CImg.h

          imn = (unsigned int)vec[7];
        const float ri = vec[4], rs = vec[5], ss = vec[6];
        switch (pixsize) {
        case 8 : {
          CImg<ucharT> buf(size_x,size_y);
          cimg::fread(buf._data,size_x*size_y,file2);
          if (cimg::endianness()) cimg::invert_endianness(buf._data,size_x*size_y);
          CImg<T>& img = (*this)[imn];
          cimg_forXY(img,x,y) img(x,y,sn) = (T)(( buf(x,y)*rs + ri )/(rs*ss));
        } break;
        case 16 : {
          CImg<ushortT> buf(size_x,size_y);
          cimg::fread(buf._data,size_x*size_y,file2);
          if (cimg::endianness()) cimg::invert_endianness(buf._data,size_x*size_y);
          CImg<T>& img = (*this)[imn];
          cimg_forXY(img,x,y) img(x,y,sn) = (T)(( buf(x,y)*rs + ri )/(rs*ss));
        } break;
        case 32 : {
          CImg<uintT> buf(size_x,size_y);
          cimg::fread(buf._data,size_x*size_y,file2);
          if (cimg::endianness()) cimg::invert_endianness(buf._data,size_x*size_y);
          CImg<T>& img = (*this)[imn];
          cimg_forXY(img,x,y) img(x,y,sn) = (T)(( buf(x,y)*rs + ri )/(rs*ss));
        } break;
        default :
          cimg::fclose(file);
          cimg::fclose(file2);
          throw CImgIOException(_cimglist_instance
                                "load_parrec(): Unsupported %d-bits pixel type for file '%s'.",
                                cimglist_instance,
                                pixsize,filename);
        }
      }
      cimg::fclose(file);
      cimg::fclose(file2);
      if (!_width)
        throw CImgIOException(_cimglist_instance
                              "load_parrec(): Failed to recognize valid PAR-REC data in file '%s'.",
                              cimglist_instance,
                              filename);
      return *this;
    }

    //! Load a list from a PAR/REC (Philips) file \newinstance.
    static CImgList<T> get_load_parrec(const char *const filename) {
      return CImgList<T>().load_parrec(filename);
    }

    //! Load a list from a YUV image sequence file.
    /**
        \param filename Filename to read data from.
        \param size_x Width of the images.
        \param size_y Height of the images.
        \param first_frame Index of first image frame to read.
        \param last_frame Index of last image frame to read.
        \param step_frame Step applied between each frame.
        \param yuv2rgb Apply YUV to RGB transformation during reading.
    **/
    CImgList<T>& load_yuv(const char *const filename,
                          const unsigned int size_x, const unsigned int size_y,
                          const unsigned int first_frame=0, const unsigned int last_frame=~0U,
                          const unsigned int step_frame=1, const bool yuv2rgb=true) {
      return _load_yuv(0,filename,size_x,size_y,first_frame,last_frame,step_frame,yuv2rgb);
    }

    //! Load a list from a YUV image sequence file \newinstance.
    static CImgList<T> get_load_yuv(const char *const filename,
                                    const unsigned int size_x, const unsigned int size_y=1,
                                    const unsigned int first_frame=0, const unsigned int last_frame=~0U,
                                    const unsigned int step_frame=1, const bool yuv2rgb=true) {
      return CImgList<T>().load_yuv(filename,size_x,size_y,first_frame,last_frame,step_frame,yuv2rgb);
    }

    //! Load a list from an image sequence YUV file \overloading.
    CImgList<T>& load_yuv(std::FILE *const file,
                          const unsigned int size_x, const unsigned int size_y,
                          const unsigned int first_frame=0, const unsigned int last_frame=~0U,
                          const unsigned int step_frame=1, const bool yuv2rgb=true) {
      return _load_yuv(file,0,size_x,size_y,first_frame,last_frame,step_frame,yuv2rgb);
    }

    //! Load a list from an image sequence YUV file \newinstance.
    static CImgList<T> get_load_yuv(std::FILE *const file,
                                    const unsigned int size_x, const unsigned int size_y=1,
                                    const unsigned int first_frame=0, const unsigned int last_frame=~0U,
                                    const unsigned int step_frame=1, const bool yuv2rgb=true) {
      return CImgList<T>().load_yuv(file,size_x,size_y,first_frame,last_frame,step_frame,yuv2rgb);
    }

    CImgList<T>& _load_yuv(std::FILE *const file, const char *const filename,
                           const unsigned int size_x, const unsigned int size_y,
                           const unsigned int first_frame, const unsigned int last_frame,
                           const unsigned int step_frame, const bool yuv2rgb) {
      if (!filename && !file)
        throw CImgArgumentException(_cimglist_instance
                                    "load_yuv(): Specified filename is (null).",
                                    cimglist_instance);
      if (size_x%2 || size_y%2)
        throw CImgArgumentException(_cimglist_instance
                                    "load_yuv(): Invalid odd XY dimensions %ux%u in file '%s'.",
                                    cimglist_instance,
                                    size_x,size_y,filename?filename:"(FILE*)");
      if (!size_x || !size_y)
        throw CImgArgumentException(_cimglist_instance
                                    "load_yuv(): Invalid sequence size (%u,%u) in file '%s'.",
                                    cimglist_instance,
                                    size_x,size_y,filename?filename:"(FILE*)");

      const unsigned int
        nfirst_frame = first_frame<last_frame?first_frame:last_frame,
        nlast_frame = first_frame<last_frame?last_frame:first_frame,
        nstep_frame = step_frame?step_frame:1;

