin);
                if (sep0=='%') nvalue0 = vmin + (vmax - vmin)*value0/100;
                if (sep1=='%') nvalue1 = vmin + (vmax - vmin)*value1/100;
              }
              gmic_apply(rand((T)nvalue0,(T)nvalue1));
            }
          } else if (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep0,&end)==2 &&
                     sep0==']' &&
                     (ind0=selection2cimg(indices,images.size(),images_names,"-rand")).height()==1) {
            if (images[*ind0]) value1 = (double)images[*ind0].max_min(value0);
            print(images,0,"Fill image%s with random values, in range [%g,%g] from image [%d].",
                  gmic_selection.data(),
                  value0,
                  value1,
                  *ind0);
            cimg_forY(selection,l) gmic_apply(rand((T)value0,(T)value1));
          } else arg_error("rand");
          is_released = false; ++position; continue;
        }

        // Rotate 3d object.
        if (!std::strcmp("-rotate3d",command)) {
          gmic_substitute_args(false);
          float u = 0, v = 0, w = 1, angle = 0;
          if (cimg_sscanf(argument,"%f,%f,%f,%f%c",
                          &u,&v,&w,&angle,&end)==4) {
            print(images,0,"Rotate 3d object%s around axis (%g,%g,%g), with angle %g deg.",
                  gmic_selection.data(),
                  u,v,w,
                  angle);
            CImg<float>::rotation_matrix(u,v,w,angle).move_to(vertices);
            cimg_forY(selection,l) {
              const unsigned int uind = selection[l];
              CImg<T>& img = images[uind];
              try { gmic_apply(rotate_CImg3d(vertices)); }
              catch (CImgException&) {
                if (!img.is_CImg3d(true,&(*message=0)))
                  error(images,0,0,
                        "Command '-rotate3d': Invalid 3d object [%d], "
                        "in selected image%s (%s).",
                        uind,gmic_selection_err.data(),message.data());
                else throw;
              }
            }
          } else arg_error("rotate3d");
          vertices.assign();
          is_released = false; ++position; continue;
        }

        // RGB to other color base.
        gmic_simple_command("-rgb2hsi",RGBtoHSI,"Convert image%s from RGB to HSI color bases.");
        gmic_simple_command("-rgb2hsl",RGBtoHSL,"Convert image%s from RGB to HSL color bases.");
        gmic_simple_command("-rgb2hsv",RGBtoHSV,"Convert image%s from RGB to HSV color bases.");
        gmic_simple_command("-rgb2srgb",RGBtosRGB,"Convert image%s from RGB to sRGB color bases.");

        if (!std::strcmp("-rgb2lab",command)) {
          gmic_substitute_args(false);
          bool use_D65 = true;
          if ((*argument=='0' || *argument=='1') && !argument[1]) {
            use_D65 = *argument=='1';
            ++position;
          }
          print(images,0,"Convert image%s from RGB to Lab color bases, with D%u illuminant.",
                gmic_selection.data(),use_D65?65:50);
          cimg_forY(selection,l) gmic_apply(RGBtoLab(use_D65));
          is_released = false; continue;
        }

        // Bitwise left rotation.
        gmic_arithmetic_command("-rol",
                                rol,
                                "Compute bitwise left rotation of image%s by %g%s",
                                gmic_selection.data(),value,ssep,unsigned int,
                                rol,
                                "Compute bitwise left rotation of image%s by image [%d]",
                                gmic_selection.data(),ind[0],
                                rol,
                                "Compute bitwise left rotation of image%s by expression %s",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Compute sequential bitwise left rotation of image%s");

        // Bitwise right rotation.
        gmic_arithmetic_command("-ror",
                                ror,
                                "Compute bitwise right rotation of image%s by %g%s",
                                gmic_selection.data(),value,ssep,unsigned int,
                                ror,
                                "Compute bitwise right rotation of image%s by image [%d]",
                                gmic_selection.data(),ind[0],
                                ror,
                                "Compute bitwise left rotation of image%s by expression %s",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Compute sequential bitwise left rotation of image%s");

        // Reverse 3d object orientation.
        if (!std::strcmp("-reverse3d",command)) {
          print(images,0,"Reverse orientation of 3d object%s.",
                gmic_selection.data());
          cimg_forY(selection,l) {
            const unsigned int uind = selection[l];
            CImg<T> &img = images[uind];
            try { gmic_apply(reverse_CImg3d()); }
            catch (CImgException&) {
              if (!img.is_CImg3d(true,&(*message=0)))
                error(images,0,0,
                      "Command '-reverse3d': Invalid 3d object [%d], "
                      "in selected image%s (%s).",
                      uind,gmic_selection_err.data(),message.data());
              else throw;
            }
          }
          is_released = false; continue;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-s...'
        //-----------------------------
      gmic_commands_s :

        // Set status.
        if (!std::strcmp("-status",item)) {
          gmic_substitute_args(false);
          print(images,0,"Set status to '%s'.",gmic_argument_text_printed());
          CImg<char>::string(argument).move_to(status);
          ++position; continue;
        }

        // Skip argument.
        if (is_skip_command) {
          gmic_substitute_args(false);
          if (is_very_verbose)
            print(images,0,"Skip argument '%s'.",
                  gmic_argument_text_printed());
          ++position;
          continue;
        }

        // Set pixel value.
        if (!std::strcmp("-set",command)) {
          gmic_substitute_args(false);
          float x = 0, y = 0, z = 0, c = 0;
          value = 0;
          sepx = sepy = sepz = sepc = *argx = *argy = *argz = *argc = 0;
          if ((cimg_sscanf(argument,"%lf%c",
                           &value,&end)==1 ||
               cimg_sscanf(argument,"%lf,%255[0-9.eE%+-]%c",
                           &value,argx,&end)==2 ||
               cimg_sscanf(argument,"%lf,%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                           &value,argx,argy,&end)==3 ||
               cimg_sscanf(argument,"%lf,%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                           &value,argx,argy,argz,&end)==4 ||
               cimg_sscanf(argument,"%lf,%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%255[0-9.eE%+-]%c",
                           &value,argx,argy,argz,argc,&end)==5) &&
              (!*argx ||
               (cimg_sscanf(argx,"%f%c%c",&x,&sepx,&end)==2 && sepx=='%') ||
               cimg_sscanf(argx,"%f%c",&x,&end)==1) &&
              (!*argy ||
               (cimg_sscanf(argy,"%f%c%c",&y,&sepy,&end)==2 && sepy=='%') ||
               cimg_sscanf(argy,"%f%c",&y,&end)==1) &&
              (!*argz ||
               (cimg_sscanf(argz,"%f%c%c",&z,&sepz,&end)==2 && sepz=='%') ||
               cimg_sscanf(argz,"%f%c",&z,&end)==1) &&
              (!*argc ||
               (cimg_sscanf(argc,"%f%c%c",&c,&sepc,&end)==2 && sepc=='%') ||
               cimg_sscanf(argc,"%f%c",&c,&end)==1)) {
            print(images,0,"Set value %g in image%s, at coordinates (%g%s,%g%s,%g%s,%g%s).",
                  value,
                  gmic_selection.data(),
                  x,sepx=='%'?"%":"",
                  y,sepy=='%'?"%":"",
                  z,sepz=='%'?"%":"",
                  c,sepc=='%'?"%":"");
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              const int
                nx = (int)cimg::round(sepx=='%'?x*(img.width() - 1)/100:x),
                ny = (int)cimg::round(sepy=='%'?y*(img.height() - 1)/100:y),
                nz = (int)cimg::round(sepz=='%'?z*(img.depth() - 1)/100:z),
                nc = (int)cimg::round(sepc=='%'?c*(img.spectrum() - 1)/100:c);
              gmic_apply(gmic_set(value,nx,ny,nz,nc));
            }
          } else arg_error("set");
          is_released = false; ++position; continue;
        }

        // Split.
        if (!std::strcmp("-split",command)) {
          bool is_valid_argument = false;
          gmic_substitute_args(false);
          float nb = -1;
          char pm = 0;
          *argx = 0;
          if (cimg_sscanf(argument,"%255[xyzc],%f%c",argx,&nb,&end)==2 ||
              (nb = -1,cimg_sscanf(argument,"%255[xyzc]%c",argx,&end))==1) {

            // Split along axes.
            nb = cimg::round(nb);
            if (nb>0)
              print(images,0,"Split image%s along the '%s'-ax%cs, into %g parts.",
                    gmic_selection.data(),
                    argx,
                    std::strlen(argx)>1?'e':'i',
                    nb);
            else if (nb<0) {
              if (nb==-1)
                print(images,0,"Split image%s along the '%s'-ax%cs.",
                      gmic_selection.data(),
                      argx,
                      std::strlen(argx)>1?'e':'i');
              else
                print(images,0,"Split image%s along the '%s'-ax%cs, into blocs of %g pixels.",
                      gmic_selection.data(),
                      argx,
                      std::strlen(argx)>1?'e':'i',
                      -nb);
            } else
              print(images,0,"Split image%s along the '%s'-ax%cs, according to constant values.",
                    gmic_selection.data(),
                    argx,
                    std::strlen(argx)>1?'e':'i');

            int off = 0;
            cimg_forY(selection,l) {
              const unsigned int uind = selection[l] + off;
              const CImg<T>& img = gmic_check(images[uind]);
              if (!img) {
                if (!is_double_hyphen) { images.remove(uind); images_names.remove(uind); off-=1; }
              } else {
                g_list.assign(img,true);
                name = images_names[uind];
                for (const char *axis = argx; *axis; ++axis) {
                  const unsigned int N = g_list.size();
                  for (unsigned int l = 0; l<N; ++l) {
                    g_list[0].get_split(*axis,(int)nb).move_to(g_list,~0U);
                    g_list.remove(0);
                  }
                }
                if (is_double_hyphen) {
                  images_names.insert(g_list.size(),name.copymark());
                  g_list.move_to(images,~0U);
                } else {
                  images.remove(uind); images_names.remove(uind);
                  off+=(int)g_list.size() - 1;
                  images_names.insert(g_list.size(),name.get_copymark(),uind);
                  name.move_to(images_names[uind]);
                  g_list.move_to(images,uind);
                }
              }
            }
            g_list.assign();
            is_valid_argument = true;
          } else if (cimg_sscanf(argument,"%c%c",&pm,&end)==2 && (pm=='+' || pm=='-') && end==',') {

            // Split according to values sequence (opt. with axes too).
            const char *s_values = argument + 2;
            *argx = 0;
            if (cimg_sscanf(s_values,"%255[xyzc]%c",argx,&end)==2 && end==',') s_values+=std::strlen(argx) + 1;
            unsigned int nb_values = 1;
            for (const char *s = s_values; *s; ++s) if (*s==',') ++nb_values;
            CImg<T> values;
            try { values.assign(nb_values,1,1,1).fill(s_values,true,false); }
            catch (CImgException&) { values.assign(); }
            if (values) {
              if (*argx)
                print(images,0,"Split image%s in '%s' mode along '%s'-ax%cs, according to value sequence '%s'.",
                      gmic_selection.data(),
                      pm=='-'?"discard":"keep",
                      argx,
                      std::strlen(argx)>1?'e':'i',
                      gmic_argument_text_printed() + (s_values - argument));
              else
                print(images,0,"Split image%s in '%s' mode, according to value sequence '%s'.",
                      gmic_selection.data(),
                      pm=='-'?"discard":"keep",
                      gmic_argument_text_printed() + 2);
              int off = 0;
              cimg_forY(selection,l) {
                const unsigned int uind = selection[l] + off;
                const CImg<T>& img = gmic_check(images[uind]);
                if (!img) {
                  if (!is_double_hyphen) { images.remove(uind); images_names.remove(uind); off-=1; }
                } else {
                  name = images_names[uind];

                  if (*argx) { // Along axes.
                    g_list.assign(img,true);
                    for (const char *axis = argx; *axis; ++axis) {
                      const unsigned int N = g_list.size();
                      for (unsigned int l = 0; l<N; ++l) {
                        g_list[0].get_split(values,*axis,pm=='+').move_to(g_list,~0U);
                        g_list.remove(0);
                      }
                    }
                  } else // Without axes.
                    img.get_split(values,0,pm=='+').move_to(g_list);

                  if (is_double_hyphen) {
                    if (g_list) {
                      images_names.insert(g_list.size(),name.copymark());
                      g_list.move_to(images,~0U);
                    }
                  } else {
                    images.remove(uind);
                    images_names.remove(uind);
                    off+=(int)g_list.size() - 1;
                    if (g_list) {
                      images_names.insert(g_list.size(),name.get_copymark(),uind);
                      name.move_to(images_names[uind]);
                      g_list.move_to(images,uind);
                    }
                  }
                }
              }
              g_list.assign();
              is_valid_argument = true;
            }
          }

          if (is_valid_argument) ++position;
          else {

            // Split as constant one-column vectors.
            print(images,0,"Split image%s as constant one-column vectors.",
                  gmic_selection.data());

            int off = 0;
            cimg_forY(selection,l) {
              const unsigned int uind = selection[l] + off;
              CImg<T>& img = gmic_check(images[uind]);
              if (!img) {
                if (!is_double_hyphen) { images.remove(uind); images_names.remove(uind); off-=1; }
              } else {
                g_list = CImg<T>(img.data(),1,(unsigned int)img.size(),1,1,true).get_split('y',0);
                name = images_names[uind];
                if (is_double_hyphen) {
                  images_names.insert(g_list.size(),name.copymark());
                  g_list.move_to(images,~0U);
                } else {
                  images.remove(uind); images_names.remove(uind);
                  off+=(int)g_list.size() - 1;
                  images_names.insert(g_list.size(),name.get_copymark(),uind);
                  name.move_to(images_names[uind]);
                  g_list.move_to(images,uind);
                }
              }
            }
          }
          g_list.assign();
          is_released = false; continue;
        }

        // Shared input.
        if (!std::strcmp("-shared",command)) {
          gmic_substitute_args(false);
          CImg<char> st0(256), st1(256), st2(256), st3(256), st4(256);
          char sep2 = 0, sep3 = 0, sep4 = 0;
          float a0 = 0, a1 = 0, a2 = 0, a3 = 0, a4 = 0;
          sep0 = sep1 = *st0 = *st1 = *st2 = *st3 = *st4 = 0;
          if (cimg_sscanf(argument,
                          "%255[0-9.eE%+],%255[0-9.eE%+],%255[0-9.eE%+],%255[0-9.eE%+],"
                          "%255[0-9.eE%+]%c",
                          st0.data(),st1.data(),st2.data(),st3.data(),st4.data(),&end)==5 &&
              (cimg_sscanf(st0,"%f%c",&a0,&end)==1 ||
               (cimg_sscanf(st0,"%f%c%c",&a0,&sep0,&end)==2 && sep0=='%')) &&
              (cimg_sscanf(st1,"%f%c",&a1,&end)==1 ||
               (cimg_sscanf(st1,"%f%c%c",&a1,&sep1,&end)==2 && sep1=='%')) &&
              (cimg_sscanf(st2,"%f%c",&a2,&end)==1 ||
               (cimg_sscanf(st2,"%f%c%c",&a2,&sep2,&end)==2 && sep2=='%')) &&
              (cimg_sscanf(st3,"%f%c",&a3,&end)==1 ||
               (cimg_sscanf(st3,"%f%c%c",&a3,&sep3,&end)==2 && sep3=='%')) &&
              (cimg_sscanf(st4,"%f%c",&a4,&end)==1 ||
               (cimg_sscanf(st4,"%f%c%c",&a4,&sep4,&end)==2 && sep4=='%'))) {
            print(images,0,
                  "Insert shared buffer%s from points (%g%s->%g%s,%g%s,%g%s,%g%s) of image%s.",
                  selection.height()>1?"s":"",
                  a0,sep0=='%'?"%":"",
                  a1,sep1=='%'?"%":"",
                  a2,sep2=='%'?"%":"",
                  a3,sep3=='%'?"%":"",
                  a4,sep4=='%'?"%":"",
                  gmic_selection.data());
            cimg_forY(selection,l) {
              CImg<T>& img = images[selection[l]];
              nvalue0 = cimg::round(sep0=='%'?a0*(img.width() - 1)/100:a0);
              nvalue1 = cimg::round(sep1=='%'?a1*(img.width() - 1)/100:a1);
              const unsigned int
                y =  (unsigned int)cimg::round(sep2=='%'?a2*(img.height() - 1)/100:a2),
                z =  (unsigned int)cimg::round(sep3=='%'?a3*(img.depth() - 1)/100:a3),
                c =  (unsigned int)cimg::round(sep4=='%'?a4*(img.spectrum() - 1)/100:a4);
              images.insert(img.get_shared_points((unsigned int)nvalue0,(unsigned int)nvalue1,y,z,c),~0U,true);
              images_names.insert(images_names[selection[l]].get_copymark());
            }
            ++position;
          } else if (cimg_sscanf(argument,
                                 "%255[0-9.eE%+],%255[0-9.eE%+],%255[0-9.eE%+],"
                                 "%255[0-9.eE%+],%c",
                                 st0.data(),st1.data(),st2.data(),st3.data(),&end)==4 &&
                     (cimg_sscanf(st0,"%f%c",&a0,&end)==1 ||
                      (cimg_sscanf(st0,"%f%c%c",&a0,&sep0,&end)==2 && sep0=='%')) &&
                     (cimg_sscanf(st1,"%f%c",&a1,&end)==1 ||
                      (cimg_sscanf(st1,"%f%c%c",&a1,&sep1,&end)==2 && sep1=='%')) &&
                     (cimg_sscanf(st2,"%f%c",&a2,&end)==1 ||
                      (cimg_sscanf(st2,"%f%c%c",&a2,&sep2,&end)==2 && sep2=='%')) &&
                     (cimg_sscanf(st3,"%f%c",&a3,&end)==1 ||
                      (cimg_sscanf(st3,"%f%c%c",&a3,&sep3,&end)==2 && sep3=='%'))) {
            print(images,0,"Insert shared buffer%s from lines (%g%s->%g%s,%g%s,%g%s) of image%s.",
                  selection.height()>1?"s":"",
                  a0,sep0=='%'?"%":"",
                  a1,sep1=='%'?"%":"",
                  a2,sep2=='%'?"%":"",
                  a3,sep3=='%'?"%":"",
                  gmic_selection.data());
            cimg_forY(selection,l) {
              CImg<T>& img = images[selection[l]];
              nvalue0 = cimg::round(sep0=='%'?a0*(img.height() - 1)/100:a0);
              nvalue1 = cimg::round(sep1=='%'?a1*(img.height() - 1)/100:a1);
              const unsigned int
                z =  (unsigned int)cimg::round(sep2=='%'?a2*(img.depth() - 1)/100:a2),
                c =  (unsigned int)cimg::round(sep3=='%'?a3*(img.spectrum() - 1)/100:a3);
              images.insert(img.get_shared_rows((unsigned int)nvalue0,(unsigned int)nvalue1,z,c),~0U,true);
              images_names.insert(images_names[selection[l]].get_copymark());
            }
            ++position;
          } else if (cimg_sscanf(argument,"%255[0-9.eE%+],%255[0-9.eE%+],%255[0-9.eE%+]%c",
                                 st0.data(),st1.data(),st2.data(),&end)==3 &&
                     (cimg_sscanf(st0,"%f%c",&a0,&end)==1 ||
                      (cimg_sscanf(st0,"%f%c%c",&a0,&sep0,&end)==2 && sep0=='%')) &&
                     (cimg_sscanf(st1,"%f%c",&a1,&end)==1 ||
                      (cimg_sscanf(st1,"%f%c%c",&a1,&sep1,&end)==2 && sep1=='%')) &&
                     (cimg_sscanf(st2,"%f%c",&a2,&end)==1 ||
                      (cimg_sscanf(st2,"%f%c%c",&a2,&sep2,&end)==2 && sep2=='%'))) {
            print(images,0,"Insert shared buffer%s from planes (%g%s->%g%s,%g%s) of image%s.",
                  selection.height()>1?"s":"",
                  a0,sep0=='%'?"%":"",
                  a1,sep1=='%'?"%":"",
                  a2,sep2=='%'?"%":"",
                  gmic_selection.data());
            cimg_forY(selection,l) {
              CImg<T>& img = images[selection[l]];
              nvalue0 = cimg::round(sep0=='%'?a0*(img.depth() - 1)/100:a0);
              nvalue1 = cimg::round(sep1=='%'?a1*(img.depth() - 1)/100:a1);
              const unsigned int
                c =  (unsigned int)cimg::round(sep2=='%'?a2*(img.spectrum() - 1)/100:a2);
              images.insert(img.get_shared_slices((unsigned int)nvalue0,(unsigned int)nvalue1,c),~0U,true);
              images_names.insert(images_names[selection[l]].get_copymark());
            }
            ++position;
          } else if (cimg_sscanf(argument,"%255[0-9.eE%+],%255[0-9.eE%+]%c",
                                 st0.data(),st1.data(),&end)==2 &&
                     (cimg_sscanf(st0,"%f%c",&a0,&end)==1 ||
                      (cimg_sscanf(st0,"%f%c%c",&a0,&sep0,&end)==2 && sep0=='%')) &&
                     (cimg_sscanf(st1,"%f%c",&a1,&end)==1 ||
                      (cimg_sscanf(st1,"%f%c%c",&a1,&sep1,&end)==2 && sep1=='%'))) {
            print(images,0,"Insert shared buffer%s from channels (%g%s->%g%s) of image%s.",
                  selection.height()>1?"s":"",
                  a0,sep0=='%'?"%":"",
                  a1,sep1=='%'?"%":"",
                  gmic_selection.data());
            cimg_forY(selection,l) {
              CImg<T>& img = images[selection[l]];
              nvalue0 = cimg::round(sep0=='%'?a0*(img.spectrum() - 1)/100:a0);
              nvalue1 = cimg::round(sep1=='%'?a1*(img.spectrum() - 1)/100:a1);
              images.insert(img.get_shared_channels((unsigned int)nvalue0,(unsigned int)nvalue1),~0U,true);
              images_names.insert(images_names[selection[l]].get_copymark());
            }
            ++position;
          } else if (cimg_sscanf(argument,"%255[0-9.eE%+]%c",
                                 st0.data(),&end)==1 &&
                     (cimg_sscanf(st0,"%f%c",&a0,&end)==1 ||
                      (cimg_sscanf(st0,"%f%c%c",&a0,&sep0,&end)==2 && sep0=='%'))) {
            print(images,0,"Insert shared buffer%s from channel %g%s of image%s.",
                  selection.height()>1?"s":"",
                  a0,sep0=='%'?"%":"",
                  gmic_selection.data());
            cimg_forY(selection,l) {
              CImg<T>& img = images[selection[l]];
              nvalue0 = cimg::round(sep0=='%'?a0*(img.spectrum() - 1)/100:a0);
              images.insert(img.get_shared_channel((unsigned int)nvalue0),~0U,true);
              images_names.insert(images_names[selection[l]].get_copymark());
            }
            ++position;
          } else {
            print(images,0,"Insert shared buffer%s from image%s.",
                  selection.height()>1?"s":"",
                  gmic_selection.data());
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              images.insert(img,~0U,true);
              images_names.insert(images_names[selection[l]].get_copymark());
            }
          }
          is_released = false; continue;
        }