      CImg<ucharT> tmp(size_x,size_y,1,3), UV(size_x/2,size_y/2,1,2);
      std::FILE *const nfile = file?file:cimg::fopen(filename,"rb");
      bool stop_flag = false;
      int err;
      if (nfirst_frame) {
        err = cimg::fseek(nfile,nfirst_frame*(size_x*size_y + size_x*size_y/2),SEEK_CUR);
        if (err) {
          if (!file) cimg::fclose(nfile);
          throw CImgIOException(_cimglist_instance
                                "load_yuv(): File '%s' doesn't contain frame number %u.",
                                cimglist_instance,
                                filename?filename:"(FILE*)",nfirst_frame);
        }
      }
      unsigned int frame;
      for (frame = nfirst_frame; !stop_flag && frame<=nlast_frame; frame+=nstep_frame) {
        tmp.fill(0);
        // *TRY* to read the luminance part, do not replace by cimg::fread!
        err = (int)std::fread((void*)(tmp._data),1,(ulongT)tmp._width*tmp._height,nfile);
        if (err!=(int)(tmp._width*tmp._height)) {
          stop_flag = true;
          if (err>0)
            cimg::warn(_cimglist_instance
                       "load_yuv(): File '%s' contains incomplete data or given image dimensions "
                       "(%u,%u) are incorrect.",
                       cimglist_instance,
                       filename?filename:"(FILE*)",size_x,size_y);
        } else {
          UV.fill(0);
          // *TRY* to read the luminance part, do not replace by cimg::fread!
          err = (int)std::fread((void*)(UV._data),1,(size_t)(UV.size()),nfile);
          if (err!=(int)(UV.size())) {
            stop_flag = true;
            if (err>0)
              cimg::warn(_cimglist_instance
                         "load_yuv(): File '%s' contains incomplete data or given image dimensions (%u,%u) "
                         "are incorrect.",
                         cimglist_instance,
                         filename?filename:"(FILE*)",size_x,size_y);
          } else {
            cimg_forXY(UV,x,y) {
              const int x2 = x*2, y2 = y*2;
              tmp(x2,y2,1) = tmp(x2 + 1,y2,1) = tmp(x2,y2 + 1,1) = tmp(x2 + 1,y2 + 1,1) = UV(x,y,0);
              tmp(x2,y2,2) = tmp(x2 + 1,y2,2) = tmp(x2,y2 + 1,2) = tmp(x2 + 1,y2 + 1,2) = UV(x,y,1);
            }
            if (yuv2rgb) tmp.YCbCrtoRGB();
            insert(tmp);
            if (nstep_frame>1) cimg::fseek(nfile,(nstep_frame - 1)*(size_x*size_y + size_x*size_y/2),SEEK_CUR);
          }
        }
      }
      if (stop_flag && nlast_frame!=~0U && frame!=nlast_frame)
        cimg::warn(_cimglist_instance
                   "load_yuv(): Frame %d not reached since only %u frames were found in file '%s'.",
                   cimglist_instance,
                   nlast_frame,frame - 1,filename?filename:"(FILE*)");

      if (!file) cimg::fclose(nfile);
      return *this;
    }

    //! Load an image from a video file, using OpenCV library.
    /**
      \param filename Filename, as a C-string.
      \param first_frame Index of the first frame to read.
      \param last_frame Index of the last frame to read.
      \param step_frame Step value for frame reading.
      \note If step_frame==0, the current video stream is forced to be released (without any frames read).
    **/
    CImgList<T>& load_video(const char *const filename,
                            const unsigned int first_frame=0, const unsigned int last_frame=~0U,
                            const unsigned int step_frame=1) {
#ifndef cimg_use_opencv
      if (first_frame || last_frame!=~0U || step_frame>1)
        throw CImgArgumentException(_cimglist_instance
                                    "load_video() : File '%s', arguments 'first_frame', 'last_frame' "
                                    "and 'step_frame' can be only set when using OpenCV "
                                    "(-Dcimg_use_opencv must be enabled).",
                                    cimglist_instance,filename);
      return load_ffmpeg_external(filename);
#else
      static CvCapture *captures[32] = { 0 };
      static CImgList<charT> filenames(32);
      static CImg<uintT> positions(32,1,1,1,0);
      static int last_used_index = -1;

      // Detect if a video capture already exists for the specified filename.
      cimg::mutex(9);
      int index = -1;
      if (filename) {
        if (last_used_index>=0 && !std::strcmp(filename,filenames[last_used_index])) {
          index = last_used_index;
        } else cimglist_for(filenames,l) if (filenames[l] && !std::strcmp(filename,filenames[l])) {
            index = l; break;
          }
      } else index = last_used_index;
      cimg::mutex(9,0);

      // Release stream if needed.
      if (!step_frame || (index>=0 && positions[index]>first_frame)) {
        if (index>=0) {
          cimg::mutex(9);
          cvReleaseCapture(&captures[index]);
          captures[index] = 0; filenames[index].assign(); positions[index] = 0;
          if (last_used_index==index) last_used_index = -1;
          index = -1;
          cimg::mutex(9,0);
        } else
          if (filename)
            cimg::warn(_cimglist_instance
                       "load_video() : File '%s', no opened video stream associated with filename found.",
                       cimglist_instance,filename);
          else
            cimg::warn(_cimglist_instance
                       "load_video() : No opened video stream found.",
                       cimglist_instance,filename);
        if (!step_frame) return *this;
      }