        // Shift.
        if (!std::strcmp("-shift",command)) {
          gmic_substitute_args(false);
          float dx = 0, dy = 0, dz = 0, dc = 0;
          sepx = sepy = sepz = sepc = *argx = *argy = *argz = *argc = 0;
          boundary = 0;
          if ((cimg_sscanf(argument,"%255[0-9.eE%+-]%c",
                           argx,&end)==1 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                           argx,argy,&end)==2 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                           argx,argy,argz,&end)==3 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%255[0-9.eE%+-]%c",
                           argx,argy,argz,argc,&end)==4 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],"
                           "%255[0-9.eE%+-],%u%c",
                           argx,argy,argz,argc,&boundary,&end)==5) &&
              (cimg_sscanf(argx,"%f%c",&dx,&end)==1 ||
               (cimg_sscanf(argx,"%f%c%c",&dx,&sepx,&end)==2 && sepx=='%')) &&
              (!*argy ||
               cimg_sscanf(argy,"%f%c",&dy,&end)==1 ||
               (cimg_sscanf(argy,"%f%c%c",&dy,&sepy,&end)==2 && sepy=='%')) &&
              (!*argz ||
               cimg_sscanf(argz,"%f%c",&dz,&end)==1 ||
               (cimg_sscanf(argz,"%f%c%c",&dz,&sepz,&end)==2 && sepz=='%')) &&
              (!*argc ||
               cimg_sscanf(argc,"%f%c",&dc,&end)==1 ||
               (cimg_sscanf(argc,"%f%c%c",&dc,&sepc,&end)==2 && sepc=='%')) &&
              boundary<=2) {
            print(images,0,
                  "Shift image%s by displacement vector (%g%s,%g%s,%g%s,%g%s) and "
                  "%s boundary conditions.",
                  gmic_selection.data(),
                  dx,sepx=='%'?"%":"",
                  dy,sepy=='%'?"%":"",
                  dz,sepz=='%'?"%":"",
                  dc,sepc=='%'?"%":"",
                  boundary==0?"dirichlet":boundary==1?"neumann":"periodic");
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              const float
                ndx = sepx=='%'?dx*img.width()/100:dx,
                ndy = sepy=='%'?dy*img.height()/100:dy,
                ndz = sepz=='%'?dz*img.depth()/100:dz,
                ndc = sepc=='%'?dc*img.spectrum()/100:dc;
              gmic_apply(gmic_shift(ndx,ndy,ndz,ndc,boundary));
            }
          } else arg_error("shift");
          is_released = false; ++position; continue;
        }

        // Keep slices.
        if (!std::strcmp("-slices",command)) {
          gmic_substitute_args(true);
          ind0.assign(); ind1.assign();
          sep0 = sep1 = *argx = *argy = *indices = 0;
          value0 = value1 = 0;
          if (cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-]%c",
                          argx,&end)==1 &&
              ((cimg_sscanf(argx,"[%255[a-zA-Z0-9_.%+-]%c%c]",indices,&sep0,&end)==2 &&
                sep0==']' &&
                (ind0=selection2cimg(indices,images.size(),images_names,"-slices")).height()==1) ||
               cimg_sscanf(argx,"%lf%c",&value0,&end)==1 ||
               (cimg_sscanf(argx,"%lf%c%c",&value0,&sep0,&end)==2 && sep0=='%'))) {
            if (ind0) { value0 = images[*ind0].depth() - 1.; sep0 = 0; }
            print(images,0,"Keep slice %g%s of image%s.",
                  value0,sep0=='%'?"%":"",
                  gmic_selection.data());
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              nvalue0 = cimg::round(sep0=='%'?value0*(img.depth() - 1)/100:value0);
              gmic_apply(slice((int)nvalue0));
            }
          } else if (cimg_sscanf(argument,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-]%c",
                                 argx,argy,&end)==2 &&
                     ((cimg_sscanf(argx,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep0,&end)==2 &&
                       sep0==']' &&
                       (ind0=selection2cimg(indices,images.size(),images_names,"-slices")).height()==1) ||
                      cimg_sscanf(argx,"%lf%c",&value0,&end)==1 ||
                      (cimg_sscanf(argx,"%lf%c%c",&value0,&sep0,&end)==2 && sep0=='%')) &&
                     ((cimg_sscanf(argx,"[%255[a-zA-Z0-9_.%+-]%c%c",formula,&sep0,&end)==2 &&
                       sep0==']' &&
                       (ind1=selection2cimg(formula,images.size(),images_names,"-slices")).height()==1) ||
                      cimg_sscanf(argy,"%lf%c",&value1,&end)==1 ||
                      (cimg_sscanf(argy,"%lf%c%c",&value1,&sep1,&end)==2 && sep1=='%'))) {
            if (ind0) { value0 = images[*ind0].depth() - 1.; sep0 = 0; }
            if (ind1) { value1 = images[*ind1].depth() - 1.; sep1 = 0; }
            print(images,0,"Keep slices %g%s...%g%s of image%s.",
                  value0,sep0=='%'?"%":"",
                  value1,sep1=='%'?"%":"",
                  gmic_selection.data());
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              nvalue0 = cimg::round(sep0=='%'?value0*(img.depth() - 1)/100:value0);
              nvalue1 = cimg::round(sep1=='%'?value1*(img.depth() - 1)/100:value1);
              gmic_apply(slices((int)nvalue0,(int)nvalue1));
            }
          } else arg_error("slices");
          is_released = false; ++position; continue;
        }

        // Sub.
        gmic_arithmetic_command("-sub",
                                operator-=,
                                "Subtract %g%s to image%s",
                                value,ssep,gmic_selection.data(),Tfloat,
                                operator-=,
                                "Subtract image [%d] to image%s",
                                ind[0],gmic_selection.data(),
                                operator_minuseq,
                                "Subtract expression %s to image%s",
                                gmic_argument_text_printed(),gmic_selection.data(),
                                "Subtract image%s");
        // Square root.
        gmic_simple_command("-sqrt",sqrt,"Compute pointwise square root of image%s.");

        // Square.
        gmic_simple_command("-sqr",sqr,"Compute pointwise square function of image%s.");

        // Sign.
        gmic_simple_command("-sign",sign,"Compute pointwise sign of image%s.");

        // Sine.
        gmic_simple_command("-sin",sin,"Compute pointwise sine of image%s.");

        // Sort.
        if (!std::strcmp("-sort",command)) {
          gmic_substitute_args(false);
          char order = '+';
          axis = 0;
          if ((cimg_sscanf(argument,"%c%c",&order,&end)==1 ||
               (cimg_sscanf(argument,"%c,%c%c",&order,&axis,&end)==2 &&
                (axis=='x' || axis=='y' || axis=='z' || axis=='c'))) &&
              (order=='+' || order=='-')) ++position;
          else { order = '+'; axis = 0; }
          if (axis) print(images,0,"Sort values of image%s in %s order, according to axis '%c'.",
                          gmic_selection.data(),order=='+'?"ascending":"descending",axis);
          else print(images,0,"Sort values of image%s in %s order.",
                     gmic_selection.data(),order=='+'?"ascending":"descending");
          cimg_forY(selection,l) gmic_apply(sort(order=='+',axis));
          is_released = false; continue;
        }

        // Solve.
        if (!std::strcmp("-solve",command)) {
          gmic_substitute_args(true);
          sep = *indices = 0;
          if (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep,&end)==2 &&
              sep==']' &&
              (ind=selection2cimg(indices,images.size(),images_names,"-solve")).height()==1) {
            print(images,0,"Solve linear system AX = B, with B-vector%s and A-matrix [%d].",
                  gmic_selection.data(),*ind);
            const CImg<T> A = gmic_image_arg(*ind);
            cimg_forY(selection,l) gmic_apply(solve(A));
          } else arg_error("solve");
          is_released = false; ++position; continue;
        }

        // Shift 3d object, with opposite displacement.
        if (!std::strcmp("-sub3d",command)) {
          gmic_substitute_args(false);
          float tx = 0, ty = 0, tz = 0;
          if (cimg_sscanf(argument,"%f%c",
                          &tx,&end)==1 ||
              cimg_sscanf(argument,"%f,%f%c",
                          &tx,&ty,&end)==2 ||
              cimg_sscanf(argument,"%f,%f,%f%c",
                          &tx,&ty,&tz,&end)==3) {
            print(images,0,"Shift 3d object%s with displacement -(%g,%g,%g).",
                  gmic_selection.data(),
                  tx,ty,tz);
            cimg_forY(selection,l) {
              const unsigned int uind = selection[l];
              CImg<T>& img = images[uind];
              try { gmic_apply(shift_CImg3d(-tx,-ty,-tz)); }
              catch (CImgException&) {
                if (!img.is_CImg3d(true,&(*message=0)))
                  error(images,0,0,
                        "Command '-sub3d': Invalid 3d object [%d], in selected image%s (%s).",
                        uind,gmic_selection_err.data(),message.data());
                else throw;
              }
            }
          } else arg_error("sub3d");
          is_released = false; ++position; continue;
        }

        // Sharpen.
        if (!std::strcmp("-sharpen",command)) {
          gmic_substitute_args(false);
          float amplitude = 0, edge = -1, alpha = 0, sigma = 0;
          if ((cimg_sscanf(argument,"%f%c",
                           &amplitude,&end)==1 ||
               cimg_sscanf(argument,"%f,%f%c",
                           &amplitude,&edge,&end)==2 ||
               cimg_sscanf(argument,"%f,%f,%f%c",
                           &amplitude,&edge,&alpha,&end)==3 ||
               cimg_sscanf(argument,"%f,%f,%f,%f%c",
                           &amplitude,&edge,&alpha,&sigma,&end)==4) &&
              amplitude>=0 && (edge==-1 || edge>=0)) {
            if (edge>=0)
              print(images,0,"Sharpen image%s with shock filters, amplitude %g, edge %g, "
                    "alpha %g and sigma %g.",
                    gmic_selection.data(),
                    amplitude,
                    edge,
                    alpha,
                    sigma);
            else
              print(images,0,"Sharpen image%s with inverse diffusion and amplitude %g.",
                    gmic_selection.data(),
                    amplitude);
            cimg_forY(selection,l) gmic_apply(sharpen(amplitude,(bool)(edge>=0),edge,alpha,sigma));
          } else arg_error("sharpen");
          is_released = false; ++position; continue;
        }

        // Set random generator seed.
        if (!std::strcmp("-srand",item)) {
          gmic_substitute_args(false);
          value = 0;
          if (cimg_sscanf(argument,"%lf%c",
                          &value,&end)==1) {
            value = cimg::round(value);
            print(images,0,"Set random generator seed to %u.",
                  (unsigned int)value);
            cimg::srand((unsigned int)value);
            ++position;
          } else {
            print(images,0,"Set random generator seed to random.");
            cimg::srand();
          }
          continue;
        }

        // Anisotropic PDE-based smoothing.
        if (!std::strcmp("-smooth",command)) {
          gmic_substitute_args(true);
          float amplitude = 0, sharpness = 0.7f, anisotropy = 0.3f, alpha = 0.6f,
            sigma = 1.1f, dl =0.8f, da = 30.0f, gauss_prec = 2.0f;
          unsigned int interpolation = 0, is_fast_approximation = 1;
          sep = 0;
          if ((cimg_sscanf(argument,"%f%c",
                           &amplitude,&end)==1 ||
               cimg_sscanf(argument,"%f,%f%c",
                           &amplitude,&sharpness,&end)==2 ||
               cimg_sscanf(argument,"%f,%f,%f%c",
                           &amplitude,&sharpness,&anisotropy,&end)==3 ||
               cimg_sscanf(argument,"%f,%f,%f,%f%c",
                           &amplitude,&sharpness,&anisotropy,&alpha,&end)==4 ||
               cimg_sscanf(argument,"%f,%f,%f,%f,%f%c",
                           &amplitude,&sharpness,&anisotropy,&alpha,&sigma,&end)==5 ||
               cimg_sscanf(argument,"%f,%f,%f,%f,%f,%f%c",
                           &amplitude,&sharpness,&anisotropy,&alpha,&sigma,&dl,&end)==6 ||
               cimg_sscanf(argument,"%f,%f,%f,%f,%f,%f,%f%c",
                           &amplitude,&sharpness,&anisotropy,&alpha,&sigma,&dl,&da,&end)==7 ||
               cimg_sscanf(argument,"%f,%f,%f,%f,%f,%f,%f,%f%c",
                           &amplitude,&sharpness,&anisotropy,&alpha,&sigma,&dl,&da,&gauss_prec,
                           &end)==8 ||
               cimg_sscanf(argument,"%f,%f,%f,%f,%f,%f,%f,%f,%u%c",
                           &amplitude,&sharpness,&anisotropy,&alpha,&sigma,&dl,&da,&gauss_prec,
                           &interpolation,&end)==9 ||
               cimg_sscanf(argument,"%f,%f,%f,%f,%f,%f,%f,%f,%u,%u%c",
                           &amplitude,&sharpness,&anisotropy,&alpha,&sigma,&dl,&da,&gauss_prec,
                           &interpolation,&is_fast_approximation,&end)==10) &&
              amplitude>=0 && sharpness>=0 && anisotropy>=0 && anisotropy<=1 && dl>0 &&
              da>=0 && gauss_prec>0 && interpolation<=2 && is_fast_approximation<=1) {
            if (da>0)
              print(images,0,"Smooth image%s anisotropically, with amplitude %g, sharpness %g, "
                    "anisotropy %g, alpha %g, sigma %g, dl %g, da %g, precision %g, "
                    "%s interpolation and fast approximation %s.",
                    gmic_selection.data(),
                    amplitude,
                    sharpness,
                    anisotropy,
                    alpha,
                    sigma,
                    dl,
                    da,
                    gauss_prec,
                    interpolation==0?"nearest-neighbor":interpolation==1?"linear":"runge-kutta",
                    is_fast_approximation?"enabled":"disabled");
            else
              print(images,0,"Smooth image%s anisotropically, with %d iterations, sharpness %g, "
                    "anisotropy %g, alpha %g, sigma %g and dt %g.",
                    gmic_selection.data(),
                    (int)amplitude,
                    sharpness,
                    anisotropy,
                    alpha,
                    sigma,
                    dl);
            cimg_forY(selection,l) gmic_apply(blur_anisotropic(amplitude,sharpness,anisotropy,alpha,sigma,dl,da,
                                                               gauss_prec,interpolation,(bool)is_fast_approximation));
          } else if (((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",
                                   indices,&sep,&end)==2 && sep==']') ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f%c",
                                  indices,&amplitude,&end)==2 ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f%c",
                                  indices,&amplitude,&dl,&end)==3 ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f%c",
                                  indices,&amplitude,&dl,&da,&end)==4 ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f,%f%c",
                                  indices,&amplitude,&dl,&da,&gauss_prec,&end)==5 ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f,%f,%u%c",
                                  indices,&amplitude,&dl,&da,&gauss_prec,
                                  &interpolation,&end)==6 ||
                      cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%f,%f,%f,%f,%u,%u%c",
                                  indices,&amplitude,&dl,&da,&gauss_prec,&interpolation,
                                  &is_fast_approximation,&end)==7) &&
                     (ind=selection2cimg(indices,images.size(),images_names,"-smooth")).height()==1 &&
                     amplitude>=0 && dl>0 && da>=0 && gauss_prec>0 && interpolation<=2 &&
                     is_fast_approximation<=1) {
            const CImg<T> tensors = gmic_image_arg(*ind);
            if (da>0)
              print(images,0,
                    "Smooth image%s anisotropically, with tensor field [%u], amplitude %g, "
                    "dl %g, da %g, precision %g, %s interpolation and fast approximation %s.",
                    gmic_selection.data(),
                    *ind,
                    amplitude,
                    dl,
                    da,
                    gauss_prec,
                    interpolation==0?"nearest-neighbor":interpolation==1?"linear":"runge-kutta",
                    is_fast_approximation?"enabled":"disabled");
            else
              print(images,0,
                    "Smooth image%s anisotropically, with tensor field [%u], %d iterations "
                    "and dt %g.",
                    gmic_selection.data(),
                    *ind,
                    (int)amplitude,
                    dl);
            cimg_forY(selection,l) gmic_apply(blur_anisotropic(tensors,amplitude,dl,da,gauss_prec,interpolation,
                                                               is_fast_approximation));
          } else arg_error("smooth");
          is_released = false; ++position; continue;
        }

        // Split 3d objects, into 6 vector images
        // { header,N,vertices,primitives,colors,opacities }
        if (!std::strcmp("-split3d",command)) {
          bool keep_shared = true;
          gmic_substitute_args(false);
          if ((*argument=='0' || *argument=='1') && !argument[1]) {
            keep_shared = *argument=='1';
            ++position;
          }
          print(images,0,"Split 3d object%s into 6 property vectors%s.",
                gmic_selection.data(),
                keep_shared?"":" and clone shared data");
          unsigned int off = 0;
          cimg_forY(selection,l) {
            const unsigned int uind = selection[l] + off;
            const CImg<T> &img = gmic_check(images[uind]);
            name = images_names[uind];
            try {
              if (!keep_shared) {
                CImg<T> _vertices;
                CImgList<T> Tcolors, opacities;
                img.get_CImg3dtoobject3d(primitives,Tcolors,opacities,false).move_to(_vertices);
                CImgList<T> _colors(Tcolors,false), _opacities(opacities,false);
                _colors.move_to(Tcolors.assign());
                _opacities.move_to(opacities.assign());
                _vertices.object3dtoCImg3d(primitives,Tcolors,opacities,false).get_split_CImg3d().
                  move_to(g_list);
                primitives.assign();
              } else img.get_split_CImg3d().move_to(g_list);
            } catch (CImgException&) {
              if (!img.is_CImg3d(true,&(*message=0)))
                error(images,0,0,
                      "Command '-split3d': Invalid 3d object [%d], in selected image%s (%s).",
                      uind - off,gmic_selection_err.data(),message.data());
              else throw;
            }
            if (is_double_hyphen) {
              images_names.insert(g_list.size(),name.copymark());
              g_list.move_to(images,~0U);
            } else {
              images.remove(uind);
              images_names.remove(uind);
              off+=g_list.size() - 1;
              images_names.insert(g_list.size(),name.get_copymark(),uind);
              name.move_to(images_names[uind]);
              g_list.move_to(images,uind);
            }
          }
          g_list.assign();
          is_released = false; continue;
        }

        // Screenshot.
        if (!std::strcmp("-screen",item)) {
          gmic_substitute_args(false);
          sepx = sepy = sepz = sepc = *argx = *argy = *argz = *argc = 0;
          if (cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                          argx,argy,argz,argc,&end)==4 &&
              (cimg_sscanf(argx,"%lf%c",&value0,&end)==1 ||
               (cimg_sscanf(argx,"%lf%c%c",&value0,&sepx,&end)==2 && sepx=='%')) &&
              (cimg_sscanf(argy,"%lf%c",&value1,&end)==1 ||
               (cimg_sscanf(argy,"%lf%c%c",&value1,&sepy,&end)==2 && sepy=='%')) &&
              (cimg_sscanf(argz,"%lf%c",&nvalue0,&end)==1 ||
               (cimg_sscanf(argz,"%lf%c%c",&nvalue0,&sepz,&end)==2 && sepz=='%')) &&
              (cimg_sscanf(argc,"%lf%c",&nvalue1,&end)==1 ||
               (cimg_sscanf(argc,"%lf%c%c",&nvalue1,&sepc,&end)==2 && sepc=='%'))) {
            print(images,0,"Take screenshot, with coordinates (%s,%s) - (%s,%s).",
                  argx,argy,argz,argc);
            if (sepx=='%') value0 = value0*CImgDisplay::screen_width()/100;
            if (sepy=='%') value1 = value1*CImgDisplay::screen_height()/100;
            if (sepz=='%') nvalue0 = nvalue0*CImgDisplay::screen_width()/100;
            if (sepc=='%') nvalue1 = nvalue1*CImgDisplay::screen_height()/100;
            value0 = cimg::round(value0);
            value1 = cimg::round(value1);
            nvalue0 = cimg::round(nvalue0);
            nvalue1 = cimg::round(nvalue1);
            cimg_snprintf(title,_title.width(),"[Screenshot (%g,%g)-(%g,%g)]",
                          value0,value1,nvalue0,nvalue1);
            images.insert(1);
            CImgDisplay::screenshot((int)value0,(int)value1,(int)nvalue0,(int)nvalue1,images.back());
            ++position;
          } else {
            print(images,0,"Take screenshot.");
            cimg_snprintf(title,_title.width(),"[Screenshot]");
            images.insert(1);
            CImgDisplay::screenshot(images.back());
          }
          CImg<char>::string(title).move_to(images_names);
          is_released = false; continue;
        }

        // SVD.
        if (!std::strcmp("-svd",command)) {
          print(images,0,"Compute SVD decomposition%s of matri%s%s.",
                selection.height()>1?"s":"",selection.height()>1?"ce":"x",gmic_selection.data());
          CImg<float> U, S, V;
          unsigned int off = 0;
          cimg_forY(selection,l) {
            const unsigned int uind = selection[l] + off;
            const CImg<T>& img = gmic_check(images[uind]);
            name = images_names[uind];
            img.SVD(U,S,V,true,100);
            if (is_double_hyphen) {
              images_names.insert(2,name.copymark());
              name.move_to(images_names);
              U.move_to(images);
              S.move_to(images);
              V.move_to(images);
            } else {
              images_names.insert(2,name.get_copymark(),uind + 1);
              name.move_to(images_names[uind]);
              U.move_to(images[uind].assign());
              images.insert(S,uind + 1);
              images.insert(V,uind + 2);
              off+=2;
            }
          }
          is_released = false; continue;
        }

        // Input 3d sphere.
        if (!std::strcmp("-sphere3d",item)) {
          gmic_substitute_args(false);
          float radius = 100, recursions = 3;
          if ((cimg_sscanf(argument,"%f%c",
                           &radius,&end)==1 ||
               cimg_sscanf(argument,"%f,%f%c",
                           &radius,&recursions,&end)==2) &&
              recursions>=0) {
            recursions = cimg::round(recursions);
            print(images,0,"Input 3d sphere, with radius %g and %g recursions.",
                  radius,
                  recursions);
            CImg<T>::sphere3d(primitives,radius,(unsigned int)recursions).move_to(vertices);
            vertices.object3dtoCImg3d(primitives,false).move_to(images);
            primitives.assign();
            CImg<char>::string("[3d sphere]").move_to(images_names);
          } else arg_error("sphere3d");
          is_released = false; ++position; continue;
        }

        // Set 3d specular light parameters.
        if (!std::strcmp("-specl3d",item)) {
          gmic_substitute_args(false);
          value = 0.15;
          if (cimg_sscanf(argument,"%lf%c",
                          &value,&end)==1 && value>=0) ++position;
          else value = 0.15;
          specular_lightness3d = (float)value;
          print(images,0,"Set lightness of 3d specular light to %g.",
                specular_lightness3d);
          continue;
        }

        if (!std::strcmp("-specs3d",item)) {
          gmic_substitute_args(false);
          value = 0.8;
          if (cimg_sscanf(argument,"%lf%c",
                          &value,&end)==1 && value>=0) ++position;
          else value = 0.8;
          specular_shininess3d = (float)value;
          print(images,0,"Set shininess of 3d specular light to %g.",
                specular_shininess3d);
          continue;
        }

        // Sine-cardinal.
        gmic_simple_command("-sinc",sinc,"Compute pointwise sinc function of image%s.");

        // Hyperbolic sine.
        gmic_simple_command("-sinh",sinh,"Compute pointwise hyperpolic sine of image%s.");

        // sRGB to RGB.
        gmic_simple_command("-srgb2rgb",sRGBtoRGB,"Convert image%s from sRGB to RGB color bases.");

        // Extract 3d streamline.
        if (!std::strcmp("-streamline3d",command)) {
          gmic_substitute_args(false);
          unsigned int interp = 2, is_backward = 0, is_oriented_only = 0;
          float x = 0, y = 0, z = 0, L = 100, dl = 0.1f;
          sepx = sepy = sepz = *formula = 0;
          if ((cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                           argx,argy,argz,&end)==3 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],%f%c",
                           argx,argy,argz,&L,&end)==4 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],%f,%f%c",
                           argx,argy,argz,&L,&dl,&end)==5 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],%f,%f,%u%c",
                           argx,argy,argz,&L,&dl,&interp,&end)==6 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],%f,%f,%u,"
                           "%u%c",
                           argx,argy,argz,&L,&dl,&interp,&is_backward,&end)==7 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],%f,%f,%u,"
                           "%u,%u%c",
                           argx,argy,argz,&L,&dl,&interp,&is_backward,
                           &is_oriented_only,&end)==8) &&
              (cimg_sscanf(argx,"%f%c",&x,&end)==1 ||
               (cimg_sscanf(argx,"%f%c%c",&x,&sepx,&end)==2 && sepx=='%')) &&
              (!*argy ||
               cimg_sscanf(argy,"%f%c",&y,&end)==1 ||
               (cimg_sscanf(argy,"%f%c%c",&y,&sepy,&end)==2 && sepy=='%')) &&
              (!*argz ||
               cimg_sscanf(argz,"%f%c",&z,&end)==1 ||
               (cimg_sscanf(argz,"%f%c%c",&z,&sepz,&end)==2 && sepz=='%')) &&
              L>=0 && dl>0 && interp<4 && is_backward<=1 && is_oriented_only<=1) {
            print(images,0,"Extract 3d streamline from image%s, starting from (%g%s,%g%s,%g%s).",
                  gmic_selection.data(),
                  x,sepx=='%'?"%":"",
                  y,sepy=='%'?"%":"",
                  z,sepz=='%'?"%":"");
            cimg_forY(selection,l) {
              const unsigned int uind = selection[l];
              CImg<T>& img = gmic_check(images[uind]);
              const float
                nx = cimg::round(sepx=='%'?x*(img.width() - 1)/100:x),
                ny = cimg::round(sepy=='%'?y*(img.height() - 1)/100:y),
                nz = cimg::round(sepz=='%'?z*(img.depth() - 1)/100:z);
              img.get_streamline(nx,ny,nz,L,dl,interp,
                                 (bool)is_backward,(bool)is_oriented_only).move_to(vertices);
              if (vertices.width()>1) {
                primitives.assign(vertices.width() - 1,1,2);
                cimglist_for(primitives,l) { primitives(l,0) = (unsigned int)l; primitives(l,1) = l + 1U; }
                g_list_uc.assign(primitives.size(),1,3,1,1,200);
              } else {
                vertices.assign();
                warn(images,0,false,
                     "Command '-streamline3d': Empty streamline starting from "
                     "(%g%s,%g%s,%g%s) in image [%u].",
                     x,sepx=='%'?"%":"",
                     y,sepy=='%'?"%":"",
                     z,sepz=='%'?"%":"",
                     uind);
              }
              vertices.object3dtoCImg3d(primitives,g_list_uc,false);
              gmic_apply(replace(vertices));
              primitives.assign();
              g_list_uc.assign();
            }
          } else if ((cimg_sscanf(argument,"'%4095[^']',%f,%f,%f%c",
                                  formula,&x,&y,&z,&end)==4 ||
                      cimg_sscanf(argument,"'%4095[^']',%f,%f,%f,%f%c",
                                  formula,&x,&y,&z,&L,&end)==5 ||
                      cimg_sscanf(argument,"'%4095[^']',%f,%f,%f,%f,%f%c",
                                  formula,&x,&y,&z,&L,&dl,&end)==6 ||
                      cimg_sscanf(argument,"'%4095[^']',%f,%f,%f,%f,%f,%u%c",
                                  formula,&x,&y,&z,&L,&dl,&interp,&end)==7 ||
                      cimg_sscanf(argument,"'%4095[^']',%f,%f,%f,%f,%f,%u,%u%c",
                                  formula,&x,&y,&z,&L,&dl,&interp,&is_backward,&end)==8 ||
                      cimg_sscanf(argument,"'%4095[^']',%f,%f,%f,%f,%f,%u,%u,%u%c",
                                  formula,&x,&y,&z,&L,&dl,&interp,&is_backward,
                                  &is_oriented_only,&end)==9) &&
                     dl>0 && interp<4) {
            strreplace_fw(formula);
            print(images,0,"Extract 3d streamline from formula '%s', starting from (%g,%g,%g).",
                  formula,
                  x,y,z);
            CImg<T>::streamline((const char *)formula,x,y,z,L,dl,interp,
                                (bool)is_backward,(bool)is_oriented_only).move_to(vertices);
            if (vertices.width()>1) {
              primitives.assign(vertices.width() - 1,1,2);
              cimglist_for(primitives,l) { primitives(l,0) = (unsigned int)l; primitives(l,1) = l + 1U; }
              g_list_uc.assign(primitives.size(),1,3,1,1,200);
            } else {
              vertices.assign();
              warn(images,0,false,
                   "Command '-streamline3d': Empty streamline starting from (%g,%g,%g) "
                   "in expression '%s'.",
                   x,y,z,formula);
            }
            vertices.object3dtoCImg3d(primitives,g_list_uc,false).move_to(images);
            primitives.assign();
            g_list_uc.assign();
            cimg_snprintf(title,_title.width(),"[3d streamline of '%s' at (%g,%g,%g)]",
                          formula,x,y,z);
            CImg<char>::string(title).move_to(images_names);
          } else arg_error("streamline3d");
          is_released = false; ++position; continue;
        }

        // Compute structure tensor field.
        if (!std::strcmp("-structuretensors",command)) {
          gmic_substitute_args(false);
          unsigned int is_fwbw_scheme = 0;
          if (cimg_sscanf(argument,"%u%c",&is_fwbw_scheme,&end)==1 &&
              is_fwbw_scheme<=1) ++position;
          else is_fwbw_scheme = 1;
          print(images,0,"Compute structure tensor field of image%s, with %s scheme.",
                gmic_selection.data(),
                is_fwbw_scheme==1?"forward-backward":"centered");
          cimg_forY(selection,l) gmic_apply(structure_tensors((bool)is_fwbw_scheme));
          is_released = false; continue;
        }

        // Select image feature.
        if (!std::strcmp("-select",command)) {
          gmic_substitute_args(false);
          unsigned int feature_type = 0, X = ~0U, Y = ~0U, Z = ~0U;
          bool is_xyz = false;
          exit_on_anykey = 0;
          if ((cimg_sscanf(argument,"%u%c",&feature_type,&end)==1 ||
               (is_xyz=(cimg_sscanf(argument,"%u,%u,%u,%u%c",&feature_type,&X,&Y,&Z,&end)==4)) ||
               (is_xyz=(cimg_sscanf(argument,"%u,%u,%u,%u,%u%c",&feature_type,&X,&Y,&Z,&exit_on_anykey,&end)==5))) &&
              feature_type<=3 && exit_on_anykey<=1) {
#if cimg_display==0
            print(images,0,"Select %s in image%s in interactive mode",
                  feature_type==0?"point":feature_type==1?"segment":feature_type==2?"rectangle":
                  "ellipse",gmic_selection.data());
            if (is_verbose) {
              cimg::mutex(29);
              if (is_xyz) std::fprintf(cimg::output(),", from point (%u,%u,%u)",X,Y,Z);
              std::fprintf(cimg::output()," (skipped, no display support).");
              std::fflush(cimg::output());
              cimg::mutex(29,0);
            }
            CImg<char>::string("-1").move_to(status);
#else // #if cimg_display==0
            bool is_available_display = false;
            try {
              is_available_display = (bool)CImgDisplay::screen_width();
            } catch (CImgDisplayException&) {
              print(images,0,
                    "Select %s in image%s in interactive mode",
                    feature_type==0?"point":feature_type==1?"segment":
                    feature_type==2?"rectangle":"ellipse",gmic_selection.data());
              if (is_verbose) {
                cimg::mutex(29);
                if (is_xyz) std::fprintf(cimg::output(),", from point (%u,%u,%u)",X,Y,Z);
                std::fprintf(cimg::output()," (skipped, no display available).");
                std::fflush(cimg::output());
                cimg::mutex(29,0);
              }
            }
            if (is_available_display) {
              print(images,0,"Select %s in image%s in interactive mode",
                    feature_type==0?"point":feature_type==1?"segment":
                    feature_type==2?"rectangle":"ellipse",gmic_selection.data());
              if (is_verbose) {
                cimg::mutex(29);
                if (is_xyz) std::fprintf(cimg::output(),", from point (%u,%u,%u).",X,Y,Z);
                else std::fprintf(cimg::output(),".");
                std::fflush(cimg::output());
                cimg::mutex(29,0);
              }
              unsigned int XYZ[3];
              XYZ[0] = X; XYZ[1] = Y; XYZ[2] = Z;
              if (_display_window[0]) {
                cimg_forY(selection,l)
                  gmic_apply(select(_display_window[0],feature_type,is_xyz?XYZ:0,
                                    (bool)exit_on_anykey));
              }
              else {
                cimg_forY(selection,l)
                  gmic_apply(select(images_names[selection[l]].data(),feature_type,is_xyz?XYZ:0,
                                    (bool)exit_on_anykey));
              }
            }
            if (is_double_hyphen) images.back().value_string().move_to(status);
            else images[selection.back()].value_string().move_to(status);
#endif // #if cimg_display==0
          } else arg_error("select");
          is_released = false; ++position; continue;
        }

        // Serialize.
        if (!std::strcmp("-serialize",command)) {
#define gmic_serialize(value_type,svalue_type) \
          if (!std::strcmp(argx,svalue_type)) \
            CImgList<value_type>(g_list,cimg::type<T>::string()==cimg::type<value_type>::string()). \
              get_serialize((bool)is_compressed).move_to(serialized);

          gmic_substitute_args(false);
          bool is_compressed0 = false;
#ifdef cimg_use_zlib
          is_compressed0 = true;
#endif
          unsigned int is_compressed = is_compressed0?1U:0U, is_gmz = 1;
          if ((cimg_sscanf(argument,"%255[a-z ]%c",
                           argx,&end)==1 ||
               cimg_sscanf(argument,"%255[a-z ],%u%c",
                           argx,&is_compressed,&end)==2 ||
               cimg_sscanf(argument,"%255[a-z ],%u,%u%c",
                           argx,&is_compressed,&is_gmz,&end)==3) &&
              (!std::strcmp(argx,"uchar") || !std::strcmp(argx,"unsigned char") ||
               !std::strcmp(argx,"char") || !std::strcmp(argx,"ushort") ||
               !std::strcmp(argx,"unsigned short") || !std::strcmp(argx,"short") ||
               !std::strcmp(argx,"uint") || !std::strcmp(argx,"unsigned int") ||
               !std::strcmp(argx,"int") || !std::strcmp(argx,"uint64") ||
               !std::strcmp(argx,"unsigned int64") || !std::strcmp(argx,"int64") ||
               !std::strcmp(argx,"float") || !std::strcmp(argx,"double")) &&
              is_compressed<=1 && is_gmz<=1) ++position;
          else { std::strcpy(argx,cimg::type<T>::string()); is_compressed = is_compressed0?1U:0U; is_gmz = 1; }

          print(images,0,
                "Serialize %simage%s viewed as %sbuffer%s of %s values into a single %scompressed image.",
                is_gmz?"names ":"",
                gmic_selection.data(),
                selection.height()>1?"":"a ",
                selection.height()>1?"s":"",
                argx,
                is_compressed?"":"un");
          if (selection) {
            g_list.assign(selection.height());
            CImgList<unsigned char> gmz_info;
            if (is_gmz) {
              gmz_info.assign(1 + selection.height());
              CImg<char>::string("GMZ").move_to(gmz_info[0]);
            }
            cimg_forY(selection,l) {
              const unsigned int uind = selection[l];
              g_list[l].assign(images[uind],images[uind]?true:false);
              if (is_gmz) CImg<char>::string(images_names[uind]).move_to(gmz_info[1 + l]);
            }
            if (is_gmz) (gmz_info>'x').unroll('y').move_to(g_list);

            CImg<T> serialized;
            gmic_serialize(unsigned char,"uchar")
            else gmic_serialize(unsigned char,"unsigned char")
              else gmic_serialize(char,"char")
                else gmic_serialize(unsigned short,"ushort")
                  else gmic_serialize(unsigned short,"unsigned short")
                    else gmic_serialize(short,"short")
                      else gmic_serialize(unsigned int,"uint")
                        else gmic_serialize(unsigned int,"unsigned int")
                          else gmic_serialize(int,"int")
                            else gmic_serialize(uint64T,"uint64")
                              else gmic_serialize(uint64T,"unsigned int64")
                                else gmic_serialize(int64T,"int64")
                                  else gmic_serialize(float,"float")
                                    else gmic_serialize(double,"double")
                                      else error(images,0,0,
                                                 "Command '-serialize': Invalid "
                                                 "specified pixel type '%s'.",
                                                 argx);
            if (is_double_hyphen) {
              serialized.move_to(images);
              images_names[selection[0]].get_copymark().move_to(images_names);
            } else {
              remove_images(images,images_names,selection,1,selection.height() - 1);
              serialized.move_to(images[selection[0]].assign());
            }
            g_list.assign();
          }
          is_released = false; continue;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-t...'
        //-----------------------------
      gmic_commands_t :

        // Threshold.
        if (!std::strcmp("-threshold",command)) {
          gmic_substitute_args(false);
          unsigned int is_soft = 0;
          value = 0;
          sep = 0;
          if ((cimg_sscanf(argument,"%lf%c",
                           &value,&end)==1 ||
               (cimg_sscanf(argument,"%lf%c%c",
                            &value,&sep,&end)==2 && sep=='%') ||
               cimg_sscanf(argument,"%lf,%u%c",
                           &value,&is_soft,&end)==2 ||
               (cimg_sscanf(argument,"%lf%c,%u%c",
                            &value,&sep,&is_soft,&end)==3 && sep=='%')) &&
              is_soft<=1) {
            print(images,0,"%s-threshold image%s by %g%s.",
                  is_soft?"Soft":"Hard",
                  gmic_selection.data(),
                  value,sep=='%'?"%":"");
            cimg_forY(selection,l) {
              CImg<T>& img = gmic_check(images[selection[l]]);
              nvalue = value;
              if (sep=='%' && img) {
                vmax = (double)img.max_min(vmin);
                nvalue = vmin + (vmax - vmin)*value/100;
              }
              gmic_apply(threshold((T)nvalue,(bool)is_soft));
            }
            ++position;
          } else {
            g_img.assign(1,selection.height()).fill((T)0);
#if cimg_display==0
            print(images,0,
                  "Threshold image%s in interactive mode (skipped, no display support).",
                  gmic_selection.data());
#else // #if cimg_display==0
            bool is_available_display = false;
            try {
              is_available_display = (bool)CImgDisplay::screen_width();
            } catch (CImgDisplayException&) {
              print(images,0,
                    "Threshold image%s in interactive mode (skipped, no display available).",
                    gmic_selection.data());
            }
            if (is_available_display) {
              print(images,0,"Threshold image%s in interactive mode.",
                    gmic_selection.data());
              CImgDisplay _disp, &disp = _display_window[0]?_display_window[0]:_disp;
              cimg_forY(selection,l) {
                CImg<T>& img = gmic_check(images[selection[l]]);
                value = 0;
                if (img) {
                  CImg<T> visu = img.depth()>1?img.get_projections2d(img.width()/2,
                                                                     img.height()/2,
                                                                     img.depth()/2).
                    channels(0,std::min(3,img.spectrum()) - 1):
                    img.get_channels(0,std::min(3,img.spectrum() - 1));
                  const unsigned int
                    w = CImgDisplay::_fitscreen(visu.width(),visu.height(),1,256,-85,false),
                    h = CImgDisplay::_fitscreen(visu.width(),visu.height(),1,256,-85,true);
                  if (disp) disp.resize(w,h,false); else disp.assign(w,h,0,0);
                  double percent = 50;
                  bool stopflag = false, is_clicked = false;
                  int omx = -1, omy = -1;
                  g_img_uc.assign();
                  vmax = (double)img.max_min(vmin);
                  for (disp.show().flush(); !stopflag; ) {
                    static const unsigned char white[] = { 255,255,255 }, black[] = { 0,0,0 };
                    const unsigned int key = disp.key();
                    if (!g_img_uc) {
                      value = vmin + percent*(vmax - vmin)/100;
                      disp.display(((g_img_uc=visu.get_threshold((T)value)*=255).resize(disp)).
                                   draw_text(0,0,"Threshold %g = %.3g%%",
                                             white,black,0.7f,13,value,percent)).
                        set_title("%s (%dx%dx%dx%d)",
                                  basename(images_names[selection[l]]),
                                  img.width(),img.height(),img.depth(),img.spectrum()).wait();
                    }
                    const int mx = disp.mouse_x(), my = disp.mouse_y();
                    if (disp.button()) {
                      if (mx>=0 && my>=0 && (mx!=omx || my!=omy)) {
                        percent = (my - 16)*100.0/(disp.height() - 32);
                        if (percent<0) percent = 0; else if (percent>101) percent = 101;
                        omx = mx; omy = my; g_img_uc.assign();
                      }
                      is_clicked = true;
                    } else if (is_clicked) break;
                    if (disp.is_closed() || (key && key!=cimg::keyCTRLLEFT)) stopflag = true;
                    if (key==cimg::keyD && disp.is_keyCTRLLEFT()) {
                      disp.resize(cimg_fitscreen(3*disp.width()/2,3*disp.height()/2,1),
                                  stopflag=false).set_key(cimg::keyD,false);
                      g_img_uc.assign();
                    }
                    if (key==cimg::keyC && disp.is_keyCTRLLEFT()) {
                      disp.resize(cimg_fitscreen(2*disp.width()/3,2*disp.height()/3,1),
                                  stopflag=false).set_key(cimg::keyC,false);
                      g_img_uc.assign();
                    }
                    if (disp.is_resized()) { disp.resize(false); g_img_uc.assign(); }
                  }
                  value = vmin + percent*(vmax - vmin)/100;
                  print(images,0,
                        "Hard-threshold image [%d] by %g = %.3g%%.",
                        selection[l],value,percent);
                  gmic_apply(threshold((T)value));
                  cimg_snprintf(title,_title.width(),"%g",value);
                  CImg<char>::string(title).move_to(status);
                } else gmic_apply(replace(img));
                g_img[l] = (T)value;
              }
              g_img_uc.assign();
            }
#endif // #if cimg_display==0
            g_img.value_string().move_to(status);
            g_img.assign();
          }
          is_released = false; continue;
        }

        // Tangent.
        gmic_simple_command("-tan",tan,"Compute pointwise tangent of image%s.");

        // Draw text.
        if (!std::strcmp("-text",command)) {
          gmic_substitute_args(false);
          name.assign(4096);
          *argx = *argy = *argz = *name = *color = 0;
          float x = 0, y = 0, height = 13;
          sep = sepx = sepy = 0;
          opacity = 1;
          if ((cimg_sscanf(argument,"%4095[^,]%c",
                           name.data(),&end)==1 ||
               cimg_sscanf(argument,"%4095[^,],%255[0-9.eE%+-]%c",
                           name.data(),argx,&end)==2 ||
               cimg_sscanf(argument,"%4095[^,],%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                           name.data(),argx,argy,&end)==3 ||
               cimg_sscanf(argument,"%4095[^,],%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                           name.data(),argx,argy,argz,&end)==4 ||
               cimg_sscanf(argument,"%4095[^,],%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],%f%c",
                           name.data(),argx,argy,argz,&opacity,&end)==5 ||
               cimg_sscanf(argument,"%4095[^,],%255[0-9.eE%+-],%255[0-9.eE%+-],%255[0-9.eE%+-],%f,"
                           "%4095[0-9.eEinfa,+-]%c",
                           name.data(),argx,argy,argz,&opacity,color,&end)==6) &&
              (!*argx ||
               cimg_sscanf(argx,"%f%c",&x,&end)==1 ||
               (cimg_sscanf(argx,"%f%c%c",&x,&sepx,&end)==2 && sepx=='%')) &&
              (!*argy ||
               cimg_sscanf(argy,"%f%c",&y,&end)==1 ||
               (cimg_sscanf(argy,"%f%c%c",&y,&sepy,&end)==2 && sepy=='%')) &&
              (!*argz ||
               cimg_sscanf(argz,"%f%c",&height,&end)==1 ||
               (cimg_sscanf(argz,"%f%c%c",&height,&sep,&end)==2 && sep=='%')) &&
              height>=0) {
            strreplace_fw(name);
            print(images,0,"Draw text '%s' at position (%g%s,%g%s) on image%s, with font "
                  "height %g%s, opacity %g and color (%s).",
                  name.data(),
                  x,sepx=='%'?"%":"",
                  y,sepy=='%'?"%":"",
                  gmic_selection.data(),
                  height,sep=='%'?"%":"",
                  opacity,
                  *color?color:"default");
            cimg::strunescape(name);
            unsigned int nb_cols = 1;
            for (const char *s = color; *s; ++s) if (*s==',') ++nb_cols;
            cimg_forY(selection,l) {
              CImg<T> &img = images[selection[l]];
              const unsigned int font_height = (unsigned int)cimg::round(sep=='%'?
                                                                         height*img.height()/100:height);
              g_img.assign(std::max(img.spectrum(),(int)nb_cols),1,1,1,(T)0).fill(color,true,false);
              const int
                nx = (int)cimg::round(sepx=='%'?x*(img.width() - 1)/100:x),
                ny = (int)cimg::round(sepy=='%'?y*(img.height() - 1)/100:y);
              gmic_apply(gmic_draw_text(nx,ny,name,g_img,0,opacity,font_height,nb_cols));
            }
          } else arg_error("text");
          g_img.assign();
          is_released = false; ++position; continue;
        }