      // Find empty slot for capturing video stream.
      if (index<0) {
        if (!filename)
          throw CImgArgumentException(_cimglist_instance
                                      "load_video(): No already open video reader found. You must specify a "
                                      "non-(null) filename argument for the first call.",
                                      cimglist_instance);
        else { cimg::mutex(9); cimglist_for(filenames,l) if (!filenames[l]) { index = l; break; } cimg::mutex(9,0); }
        if (index<0)
          throw CImgIOException(_cimglist_instance
                                "load_video(): File '%s', no video reader slots available. "
                                "You have to release some of your previously opened videos.",
                                cimglist_instance,filename);
        cimg::mutex(9);
        captures[index] = cvCaptureFromFile(filename);
        CImg<charT>::string(filename).move_to(filenames[index]);
        positions[index] = 0;
        cimg::mutex(9,0);
        if (!captures[index]) {
          filenames[index].assign();
          std::fclose(cimg::fopen(filename,"rb"));  // Check file availability.
          throw CImgIOException(_cimglist_instance
                                "load_video(): File '%s', unable to detect format of video file.",
                                cimglist_instance,filename);
        }
      }

      cimg::mutex(9);
      const unsigned int nb_frames = (unsigned int)std::max(0.,cvGetCaptureProperty(captures[index],
                                                                                     CV_CAP_PROP_FRAME_COUNT));
      cimg::mutex(9,0);
      assign();

      // Skip frames if necessary.
      bool go_on = true;
      unsigned int &pos = positions[index];
      while (pos<first_frame) {
        cimg::mutex(9);
        if (!cvGrabFrame(captures[index])) { cimg::mutex(9,0); go_on = false; break; }
        cimg::mutex(9,0);
        ++pos;
      }

      // Read and convert frames.
      const IplImage *src = 0;
      if (go_on) {
        const unsigned int _last_frame = std::min(nb_frames?nb_frames - 1:~0U,last_frame);
        while (pos<=_last_frame) {
          cimg::mutex(9);
          src = cvQueryFrame(captures[index]);
          if (src) {
            CImg<T> frame(src->width,src->height,1,3);
            const int step = (int)(src->widthStep - 3*src->width);
            const unsigned char* ptrs = (unsigned char*)src->imageData;
            T *ptr_r = frame.data(0,0,0,0), *ptr_g = frame.data(0,0,0,1), *ptr_b = frame.data(0,0,0,2);
            if (step>0) cimg_forY(frame,y) {
                cimg_forX(frame,x) { *(ptr_b++) = (T)*(ptrs++); *(ptr_g++) = (T)*(ptrs++); *(ptr_r++) = (T)*(ptrs++); }
                ptrs+=step;
              } else for (ulongT siz = (ulongT)src->width*src->height; siz; --siz) {
                *(ptr_b++) = (T)*(ptrs++); *(ptr_g++) = (T)*(ptrs++); *(ptr_r++) = (T)*(ptrs++);
              }
            frame.move_to(*this);
            ++pos;

            bool skip_failed = false;
            for (unsigned int i = 1; i<step_frame && pos<=_last_frame; ++i, ++pos)
              if (!cvGrabFrame(captures[index])) { skip_failed = true; break; }
            if (skip_failed) src = 0;
          }
          cimg::mutex(9,0);
          if (!src) break;
        }
      }

      if (!src || (nb_frames && pos>=nb_frames)) { // Close video stream when necessary.
        cimg::mutex(9);
        cvReleaseCapture(&captures[index]);
        captures[index] = 0;
        filenames[index].assign();
        positions[index] = 0;
        index = -1;
        cimg::mutex(9,0);
      }

      cimg::mutex(9);
      last_used_index = index;
      cimg::mutex(9,0);

      if (is_empty())
        throw CImgIOException(_cimglist_instance
                              "load_video(): File '%s', unable to locate frame %u.",
                              cimglist_instance,filename,first_frame);
      return *this;
#endif
    }

    //! Load an image from a video file, using OpenCV library \newinstance.
    static CImgList<T> get_load_video(const char *const filename,
                           const unsigned int first_frame=0, const unsigned int last_frame=~0U,
                           const unsigned int step_frame=1) {
      return CImgList<T>().load_video(filename,first_frame,last_frame,step_frame);
    }

    //! Load an image from a video file using the external tool 'ffmpeg'.
    /**
      \param filename Filename to read data from.
    **/
    CImgList<T>& load_ffmpeg_external(const char *const filename) {
      if (!filename)
        throw CImgArgumentException(_cimglist_instance
                                    "load_ffmpeg_external(): Specified filename is (null).",
                                    cimglist_instance);
      std::fclose(cimg::fopen(filename,"rb"));            // Check if file exists.
      CImg<charT> command(1024), filename_tmp(256), filename_tmp2(256);
      std::FILE *file = 0;
      do {
        cimg_snprintf(filename_tmp,filename_tmp._width,"%s%c%s",
                      cimg::temporary_path(),cimg_file_separator,cimg::filenamerand());
        cimg_snprintf(filename_tmp2,filename_tmp2._width,"%s_000001.ppm",filename_tmp._data);
        if ((file=std_fopen(filename_tmp2,"rb"))!=0) cimg::fclose(file);
      } while (file);
      cimg_snprintf(filename_tmp2,filename_tmp2._width,"%s_%%6d.ppm",filename_tmp._data);
#if cimg_OS!=2
      cimg_snprintf(command,command._width,"%s -i \"%s\" \"%s\" >/dev/null 2>&1",
                    cimg::ffmpeg_path(),
                    CImg<charT>::string(filename)._system_strescape().data(),
                    CImg<charT>::string(filename_tmp2)._system_strescape().data());
#else
      cimg_snprintf(command,command._width,"\"%s -i \"%s\" \"%s\"\" >NUL 2>&1",
                    cimg::ffmpeg_path(),
                    CImg<charT>::string(filename)._system_strescape().data(),
                    CImg<charT>::string(filename_tmp2)._system_strescape().data());
#endif
      cimg::system(command,0);
      const unsigned int omode = cimg::exception_mode();
      cimg::exception_mode(0);
      assign();
      unsigned int i = 1;
      for (bool stop_flag = false; !stop_flag; ++i) {
        cimg_snprintf(filename_tmp2,filename_tmp2._width,"%s_%.6u.ppm",filename_tmp._data,i);
        CImg<T> img;
        try { img.load_pnm(filename_tmp2); }
        catch (CImgException&) { stop_flag = true; }
        if (img) { img.move_to(*this); std::remove(filename_tmp2); }
      }
      cimg::exception_mode(omode);
      if (is_empty())
        throw CImgIOException(_cimglist_instance
                              "load_ffmpeg_external(): Failed to open file '%s' with external command 'ffmpeg'.",
                              cimglist_instance,
                              filename);
      return *this;
    }