        // Texturize 3d object.
        if (!std::strcmp("-texturize3d",command)) {
          gmic_substitute_args(true);
          CImg<unsigned int> ind_texture, ind_coords;
          sep = *argx = *argy = 0;
          if (((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",
                            argx,&sep,&end)==2 && sep==']') ||
               (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],[%255[a-zA-Z0-9_.%+-]%c%c",
                            argx,argy,&sep,&end)==3 && sep==']')) &&
              (ind_texture=selection2cimg(argx,images.size(),images_names,"-texturize3d")).height()==1 &&
              (!*argy || (ind_coords=selection2cimg(argy,images.size(),images_names,"-texturize3d")).height()==1)) {
            if (ind_coords)
              print(images,0,
                    "Texturize 3d object%s with texture [%u] and texture coordinates [%u].",
                    gmic_selection.data(),*ind_texture,*ind_coords);
            else
              print(images,0,"Texturize 3d object%s with texture [%u].",
                    gmic_selection.data(),*ind_texture);
            const CImg<T>
              texture = gmic_image_arg(*ind_texture),
              coords = ind_coords?gmic_image_arg(*ind_coords):CImg<T>();
            cimg_forY(selection,l) {
              const unsigned int uind = selection[l];
              CImg<T>& img = images[uind];
              try { gmic_apply(texturize_CImg3d(texture,coords)); }
              catch (CImgException&) {
                if (!img.is_CImg3d(true,&(*message=0)))
                  error(images,0,0,
                        "Command '-texturize3d': Invalid 3d object [%d], "
                        "in selected image%s (%s).",
                        uind,gmic_selection_err.data(),message.data());
                else throw;
              }
            }
          } else arg_error("texturize3d");
          is_released = false; ++position; continue;
        }

        // Tridiagonal solve.
        if (!std::strcmp("-trisolve",command)) {
          gmic_substitute_args(true);
          sep = *indices = 0;
          if (cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep,&end)==2 &&
              sep==']' &&
              (ind=selection2cimg(indices,images.size(),images_names,"-trisolve")).height()==1) {
            print(images,0,"Solve tridiagonal system AX = B, with B-vector%s and tridiagonal "
                  "A-matrix [%d].",
                  gmic_selection.data(),*ind);
            const CImg<T> A = gmic_image_arg(*ind);
            cimg_forY(selection,l) gmic_apply(solve_tridiagonal(A));
          } else arg_error("trisolve");
          is_released = false; ++position; continue;
        }

        // Hyperbolic tangent.
        gmic_simple_command("-tanh",tanh,"Compute pointwise hyperbolic tangent of image%s.");

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-u...'
        //-----------------------------
      gmic_commands_u :

        // Unroll.
        if (!std::strcmp("-unroll",command)) {
          gmic_substitute_args(false);
          axis = 'y';
          if ((*argument=='x' || *argument=='y' ||
               *argument=='z' || *argument=='c') && !argument[1]) {
            axis = *argument;
            ++position;
          }
          print(images,0,"Unroll image%s along the '%c'-axis.",
                gmic_selection.data(),
                axis);
          cimg_forY(selection,l) gmic_apply(unroll(axis));
          is_released = false; continue;
        }

        // Remove custom command.
        if (!std::strcmp("-uncommand",item)) {
          gmic_substitute_args(false);
          if (argument[0]=='*' && !argument[1]) { // Discard all custom commands.
            unsigned int nb_commands = 0;
            for (unsigned int i = 0; i<512; ++i) {
              nb_commands+=commands[i].size();
              commands[i].assign();
              commands_names[i].assign();
              commands_has_arguments[i].assign();
            }
            print(images,0,"Discard definitions of all custom commmands (%u command%s discarded).",
                  nb_commands,nb_commands>1?"s":"");
          } else { // Discard one or several custom command.
            g_list_c = CImg<char>::string(argument).get_split(CImg<char>::vector(','),0,false);
            print(images,0,"Discard last definition of custom command%s '%s'",
                  g_list_c.width()>1?"s":"",
                  gmic_argument_text_printed());
            unsigned int nb_removed = 0;
            cimglist_for(g_list_c,l) {
              CImg<char>& arg_command = g_list_c[l];
              arg_command.resize(1,arg_command.height() + 1,1,1,0);
              strreplace_fw(arg_command);
              if (*arg_command) {
                const int ind = (int)hashcode(arg_command,false);
                cimglist_for(commands_names[ind],l)
                  if (!std::strcmp(commands_names[ind][l],arg_command)) {
                    commands_names[ind].remove(l);
                    commands[ind].remove(l);
                    commands_has_arguments[ind].remove(l);
                    ++nb_removed; break;
                  }
              }
            }
            if (is_verbose) {
              cimg::mutex(29);
              unsigned int siz = 0;
              for (unsigned int l = 0; l<512; ++l) siz+=commands[l].size();
              std::fprintf(cimg::output()," (%u found, %u command%s left).",
                           nb_removed,siz,siz>1?"s":"");
              std::fflush(cimg::output());
              cimg::mutex(29,0);
            }
            g_list_c.assign();
          }
          ++position; continue;
        }

        // Unserialize.
        if (!std::strcmp("-unserialize",command)) {
          print(images,0,"Unserialize image%s.",
                gmic_selection.data());
          int off = 0;
          cimg_forY(selection,l) {
            const unsigned int uind = selection[l] + off;
            const CImg<T>& img = gmic_check(images[uind]);
            g_list = CImgList<T>::get_unserialize(img);
            if (g_list) {
              const CImg<T>& back = g_list.back();
              if (back.width()==1 && back.depth()==1 && back.spectrum()==1 &&
                  back[0]=='G' && back[1]=='M' && back[2]=='Z' && !back[3]) { // .gmz serialization.
                g_list_c = back.get_split(CImg<char>::vector(0),0,false);
                g_list_c.remove(0);
                cimglist_for(g_list_c,l)
                  g_list_c[l].resize(1,g_list_c[l].height() + 1,1,1,0).unroll('x');
                if (g_list_c) g_list.remove();
              } else { // .cimg[z] serialization.
                g_list_c.insert(images_names[uind]);
                g_list_c.insert(g_list.width() - 1,images_names[uind].get_copymark());
              }
              if (g_list_c.width()>g_list.width())
                g_list_c.remove(g_list.width(),g_list_c.width() - 1);
              else if (g_list_c.width()<g_list.width())
                g_list_c.insert(g_list.width() - g_list_c.width(),CImg<char>::string("[unnamed]"));
              if (is_double_hyphen) {
                g_list.move_to(images,~0U);
                g_list_c.move_to(images_names,~0U);
              } else {
                images.remove(uind); images_names.remove(uind);
                off+=(int)g_list.size() - 1;
                g_list.move_to(images,uind);
                g_list_c.move_to(images_names,uind);
              }
            }
          }
          g_list.assign(); g_list_c.assign();
          is_released = false; continue;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-v...'
        //-----------------------------
      gmic_commands_v :

        // Set verbosity
        // (actually only display a log message, since it has been already processed before).
        if (is_verbose_command) {
          if (*argument=='-' && !argument[1])
            print(images,0,"Decrement verbosity level (set to %d).",
                  verbosity);
          else if (*argument=='+' && !argument[1]) {
            if (is_very_verbose) print(images,0,"Increment verbosity level (set to %d).",
                                       verbosity);
          } else if ((verbosity>=0 && old_verbosity>=0) || is_debug)
            print(images,0,"Set verbosity level to %d.",
                  verbosity);
          if (is_verbose_argument) ++position;
          continue;
        }

        // Vanvliet filter.
        if (!std::strcmp("-vanvliet",command)) {
          gmic_substitute_args(false);
          unsigned int order = 0;
          float sigma = 0;
          axis = sep = 0;
          boundary = 1;
          if ((cimg_sscanf(argument,"%f,%u,%c%c",&sigma,&order,&axis,&end)==3 ||
               (cimg_sscanf(argument,"%f%c,%u,%c%c",&sigma,&sep,&order,&axis,&end)==4 &&
                sep=='%') ||
               cimg_sscanf(argument,"%f,%u,%c,%u%c",&sigma,&order,&axis,&boundary,&end)==4 ||
               (cimg_sscanf(argument,"%f%c,%u,%c,%u%c",
                            &sigma,&sep,&order,&axis,&boundary,&end)==5 && sep=='%')) &&
              sigma>=0 && order<=3 && (axis=='x' || axis=='y' || axis=='z' || axis=='c') &&
              boundary<=1) {
            print(images,0,"Apply %u-order Vanvliet filter on image%s, along axis '%c' with standard "
                  "deviation %g%s and %s boundary conditions.",
                  order,gmic_selection.data(),axis,
                  sigma,sep=='%'?"%":"",
                  boundary?"neumann":"dirichlet");
            if (sep=='%') sigma = -sigma;
            cimg_forY(selection,l) gmic_apply(vanvliet(sigma,order,axis,(bool)boundary));
          } else arg_error("vanvliet");
          is_released = false; ++position; continue;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-w...'
        //-----------------------------
      gmic_commands_w :

        // While.
        if (!std::strcmp("-while",item)) {
          gmic_substitute_args(false);
          const CImg<char>& s = callstack.back();
          if (s[0]!='*' || s[1]!='d')
            error(images,0,0,
                  "Command '-while': Not associated to a '-do' command within the same scope.");
          float _is_cond = 0;
          bool is_filename = false;
          if (cimg_sscanf(argument,"%f%c",&_is_cond,&end)!=1) {
            is_filename = true;
            name.assign(argument,(unsigned int)std::strlen(argument) + 1);
            strreplace_fw(name);
            _is_cond = (float)check_filename(name);
          }
          const bool is_cond = (bool)_is_cond;
          if (is_very_verbose) print(images,0,"Reach '-while' command -> %s '%s' %s.",
                                     is_filename?"file":"boolean",
                                     gmic_argument_text_printed(),
                                     is_filename?(is_cond?"exists":
                                                  "does not exist"):
                                     (is_cond?"is true":"is false"));
          if (is_cond) {
            position = dowhiles.back()(0);
            next_debug_line = debug_line; next_debug_filename = debug_filename;
            continue;
          } else {
            if (is_very_verbose) print(images,0,"End 'do...while' block.");
            dowhiles.remove();
            callstack.remove();
          }
          ++position; continue;
        }

        // Warning.
        if (!is_double_hyphen && !std::strcmp("-warn",command)) {
          gmic_substitute_args(false);
          bool force_visible = false;
          if ((*argument=='0' || *argument=='1') && argument[1]==',') {
            force_visible = *argument=='1'; argument+=2;
          }
          name.assign(argument,(unsigned int)std::strlen(argument) + 1);
          cimg::strunescape(name);
          if (is_restriction) warn(images,&selection,force_visible,"%s",name.data());
          else warn(images,0,force_visible,"%s",name.data());
          ++position; continue;
        }

        // Display images in display window.
        wind = 0;
        if (!is_double_hyphen &&
            (!std::strcmp("-window",command) ||
             cimg_sscanf(command,"-window%u%c",&wind,&end)==1 ||
             cimg_sscanf(command,"-w%u%c",&wind,&end)==1) &&
            wind<10) {
          gmic_substitute_args(false);
          int norm = -1, fullscreen = -1;
          float dimw = -1, dimh = -1, posx = -1, posy = -1;
          sep0 = sep1 = sepx = sepy = *argx = *argy = *argz = *argc = *title = 0;
          if ((cimg_sscanf(argument,"%255[0-9.eE%+-]%c",
                           argx,&end)==1 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-]%c",
                           argx,argy,&end)==2 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%d%c",
                           argx,argy,&norm,&end)==3 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%d,%d%c",
                           argx,argy,&norm,&fullscreen,&end)==4 ||
               cimg_sscanf(argument,
                           "%255[0-9.eE%+-],%255[0-9.eE%+-],%d,%d,%255[0-9.eE%+-],"
                           "%255[0-9.eE%+-]%c",
                           argx,argy,&norm,&fullscreen,argz,argc,&end)==6 ||
               cimg_sscanf(argument,
                           "%255[0-9.eE%+-],%255[0-9.eE%+-],%d,%d,%255[0-9.eE%+-],"
                           "%255[0-9.eE%+-],%255[^\n]",
                           argx,argy,&norm,&fullscreen,argz,argc,title)==7 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%d,%d,%255[^\n]",
                           &(*argx=*argz=*argc=0),argy,&norm,&fullscreen,title)==5 ||
               cimg_sscanf(argument,"%255[0-9.eE%+-],%255[0-9.eE%+-],%d,%255[^\n]",
                           argx,argy,&(norm=fullscreen=-1),title)==4 ||
               (norm=fullscreen=-1,cimg_sscanf(argument,
                                               "%255[0-9.eE%+-],%255[0-9.eE%+-],%255[^\n]",
                                               argx,argy,title))==3) &&
              (cimg_sscanf(argx,"%f%c",&dimw,&end)==1 ||
               (cimg_sscanf(argx,"%f%c%c",&dimw,&sep0,&end)==2 && sep0=='%')) &&
              (!*argy ||
               cimg_sscanf(argy,"%f%c",&dimh,&end)==1 ||
               (cimg_sscanf(argy,"%f%c%c",&dimh,&sep1,&end)==2 && sep1=='%')) &&
              (!*argz ||
               cimg_sscanf(argz,"%f%c",&posx,&end)==1 ||
               (cimg_sscanf(argz,"%f%c%c",&posx,&sepx,&end)==2 && sepx=='%')) &&
              (!*argc ||
               cimg_sscanf(argc,"%f%c",&posy,&end)==1 ||
               (cimg_sscanf(argc,"%f%c%c",&posy,&sepy,&end)==2 && sepy=='%')) &&
              (dimw>=0 || dimw==-1) &&
              (dimh>=0 || dimh==-1) &&
              norm>=-1 && norm<=3) ++position;
          else {
            dimw = dimh = -1;
            norm = fullscreen = -1;
            posx = posy = -1;
            sep0 = sep1 = 0;
          }
          if (dimh==0) dimw = 0;
          strreplace_fw(title);

#if cimg_display==0
          print(images,0,
                "Display image%s in display window [%d] (skipped, no display support).",
                gmic_selection.data(),
                wind);
#else // #if cimg_display==0

          // Get images to display and compute associated optimal size.
          unsigned int optw = 0, opth = 0;
          if (dimw && dimh) cimg_forY(selection,l) {
              const CImg<T>& img = gmic_check(images[selection[l]]);
              if (img) {
                g_list.insert(img,~0U,true);
                optw+=img._width + (img.depth()>1?img._depth:0U);
                if (img.height()>(int)opth) opth = img._height + (img._depth>1?img._depth:0U);
              }
            }
          optw = optw?optw:sep0=='%'?CImgDisplay::screen_width():256;
          opth = opth?opth:sep1=='%'?CImgDisplay::screen_height():256;
          dimw = dimw<0?-1:cimg::round(sep0=='%'?optw*dimw/100:dimw);
          dimh = dimh<0?-1:cimg::round(sep1=='%'?opth*dimh/100:dimh);

          const bool is_move = posx!=-1 || posy!=-1;
          bool is_available_display = false;
          try {
            is_available_display = (bool)CImgDisplay::screen_width();
          } catch (CImgDisplayException&) {
            print(images,0,
                  "Display image%s in display window [%d] (skipped, no display available).",
                  gmic_selection.data(),
                  wind);
          }
          if (is_available_display) {
            CImgDisplay &disp = _display_window[wind];

            if (!dimw || !dimh) { // Close.
              print(images,0,"Close display window [%d].",
                    wind);
              disp.assign();
            } else {
              if (disp) { // Update.
                if (!selection) disp.show();
                disp.resize(dimw>0?(int)dimw:disp.window_width(),
                            dimh>0?(int)dimh:disp.window_height(),
                            false);
                if (is_move) {
                  if (sepx=='%') posx*=(CImgDisplay::screen_width() - disp.window_width())/100.0f;
                  if (sepy=='%') posy*=(CImgDisplay::screen_height() - disp.window_height())/100.0f;
                  disp.move((int)posx,(int)posy);
                }
                if (norm>=0) disp._normalization = (unsigned int)norm;
                if (*title && std::strcmp(disp.title(),title)) disp.set_title("%s",title);
                if (fullscreen>=0 && (bool)fullscreen!=disp.is_fullscreen()) disp.toggle_fullscreen(false);
              } else { // Create.
                if (!*title) cimg_snprintf(title,_title.width(),"[G'MIC] Window #%u",wind);
                disp.assign(dimw>0?(int)dimw:optw,
                            dimh>0?(int)dimh:opth,
                            title,norm<0?3:norm,
                            fullscreen<0?false:(bool)fullscreen,
                            is_move);
                if (is_move) {
                  if (sepx=='%') posx*=(CImgDisplay::screen_width() - disp.window_width())/100.0f;
                  if (sepy=='%') posy*=(CImgDisplay::screen_height() - disp.window_height())/100.0f;
                  disp.move((int)posx,(int)posy);
                }
                if (norm==2) {
                  if (g_list) disp._max = (float)g_list.max_min(disp._min);
                  else { disp._min = 0; disp._max = 255; }
                }
              }
              if (is_move) print(images,0,
                                 "Display image%s in %dx%d %sdisplay window [%d], "
                                 "with%snormalization, "
                                 "%sfullscreen, at position (%s,%s) and title '%s'.",
                                 gmic_selection.data(),
                                 disp.width(),disp.height(),disp.is_fullscreen()?"fullscreen ":"",
                                 wind,
                                 disp.normalization()==0?"out ":disp.normalization()==1?" ":
                                 disp.normalization()==2?" 1st-time ":" auto-",
                                 disp.is_fullscreen()?"":"no ",
                                 argz,argc,
                                 disp.title());
              else print(images,0,
                         "Display image%s in %dx%d %sdisplay window [%d], with%snormalization, "
                         "%sfullscreen and title '%s'.",
                         gmic_selection.data(),
                         disp.width(),disp.height(),disp.is_fullscreen()?"fullscreen ":"",
                         wind,
                         disp.normalization()==0?"out ":disp.normalization()==1?" ":
                         disp.normalization()==2?" 1st-time ":" auto-",
                         disp.is_fullscreen()?"":"no ",
                         disp.title());
              if (g_list) g_list.display(disp);
            }
          }
          g_list.assign();

#endif // #if cimg_display==0
          is_released = true; continue;
        }

        // Warp.
        if (!std::strcmp("-warp",command)) {
          gmic_substitute_args(true);
          unsigned int interpolation = 1, mode = 0;
          float nb_frames = 1;
          boundary = 1;
          sep = 0;
          if (((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",
                            indices,&sep,&end)==2 && sep==']')||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u%c",
                           indices,&mode,&end)==2 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u,%u%c",
                           indices,&mode,&interpolation,&end)==3 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u,%u,%u%c",
                           indices,&mode,&interpolation,&boundary,&end)==4 ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u,%u,%u,%f%c",
                           indices,&mode,&interpolation,&boundary,&nb_frames,&end)==5) &&
              (ind=selection2cimg(indices,images.size(),images_names,"-warp")).height()==1 &&
              mode<=3 && interpolation<=2 && boundary<=2 && nb_frames>=0.5) {
            const CImg<T> warping_field = gmic_image_arg(*ind);
            nb_frames = cimg::round(nb_frames);
            if (nb_frames==1) {
              print(images,0,"Warp image%s with %s-%s displacement field [%u], %s interpolation, "
                    "%s boundary conditions.",
                    gmic_selection.data(),
                    mode<=2?"backward":"forward",mode%2?"relative":"absolute",
                    *ind,
                    interpolation==2?"cubic":interpolation==1?"linear":"nearest-neighbor",
                    boundary==0?"dirichlet":boundary==1?"neumann":"periodic");
              cimg_forY(selection,l) gmic_apply(warp(warping_field,mode,interpolation,boundary));
            } else {
              print(images,0,"Warp image%s with %s-%s displacement field [%u], %s interpolation, "
                    "%s boundary conditions and %d frames.",
                    gmic_selection.data(),
                    mode<=2?"backward":"forward",mode%2?"relative":"absolute",
                    *ind,
                    interpolation==2?"cubic":interpolation==1?"linear":"nearest-neighbor",
                    boundary==0?"dirichlet":boundary==1?"neumann":"periodic",
                    (int)nb_frames);
              unsigned int off = 0;
              cimg_forY(selection,l) {
                const unsigned int _ind = selection[l] + off;
                CImg<T>& img = gmic_check(images[_ind]);
                g_list.assign((int)nb_frames);
                name = images_names[_ind];
                cimglist_for(g_list,t)
                  g_list[t] = img.get_warp(warping_field*((t + 1.0f)/nb_frames),mode,
                                           interpolation,boundary);
                if (is_double_hyphen) {
                  images_names.insert((int)nb_frames,name.copymark());
                  g_list.move_to(images,~0U);
                } else {
                  off+=(int)nb_frames - 1;
                  images_names.insert((int)nb_frames - 1,name.get_copymark(),_ind);
                  images.remove(_ind); g_list.move_to(images,_ind);
                }
              }
              g_list.assign();
            }
          } else arg_error("warp");
          is_released = false; ++position; continue;
        }

        // Watershed transform.
        if (!std::strcmp("-watershed",command)) {
          gmic_substitute_args(true);
          is_high_connectivity = 1;
          sep = *indices = 0;
          if (((cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sep,&end)==2 &&
                sep==']') ||
               cimg_sscanf(argument,"[%255[a-zA-Z0-9_.%+-]],%u%c",
                           indices,&is_high_connectivity,&end)==2) &&
              (ind=selection2cimg(indices,images.size(),images_names,"-watershed")).height()==1 &&
              is_high_connectivity<=1) {
            print(images,0,"Compute watershed transform of image%s with priority map [%u] and "
                  "%s connectivity.",
                  gmic_selection.data(),*ind,is_high_connectivity?"high":"low");
            const CImg<T> priority = gmic_image_arg(*ind);
            cimg_forY(selection,l) gmic_apply(watershed(priority,(bool)is_high_connectivity));
          } else arg_error("watershed");
          is_released = false; ++position; continue;
        }