    //! Load an image from a video file using the external tool 'ffmpeg' \newinstance.
    static CImgList<T> get_load_ffmpeg_external(const char *const filename) {
      return CImgList<T>().load_ffmpeg_external(filename);
    }

    //! Load gif file, using ImageMagick or GraphicsMagick's external tools.
    /**
      \param filename Filename to read data from.
      \param use_graphicsmagick Tells if GraphicsMagick's tool 'gm' is used instead of ImageMagick's tool 'convert'.
    **/
    CImgList<T>& load_gif_external(const char *const filename) {
      if (!filename)
        throw CImgArgumentException(_cimglist_instance
                                    "load_gif_external(): Specified filename is (null).",
                                    cimglist_instance);
      std::fclose(cimg::fopen(filename,"rb"));            // Check if file exists.
      if (!_load_gif_external(filename,false))
        if (!_load_gif_external(filename,true))
          try { assign(CImg<T>().load_other(filename)); } catch (CImgException&) { assign(); }
      if (is_empty())
        throw CImgIOException(_cimglist_instance
                              "load_gif_external(): Failed to open file '%s'.",
                              cimglist_instance,filename);
      return *this;
    }

    CImgList<T>& _load_gif_external(const char *const filename, const bool use_graphicsmagick=false) {
      CImg<charT> command(1024), filename_tmp(256), filename_tmp2(256);
      std::FILE *file = 0;
      do {
        cimg_snprintf(filename_tmp,filename_tmp._width,"%s%c%s",
                      cimg::temporary_path(),cimg_file_separator,cimg::filenamerand());
        if (use_graphicsmagick) cimg_snprintf(filename_tmp2,filename_tmp2._width,"%s.png.0",filename_tmp._data);
        else cimg_snprintf(filename_tmp2,filename_tmp2._width,"%s-0.png",filename_tmp._data);
        if ((file=std_fopen(filename_tmp2,"rb"))!=0) cimg::fclose(file);
      } while (file);
#if cimg_OS!=2
      if (use_graphicsmagick) cimg_snprintf(command,command._width,"%s convert \"%s\" \"%s.png\" >/dev/null 2>&1",
                                            cimg::graphicsmagick_path(),
                                            CImg<charT>::string(filename)._system_strescape().data(),
                                            CImg<charT>::string(filename_tmp)._system_strescape().data());
      else cimg_snprintf(command,command._width,"%s \"%s\" \"%s.png\" >/dev/null 2>&1",
                         cimg::imagemagick_path(),
                         CImg<charT>::string(filename)._system_strescape().data(),
                         CImg<charT>::string(filename_tmp)._system_strescape().data());
#else
      if (use_graphicsmagick) cimg_snprintf(command,command._width,"\"%s convert \"%s\" \"%s.png\"\" >NUL 2>&1",
                                            cimg::graphicsmagick_path(),
                                            CImg<charT>::string(filename)._system_strescape().data(),
                                            CImg<charT>::string(filename_tmp)._system_strescape().data());
      else cimg_snprintf(command,command._width,"\"%s \"%s\" \"%s.png\"\" >NUL 2>&1",
                         cimg::imagemagick_path(),
                         CImg<charT>::string(filename)._system_strescape().data(),
                         CImg<charT>::string(filename_tmp)._system_strescape().data());
#endif
      cimg::system(command,0);
      const unsigned int omode = cimg::exception_mode();
      cimg::exception_mode(0);
      assign();

      // Try to read a single frame gif.
      cimg_snprintf(filename_tmp2,filename_tmp2._width,"%s.png",filename_tmp._data);
      CImg<T> img;
      try { img.load_png(filename_tmp2); }
      catch (CImgException&) { }
      if (img) { img.move_to(*this); std::remove(filename_tmp2); }
      else { // Try to read animated gif.
        unsigned int i = 0;
        for (bool stop_flag = false; !stop_flag; ++i) {
          if (use_graphicsmagick) cimg_snprintf(filename_tmp2,filename_tmp2._width,"%s.png.%u",filename_tmp._data,i);
          else cimg_snprintf(filename_tmp2,filename_tmp2._width,"%s-%u.png",filename_tmp._data,i);
          CImg<T> img;
          try { img.load_png(filename_tmp2); }
          catch (CImgException&) { stop_flag = true; }
          if (img) { img.move_to(*this); std::remove(filename_tmp2); }
        }
      }
      cimg::exception_mode(omode);
      return *this;
    }

    //! Load gif file, using ImageMagick or GraphicsMagick's external tools \newinstance.
    static CImgList<T> get_load_gif_external(const char *const filename) {
      return CImgList<T>().load_gif_external(filename);
    }