        // Wait for a given delay of for user events on display window.
        if (!is_double_hyphen && !std::strcmp("-wait",command)) {
          gmic_substitute_args(false);
          if (!is_restriction)
            CImg<unsigned int>::vector(0,1,2,3,4,5,6,7,8,9).move_to(selection);
          float delay = 0;
          if (cimg_sscanf(argument,"%f%c",
                          &delay,&end)==1) ++position;
          else delay = 0;
#if cimg_display==0
          if (!delay)
            print(images,0,
                  "Wait for user events on display window%s (skipped, no display support).",
                  gmic_selection.data());
          else {
            delay = cimg::round(delay);
            print(images,0,
                  "%s for %g milliseconds according to display window%s.",
                  delay<0?"Sleep":"Wait",delay,
                  gmic_selection.data());
            if (delay<0) cimg::sleep((unsigned int)-delay);
            else cimg::wait((unsigned int)delay);
          }
#else // #if cimg_display==0
          if (!delay) {
            print(images,0,"Wait for user events on display window%s.",
                  gmic_selection.data());
            CImgDisplay *const iw = _display_window;
            switch (selection.height()) {
            case 1 : CImgDisplay::wait(iw[selection[0]]); break;
            case 2 : CImgDisplay::wait(iw[selection[0]],iw[selection[1]]); break;
            case 3 : CImgDisplay::wait(iw[selection[0]],iw[selection[1]],iw[selection[2]]);
              break;
            case 4 : CImgDisplay::wait(iw[selection[0]],iw[selection[1]],iw[selection[2]],
                                       iw[selection[3]]);
              break;
            case 5 : CImgDisplay::wait(iw[selection[0]],iw[selection[1]],iw[selection[2]],
                                       iw[selection[3]],iw[selection[4]]);
              break;
            case 6 : CImgDisplay::wait(iw[selection[0]],iw[selection[1]],iw[selection[2]],
                                       iw[selection[3]],iw[selection[4]],iw[selection[5]]);
              break;
            case 7 : CImgDisplay::wait(iw[selection[0]],iw[selection[1]],iw[selection[2]],
                                       iw[selection[3]],iw[selection[4]],iw[selection[5]],
                                       iw[selection[6]]);
              break;
            case 8 : CImgDisplay::wait(iw[selection[0]],iw[selection[1]],iw[selection[2]],
                                       iw[selection[3]],iw[selection[4]],iw[selection[5]],
                                       iw[selection[6]],iw[selection[7]]);
              break;
            case 9 : CImgDisplay::wait(iw[selection[0]],iw[selection[1]],iw[selection[2]],
                                       iw[selection[3]],iw[selection[4]],iw[selection[5]],
                                       iw[selection[6]],iw[selection[7]],iw[selection[8]]);
              break;
            case 10 : CImgDisplay::wait(iw[selection[0]],iw[selection[1]],iw[selection[2]],
                                        iw[selection[3]],iw[selection[4]],iw[selection[5]],
                                        iw[selection[6]],iw[selection[7]],iw[selection[8]],
                                        iw[selection[9]]);
              break;
            }
          } else if (delay<0) {
            delay = cimg::round(-delay);
            print(images,0,
                  "Flush display events of display window%s and wait for %g milliseconds.",
                  gmic_selection.data(),delay);
            cimg_forY(selection,l) _display_window[selection[l]].flush();
            if (selection && _display_window[selection[0]])
              _display_window[selection[0]].wait((unsigned int)delay);
            else cimg::wait((unsigned int)delay);
          } else {
            delay = cimg::round(delay);
            print(images,0,"Wait for %g milliseconds according to display window%s.",
                  delay,
                  gmic_selection.data());
            if (selection && _display_window[selection[0]])
              _display_window[selection[0]].wait((unsigned int)delay);
            else cimg::sleep((unsigned int)delay);
          }
#endif // #if cimg_display==0
          continue;
        }

        goto gmic_commands_others;

        //-----------------------------
        // Commands starting by '-x...'
        //-----------------------------
      gmic_commands_x :

        // Bitwise xor.
        gmic_arithmetic_command("-xor",
                                operator^=,
                                "Compute bitwise XOR of image%s by %g%s",
                                gmic_selection.data(),value,ssep,Tlong,
                                operator^=,
                                "Compute bitwise XOR of image%s by image [%d]",
                                gmic_selection.data(),ind[0],
                                operator_xoreq,
                                "Compute bitwise XOR of image%s by expression %s",
                                gmic_selection.data(),gmic_argument_text_printed(),
                                "Compute sequential bitwise XOR of image%s");

        goto gmic_commands_others;

        //----------------------------
        // Other (special) commands.
        //----------------------------
      gmic_commands_others :

        // If...[elif]...[else]...endif.
        if (!std::strcmp("-if",item) || (!std::strcmp("-elif",item) && check_elif)) {
          gmic_substitute_args(false);
          check_elif = false;
          float _is_cond = 0;
          bool is_filename = false;
          if (cimg_sscanf(argument,"%f%c",&_is_cond,&end)!=1) {
            is_filename = true;
            name.assign(argument,(unsigned int)std::strlen(argument) + 1);
            strreplace_fw(name);
            _is_cond = (float)check_filename(name);
          }
          const bool is_cond = (bool)_is_cond;
          if (item[1]=='i') {
            if (is_debug_info && debug_line!=~0U) {
              cimg_snprintf(argx,_argx.width(),"*if#%u",debug_line);
              CImg<char>::string(argx).move_to(callstack);
            } else CImg<char>::string("*if").move_to(callstack);
            if (is_very_verbose) print(images,0,"Start '-if...-endif' block -> %s '%s' %s.",
                                       is_filename?"file":"boolean",
                                       gmic_argument_text_printed(),
                                       is_filename?(is_cond?"exists":"does not exist"):
                                       (is_cond?"is true":"is false"));
          } else if (is_very_verbose) print(images,0,"Reach '-elif' block -> %s '%s' %s.",
                                            is_filename?"file":"boolean",
                                            gmic_argument_text_printed(),
                                            is_filename?(is_cond?"exists":
                                                         "does not exist"):
                                            (is_cond?"is true":"is false"));
          if (!is_cond) {
            for (int nb_ifs = 1; nb_ifs && position<commands_line.size(); ++position) {
              const char *const it = commands_line[position].data();
              if (*it==1 &&
                  cimg_sscanf(commands_line[position].data() + 1,"%x,%x",&_debug_line,&(_debug_filename=0))>0) {
                is_debug_info = true; next_debug_line = _debug_line; next_debug_filename = _debug_filename;
              } else if (!std::strcmp("-if",it)) ++nb_ifs;
              else if (!std::strcmp("-endif",it)) { --nb_ifs; if (!nb_ifs) --position; }
              else if (nb_ifs==1) {
                if (!std::strcmp("-else",it)) --nb_ifs;
                else if (!std::strcmp("-elif",it)) { --nb_ifs; check_elif = true; --position;}
              }
            }
            continue;
          }
          ++position; continue;
        }

        // Break and continue.
        bool is_continue = false;
        if (!std::strcmp("-break",item) ||
            (!std::strcmp("-continue",item) && (is_continue=true)==true)) {
          const char
	    *const com = is_continue?"continue":"break",
	    *const Com = is_continue?"Continue":"Break";
          unsigned int callstack_repeat = 0, callstack_do = 0, callstack_local = 0;
          for (unsigned int l = callstack.size() - 1; l; --l) {
            const char *const s = callstack[l].data();
            if (s[0]=='*' && s[1]=='r') { callstack_repeat = l; break; }
            else if (s[0]=='*' && s[1]=='d') { callstack_do = l; break; }
            else if (s[0]=='*' && s[1]=='l') { callstack_local = l; break; }
            else if (s[0]!='*' || s[1]!='i') break;
          }
          const char *stb = 0, *ste = 0;
          unsigned int callstack_ind = 0;
          int level = 0;
          if (callstack_repeat) {
            print(images,0,"%s %scurrent 'repeat...done' block.",
                  Com,is_continue?"to next iteration of ":"");
            for (level = 1; level && position<commands_line.size(); ++position) {
              const char *it = commands_line[position].data();
              if (!std::strcmp("-repeat",it)) ++level;
              else if (!std::strcmp("-done",it)) --level;
            }
            callstack_ind = callstack_repeat;
            stb = "repeat"; ste = "done";
          } else if (callstack_do) {
            print(images,0,"%s %scurrent 'do...while' block.",
                  Com,is_continue?"to next iteration of ":"");
            for (level = 1; level && position<commands_line.size(); ++position) {
              const char *it = commands_line[position].data();
              if (!std::strcmp("-do",it)) ++level;
              else if (!std::strcmp("-while",it)) --level;
            }
            callstack_ind = callstack_do;
            stb = "do"; ste = "while";
          } else if (callstack_local) {
            print(images,0,"%s %scurrent local environment.",
                  Com,is_continue?"to end of ":"");
            for (level = 1; level && position<commands_line.size(); ++position) {
              const char *it = commands_line[position].data();
              if (!std::strcmp("-local",it) || !std::strcmp("-l",it) ||
                  !std::strcmp("--local",it) || !std::strcmp("--l",it) ||
                  !std::strncmp("-local[",it,7) || !std::strncmp("-l[",it,3) ||
                  !std::strncmp("--local[",it,8) || !std::strncmp("--l[",it,4)) ++level;
              else if (!std::strcmp("-endlocal",it) || !std::strcmp("-endl",it)) --level;
            }
            callstack_ind = callstack_local;
            stb = "local"; ste = "endlocal";
          } else {
            print(images,0,"%s",Com);
            error(images,0,0,
                  "Command '-%s': There are no loops or local environment to %s.",com,com);
            continue;
          }
          if (level && position>=commands_line.size())
            error(images,0,0,
                  "Command '-%s': Missing associated '-%s' command.",stb,ste);
          if (is_continue || callstack_local) {
	    if (callstack_ind<callstack.size() - 1) callstack.remove(callstack_ind + 1,callstack.size() - 1);
	    --position;
	  } else {
            callstack.remove(callstack_ind,callstack.size() - 1);
            if (callstack_do) { dowhiles.remove(); ++position; } else repeatdones.remove();
          }
          continue;
        }

        // Compute direct or inverse FFT.
        const bool inv_fft = !std::strcmp("-ifft",command);
        if (!std::strcmp("-fft",command) || inv_fft) {
          gmic_substitute_args(false);
          bool is_valid_argument = *argument!=0;
          if (is_valid_argument) for (const char *s = argument; *s; ++s) {
              const char _s = *s;
              if (_s!='x' && _s!='y' && _s!='z') { is_valid_argument = false; break; }
            }
          if (is_valid_argument) {
            print(images,0,"Compute %sfourier transform of image%s along the '%s'-ax%cs with complex pair%s",
                  inv_fft?"inverse ":"",
                  gmic_selection.data(),
                  gmic_argument_text_printed(),
                  std::strlen(argument)>1?'e':'i',
                  selection.height()>2?"s":selection.height()>=1?"":"().");
            ++position;
          } else
            print(images,0,"Compute %sfourier transform of image%s with complex pair%s",
                  inv_fft?"inverse ":"",
                  gmic_selection.data(),
                  selection.height()>2?"s":selection.height()>=1?"":" ().");
          cimg_forY(selection,l) {
            const unsigned int
	      uind0 = selection[l],
	      uind1 = l + 1<selection.height()?selection[l + 1]:~0U;
            CImg<T> &img0 = gmic_check(images[uind0]),
                    &img1 = uind1!=~0U?gmic_check(images[uind1]):CImg<T>::empty();
            name = images_names[uind0];
            if (uind1!=~0U) { // Complex transform.
              if (is_verbose) {
                cimg::mutex(29);
                std::fprintf(cimg::output()," ([%u],[%u])%c",uind0,uind1,
			     l>=selection.height() - 2?'.':',');
                std::fflush(cimg::output());
                cimg::mutex(29,0);
              }
              if (is_double_hyphen) {
                g_list.assign(img0,img1);
                if (is_valid_argument) for (const char *s = argument; *s; ++s) g_list.FFT(*s,inv_fft);
                else g_list.FFT(inv_fft);
                g_list.move_to(images,~0U);
                images_names.insert(2,name.copymark());
              } else {
                g_list.assign(2);
                g_list[0].swap(img0);
                g_list[1].swap(img1);
                if (is_valid_argument) for (const char *s = argument; *s; ++s) g_list.FFT(*s,inv_fft);
                else g_list.FFT(inv_fft);
                g_list[0].swap(img0);
                g_list[1].swap(img1);
                name.get_copymark().move_to(images_names[uind1]);
                name.move_to(images_names[uind0]);
              }
              ++l;
            } else { // Real transform.
              if (is_verbose) {
                cimg::mutex(29);
                std::fprintf(cimg::output()," ([%u],0)%c",uind0,
			     l>=selection.height() - 2?'.':',');
                std::fflush(cimg::output());
                cimg::mutex(29,0);
              }
              if (is_double_hyphen) {
                g_list.assign(img0);
                CImg<T>(g_list[0].width(),g_list[0].height(),g_list[0].depth(),g_list[0].spectrum(),(T)0).
                  move_to(g_list);
                if (is_valid_argument) for (const char *s = argument; *s; ++s) g_list.FFT(*s,inv_fft);
                else g_list.FFT(inv_fft);
                g_list.move_to(images,~0U);
                images_names.insert(2,name.copymark());
              } else {
                g_list.assign(1);
                g_list[0].swap(img0);
                CImg<T>(g_list[0].width(),g_list[0].height(),g_list[0].depth(),g_list[0].spectrum(),(T)0).
                  move_to(g_list);
                if (is_valid_argument) for (const char *s = argument; *s; ++s) g_list.FFT(*s,inv_fft);
                else g_list.FFT(inv_fft);
                g_list[0].swap(img0);
                g_list[1].move_to(images,uind0 + 1);
                name.get_copymark().move_to(images_names,uind0 + 1);
                name.move_to(images_names[uind0]);
              }
            }
          }
          g_list.assign();
          is_released = false; continue;
        }

        // Rescale a 3d object (* or /).
        const bool divide3d = !std::strcmp("-div3d",command);
        if (!std::strcmp("-mul3d",command) || divide3d) {
          gmic_substitute_args(false);
          float sx = 0, sy = 1, sz = 1;
          if ((cimg_sscanf(argument,"%f%c",
                           &sx,&end)==1 && ((sz=sy=sx),1)) ||
              cimg_sscanf(argument,"%f,%f%c",
                          &sx,&sy,&end)==2 ||
              cimg_sscanf(argument,"%f,%f,%f%c",
                          &sx,&sy,&sz,&end)==3) {
            if (divide3d)
              print(images,0,"Scale 3d object%s with factors (1/%g,1/%g,1/%g).",
                    gmic_selection.data(),
                    sx,sy,sz);
            else
              print(images,0,"Scale 3d object%s with factors (%g,%g,%g).",
                    gmic_selection.data(),
                    sx,sy,sz);
            cimg_forY(selection,l) {
              const unsigned int uind = selection[l];
              CImg<T>& img = images[uind];
              try {
                if (divide3d) { gmic_apply(scale_CImg3d(1/sx,1/sy,1/sz)); }
                else gmic_apply(scale_CImg3d(sx,sy,sz));
              } catch (CImgException&) {
                if (!img.is_CImg3d(true,&(*message=0)))
                  error(images,0,0,
                        "Command '-%s3d': Invalid 3d object [%d], in selected image%s (%s).",
                        divide3d?"div":"mul",uind,gmic_selection_err.data(),message.data());
                else throw;
              }
            }
          } else { if (divide3d) arg_error("div3d"); else arg_error("mul3d"); }
          is_released = false; ++position; continue;
        }

        // Check for a custom command, and execute it, if found.
        if (!is_input_command) {
          const char *custom_command = 0, cc = *(command + 1);
          bool custom_command_found = false, has_arguments = false, _is_noarg = false;
          CImg<char> substituted_command(1024);
          char *ptr_sub = substituted_command.data();
          if ((cc>='a' && cc<='z') || (cc>='A' && cc<='Z') || cc=='_') {
            const int ind = (int)hashcode(command + 1,false);
            cimglist_for(commands_names[ind],l) {
              custom_command = commands_names[ind][l].data();
              const char
                *const command_code = commands[ind][l].data(),
                *const command_code_back = &commands[ind][l].back();

              if (!std::strcmp(command + 1,custom_command)) {
                custom_command_found = true;
                if (is_debug) {
                  CImg<char> command_code_text(264);
                  const unsigned int ls = (unsigned int)std::strlen(command_code);
                  if (ls>=264) {
                    std::memcpy(command_code_text.data(),command_code,128);
                    std::memcpy(command_code_text.data() + 128,"(...)",5);
                    std::memcpy(command_code_text.data() + 133,command_code + ls - 130,131);
                  } else std::strcpy(command_code_text.data(),command_code);
                  for (char *ptrs = command_code_text, *ptrd = ptrs; *ptrs || (bool)(*ptrd=0);
                       ++ptrs)
                    if (*ptrs==1) while (*ptrs!=' ') ++ptrs; else *(ptrd++) = *ptrs;
                  debug(images,"Found custom command '%s: %s' (%s).",
                        custom_command,command_code_text.data(),
                        commands_has_arguments[ind](l,0)?"takes arguments":"takes no arguments");
                }

                CImgList<char> arguments(32);
                // Set $0 to be the command name.
                CImg<char>::string(custom_command).move_to(arguments[0]);
                unsigned int nb_arguments = 0;

                if (commands_has_arguments[ind](l,0)) { // Command takes arguments.
                  gmic_substitute_args(false);

                  // Extract possible command arguments.
                  for (const char *ss = argument, *_ss = ss; _ss; ss =_ss + 1)
                    if ((_ss=std::strchr(ss,','))!=0) {
                      if (ss==_ss) ++nb_arguments;
                      else {
                        if (++nb_arguments>=arguments.size())
                          arguments.insert(2 + 2*nb_arguments - arguments.size());
                        CImg<char> arg_item(ss,(unsigned int)(_ss - ss + 1));
                        arg_item.back() = 0;
                        arg_item.move_to(arguments[nb_arguments]);
                      }
                    } else {
                      if (*ss) {
                        if (++nb_arguments>=arguments.size())
                          arguments.insert(1 + nb_arguments - arguments.size());
                        if (*ss!=',') CImg<char>::string(ss).move_to(arguments[nb_arguments]);
                      }
                      break;
                    }

                  if (is_debug) {
                    debug(images,"Found %d given argument%s for command '%s'%s",
                          nb_arguments,nb_arguments!=1?"s":"",
                          custom_command,nb_arguments>0?":":".");
                    for (unsigned int i = 1; i<=nb_arguments; ++i)
                      if (arguments[i]) debug(images,"  $%d = '%s'",i,arguments[i].data());
                      else debug(images,"  $%d = (undefined)",i);
                  }
                }

                // Substitute arguments in custom command expression.
                CImg<char> inbraces;

                for (const char *nsource = command_code; *nsource;)
                  if (*nsource!='$') {

                    // If not starting with '$'.
                    const char *const nsource0 = nsource;
                    nsource = std::strchr(nsource0,'$');
                    if (!nsource) nsource = command_code_back;
                    CImg<char>(nsource0,(unsigned int)(nsource - nsource0),1,1,1,true).
                      append_string_to(substituted_command,ptr_sub);
                  } else { // '$' expression found.
                    CImg<char> substr(324);
                    inbraces.assign(1,1,1,1,0);
                    int ind = 0, ind1 = 0, l_inbraces = 0;
                    bool is_braces = false;
                    sep = 0;

                    if (nsource[1]=='{') {
                      const char *const ptr_beg = nsource + 2, *ptr_end = ptr_beg;
                      unsigned int p = 0;
                      for (p = 1; p>0 && *ptr_end; ++ptr_end) {
                        if (*ptr_end=='{') ++p;
                        if (*ptr_end=='}') --p;
                      }
                      if (p) { CImg<char>::append_string_to(*(nsource++),substituted_command,ptr_sub); continue; }
                      l_inbraces = (int)(ptr_end - ptr_beg - 1);
                      if (l_inbraces>0) inbraces.assign(ptr_beg,l_inbraces + 1).back() = 0;
                      is_braces = true;
                    }

                    // Substitute $# -> maximum indice of known arguments.
                    if (nsource[1]=='#') {
                      nsource+=2;
                      cimg_snprintf(substr,substr.width(),"%u",nb_arguments);
                      CImg<char>(substr.data(),(unsigned int)std::strlen(substr),1,1,1,true).
                        append_string_to(substituted_command,ptr_sub);
                      has_arguments = true;

                      // Substitute $* -> copy of the specified arguments string.
                    } else if (nsource[1]=='*') {
                      nsource+=2;
                      CImg<char>(argument,(unsigned int)std::strlen(argument),1,1,1,true).
                        append_string_to(substituted_command,ptr_sub);
                      has_arguments = true;

                      // Substitute $"*" -> copy of the specified "quoted" arguments string.
                    } else if (nsource[1]=='\"' && nsource[2]=='*' && nsource[3]=='\"') {
                      nsource+=4;
                      for (unsigned int i = 1; i<=nb_arguments; ++i) {
                        CImg<char>::append_string_to('\"',substituted_command,ptr_sub);
                        CImg<char>(arguments[i].data(),arguments[i].width() - 1,1,1,1,true).
                          append_string_to(substituted_command,ptr_sub);
                        CImg<char>::append_string_to('\"',substituted_command,ptr_sub);
                        if (i!=nb_arguments) CImg<char>::append_string_to(',',substituted_command,ptr_sub);
                      }
                      has_arguments = true;

                      // Substitute $= -> transfer (quoted) arguments to named variables.
                    } else if (nsource[1]=='=' &&
                               cimg_sscanf(nsource + 2,"%255[a-zA-Z0-9_]",title)==1 &&
                               (*title<'0' || *title>'9')) {
                      nsource+=2 + std::strlen(title);
                      for (unsigned int i = 0; i<=nb_arguments; ++i) {
                        cimg_snprintf(substr,substr.width()," %s%u=\"",title,i);
                        CImg<char>(substr.data(),(unsigned int)std::strlen(substr),1,1,1,true).
                          append_string_to(substituted_command,ptr_sub);
                        CImg<char>(arguments[i].data(),arguments[i].width() - 1,1,1,1,true).
                          append_string_to(substituted_command,ptr_sub);
                        CImg<char>::append_string_to('\"',substituted_command,ptr_sub);
                        CImg<char>::append_string_to(' ',substituted_command,ptr_sub);
                      }
                      has_arguments = true;

                      // Substitute $i and ${i} -> value of the i^th argument.
                    } else if ((cimg_sscanf(nsource,"$%d",&ind)==1 ||
                                (cimg_sscanf(nsource,"${%d%c",&ind,&sep)==2 && sep=='}'))) {
                      const int nind = ind + (ind<0?(int)nb_arguments + 1:0);
                      if ((nind<=0 && ind) || nind>=arguments.width() || !arguments[nind]) {
                        error(images,0,custom_command,
                              "Command '-%s': Undefined argument '$%d', in expression '$%s%d%s' "
                              "(for %u argument%s specified).",
                              custom_command,ind,sep=='}'?"{":"",ind,sep=='}'?"}":"",
                              nb_arguments,nb_arguments!=1?"s":"");
                      }
                      nsource+=cimg_snprintf(substr,substr.width(),"$%d",ind) + (sep=='}'?2:0);
                      if (arguments[nind].width()>1)
                        CImg<char>(arguments[nind].data(),arguments[nind].width() - 1,1,1,1,true).
                          append_string_to(substituted_command,ptr_sub);
                      if (nind!=0) has_arguments = true;

                      // Substitute ${i=$j} -> value of the i^th argument, or the default value,
                      // i.e. the value of another argument.
                    } else if (cimg_sscanf(nsource,"${%d=$%d%c",&ind,&ind1,&sep)==3 && sep=='}' &&
                               ind>0) {
                      const int nind1 = ind1 + (ind1<0?(int)nb_arguments + 1:0);
                      if (nind1<=0 || nind1>=arguments.width() || !arguments[nind1])
                        error(images,0,custom_command,
                              "Command '-%s': Undefined argument '$%d', in expression '${%d=$%d}' "
                              "(for %u argument%s specified).",
                              custom_command,ind1,ind,ind1,
                              nb_arguments,nb_arguments!=1?"s":"");
                      nsource+=cimg_snprintf(substr,substr.width(),"${%d=$%d}",ind,ind1);
                      if (ind>=arguments.width()) arguments.insert(2 + 2*ind - arguments.size());
                      if (!arguments[ind]) {
                        arguments[ind] = arguments[nind1];
                        if (ind>(int)nb_arguments) nb_arguments = (unsigned int)ind;
                      }
                      if (arguments[ind].width()>1)
                        CImg<char>(arguments[ind].data(),arguments[ind].width() - 1,1,1,1,true).
                          append_string_to(substituted_command,ptr_sub);
                      has_arguments = true;