    //! Load a gzipped list, using external tool 'gunzip'.
    /**
      \param filename Filename to read data from.
    **/
    CImgList<T>& load_gzip_external(const char *const filename) {
      if (!filename)
        throw CImgIOException(_cimglist_instance
                              "load_gzip_external(): Specified filename is (null).",
                              cimglist_instance);
      std::fclose(cimg::fopen(filename,"rb"));            // Check if file exists.
      CImg<charT> command(1024), filename_tmp(256), body(256);
      const char
        *ext = cimg::split_filename(filename,body),
        *ext2 = cimg::split_filename(body,0);
      std::FILE *file = 0;
      do {
        if (!cimg::strcasecmp(ext,"gz")) {
          if (*ext2) cimg_snprintf(filename_tmp,filename_tmp._width,"%s%c%s.%s",
                                   cimg::temporary_path(),cimg_file_separator,cimg::filenamerand(),ext2);
          else cimg_snprintf(filename_tmp,filename_tmp._width,"%s%c%s",
                             cimg::temporary_path(),cimg_file_separator,cimg::filenamerand());
        } else {
          if (*ext) cimg_snprintf(filename_tmp,filename_tmp._width,"%s%c%s.%s",
                                  cimg::temporary_path(),cimg_file_separator,cimg::filenamerand(),ext);
          else cimg_snprintf(filename_tmp,filename_tmp._width,"%s%c%s",
                             cimg::temporary_path(),cimg_file_separator,cimg::filenamerand());
        }
        if ((file=std_fopen(filename_tmp,"rb"))!=0) cimg::fclose(file);
      } while (file);
      cimg_snprintf(command,command._width,"%s -c \"%s\" > \"%s\"",
                    cimg::gunzip_path(),
                    CImg<charT>::string(filename)._system_strescape().data(),
                    CImg<charT>::string(filename_tmp)._system_strescape().data());
      cimg::system(command);
      if (!(file = std_fopen(filename_tmp,"rb"))) {
        cimg::fclose(cimg::fopen(filename,"r"));
        throw CImgIOException(_cimglist_instance
                              "load_gzip_external(): Failed to open file '%s'.",
                              cimglist_instance,
                              filename);

      } else cimg::fclose(file);
      load(filename_tmp);
      std::remove(filename_tmp);
      return *this;
    }

    //! Load a gzipped list, using external tool 'gunzip' \newinstance.
    static CImgList<T> get_load_gzip_external(const char *const filename) {
      return CImgList<T>().load_gzip_external(filename);
    }

    //! Load a 3d object from a .OFF file.
    /**
      \param filename Filename to read data from.
      \param[out] primitives At return, contains the list of 3d object primitives.
      \param[out] colors At return, contains the list of 3d object colors.
      \return List of 3d object vertices.
    **/
    template<typename tf, typename tc>
    CImgList<T>& load_off(const char *const filename,
                          CImgList<tf>& primitives, CImgList<tc>& colors) {
      return get_load_off(filename,primitives,colors).move_to(*this);
    }

    //! Load a 3d object from a .OFF file \newinstance.
    template<typename tf, typename tc>
      static CImgList<T> get_load_off(const char *const filename,
                                      CImgList<tf>& primitives, CImgList<tc>& colors) {
      return CImg<T>().load_off(filename,primitives,colors)<'x';
    }

    //! Load images from a TIFF file.
    /**
        \param filename Filename to read data from.
        \param first_frame Index of first image frame to read.
        \param last_frame Index of last image frame to read.
        \param step_frame Step applied between each frame.
    **/
    CImgList<T>& load_tiff(const char *const filename,
                           const unsigned int first_frame=0, const unsigned int last_frame=~0U,
                           const unsigned int step_frame=1,
                           float *const voxel_size=0,
                           CImg<charT> *const description=0) {
      const unsigned int
        nfirst_frame = first_frame<last_frame?first_frame:last_frame,
        nstep_frame = step_frame?step_frame:1;
      unsigned int nlast_frame = first_frame<last_frame?last_frame:first_frame;
#ifndef cimg_use_tiff
      cimg::unused(voxel_size,description);
      if (nfirst_frame || nlast_frame!=~0U || nstep_frame!=1)
        throw CImgArgumentException(_cimglist_instance
                                    "load_tiff(): Unable to load sub-images from file '%s' unless libtiff is enabled.",
                                    cimglist_instance,
                                    filename);

      return assign(CImg<T>::get_load_tiff(filename));
#else
#if cimg_verbosity<3
        TIFFSetWarningHandler(0);
        TIFFSetErrorHandler(0);
#endif
      TIFF *tif = TIFFOpen(filename,"r");
      if (tif) {
        unsigned int nb_images = 0;
        do ++nb_images; while (TIFFReadDirectory(tif));
        if (nfirst_frame>=nb_images || (nlast_frame!=~0U && nlast_frame>=nb_images))
          cimg::warn(_cimglist_instance
                     "load_tiff(): Invalid specified frame range is [%u,%u] (step %u) since "
                     "file '%s' contains %u image(s).",
                     cimglist_instance,
                     nfirst_frame,nlast_frame,nstep_frame,filename,nb_images);

        if (nfirst_frame>=nb_images) return assign();
        if (nlast_frame>=nb_images) nlast_frame = nb_images - 1;
        assign(1 + (nlast_frame - nfirst_frame)/nstep_frame);
        TIFFSetDirectory(tif,0);
        cimglist_for(*this,l) _data[l]._load_tiff(tif,nfirst_frame + l*nstep_frame,voxel_size,description);
        TIFFClose(tif);
      } else throw CImgIOException(_cimglist_instance
                                   "load_tiff(): Failed to open file '%s'.",
                                   cimglist_instance,
                                   filename);
      return *this;
#endif
    }