                      // Substitute ${i=$#} -> value of the i^th argument, or the default value,
                      // i.e. the maximum indice of known arguments.
                    } else if (cimg_sscanf(nsource,"${%d=$#%c",&ind,&sep)==2 && sep=='}' &&
                               ind>0) {
                      if (ind>=arguments.width()) arguments.insert(2 + 2*ind - arguments.size());
                      if (!arguments[ind]) {
                        cimg_snprintf(substr,substr.width(),"%u",nb_arguments);
                        CImg<char>::string(substr).move_to(arguments[ind]);
                        if (ind>(int)nb_arguments) nb_arguments = (unsigned int)ind;
                      }
                      nsource+=cimg_snprintf(substr,substr.width(),"${%d=$#}",ind);
                      if (arguments[ind].width()>1)
                        CImg<char>(arguments[ind].data(),arguments[ind].width() - 1,1,1,1,true).
                          append_string_to(substituted_command,ptr_sub);
                      has_arguments = true;

                      // Substitute ${i=default} -> value of the i^th argument,
                      // or the specified default value.
                    } else if (cimg_sscanf(inbraces,"%d%c",&ind,&sep)==2 && sep=='=' &&
                               ind>0) {
                      nsource+=l_inbraces + 3;
                      if (ind>=arguments.width()) arguments.insert(2 + 2*ind - arguments.size());
                      if (!arguments[ind]) {
                        CImg<char>::string(inbraces.data() +
                                           cimg_snprintf(substr,substr.width(),"%d=",ind)).
                          move_to(arguments[ind]);
                        if (ind>(int)nb_arguments) nb_arguments = (unsigned int)ind;
                      }
                      if (arguments[ind].width()>1)
                        CImg<char>(arguments[ind].data(),arguments[ind].width() - 1,1,1,1,true).
                          append_string_to(substituted_command,ptr_sub);
                      has_arguments = true;

                      // Substitute any other expression starting by '$'.
                    } else {

                      // Substitute ${subset} -> values of the selected subset of arguments,
                      // separated by ','.
                      bool is_valid_subset = false;
                      if (is_braces) {
                        const char c = *inbraces, nc = c?inbraces[1]:0;
                        if (c=='^' || c==':' || c=='.' || (c>='0' && c<='9') ||
                            (c=='-' && !((nc>='a' && nc<='z') ||
                                         (nc>='A' && nc<='Z') ||
                                         nc=='_'))) {

                          CImg<unsigned int> inds;
                          CImg<char> _status;
                          const int _verbosity = verbosity;
                          const bool _is_debug = is_debug;
                          verbosity = -16384; is_debug = false;
                          status.move_to(_status); // Save status because 'selection2cimg' can change it.
                          try {
                            inds = selection2cimg(inbraces,nb_arguments + 1,
                                                  CImgList<char>::empty(),"",false);
                            is_valid_subset = true;
                          } catch (...) { inds.assign(); is_valid_subset = false; }
                          _status.move_to(status);
                          verbosity = _verbosity; is_debug = _is_debug;

                          if (is_valid_subset) {
                            nsource+=l_inbraces + 3;
                            if (inds) {
                              cimg_forY(inds,j) {
                                const unsigned int uind = inds[j];
                                if (uind) has_arguments = true;
                                if (!arguments[uind])
                                  error(images,0,custom_command,
                                        "Command '-%s': Undefined argument '$%d', "
                                        "in expression '${%s}'.",
                                        custom_command,uind,inbraces.data());
                                CImg<char>(arguments[uind],true).append_string_to(substituted_command,ptr_sub);
                                *(ptr_sub - 1) = ',';
                              }
                              --ptr_sub;
                              has_arguments = true;
                            }
                          }
                        }
                      }
                      if (!is_valid_subset) CImg<char>::append_string_to(*(nsource++),substituted_command,ptr_sub);
                    }
                  }
                *ptr_sub = 0;

                // Substitute special character codes appearing outside strings.
                bool is_dquoted = false, is_escaped = false;
                for (char *s = substituted_command.data(); *s; ++s) {
                  const char c = *s;
                  if (is_escaped) is_escaped = false;
                  else if (c=='\\') is_escaped = true;
                  else if (c=='\"') is_dquoted = !is_dquoted;
                  if (!is_dquoted) *s = c<' '?(c==gmic_dollar?'$':c==gmic_lbrace?'{':c==gmic_rbrace?'}':
                                               c==gmic_comma?',':c==gmic_dquote?'\"':c):c;
                }

                if (is_debug) {
                  CImg<char> command_code_text(264);
                  const unsigned int l = (unsigned int)std::strlen(substituted_command.data());
                  if (l>=264) {
                    std::memcpy(command_code_text.data(),substituted_command.data(),128);
                    std::memcpy(command_code_text.data() + 128,"(...)",5);
                    std::memcpy(command_code_text.data() + 133,substituted_command.data() + l - 130,131);
                  } else std::strcpy(command_code_text.data(),substituted_command.data());
                  for (char *ptrs = command_code_text, *ptrd = ptrs; *ptrs || (bool)(*ptrd=0);
                       ++ptrs)
                    if (*ptrs==1) while (*ptrs!=' ') ++ptrs; else *(ptrd++) = *ptrs;
                  debug(images,"Expand command line for command '%s' to: '%s'.",
                        custom_command,command_code_text.data());
                }
                break;
              }
            }
          }

          if (custom_command_found) {
            const CImgList<char>
	      ncommands_line = commands_line_to_CImgList(substituted_command.data());
            CImg<unsigned int> nvariables_sizes(512);
	    cimg_forX(nvariables_sizes,l) nvariables_sizes[l] = variables[l]->size();
            g_list.assign(selection.height());
            g_list_c.assign(selection.height());

            unsigned int nposition = 0;
            gmic_exception exception;
            const unsigned int
              previous_debug_filename = debug_filename,
              previous_debug_line = debug_line;
            CImg<char>::string(custom_command).move_to(callstack);
            if (is_double_hyphen) {
              cimg_forY(selection,l) {
                const unsigned int uind = selection[l];
                g_list[l] = images[uind];
                g_list_c[l] = images_names[uind];
              }
              try {
                is_debug_info = false;
                _run(ncommands_line,nposition,g_list,g_list_c,images,images_names,nvariables_sizes,&_is_noarg,
                     argument,&selection);
              } catch (gmic_exception &e) {
                cimg::swap(exception._command_help,e._command_help);
                cimg::swap(exception._message,e._message);
              }
              g_list.move_to(images,~0U);
              cimglist_for(g_list_c,l) g_list_c[l].copymark();
              g_list_c.move_to(images_names,~0U);
            } else {
              cimg::mutex(27);
              cimg_forY(selection,l) {
                const unsigned int uind = selection[l];
                if ((images[uind].width() || images[uind].height()) && !images[uind].spectrum()) {
                  selection2string(selection,images_names,1,name);
                  error(images,0,0,
                        "Command '-%s': Invalid selection%s "
                        "(image [%u] is already used in another thread).",
                        custom_command,name.data() + (*name=='s'?1:0),uind);
                }
                if (images[uind].is_shared())
                  g_list[l].assign(images[uind],false);
                else {
                  g_list[l].swap(images[uind]);
                  // Small hack to be able to track images of the selection passed to the new environment.
                  std::memcpy(&images[uind]._width,&g_list[l]._data,sizeof(void*));
                  images[uind]._spectrum = 0;
                }
                g_list_c[l] = images_names[uind];   // Make a copy to be still able to recognize '-pass[label]'.
              }
              cimg::mutex(27,0);

              try {
                is_debug_info = false;
                _run(ncommands_line,nposition,g_list,g_list_c,images,images_names,nvariables_sizes,&_is_noarg,
                     argument,&selection);
              } catch (gmic_exception &e) {
                cimg::swap(exception._command_help,e._command_help);
                cimg::swap(exception._message,e._message);
              }

              const unsigned int nb = std::min((unsigned int)selection.height(),g_list.size());
              if (nb>0) {
                for (unsigned int i = 0; i<nb; ++i) {
                  const unsigned int uind = selection[i];
                  if (images[uind].is_shared()) {
                    images[uind] = g_list[i];
                    g_list[i].assign();
                  } else images[uind].swap(g_list[i]);
                  images_names[uind].swap(g_list_c[i]);
                }
                g_list.remove(0,nb - 1);
                g_list_c.remove(0,nb - 1);
              }
              if (nb<(unsigned int)selection.height())
                remove_images(images,images_names,selection,nb,selection.height() - 1);
              else if (g_list) {
                const unsigned int uind0 = selection?selection.back() + 1:images.size();
                g_list_c.move_to(images_names,uind0);
                g_list.move_to(images,uind0);
              }
            }
	    for (unsigned int l = 0; l<nvariables_sizes._width - 2; ++l) if (variables[l]->size()>nvariables_sizes[l]) {
		variables_names[l]->remove(nvariables_sizes[l],variables[l]->size() - 1);
		variables[l]->remove(nvariables_sizes[l],variables[l]->size() - 1);
	      }
            callstack.remove();
            debug_filename = previous_debug_filename;
            debug_line = previous_debug_line;
            is_return = false;
            g_list.assign();
            g_list_c.assign();
            if (has_arguments && !_is_noarg) ++position;
            if (exception._message) throw exception;
            continue;
          }
        }
      }  // if (*item=='-') {

      // Variable assignment.
      if (!is_input_command) {
        const char *const s_eq = std::strchr(item,'='), *new_value = 0;
        if (s_eq) {
          sep0 = s_eq>item?*(s_eq - 1):0;
          sep1 = s_eq>item + 1?*(s_eq - 2):0;
          if (cimg_sscanf(item,"%255[a-zA-Z0-9_]",title)==1 && (*title<'0' || *title>'9')) {
            pattern = (unsigned int)std::strlen(title);
            if ((sep0=='<' || sep0=='>') && sep1==sep0 && s_eq==item + pattern + 2) {
              new_value = set_variable(title,s_eq + 1,sep0,variables_sizes);
              _gmic_argument_text(s_eq + 1,name.assign(128),is_verbose);
              print(images,0,"Update %s variable %s%c%c='%s' -> %s='%s'.",
                    *title=='_'?"global":"local",
                    title,sep0,sep0,name.data(),title,new_value);
              continue;
            } else if ((sep0=='+' || sep0=='-' || sep0=='*' || sep0=='/' ||
                        sep0=='%' || sep0=='&' || sep0=='|' || sep0=='^') && s_eq==item + pattern + 1) {
              new_value = set_variable(title,s_eq + 1,sep0,variables_sizes);
              _gmic_argument_text(s_eq + 1,name.assign(128),is_verbose);
              print(images,0,"Update %s variable %s%c='%s' -> %s='%s'.",
                    *title=='_'?"global":"local",
                    title,sep0,name.data(),title,new_value);
              continue;
            } else if (s_eq==item + pattern) {
              set_variable(title,s_eq + 1,'=',variables_sizes);
              _gmic_argument_text(s_eq + 1,name.assign(128),is_verbose);
              print(images,0,"Set %s variable %s='%s'.",
                    *title=='_'?"global":"local",
                    title,name.data());
              continue;
            }
          }
        }
      }

      // Input.
      if (is_input_command) ++position; else { std::strcpy(command,"-input"); argument = item; *restriction = 0; }
      gmic_substitute_args(true);
      if (!is_restriction || !selection) selection.assign(1,1,1,1,images.size());

      CImg<char> indicesy(256), indicesz(256), indicesc(256);
      float dx = 0, dy = 1, dz = 1, dc = 1, nb = 1;
      CImg<unsigned int> indx, indy, indz, indc;
      CImgList<char> input_images_names;
      CImgList<T> input_images;
      sepx = sepy = sepz = sepc = *indices = *indicesy = *indicesz = *indicesc = *argx = *argy = *argz = *argc = 0;

      CImg<char> arg_input(argument,(unsigned int)std::strlen(argument) + 1);
      strreplace_fw(arg_input);

      CImg<char> _gmic_selection;
      if (is_verbose) selection2string(selection,images_names,0,_gmic_selection);

      if (*arg_input=='0' && !arg_input[1]) {

        // Empty image.
        print(images,0,"Input empty image at position%s",
              _gmic_selection.data());
        input_images.assign(1);
        CImg<char>::string("[empty]").move_to(input_images_names);


      } else if ((cimg_sscanf(arg_input,"[%255[a-zA-Z_0-9%.eE%^,:+-]%c%c",indices,&sep,&end)==2 &&
                  sep==']') ||
                 cimg_sscanf(arg_input,"[%255[a-zA-Z_0-9%.eE%^,:+-]]x%f%c",indices,&nb,&end)==2) {

        // Nb copies of existing images.
        nb = cimg::round(nb);
        const CImg<unsigned int> inds = selection2cimg(indices,images.size(),images_names,"-input");
        CImg<char> s_tmp;
        if (is_verbose) selection2string(inds,images_names,1,s_tmp);
        if (nb<=0) arg_error("input");
        if (nb!=1)
          print(images,0,"Input %u copies of image%s at position%s",
                (unsigned int)nb,
                s_tmp.data(),
                _gmic_selection.data());
        else
          print(images,0,"Input copy of image%s at position%s",
                s_tmp.data(),
                _gmic_selection.data());
        for (unsigned int i = 0; i<(unsigned int)nb; ++i) cimg_foroff(inds,l) {
            input_images.insert(gmic_check(images[inds[l]]));
            input_images_names.insert(images_names[inds[l]].get_copymark());
          }
      } else if ((sep=0,true) &&
                 (cimg_sscanf(arg_input,"%255[][a-zA-Z0-9_.eE%+-]%c",
                              argx,&end)==1 ||
                  cimg_sscanf(arg_input,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-]%c",
                              argx,argy,&end)==2 ||
                  cimg_sscanf(arg_input,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-],"
			      "%255[][a-zA-Z0-9_.eE%+-]%c",
                              argx,argy,argz,&end)==3 ||
                  cimg_sscanf(arg_input,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-],"
			      "%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-]%c",
                              argx,argy,argz,argc,&end)==4 ||
                  cimg_sscanf(arg_input,"%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-],"
			      "%255[][a-zA-Z0-9_.eE%+-],%255[][a-zA-Z0-9_.eE%+-],%c",
                              argx,argy,argz,argc,&sep)==5) &&
                 ((cimg_sscanf(argx,"[%255[a-zA-Z0-9_.%+-]%c%c",indices,&sepx,&end)==2 &&
		   sepx==']' &&
                   (indx=selection2cimg(indices,images.size(),images_names,"-input")).height()==1) ||
                  (cimg_sscanf(argx,"%f%c",&dx,&end)==1 && dx>=1) ||
                  (cimg_sscanf(argx,"%f%c%c",&dx,&sepx,&end)==2 && dx>0 && sepx=='%')) &&
                 (!*argy ||
                  (cimg_sscanf(argy,"[%255[a-zA-Z0-9_.%+-]%c%c",indicesy.data(),&sepy,&end)==2 &&
		   sepy==']' &&
                   (indy=selection2cimg(indicesy,images.size(),images_names,"-input")).height()==1) ||
                  (cimg_sscanf(argy,"%f%c",&dy,&end)==1 && dy>=1) ||
                  (cimg_sscanf(argy,"%f%c%c",&dy,&sepy,&end)==2 && dy>0 && sepy=='%')) &&
                 (!*argz ||
                  (cimg_sscanf(argz,"[%255[a-zA-Z0-9_.%+-]%c%c",indicesz.data(),&sepz,&end)==2 &&
		   sepz==']' &&
                   (indz=selection2cimg(indicesz,images.size(),images_names,"-input")).height()==1) ||
                  (cimg_sscanf(argz,"%f%c",&dz,&end)==1 && dz>=1) ||
                  (cimg_sscanf(argz,"%f%c%c",&dz,&sepz,&end)==2 && dz>0 && sepz=='%')) &&
                 (!*argc ||
                  (cimg_sscanf(argc,"[%255[a-zA-Z0-9_.%+-]%c%c",indicesc.data(),&sepc,&end)==2 &&
		   sepc==']' &&
                   (indc=selection2cimg(indicesc,images.size(),images_names,"-input")).height()==1) ||
                  (cimg_sscanf(argc,"%f%c",&dc,&end)==1 && dc>=1) ||
                  (cimg_sscanf(argc,"%f%c%c",&dc,&sepc,&end)==2 && dc>0 && sepc=='%'))) {

        // New image with specified dimensions and optionally values.
        if (indx) { dx = (float)gmic_check(images[*indx]).width(); sepx = 0; }
        if (indy) { dy = (float)gmic_check(images[*indy]).height(); sepy = 0; }
        if (indz) { dz = (float)gmic_check(images[*indz]).depth(); sepz = 0; }
        if (indc) { dc = (float)gmic_check(images[*indc]).spectrum(); sepc = 0; }
        int idx = 0, idy = 0, idz = 0, idc = 0;
        const CImg<T>& img = images.size()?gmic_check(images.back()):CImg<T>::empty();
        if (sepx=='%') { idx = (int)cimg::round(dx*img.width()/100); if (!idx) ++idx; }
        else idx = (int)cimg::round(dx);
        if (sepy=='%') { idy = (int)cimg::round(dy*img.height()/100); if (!idy) ++idy; }
        else idy = (int)cimg::round(dy);
        if (sepz=='%') { idz = (int)cimg::round(dz*img.depth()/100); if (!idz) ++idz; }
        else idz = (int)cimg::round(dz);
        if (sepc=='%') { idc = (int)cimg::round(dc*img.spectrum()/100); if (!idc) ++idc; }
        else idc = (int)cimg::round(dc);
        if (idx<=0 || idy<=0 || idz<=0 || idc<=0) arg_error("input");
        CImg<char> s_values;
        if (sep) {
          const char *_s_values = arg_input.data() + std::strlen(argx) + std::strlen(argy) +
            std::strlen(argz) + std::strlen(argc) + 4;
          s_values.assign(_s_values,(unsigned int)std::strlen(_s_values) + 1);
          cimg::strpare(s_values,'\'',true,false);
          strreplace_fw(s_values);
          CImg<char> s_values_text(72);
          const unsigned int l = (unsigned int)std::strlen(s_values);
          if (l>=72) {
            std::memcpy(s_values_text.data(),s_values.data(),32);
            std::memcpy(s_values_text.data() + 32,"(...)",5);
            std::memcpy(s_values_text.data() + 37,s_values.data() + l - 34,35);  // Last '\0' is included.
          } else std::strcpy(s_values_text,s_values);
          print(images,0,"Input image at position%s, with values '%s'",
                _gmic_selection.data(),s_values_text.data());
        } else
          print(images,0,"Input black image at position%s",
                _gmic_selection.data());
        CImg<T> new_image(idx,idy,idz,idc,(T)0);
        if (s_values) {
          new_image.fill(s_values.data(),true,true,&images,&images);
          cimg_snprintf(title,_title.width(),"[image of '%s']",s_values.data());
          CImg<char>::string(title).move_to(input_images_names);
        } else CImg<char>::string("[unnamed]").move_to(input_images_names);
        new_image.move_to(input_images);

      } else if (*arg_input=='(' && arg_input[std::strlen(arg_input) - 1]==')') {

        // New IxJxKxL image specified as array.
        unsigned int cx = 0, cy = 0, cz = 0, cc = 0, maxcx = 0, maxcy = 0, maxcz = 0;
        const char *nargument = 0;
        for (nargument = arg_input.data() + 1; *nargument; ) {
          CImg<char> s_value(256); *s_value = 0;
          char separator = 0;
          value = 0;
          if (cimg_sscanf(nargument,"%255[0-9.eE+-]%c",s_value.data(),&separator)==2 &&
              cimg_sscanf(s_value,"%lf%c",&value,&end)==1) {
            if (cx>maxcx) maxcx = cx;
            if (cy>maxcy) maxcy = cy;
            if (cz>maxcz) maxcz = cz;
            switch (separator) {
            case '^' : cx = cy = cz = 0; ++cc; break;
            case '/' : cx = cy = 0; ++cz; break;
            case ';' : cx = 0; ++cy; break;
            case ',' : ++cx; break;
            case ')' : break;
            default : arg_error("input");
            }
            nargument+=std::strlen(s_value) + 1;
          } else break;
        }
        if (*nargument) arg_error("input");
        CImg<T> img(maxcx + 1,maxcy + 1,maxcz + 1,cc + 1,(T)0);
        cx = cy = cz = cc = 0;
        for (nargument = arg_input.data() + 1; *nargument; ) {
          CImg<char> s_value(256); *s_value = 0;
          char separator = 0;
          value = 0;
          if (cimg_sscanf(nargument,"%255[0-9.eE+-]%c",s_value.data(),&separator)==2 &&
              cimg_sscanf(s_value,"%lf%c",&value,&end)==1) {
            img(cx,cy,cz,cc) = (T)value;
            switch (separator) {
            case '^' : cx = cy = cz = 0; ++cc; break;
            case '/' : cx = cy = 0; ++cz; break;
            case ';' : cx = 0; ++cy; break;
            default : ++cx;
            }
            nargument+=std::strlen(s_value) + (separator?1:0);
          } else break;
        }
        print(images,0,"Input image at position%s, with values %s",
              _gmic_selection.data(),
              gmic_argument_text_printed());
        img.move_to(input_images);
        arg_input.move_to(input_images_names);

      } else {

        // Input filename.
        char cext[12];
        CImg<char> _filename(4096), filename_tmp(256), options(256);
        *cext = *_filename = *filename_tmp = *options = 0;
        bool is_network_file = false;
        if (cimg_sscanf(argument,"%11[a-zA-Z]:%4095[^,],%255s",
                        cext,_filename.data(),options.data())<2 ||
            !cext[1] || // length of 'ext' must be >=2 (avoid case 'C:\\...' on Windows).
            !cimg::strcasecmp(cext,"http") || !cimg::strcasecmp(cext,"https")) {
          *cext = *_filename = *options = 0;
          if (cimg_sscanf(argument,"%4095[^,],%255s",_filename.data(),options.data())!=2) {
            std::strncpy(_filename,argument,_filename.width() - 1);
            _filename[_filename.width() - 1] = 0;
          }
        }
        strreplace_fw(_filename);
        strreplace_fw(options);
        CImg<char> __filename0 = CImg<char>::string(_filename);
        const char *const _filename0 = __filename0.data();

        // Test for network file requests.
        if (!cimg::strncasecmp(_filename,"http://",7) ||
            !cimg::strncasecmp(_filename,"https://",8)) {
          try {
            cimg::load_network(_filename,filename_tmp);
          } catch (CImgIOException&) {
            print(images,0,"Input file '%s' at position%s",
                  _filename0,
                  _gmic_selection.data());
            error(images,0,0,
                  "Unreachable network file '%s'.",
                  gmic_argument_text());
          }
          is_network_file = true;
          std::strncpy(_filename,filename_tmp,_filename.width() - 1);
          _filename[_filename.width() - 1] = 0;
          *filename_tmp = 0;
        }

        if (*cext) { // Force input to be read as a '.ext' file : generate random filename.
          if (*_filename=='-' && (!_filename[1] || _filename[1]=='.')) {
            // Simplify filename 'ext:-.foo' as '-.ext'.
            cimg_snprintf(_filename,_filename.width(),"-.%s",cext);
            *cext = 0;
          } else {
            std::FILE *file = 0;
            do {
              cimg_snprintf(filename_tmp,filename_tmp.width(),"%s%c%s.%s",
                            cimg::temporary_path(),cimg_file_separator,
                            cimg::filenamerand(),cext);
              if ((file=std::fopen(filename_tmp,"rb"))!=0) std::fclose(file);
            } while (file);

            // Make a temporary copy (or link) of the original file.
#if cimg_OS==1
            const char *const _filename_path = realpath(_filename,0);
            if (symlink(_filename_path,filename_tmp))
              CImg<unsigned char>::get_load_raw(_filename).save_raw(filename_tmp);
            std::free((void*)_filename_path);
#else // #if cimg_OS==1
            CImg<unsigned char>::get_load_raw(_filename).save_raw(filename_tmp);
#endif // #if cimg_OS==1
          }
        }

        const char
          *const filename = *filename_tmp?filename_tmp:_filename,
          *const ext = cimg::split_filename(filename);
        const bool is_stdin = *filename=='-' && (!filename[1] || filename[1]=='.');

        const char *file_type = 0;
        std::FILE *const file = is_stdin?0:std::fopen(filename,"rb");
        longT siz = 0;
        if (file) {
          std::fseek(file,0,SEEK_END);
          siz = std::ftell(file);
          std::rewind(file);
          file_type = *ext?0:cimg::ftype(file,0);
          std::fclose(file);
        }
        if (!is_stdin && file && siz==0) { // Empty file -> Insert an empty image.
          input_images_names.insert(__filename0);
          input_images.insert(1);
        } else if (!cimg::strcasecmp("off",ext) || (file_type && !std::strcmp(file_type,"off"))) {

          // 3d object .off file.
          print(images,0,"Input 3d object '%s' at position%s",
                _filename0,_gmic_selection.data());

          if (*options)
            error(images,0,0,
                  "Command '-input': File '%s', format does not take any input options (options '%s' specified).",
                  _filename0,options.data());

          CImg<float>::get_load_off(primitives,g_list_f,filename).move_to(vertices);
          const CImg<float> opacities(1,primitives.size(),1,1,1);
          vertices.object3dtoCImg3d(primitives,g_list_f,opacities,false).move_to(input_images);
          primitives.assign();
          g_list_f.assign();
          input_images_names.insert(__filename0);
        } else if (!cimg::strcasecmp(ext,"cimg") && *options) {

          // Part of a .cimg file (non-compressed).
          float
            n0 = -1, x0 = -1, y0 = -1, z0 = -1, c0 = -1,
            n1 = -1, x1 = -1, y1 = -1, z1 = -1, c1 = -1;
          if ((cimg_sscanf(options,"%f,%f%c",
                           &n0,&n1,&end)==2 ||
               cimg_sscanf(options,"%f,%f,%f,%f%c",
                           &n0,&n1,&x0,&x1,&end)==4 ||
               cimg_sscanf(options,"%f,%f,%f,%f,%f,%f%c",
                           &n0,&n1,&x0,&y0,&x1,&y1,&end)==6 ||
               cimg_sscanf(options,"%f,%f,%f,%f,%f,%f,%f,%f%c",
                           &n0,&n1,&x0,&y0,&z0,&x1,&y1,&z1,&end)==8 ||
               cimg_sscanf(options,"%f,%f,%f,%f,%f,%f,%f,%f,%f,%f%c",
                           &n0,&n1,&x0,&y0,&z0,&c0,&x1,&y1,&z1,&c1,&end)==10) &&
              (n0==-1 || n0>=0) && (n1==-1 || n1>=0) &&
              (x0==-1 || x0>=0) && (x1==-1 || x1>=0) &&
              (y0==-1 || y0>=0) && (y1==-1 || y1>=0) &&
              (z0==-1 || z0>=0) && (z1==-1 || z1>=0) &&
              (c0==-1 || c0>=0) && (c1==-1 || c1>=0)) {
            n0 = cimg::round(n0); n1 = cimg::round(n1);
            x0 = cimg::round(x0); x1 = cimg::round(x1);
            y0 = cimg::round(y0); y1 = cimg::round(y1);
            z0 = cimg::round(z0); z1 = cimg::round(z1);
            c0 = cimg::round(c0); c1 = cimg::round(c1);
            if (c0==-1 && c1==-1) {
              if (z0==-1 && z1==-1) {
                if (y0==-1 && y1==-1) {
                  if (x0==-1 && x1==-1) {
                    print(images,0,"Input crop [%d] -> [%d] of file '%s' at position%s",
                          (int)n0,(int)n1,
                          _filename0,_gmic_selection.data());
                    input_images.load_cimg(filename,
                                           (unsigned int)n0,(unsigned int)n1,
                                           0U,0U,0U,0U,~0U,~0U,~0U,~0U);
                  } else {
                    print(images,0,"Input crop [%d](%d) -> [%d](%d) of file '%s' at position%s",
                          (int)n0,(int)x0,(int)n1,(int)x1,
                          _filename0,_gmic_selection.data());
                    input_images.load_cimg(filename,
                                           (unsigned int)n0,(unsigned int)n1,
                                           (unsigned int)x0,0U,0U,0U,
                                           (unsigned int)x1,~0U,~0U,~0U);
                  }
                } else {
                  print(images,0,"Input crop [%d](%d,%d) -> [%d](%d,%d) of file '%s' at position%s",
                        (int)n0,(int)n1,(int)x0,(int)y0,(int)x1,(int)y1,
                        _filename0,_gmic_selection.data());
                  input_images.load_cimg(filename,
                                         (unsigned int)n0,(unsigned int)n1,
                                         (unsigned int)x0,(unsigned int)y0,0U,0U,
                                         (unsigned int)x1,(unsigned int)y1,~0U,~0U);
                }
              } else {
                print(images,0,"Input crop [%d](%d,%d,%d) -> [%d](%d,%d,%d) of file '%s' "
                      "at position%s",
                      (int)n0,(int)n1,(int)x0,(int)y0,(int)z0,(int)x1,(int)y1,(int)z1,
                      _filename0,_gmic_selection.data());
                input_images.load_cimg(filename,
                                       (unsigned int)n0,(unsigned int)n1,
                                       (unsigned int)x0,(unsigned int)y0,(unsigned int)z0,0U,
                                       (unsigned int)x1,(unsigned int)y1,(unsigned int)z1,~0U);
              }
            } else {
                print(images,0,"Input crop [%d](%d,%d,%d,%d) -> [%d](%d,%d,%d,%d) of file '%s' "
                      "at position%s",
                      (int)n0,(int)n1,
                      (int)x0,(int)y0,(int)z0,(int)c0,
                      (int)x1,(int)y1,(int)z1,(int)c1,
                      _filename0,_gmic_selection.data());
                input_images.load_cimg(filename,
                                       (unsigned int)n0,(unsigned int)n1,
                                       (unsigned int)x0,(unsigned int)y0,
                                       (unsigned int)z0,(unsigned int)c0,
                                       (unsigned int)x1,(unsigned int)y1,
                                       (unsigned int)z1,(unsigned int)c1);
            }

            if (input_images) {
              input_images_names.insert(__filename0);
              if (input_images.size()>1)
                input_images_names.insert(input_images.size() - 1,__filename0.copymark());
            }
          } else
            error(images,0,0,
                  "Command '-input': .cimg file '%s', invalid file options '%s'.",
                  _filename0,options.data());

        } else if (!cimg::strcasecmp(ext,"gmz")) {
          print(images,0,"Input file '%s' at position%s",
                _filename0,
                _gmic_selection.data());
          input_images.load_cimg(filename);
          bool is_gmz = false;
          const CImg<char> back = input_images?CImg<char>(input_images.back()):CImg<char>::empty();
          if (back.width()==1 && back.depth()==1 && back.spectrum()==1 &&
              back[0]=='G' && back[1]=='M' && back[2]=='Z' && !back[3]) {
            input_images_names = back.get_split(CImg<char>::vector(0),0,false);
            if (input_images_names) {
              is_gmz = true;
              input_images_names.remove(0);
              cimglist_for(input_images_names,l)
                input_images_names[l].resize(1,input_images_names[l].height() + 1,1,1,0).
                unroll('x');
              input_images.remove();
            }
          }
          if (!is_gmz)
            error(images,0,0,"Command '-input': File '%s' is not in .gmz format (magic number not found).",
                  _filename0);
          if (input_images.size()!=input_images_names.size())
            error(images,0,0,"Command '-input': File '%s' is not in .gmz format "
                  "(numbers of images and names do not match).",
                  _filename0);

        } else if (!cimg::strcasecmp(ext,"cimg") || !cimg::strcasecmp(ext,"cimgz")) {
          print(images,0,"Input file '%s' at position%s",
                _filename0,
                _gmic_selection.data());
          input_images.load_cimg(filename);
          if (input_images) {
            input_images_names.insert(__filename0);
            if (input_images.size()>1)
              input_images_names.insert(input_images.size() - 1,__filename0.copymark());
          }

        } else if (!cimg::strcasecmp(ext,"avi") ||
                   !cimg::strcasecmp(ext,"mov") ||
                   !cimg::strcasecmp(ext,"asf") ||
                   !cimg::strcasecmp(ext,"divx") ||
                   !cimg::strcasecmp(ext,"flv") ||
                   !cimg::strcasecmp(ext,"mpg") ||
                   !cimg::strcasecmp(ext,"m1v") ||
                   !cimg::strcasecmp(ext,"m2v") ||
                   !cimg::strcasecmp(ext,"m4v") ||
                   !cimg::strcasecmp(ext,"mjp") ||
                   !cimg::strcasecmp(ext,"mp4") ||
                   !cimg::strcasecmp(ext,"mkv") ||
                   !cimg::strcasecmp(ext,"mpe") ||
                   !cimg::strcasecmp(ext,"movie") ||
                   !cimg::strcasecmp(ext,"ogm") ||
                   !cimg::strcasecmp(ext,"ogg") ||
                   !cimg::strcasecmp(ext,"qt") ||
                   !cimg::strcasecmp(ext,"rm") ||
                   !cimg::strcasecmp(ext,"vob") ||
                   !cimg::strcasecmp(ext,"wmv") ||
                   !cimg::strcasecmp(ext,"xvid") ||
                   !cimg::strcasecmp(ext,"mpeg")) {

          // Image sequence file.
          float first_frame = 0, last_frame = -1, step = 1;
          if ((cimg_sscanf(options,"%f,%f%c",&first_frame,&last_frame,&end)==2 ||
              cimg_sscanf(options,"%f,%f,%f%c",&first_frame,&last_frame,&step,&end)==3) &&
              first_frame>=0 && (last_frame>=first_frame || last_frame==-1) && step>=0) {

            // Read several frames.
            step = cimg::round(step);
            const unsigned int
              _first_frame = (unsigned int)first_frame,
              _last_frame = last_frame>=0?(unsigned int)last_frame:~0U;
            if (_last_frame!=~0U)
              print(images,0,"Input frames %u...%u with step %g of file '%s' at position%s",
                    _first_frame,_last_frame,step,
                    _filename0,
                    _gmic_selection.data());
            else
              print(images,0,"Input frames %u...(last) with step %g of file '%s' at position%s",
                    _first_frame,step,
                    _filename0,
                    _gmic_selection.data());

            input_images.load_video(filename,_first_frame,_last_frame,(unsigned int)step);
          } else if (cimg_sscanf(options,"%f%c",&first_frame,&end)==1 &&
                     first_frame>=0) {
            // Read a single frame.
            const unsigned int _first_frame = (unsigned int)first_frame;
            print(images,0,"Input frame %u of file '%s' at position%s",
                  _first_frame,_filename0,
                  _gmic_selection.data());
            input_images.load_video(filename,_first_frame,_first_frame);
          } else if (!*options) {
            // Read all frames.
            print(images,0,"Input all frames of file '%s' at position%s",
                  _filename0,
                  _gmic_selection.data());
            input_images.load_video(filename);
          } else
            error(images,0,0,
                  "Command '-input': video file '%s', invalid file options '%s'.",
                  _filename0,options.data());
          if (input_images) {
            input_images_names.insert(__filename0);
            if (input_images.size()>1)
              input_images_names.insert(input_images.size() - 1,__filename0.copymark());
          }
        } else if (!cimg::strcasecmp("raw",ext)) {

          // Raw file.
          float dx = 0, dy = 1, dz = 1, dc = 1;
          ulongT offset = 0;
          *argx = 0;
          if (!*options ||
              cimg_sscanf(options,"%f%c",&dx,&end)==1 ||
              cimg_sscanf(options,"%f,%f%c",&dx,&dy,&end)==2 ||
              cimg_sscanf(options,"%f,%f,%f%c",&dx,&dy,&dz,&end)==3 ||
              cimg_sscanf(options,"%f,%f,%f,%f%c",&dx,&dy,&dz,&dc,&end)==4 ||
              cimg_sscanf(options,"%f,%f,%f,%f,%lu%c",&dx,&dy,&dz,&dc,&offset,&end)==5 ||
              cimg_sscanf(options,"%255[a-z64]%c",argx,&end)==1 ||
              cimg_sscanf(options,"%255[a-z64],%f%c",argx,&dx,&end)==2 ||
              cimg_sscanf(options,"%255[a-z64],%f,%f%c",argx,&dx,&dy,&end)==3 ||
              cimg_sscanf(options,"%255[a-z64],%f,%f,%f%c",argx,&dx,&dy,&dz,&end)==4 ||
              cimg_sscanf(options,"%255[a-z64],%f,%f,%f,%f%c",argx,&dx,&dy,&dz,&dc,&end)==5 ||
              cimg_sscanf(options,"%255[a-z64],%f,%f,%f,%f,%lu%c",argx,&dx,&dy,&dz,&dc,&offset,
                          &end)==6) {
            const char *const stype = *argx?argx:cimg::type<T>::string();
            dx = cimg::round(dx);
            dy = cimg::round(dy);
            dz = cimg::round(dz);
            dc = cimg::round(dc);
            if (dx<0 || dy<=0 || dz<=0 || dc<=0)
              error(images,0,0,
                    "Command '-input': raw file '%s', invalid specified "
		    "dimensions %gx%gx%gx%g.",
                    _filename0,dx,dy,dz,dc);

            if (offset)
              print(images,0,"Input raw file '%s' (offset: %lu) with type '%s' at position%s",
                    _filename0,offset,stype,
                    _gmic_selection.data());
            else
              print(images,0,"Input raw file '%s' with type '%s' at position%s",
                    _filename0,stype,
                    _gmic_selection.data());

#define gmic_load_raw(value_type,svalue_type) \
            if (!cimg::strcasecmp(stype,svalue_type)) \
              CImg<value_type>::get_load_raw(filename, \
                                             (unsigned int)dx,(unsigned int)dy, \
                                             (unsigned int)dz,(unsigned int)dc,false,false,offset).\
                move_to(input_images);
            gmic_load_raw(unsigned char,"uchar")
            else gmic_load_raw(unsigned char,"unsigned char")
              else gmic_load_raw(char,"char")
                else gmic_load_raw(unsigned short,"ushort")
                  else gmic_load_raw(unsigned short,"unsigned short")
                    else gmic_load_raw(short,"short")
                      else gmic_load_raw(unsigned int,"uint")
                        else gmic_load_raw(unsigned int,"unsigned int")
                          else gmic_load_raw(int,"int")
                            else gmic_load_raw(uint64T,"uint64")
                              else gmic_load_raw(uint64T,"unsigned int64")
                                else gmic_load_raw(int64T,"int64")
                                  else gmic_load_raw(float,"float")
                                    else gmic_load_raw(double,"double")
                                      else error(images,0,0,
                                                 "Command '-input': raw file '%s', "
                                                 "invalid specified pixel type '%s'.\n",
                                                 _filename0,stype);
            input_images_names.insert(__filename0);
          } else
            error(images,0,0,
                  "Command '-input': raw file '%s', invalid file options '%s'.",
                  _filename0,options.data());
        } else if (!cimg::strcasecmp("yuv",ext)) {

          // YUV file.
          float first_frame = 0, last_frame = 0, step = 1, dx = 0, dy = 1;
          if ((err = cimg_sscanf(options,"%f,%f,%f,%f,%f",
                                 &dx,&dy,&first_frame,&last_frame,&step))>=1) {
            dx = cimg::round(dx);
            dy = cimg::round(dy);
            if (dx<=0 || dy<=0)
              error(images,0,0,
                    "Command '-input': YUV file '%s', invalid specified dimensions %gx%g.",
                    _filename0,dx,dy);
            first_frame = cimg::round(first_frame);
            if (err>3) { // Load multiple frames.
              last_frame = cimg::round(last_frame);
              step = cimg::round(step);
              print(images,0,"Input frames %g...%g with step %g of YUV file '%s' at position%s",
                    first_frame,last_frame,step,
                    _filename0,
                    _gmic_selection.data());
              input_images.load_yuv(filename,(unsigned int)dx,(unsigned int)dy,
                                    (unsigned int)first_frame,(unsigned int)last_frame,
                                    (unsigned int)step);
            } else if (err==3) { // Load a single frame.
              print(images,0,"Input frames %g of YUV file '%s' at position%s",
                    first_frame,
                    _filename0,
                    _gmic_selection.data());
              input_images.load_yuv(filename,(unsigned int)dx,(unsigned int)dy,
                                    (unsigned int)first_frame,(unsigned int)first_frame);
            } else { // Load all frames.
              print(images,0,"Input all frames of YUV file '%s' at position%s",
                    _filename0,
                    _gmic_selection.data());
              input_images.load_yuv(filename,(unsigned int)dx,(unsigned int)dy);
            }
            if (input_images) {
              input_images_names.insert(__filename0);
              if (input_images.size()>1)
                input_images_names.insert(input_images.size() - 1,__filename0.copymark());
            }
          } else
            error(images,0,0,
                  "Command '-input': YUV file '%s', invalid or missing file options '%s'.",
                  _filename0,options.data());

          } else if (!cimg::strcasecmp("tif",ext) || !cimg::strcasecmp("tiff",ext) ||
                     (file_type && !std::strcmp(file_type,"tif"))) {

          // TIFF file.
          float first_frame = 0, last_frame = 0, step = 1;
#ifdef cimg_use_tiff
          static const TIFFErrorHandler default_handler = TIFFSetWarningHandler(0);
          if (is_very_verbose) TIFFSetWarningHandler(default_handler);
          else TIFFSetWarningHandler(0);
#endif // #ifdef cimg_use_tiff
          if ((err = cimg_sscanf(options,"%f,%f,%f",&first_frame,&last_frame,&step))>0) {
            first_frame = cimg::round(first_frame);
            if (err>1) { // Load multiple frames.
              last_frame = cimg::round(last_frame);
              step = cimg::round(step);
              print(images,0,"Input frames %g...%g with step %g of TIFF file '%s' at position%s",
                    first_frame,last_frame,step,
                    _filename0,
                    _gmic_selection.data());
              input_images.load_tiff(filename,(unsigned int)first_frame,(unsigned int)last_frame,
                                     (unsigned int)step);
            } else if (err==1) { // Load a single frame.
              print(images,0,"Input frames %g of TIFF file '%s' at position%s",
                    first_frame,
                    _filename0,
                    _gmic_selection.data());
              input_images.load_tiff(filename,(unsigned int)first_frame,(unsigned int)first_frame);
            }
          } else { // Load all frames.
            if (*options) error(images,0,0,
                                "Command '-input': TIFF file '%s', "
                                "invalid file options '%s'.",
                                _filename0,options.data());
            print(images,0,"Input all frames of TIFF file '%s' at position%s",
                  _filename0,
                  _gmic_selection.data());
            input_images.load_tiff(filename);
          }
          if (input_images) {
            input_images_names.insert(__filename0);
            if (input_images.size()>1)
              input_images_names.insert(input_images.size() - 1,__filename0.copymark());
          }
        } else if (!cimg::strcasecmp("gmic",ext)) {

          // G'MIC command file.
          const bool add_debug_info = (*options!='0');
          print(images,0,"Input custom command file '%s'%s",
                _filename0,!add_debug_info?" without debug info":"");
          unsigned int siz = 0;
          for (unsigned int l = 0; l<512; ++l) siz+=commands[l].size();
          std::FILE *const file = cimg::fopen(filename,"rb");

          bool is_command_error = false;
          CImg<char> _status;
          status.move_to(_status); // Save status because 'add_commands' can change it.
          const int _verbosity = verbosity;
          const bool _is_debug = is_debug;
          verbosity = -1; is_debug = false;
          try {
            add_commands(file,add_debug_info?filename:0);
          } catch (...) {
            is_command_error = true;
          }
          verbosity = _verbosity; is_debug = _is_debug;
          _status.move_to(status);
          if (is_command_error) {
            if (is_network_file)
              error(images,0,0,
                    "Command '-input': Unable to load custom command file '%s' from network.",
                    _filename0);
            else
              error(images,0,0,
                    "Command '-input': File '%s' is not recognized as a custom command file.",
                    _filename0);
          }
          cimg::fclose(file);
          if (is_verbose) {
            unsigned int nb_added = 0;
            for (unsigned int l = 0; l<512; ++l) nb_added+=commands[l].size();
            nb_added-=siz;
            cimg::mutex(29);
            std::fprintf(cimg::output()," (added %u command%s, total %u).",
                         nb_added,nb_added>1?"s":"",siz + nb_added);
            std::fflush(cimg::output());
            cimg::mutex(29,0);
          }
          continue;
        } else {

          // Other file types.
          print(images,0,"Input file '%s' at position%s",
                _filename0,
                _gmic_selection.data());

          if (*options)
            error(images,0,0,
                  "Command '-input': File '%s', format does not take any input options (options '%s' specified).",
                  _filename0,options.data());

          try {

            try {
              input_images.load(filename);
            } catch (CImgIOException&) {
              if (is_network_file)
                error(images,0,0,
                      "Command '-input': Unable to load image file '%s' from network.",
                      _filename0);
              else throw;
            }

            // If .gmz file without extension, process images names anyway.
            bool is_gmz = false;
            const CImg<char> back = input_images?CImg<char>(input_images.back()):CImg<char>::empty();
            if (back.width()==1 && back.depth()==1 && back.spectrum()==1 &&
                back[0]=='G' && back[1]=='M' && back[2]=='Z' && !back[3]) {
              input_images_names = back.get_split(CImg<char>::vector(0),0,false);
              if (input_images_names) {
                is_gmz = true;
                input_images_names.remove(0);
                cimglist_for(input_images_names,l)
                  input_images_names[l].resize(1,input_images_names[l].height() + 1,1,1,0).
                  unroll('x');
                input_images.remove(input_images.size() - 1);
              }
            }

            if (input_images && !is_gmz) {
              input_images_names.insert(__filename0);
              if (input_images.size()>1) {
                input_images_names.insert(input_images.size() - 1,__filename0.copymark());
              }
            }

          } catch (CImgException&) {
            std::FILE *file = 0;
            if (!(file=std::fopen(filename,"r"))) {
              if (cimg::type<T>::string()==cimg::type<float>::string() || *ext || *filename!='-') {
                if (*filename=='-' && filename[1]) { // Check for command misspelling.
                  CImg<char>::string(filename).move_to(name);
                  char *const posb = std::strchr(name,'[');
                  if (posb) *posb = 0;  // Discard selection from the command name.