    //! Load a multi-page TIFF file \newinstance.
    static CImgList<T> get_load_tiff(const char *const filename,
                                     const unsigned int first_frame=0, const unsigned int last_frame=~0U,
                                     const unsigned int step_frame=1,
                                     float *const voxel_size=0,
                                     CImg<charT> *const description=0) {
      return CImgList<T>().load_tiff(filename,first_frame,last_frame,step_frame,voxel_size,description);
    }

    //@}
    //----------------------------------
    //
    //! \name Data Output
    //@{
    //----------------------------------

    //! Print information about the list on the standard output.
    /**
      \param title Label set to the information displayed.
      \param display_stats Tells if image statistics must be computed and displayed.
    **/
    const CImgList<T>& print(const char *const title=0, const bool display_stats=true) const {
      unsigned int msiz = 0;
      cimglist_for(*this,l) msiz+=_data[l].size();
      msiz*=sizeof(T);
      const unsigned int mdisp = msiz<8*1024?0U:msiz<8*1024*1024?1U:2U;
      CImg<charT> _title(64);
      if (!title) cimg_snprintf(_title,_title._width,"CImgList<%s>",pixel_type());
      std::fprintf(cimg::output(),"%s%s%s%s: %sthis%s = %p, %ssize%s = %u/%u [%u %s], %sdata%s = (CImg<%s>*)%p",
                   cimg::t_magenta,cimg::t_bold,title?title:_title._data,cimg::t_normal,
                   cimg::t_bold,cimg::t_normal,(void*)this,
                   cimg::t_bold,cimg::t_normal,_width,_allocated_width,
                   mdisp==0?msiz:(mdisp==1?(msiz>>10):(msiz>>20)),
                   mdisp==0?"b":(mdisp==1?"Kio":"Mio"),
                   cimg::t_bold,cimg::t_normal,pixel_type(),(void*)begin());
      if (_data) std::fprintf(cimg::output(),"..%p.\n",(void*)((char*)end() - 1));
      else std::fprintf(cimg::output(),".\n");

      char tmp[16] = { 0 };
      cimglist_for(*this,ll) {
        cimg_snprintf(tmp,sizeof(tmp),"[%d]",ll);
        std::fprintf(cimg::output(),"  ");
        _data[ll].print(tmp,display_stats);
        if (ll==3 && width()>8) { ll = width() - 5; std::fprintf(cimg::output(),"  ...\n"); }
      }
      std::fflush(cimg::output());
      return *this;
    }

    //! Display the current CImgList instance in an existing CImgDisplay window (by reference).
    /**
       \param disp Reference to an existing CImgDisplay instance, where the current image list will be displayed.
       \param axis Appending axis. Can be <tt>{ 'x' | 'y' | 'z' | 'c' }</tt>.
       \param align Appending alignmenet.
       \note This function displays the list images of the current CImgList instance into an existing
         CImgDisplay window.
       Images of the list are appended in a single temporarly image for visualization purposes.
       The function returns immediately.
    **/
    const CImgList<T>& display(CImgDisplay &disp, const char axis='x', const float align=0) const {
      disp.display(*this,axis,align);
      return *this;
    }

    //! Display the current CImgList instance in a new display window.
    /**
        \param disp Display window.
        \param display_info Tells if image information are displayed on the standard output.
       \param axis Alignment axis for images viewing.
       \param align Apending alignment.
       \note This function opens a new window with a specific title and displays the list images of the
         current CImgList instance into it.
       Images of the list are appended in a single temporarly image for visualization purposes.
       The function returns when a key is pressed or the display window is closed by the user.
    **/
    const CImgList<T>& display(CImgDisplay &disp, const bool display_info,
                               const char axis='x', const float align=0,
                               unsigned int *const XYZ=0, const bool exit_on_anykey=false) const {
      bool is_exit = false;
      return _display(disp,0,0,display_info,axis,align,XYZ,exit_on_anykey,0,true,is_exit);
    }

    //! Display the current CImgList instance in a new display window.
    /**
      \param title Title of the opening display window.
      \param display_info Tells if list information must be written on standard output.
      \param axis Appending axis. Can be <tt>{ 'x' | 'y' | 'z' | 'c' }</tt>.
      \param align Appending alignment.
    **/
    const CImgList<T>& display(const char *const title=0, const bool display_info=true,
                               const char axis='x', const float align=0,
                               unsigned int *const XYZ=0, const bool exit_on_anykey=false) const {
      CImgDisplay disp;
      bool is_exit = false;
      return _display(disp,title,0,display_info,axis,align,XYZ,exit_on_anykey,0,true,is_exit);
    }