                  static const char *native_command_names[] = {
                    "a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s",
                    "t","u","v","w","x","y","z",
                    "+","-","*","/","\\\\",">","<","%","^","=","sh","mv","rm","rv","<<",">>","==",">=",
                    "<=","//","**","!=","&","|",
                    "d3d","+3d","/3d","f3d","j3d","l3d","m3d","*3d","o3d","p3d","r3d","s3d","-3d",
                    "t3d","db3d","md3d","rv3d","sl3d","ss3d","div3d",
                    "append","autocrop","add","add3d","abs","and","atan2","acos","asin","atan",
                    "axes",
                    "blur","boxfilter","bsr","bsl","bilateral","break",
                    "check","check3d","crop","channels","columns","command","camera","cut","cos",
                    "convolve","correlate","color3d","col3d","cosh","continue","cumulate",
                    "cursor",
                    "done","do","debug","divide","distance","dilate","discard","double3d","denoise",
                    "deriche","dijkstra","displacement","display","display3d",
                    "endif","else","elif","endlocal","endl","echo","exec","error","endian","exp",
                    "eq","ellipse","equalize","erode","elevation3d","eigen","eikonal",
                    "fill","flood","files","focale3d","fft",
                    "ge","gt","gradient","graph","guided",
                    "histogram","hsi2rgb","hsl2rgb","hsv2rgb","hessian",
                    "input","if","image","index","invert","isoline3d","isosurface3d","inpaint",
                    "ifft",
                    "keep",
                    "local","le","lt","log","log2","log10","line","lab2rgb","label","light3d",
                    "move","mirror","mul","mutex","mod","max","min","mmul","mode3d","moded3d",
                    "map","median","mdiv","mse","mandelbrot","mul3d",
                    "name","normalize","neq","noarg","noise",
                    "output","onfail","object3d","or","opacity3d",
                    "parallel","pass","patchmatch","permute","progress","print","pow","point","polygon",
                    "plasma","primitives3d","plot",
                    "quit",
                    "remove","repeat","resize","reverse","return","rows","rotate",
                    "round","rand","rotate3d","rgb2hsi","rgb2hsl","rgb2hsv","rgb2lab",
                    "rgb2srgb","rol","ror","reverse3d",
                    "status","skip","set","split","shared","shift","slices","srand","sub","sqrt",
                    "sqr","sign","sin","sort","solve","sub3d","sharpen","smooth","split3d",
                    "screen", "svd","sphere3d","specl3d","specs3d","sinc","sinh","srgb2rgb","streamline3d",
                    "structuretensors","select","serialize",
                    "threshold","tan","text","texturize3d","trisolve","tanh",
                    "unroll","uncommand","unserialize",
                    "vanvliet","verbose",
                    "while","warn","window","warp","watershed","wait",
                    "xor",0
                  };

                  const char *misspelled = 0;
                  const unsigned int foff = name[1]=='-'?2U:1U;
                  int dmin = 4;
                  for (unsigned int l = 0; native_command_names[l]; ++l) {
                    // Look in native commands.
                    const char *const c = native_command_names[l];
                    const int d = levenshtein(c,name.data() + foff);
                    if (d<dmin) { dmin = d; misspelled = native_command_names[l]; }
                  }
                  for (unsigned int i = 0; i<512; ++i)
                    // Look in custom commands.
                    cimglist_for(commands_names[i],l) {
                      const char *const c = commands_names[i][l].data();
                      const int d = levenshtein(c,name.data() + foff);
                      if (d<dmin) { dmin = d; misspelled = commands_names[i][l].data(); }
                    }
                  if (misspelled)
                    error(images,0,0,
                          "Unknown command or filename '%s' (did you mean '-%s%s' ?).",
                          gmic_argument_text(),foff>1?"-":"",misspelled);
                  else error(images,0,0,
                             "Unknown command or filename '%s'.",
                             gmic_argument_text());
                } else error(images,0,0,
                             "Unknown %s '%s'.",
                             *filename=='-'?"command or filename":"filename",
                             gmic_argument_text());
              } else
                error(images,0,0,
                      "Unknown command '%s' in '%s' type mode "
                      "(command defined only in 'float' type mode ?).",
                      gmic_argument_text(),cimg::type<T>::string());
            } else throw;
          }
        }

        if (*filename_tmp) std::remove(filename_tmp); // Clean temporary file if used.
        if (is_network_file) std::remove(_filename);  // Clean temporary file if network input.
      }

      if (is_verbose) {
        cimg::mutex(29);
        if (input_images) {
          const unsigned int last = input_images.size() - 1;
          if (input_images.size()==1) {
            if (input_images[0].is_CImg3d(false))
              std::fprintf(cimg::output()," (%u vertices, %u primitives).",
                           cimg::float2uint((float)input_images(0,6)),
                           cimg::float2uint((float)input_images(0,7)));
            else
              std::fprintf(cimg::output()," (1 image %dx%dx%dx%d).",
                           input_images[0].width(),input_images[0].height(),
                           input_images[0].depth(),input_images[0].spectrum());
          } else
            std::fprintf(cimg::output()," (%u images [0] = %dx%dx%dx%d, %s[%u] = %dx%dx%dx%d).",
                         input_images.size(),
                         input_images[0].width(),input_images[0].height(),
                         input_images[0].depth(),input_images[0].spectrum(),
                         last==1?"":"(...),",last,
                         input_images[last].width(),input_images[last].height(),
                         input_images[last].depth(),input_images[last].spectrum());
        } else {
          std::fprintf(cimg::output()," (no available data).");
          input_images_names.assign();
        }
        std::fflush(cimg::output());
        cimg::mutex(29,0);
      }

      for (unsigned int l = 0, siz = selection.height() - 1U, off = 0; l<=siz; ++l) {
        const unsigned int uind = selection[l] + off;
        off+=input_images.size();
        if (l!=siz) {
          images.insert(input_images,uind);
          images_names.insert(input_images_names,uind);
        } else {
          input_images.move_to(images,uind);
          input_images_names.move_to(images_names,uind);
        }
      }

      if (new_name) new_name.move_to(images_names[selection[0]]);
      is_released = false;
    } // End main parsing loop of _run().

    // Wait for remaining threads to finish.
#ifdef gmic_is_parallel
    cimglist_for(threads_data,i) cimg_forY(threads_data[i],l) {
      if (!threads_data(i,l).is_thread_running) threads_data(i,l).gmic_instance.is_abort_thread = true;
#if cimg_OS!=2
      pthread_join(threads_data(i,l).thread_id,0);
#else // #if cimg_OS!=2
      WaitForSingleObject(threads_data(i,l).thread_id,INFINITE);
      CloseHandle(threads_data(i,l).thread_id);
#endif // #if cimg_OS!=2
      is_released&=threads_data(i,l).gmic_instance.is_released;
      threads_data(i,l).is_thread_running = false;
    }
    // Check for possible exceptions thrown by threads.
    cimglist_for(threads_data,i) cimg_forY(threads_data[i],l)
      if (threads_data(i,l).exception._message)
        throw threads_data(i,l).exception;
#endif // #ifdef gmic_is_parallel

    // Post-check global environment consistency.
    if (images_names.size()!=images.size())
      error(images,0,0,
            "Internal error: Images (%u) and images names (%u) have different size, "
	    "at return point.",
            images_names.size(),images.size());
    if (!callstack)
      error(images,0,0,
            "Internal error: Empty call stack at return point.");

    // Post-check local environment consistency.
    if (!is_quit && !is_return) {
      const CImg<char>& s = callstack.back();
      if (s[0]=='*' && (s[1]=='d' || s[1]=='i' || s[1]=='r' || (s[1]=='l' && !is_endlocal))) {
        unsigned int reference_line = ~0U;
        if (cimg_sscanf(s,"*%*[a-z]#%u",&reference_line)==1)
          error(images,0,0,
                "A '-%s' command is missing (for '-%s', line #%u), before return point.",
                s[1]=='d'?"while":s[1]=='i'?"endif":s[1]=='r'?"done":"endlocal",
                s[1]=='d'?"do":s[1]=='i'?"if":s[1]=='r'?"repeat":"local",
                reference_line);
        else error(images,0,0,
              "A '-%s' command is missing, before return point.",
              s[1]=='d'?"while":s[1]=='i'?"endif":s[1]=='r'?"done":"endlocal");
      }
    } else if (initial_callstack_size<callstack.size()) callstack.remove(initial_callstack_size,callstack.size() - 1);

    // Post-check validity of shared images.
    cimglist_for(images,l) gmic_check(images[l]);

    // Display or print result, if not 'released' before.
    if (!is_released && callstack.size()==1 && images) {
#ifdef gmic_main
#if cimg_display!=0
      CImgList<unsigned int> lselection, lselection3d;
      bool is_first3d = false;
      _display_window[0].assign();
      cimglist_for(images,l) {
        const bool is_3d = images[l].is_CImg3d(false);
        if (!l) is_first3d = is_3d;
        CImg<unsigned int>::vector(l).move_to(is_3d?lselection3d:lselection);
      }
      if (is_first3d) {
        display_objects3d(images,images_names,lselection3d>'y',CImg<unsigned char>::empty(),false);
        if (lselection) display_images(images,images_names,lselection>'y',0,false);
      } else {
        if (lselection) display_images(images,images_names,lselection>'y',0,false);
        if (lselection3d) display_objects3d(images,images_names,lselection3d>'y',CImg<unsigned char>::empty(),false);
      }
#else
      CImg<unsigned int> seq(1,images.width());
      cimg_forY(seq,y) seq[y] = y;
      print_images(images,images_names,seq,true);
#endif // #if cimg_display!=0
#endif // #ifdef gmic_main
      is_released = true;
    }

    if (is_debug) debug(images,"%sExit scope '%s/'.%s\n",
                        cimg::t_bold,callstack.back().data(),cimg::t_normal);

    if (callstack.size()==1) {
      if (is_quit) {
        if (verbosity>=0 || is_debug) {
          std::fputc('\n',cimg::output());
          std::fflush(cimg::output());
        }
      } else {
        print(images,0,"End G'MIC interpreter.\n");
        is_quit = true;
      }
    }
  } catch (CImgAbortException &) { // Special case of abort (abort from a CImg method).
    // Do the same as for a cancellation point.
    const bool is_very_verbose = verbosity>0 || is_debug;
    if (is_very_verbose) print(images,0,"Abort G'MIC interpreter.");
    dowhiles.assign();
    repeatdones.assign();
    position = commands_line.size();
    is_released = is_quit = true;
  } catch (CImgException &e) {
    const char *const e_ptr = e.what() + (!std::strncmp(e.what(),"[_cimg_math_parser] ",20)?20:0);
    CImg<char> error_message(e_ptr,(unsigned int)std::strlen(e_ptr) + 1);
    for (char *str = std::strstr(error_message,"CImg<"); str; str = std::strstr(str,"CImg<")) {
      str[0] = 'g'; str[1] = 'm'; str[2] = 'i'; str[3] = 'c';
    }
    for (char *str = std::strstr(error_message,"cimg:"); str; str = std::strstr(str,"cimg:")) {
      str[0] = 'g'; str[1] = 'm'; str[2] = 'i'; str[3] = 'c';
    }
    if (*current_command && current_command[1])
      error(images,0,current_command + 1,"Command '%s': %s",current_command,error_message.data());
    else
      error(images,0,0,"%s",error_message.data());
  }

  if (!is_endlocal) debug_line = initial_debug_line;
  else {
    if (next_debug_line!=~0U) { debug_line = next_debug_line; next_debug_line = ~0U; }
    if (next_debug_filename!=~0U) { debug_filename = next_debug_filename; next_debug_filename = ~0U; }
  }

  return *this;
}

// Fallback function for segfault signals.
#if cimg_OS==1
void gmic_segfault_sigaction(int signal, siginfo_t *si, void *arg) {
  cimg::unused(signal,si,arg);
  cimg::mutex(29);
  std::fprintf(cimg::output(),
               "\n\n%s[gmic] G'MIC encountered a %sfatal error%s%s (Segmentation fault). "
               "Please submit a bug report, at: %shttps://github.com/dtschump/gmic-community/issues%s\n\n",
               cimg::t_red,cimg::t_bold,cimg::t_normal,cimg::t_red,
               cimg::t_bold,cimg::t_normal);
  std::fflush(cimg::output());
  cimg::mutex(29,0);
  std::exit(EXIT_FAILURE);
}
#endif

//----------------------
// Start CLI interface.
//----------------------
#ifdef gmic_main

#if cimg_OS==2
int _CRT_glob = 0; // Disable globbing for msys.
#endif

int main(int argc, char **argv) {

  // Set default output messages stream.
  const char *const is_debug = cimg_option("-debug",(char*)0,0);
  cimg::output(is_debug?stdout:stderr);

  // Set fallback for segfault signals.
#if cimg_OS==1
  struct sigaction sa;
  std::memset(&sa,0,sizeof(sa));
  sigemptyset(&sa.sa_mask);
  sa.sa_sigaction = gmic_segfault_sigaction;
  sa.sa_flags = SA_SIGINFO;
  sigaction(SIGSEGV,&sa,0);
#endif

  // Create resources directory.
  if (!gmic::init_rc()) {
    std::fprintf(cimg::output(),
                 "\n[gmic] Unable to create resources directory 'gmicrc'.\n");
    std::fflush(cimg::output());
  }

  // Set special path for curl on Windows
  // (in case the use of libcurl is not enabled).
#if cimg_OS==2
  cimg::curl_path("_gmic\\curl",true);
#endif

  // Declare main G'MIC instance.
  gmic gmic_instance;
  gmic_instance.add_commands("cli_start : ");

  // Load startup command files.
  CImg<char> commands_user, commands_update, filename_update;
  bool is_invalid_user = false, is_invalid_update = false;
  char sep = 0;
  gmic_instance.verbosity = -1;

  // Update file (in resources directory).
  filename_update.assign(1024);
  cimg_snprintf(filename_update,filename_update.width(),"%supdate%u.gmic",
                gmic::path_rc(),gmic_version);
  try {
    try {
      commands_update.load_cimg(filename_update);
    } catch (...) {
      commands_update.load_raw(filename_update);
    }
    commands_update.append(CImg<char>::vector(0),'y');
    try { gmic_instance.add_commands(commands_update);
    } catch (...) { is_invalid_update = true; throw; }
  } catch (...) { commands_update.assign(); }
  if (commands_update && (cimg_sscanf(commands_update," #@gmi%c",&sep)!=1 || sep!='c'))
    commands_update.assign(); // Discard invalid update file.

  // User file (in parent of resources directory).
  const char *const filename_user = gmic::path_user();
  try {
    commands_user.load_raw(filename_user).append(CImg<char>::vector(0),'y');
    try { gmic_instance.add_commands(commands_user,filename_user);
    } catch (...) { is_invalid_user = true; throw; }
  } catch (...) { commands_user.assign(); }

  // When help has been requested.
  const char
    *const is_help1 = cimg_option("-h",(char*)0,0),
    *const is_help2 = cimg_option("--h",(char*)0,0),
    *const is_help3 = cimg_option("-help",(char*)0,0),
    *const is_help4 = cimg_option("--help",(char*)0,0),
    *const help_command = is_help1?"-h":is_help2?"--h":is_help3?"-help":"--help",
    *const help_argument = is_help1?is_help1:is_help2?is_help2:is_help3?is_help3:is_help4;
  const bool
    is_help = is_help1 || is_help2 || is_help3 || is_help4,
    is_global_help = is_help && !std::strcmp(help_command,help_argument);

  if (is_help) {

    // Load specified commands definitions data (eventually).
    CImgList<gmic_pixel_type> images;
    CImgList<char> images_names;
    if (!is_global_help && commands_user) commands_user.move_to(images);
    if (commands_update) images.insert(commands_update);
    if (!is_global_help || !commands_update) images.insert(gmic::stdlib);
    commands_update.assign();

    for (int i = 1; i<argc; ++i) {
      std::FILE *file = 0;
      CImg<char> filename_tmp(256); *filename_tmp = 0;
      if ((!std::strcmp("-m",argv[i]) || !std::strcmp("-command",argv[i])) && i<argc - 1) {
        const char *const filename = argv[++i];
        if (!cimg::strncasecmp(filename,"http://",7) || !cimg::strncasecmp(filename,"https://",8))
          try {
            file = std::fopen(cimg::load_network(filename,filename_tmp),"r");
          } catch (CImgException&) { file = 0; }
        else file = std::fopen(filename,"r");
      } else if (!cimg::strcasecmp("gmic",cimg::split_filename(argv[i]))) {
        const char *const filename = argv[i];
        if (!cimg::strncasecmp(filename,"http://",7) || !cimg::strncasecmp(filename,"https://",8))
          try {
            file = std::fopen(cimg::load_network(filename,filename_tmp),"r");
          } catch (CImgException&) { file = 0; }
        else file = std::fopen(filename,"r");
      }
      if (file) {
        const unsigned int n = images.size();
        try {
          CImg<unsigned char>::get_load_cimg(file).move_to(images,0);
        } catch (CImgIOException&) {
          CImg<unsigned char>::get_load_raw(file).move_to(images,0);
        }
        if (images.size()!=n) CImg<unsigned char>::vector('\n').move_to(images,1);
        cimg::fclose(file);
        if (*filename_tmp) std::remove(filename_tmp);
      }
    }

    cimg::output(stdout);
    if (is_global_help) { // Global help.
      try {
        gmic_instance.verbosity = -1;
        gmic_instance.run("-v - -l -help \"\" -onfail -endl -q",images,images_names);
      } catch (...) { // Fallback in case default version of '-help' has been overloaded.
        images.assign();
        images_names.assign();
        images.insert(gmic::stdlib);
        gmic("-v - -l -help \"\" -onfail -endl -q",images,images_names);
      }
    } else { // Help for a specified command.
      CImg<char> tmp_line(1024);
      try {
        cimg_snprintf(tmp_line,tmp_line.width(),"-v - -l -help \"%s\",1 -onfail -endl -q",help_argument);
        gmic_instance.verbosity = -1;
        gmic_instance.run(tmp_line,images,images_names);
      } catch (...) { // Fallback in case default version of '-help' has been overloaded.
        cimg_snprintf(tmp_line,tmp_line.width(),"-v - -l -help \"%s\",1 -onfail -endl -q",help_argument);
        images.assign();
        images_names.assign();
        images.insert(gmic::stdlib);
        gmic(tmp_line,images,images_names);
      }
    }

    std::exit(0);
  }

  // Convert 'argv' into G'MIC command line.
  commands_user.assign(); commands_update.assign();

  CImgList<char> items;
  if (argc==1) { // When no args have been specified.
    gmic_instance.verbosity = -1;
    CImg<char>::string("-l[] -cli_noarg -onfail -endl").move_to(items);
  } else {
    gmic_instance.verbosity = 0;
    for (int l = 1; l<argc; ++l) { // Split argv as items.
      if (std::strchr(argv[l],' ')) {
        CImg<char>::vector('\"').move_to(items);
        CImg<char>(argv[l],(unsigned int)std::strlen(argv[l])).move_to(items);
        CImg<char>::string("\"").move_to(items);
      } else CImg<char>::string(argv[l]).move_to(items);
      if (l<argc - 1) items.back().back()=' ';
    }
  }

  // Insert startup command.
  const bool is_first_item_verbose = items.width()>1 &&
    (!std::strncmp("-v ",items[0],3) || !std::strncmp("-verbose ",items[0],9));
  items.insert(CImg<char>::string("-cli_start ",false),is_first_item_verbose?2:0);

  if (is_invalid_user) { // Display warning message in case of invalid user command file.
    CImg<char> tmpstr(1024);
    cimg_snprintf(tmpstr,tmpstr.width(),"-warn \"File '%s' is not a valid G'MIC command file.\" ",
                  filename_user);
    items.insert(CImg<char>::string(tmpstr.data(),false),is_first_item_verbose?2:0);
  }
  if (is_invalid_update) { // Display warning message in case of invalid user command file.
    CImg<char> tmpstr(1024);
    cimg_snprintf(tmpstr,tmpstr.width(),"-warn \"File '%s' is not a valid G'MIC command file.\" ",
                  filename_update.data());
    items.insert(CImg<char>::string(tmpstr.data(),false),is_first_item_verbose?2:0);
  }

  const CImg<char> commands_line(items>'x');
  items.assign();

  // Launch G'MIC interpreter.
  try {
    CImgList<gmic_pixel_type> images;
    CImgList<char> images_names;
    gmic_instance.run(commands_line.data(),images,images_names);
  } catch (gmic_exception &e) {

    // Something went wrong during the pipeline execution.
    if (gmic_instance.verbosity<0) {
      std::fprintf(cimg::output(),"\n[gmic] %s%s%s%s",
                   cimg::t_red,cimg::t_bold,
                   e.what(),cimg::t_normal);
      std::fflush(cimg::output());
    }
    if (*e.command_help()) {
      std::fprintf(cimg::output(),"\n[gmic] Command '-%s' has the following description: \n",
		   e.command_help());
      std::fflush(cimg::output());
      CImgList<gmic_pixel_type> images;
      CImgList<char> images_names;
      images.insert(gmic::stdlib);
      CImg<char> tmp_line(1024);
      cimg_snprintf(tmp_line,tmp_line.width(),
                    "-v - "
                    "-l[] -i raw:\"%s\",char -m \"%s\" -onfail -rm -endl "
                    "-l[] -i raw:\"%s\",char -m \"%s\" -onfail -rm -endl "
                    "-rv -help \"%s\",0 -q",
                    filename_update.data(),filename_update.data(),
                    filename_user,filename_user,
                    e.command_help());
      try {
        gmic(tmp_line,images,images_names);
      } catch (...) {
        cimg_snprintf(tmp_line,tmp_line.width(),"-v - -help \"%s\",1 -q",e.command_help());
        images.assign();
        images_names.assign();
        images.insert(gmic::stdlib);
        gmic(tmp_line,images,images_names);
      }
    } else { std::fprintf(cimg::output(),"\n\n"); std::fflush(cimg::output()); }
    return -1;
  }
  return 0;
}

#else

// Explicitely instanciate constructors and destructor when building the library.
#ifdef gmic_pixel_type
template gmic::gmic(const char *const commands_line,
                    gmic_list<gmic_pixel_type>& images, gmic_list<char>& images_names,
                    const char *const custom_commands, const bool include_stdlib,
                    float *const p_progress, bool *const p_is_abort);

template gmic& gmic::run(const char *const commands_line,
                         gmic_list<gmic_pixel_type> &images, gmic_list<char> &images_names,
                         float *const p_progress=0, bool *const p_is_abort=0);

template CImgList<gmic_pixel_type>::~CImgList();
#endif

#ifdef gmic_pixel_type2
template gmic::gmic(const char *const commands_line,
                    gmic_list<gmic_pixel_type2>& images, gmic_list<char>& images_names,
                    const char *const custom_commands, const bool include_stdlib,
                    float *const p_progress, bool *const p_is_abort);

template gmic& gmic::run(const char *const commands_line,
                         gmic_list<gmic_pixel_type2> &images, gmic_list<char> &images_names,
                         float *const p_progress=0, bool *const p_is_abort=0);

template CImgList<gmic_pixel_type2>::~CImgList();
#endif

template CImgList<char>::~CImgList();

#endif // #ifdef gmic_main
#endif // #ifdef cimg_plugin