    const CImgList<T>& _display(CImgDisplay &disp, const char *const title, const CImgList<charT> *const titles,
                                const bool display_info, const char axis, const float align, unsigned int *const XYZ,
                                const bool exit_on_anykey, const unsigned int orig, const bool is_first_call,
                                bool &is_exit) const {
      if (is_empty())
        throw CImgInstanceException(_cimglist_instance
                                    "display(): Empty instance.",
                                    cimglist_instance);
      if (!disp) {
        if (axis=='x') {
          unsigned int sum_width = 0, max_height = 0;
          cimglist_for(*this,l) {
            const CImg<T> &img = _data[l];
            const unsigned int
              w = CImgDisplay::_fitscreen(img._width,img._height,img._depth,128,-85,false),
              h = CImgDisplay::_fitscreen(img._width,img._height,img._depth,128,-85,true);
            sum_width+=w;
            if (h>max_height) max_height = h;
          }
          disp.assign(cimg_fitscreen(sum_width,max_height,1),title?title:titles?titles->__display()._data:0,1);
        } else {
          unsigned int max_width = 0, sum_height = 0;
          cimglist_for(*this,l) {
            const CImg<T> &img = _data[l];
            const unsigned int
              w = CImgDisplay::_fitscreen(img._width,img._height,img._depth,128,-85,false),
              h = CImgDisplay::_fitscreen(img._width,img._height,img._depth,128,-85,true);
            if (w>max_width) max_width = w;
            sum_height+=h;
          }
          disp.assign(cimg_fitscreen(max_width,sum_height,1),title?title:titles?titles->__display()._data:0,1);
        }
        if (!title && !titles) disp.set_title("CImgList<%s> (%u)",pixel_type(),_width);
      } else if (title) disp.set_title("%s",title);
      else if (titles) disp.set_title("%s",titles->__display()._data);
      const CImg<char> dtitle = CImg<char>::string(disp.title());
      if (display_info) print(disp.title());
      disp.show().flush();

      if (_width==1) {
        const unsigned int dw = disp._width, dh = disp._height;
        if (!is_first_call)
          disp.resize(cimg_fitscreen(_data[0]._width,_data[0]._height,_data[0]._depth),false);
        disp.set_title("%s (%ux%ux%ux%u)",
                       dtitle.data(),_data[0]._width,_data[0]._height,_data[0]._depth,_data[0]._spectrum);
        _data[0]._display(disp,0,false,XYZ,exit_on_anykey,!is_first_call);
        if (disp.key()) is_exit = true;
        disp.resize(cimg_fitscreen(dw,dh,1),false).set_title("%s",dtitle.data());
      } else {
        bool disp_resize = !is_first_call;
        while (!disp.is_closed() && !is_exit) {
          const CImg<intT> s = _select(disp,0,true,axis,align,exit_on_anykey,orig,disp_resize,!is_first_call,true);
          disp_resize = true;
          if (s[0]<0 && !disp.wheel()) { // No selections done.
            if (disp.button()&2) { disp.flush(); break; }
            is_exit = true;
          } else if (disp.wheel()) { // Zoom in/out.
            const int wheel = disp.wheel();
            disp.set_wheel();
            if (!is_first_call && wheel<0) break;
            if (wheel>0 && _width>=4) {
              const unsigned int
                delta = std::max(1U,(unsigned int)cimg::round(0.3*_width)),
                ind0 = (unsigned int)std::max(0,s[0] - (int)delta),
                ind1 = (unsigned int)std::min(width() - 1,s[0] + (int)delta);
              if ((ind0!=0 || ind1!=_width - 1) && ind1 - ind0>=3) {
                const CImgList<T> sublist = get_shared_images(ind0,ind1);
                CImgList<charT> t_sublist;
                if (titles) t_sublist = titles->get_shared_images(ind0,ind1);
                sublist._display(disp,0,titles?&t_sublist:0,false,axis,align,XYZ,exit_on_anykey,
                                 orig + ind0,false,is_exit);
              }
            }
          } else if (s[0]!=0 || s[1]!=width() - 1) {
            const CImgList<T> sublist = get_shared_images(s[0],s[1]);
            CImgList<charT> t_sublist;
            if (titles) t_sublist = titles->get_shared_images(s[0],s[1]);
            sublist._display(disp,0,titles?&t_sublist:0,false,axis,align,XYZ,exit_on_anykey,
                             orig + s[0],false,is_exit);
          }
          disp.set_title("%s",dtitle.data());
        }
      }
      return *this;
    }

    // [internal] Return string to describe display title.
    CImg<charT> __display() const {
      CImg<charT> res, str;
      cimglist_for(*this,l) {
        CImg<charT>::string(_data[l]).move_to(str);
        if (l!=width() - 1) {
          str.resize(str._width + 1,1,1,1,0);
          str[str._width - 2] = ',';
          str[str._width - 1] = ' ';
        }
        res.append(str,'x');
      }
      if (!res) return CImg<charT>(1,1,1,1,0).move_to(res);
      cimg::strellipsize(res,128,false);
      if (_width>1) {
        const unsigned int l = (unsigned int)std::strlen(res);
        if (res._width<=l + 16) res.resize(l + 16,1,1,1,0);
        cimg_snprintf(res._data + l,16," (#%u)",_width);
      }
      return res;
    }

    //! Save list into a file.
    /**
      \param filename Filename to write data to.
      \param number When positive, represents an index added to the filename. Otherwise, no number is added.
      \param digits Number of digits used for adding the number to the filename.
    **/
    const CImgList<T>& save(const char *const filename, const int number=-1, const unsigned int digits=6) const {
      if (!filename)
        throw CImgArgumentException(_cimglist_instance
                                    "save(): Specified filename is (null).",
                                    cimglist_instance);
      // Do not test for empty instances, since .cimg format is able to manage empty instances.
      const bool is_stdout = *filename=='-' && (!filename[1] || filename[1]=='.');
      const char *const ext = cimg::split_filename(filename);
      CImg<charT> nfilename(1024);
      const char *const fn = is_stdout?filename:number>=0?cimg::number_filename(filename,number,digits,nfilename):
        filename;

#ifdef cimglist_save_plugin
      cimglist_save_plugin(fn);
#endif
#ifdef cimglist_save_plugin1
      cimglist_save_plugin1(fn);
#endif
#ifdef cimglist_save_plugin2
      cimglist_save_plugin2(fn);
#endif
#ifdef cimglist_save_plugin3
      cimglist_save_plugin3(fn);
#endif
#ifdef cimglist_save_plugin4
      cimglist_save_plugin4(fn);
#endif
#ifdef cimglist_save_plugin5
      cimglist_save_plugin5(fn);
#endif
#ifdef cimglist_save_plugin6
      cimglist_save_plugin6(fn);
#endif
#ifdef cimglist_save_plugin7
      cimglist_save_plugin7(fn);
#endif
#ifdef cimglist_save_plugin8
      cimglist_save_plugin8(fn);
#endif
      if (!cimg::strcasecmp(ext,"cimgz")) return save_cimg(fn,true);
      else if (!cimg::strcasecmp(ext,"cimg") || !*ext) return save_cimg(fn,false);
      else if (!cimg::strcasecmp(ext,"yuv")) return save_yuv(fn,true);
      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")) return save_video(fn);
#ifdef cimg_use_tiff
      else if (!cimg::strcasecmp(ext,"tif") ||
          !cimg::strcasecmp(ext,"tiff")) return save_tiff(fn);
#endif
      else if (!cimg::strcasecmp(ext,"gz")) return save_gzip_external(fn);
      else {
        if (_width==1) _data[0].save(fn,-1);
        else cimglist_for(*this,l) { _data[l].save(fn,is_stdout?-1:l); if (is_stdout) std::fputc(EOF,cimg::_stdout()); }
      }
      return *this;
    }

    //! Tell if an image list can be saved as one single file.
    /**
       \param filename Filename, as a C-string.
       \return \c true if the file format supports multiple images, \c false otherwise.
    **/
    static bool is_saveable(const char *const filename) {
      const char *const ext = cimg::split_filename(filename);
      if (!cimg::strcasecmp(ext,"cimgz") ||
#ifdef cimg_use_tiff
          !cimg::strcasecmp(ext,"tif") ||
          !cimg::strcasecmp(ext,"tiff") ||
#endif
          !cimg::strcasecmp(ext,"yuv") ||
          !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")) return true;
      return false;
    }

    //! Save image sequence as a GIF animated file.
    /**
       \param filename Filename to write data to.
       \param fps Number of desired frames per second.
       \param nb_loops Number of loops (\c 0 for infinite looping).
    **/
    const CImgList<T>& save_gif_external(const char *const filename, const float fps=25,
                                         const unsigned int nb_loops=0) {
      CImg<charT> command(1024), filename_tmp(256), filename_tmp2(256);
      CImgList<charT> filenames;
      std::FILE *file = 0;

#ifdef cimg_use_png
#define _cimg_save_gif_ext "png"
#else
#define _cimg_save_gif_ext "ppm"
#endif

      do {
        cimg_snprintf(filename_tmp,filename_tmp._width,"%s%c%s",
                      cimg::temporary_path(),cimg_file_separator,cimg::filenamerand());
        cimg_snprintf(filename_tmp2,filename_tmp2._width,"%s_000001." _cimg_save_gif_ext,filename_tmp._data);
        if ((file=std_fopen(filename_tmp2,"rb"))!=0) cimg::fclose(file);
      } while (file);
      cimglist_for(*this,l) {
        cimg_snprintf(filename_tmp2,filename_tmp2._width,"%s_%.6u." _cimg_save_gif_ext,filename_tmp._data,l + 1);
        CImg<charT>::string(filename_tmp2).move_to(filenames);
        if (_data[l]._depth>1 || _data[l]._spectrum!=3) _data[l].get_resize(-100,-100,1,3).save(filename_tmp2);
        else _data[l].save(filename_tmp2);
      }

#if cimg_OS!=2
      cimg_snprintf(command,command._width,"%s -delay %u -loop %u",
                    cimg::imagemagick_path(),(unsigned int)std::max(0.0f,cimg::round(100/fps)),nb_loops);
      CImg<ucharT>::string(command).move_to(filenames,0);
      cimg_snprintf(command,command._width,"\"%s\" >/dev/null 2>&1",
                    CImg<charT>::string(filename)._system_strescape().data());
      CImg<ucharT>::string(command).move_to(filenames);
#else
      cimg_snprintf(command,command._width,"\"%s -delay %u -loop %u",
                    cimg::imagemagick_path(),(unsigned int)std::max(0.0f,cimg::round(100/fps)),nb_loops);
      CImg<ucharT>::string(command).move_to(filenames,0);
      cimg_snprintf(command,command._width,"\"%s\"\" >NUL 2>&1",
                    CImg<charT>::string(filename)._system_strescape().data());
      CImg<ucharT>::string(command).move_to(filenames);
#endif
      CImg<charT> _command = filenames>'x';
      cimg_for(_command,p,char) if (!*p) *p = ' ';
      _command.back() = 0;

      cimg::system(_command);
      file = std_fopen(filename,"rb");
      if (!file)
        throw CImgIOException(_cimglist_instance
                              "save_gif_external(): Failed to save file '%s' with external command 'convert'.",
                              cimglist_instance,
                              filename);
      else cimg::fclose(file);
      cimglist_for_in(*this,1,filenames._width - 1,l) std::remove(filenames[l]);
      return *this;
    }

    const CImgList<T>& _save_yuv(std::FILE *const file, const char *const filename, const bool is_rgb) const {
      if (!file && !filename)
        throw CImgArgumentException(_cimglist_instance
                                    "save_yuv(): Specified filename is (null).",
                                    cimglist_instance);
      if (is_empty()) { cimg::fempty(file,filename); return *this; }
      if ((*this)[0].width()%2 || (*this)[0].height()%2)
        throw CImgInstanceException(_cimglist_instance
                                    "save_yuv(): Invalid odd instance dimensions (%u,%u) for file '%s'.",
                                    cimglist_instance,
                                    (*this)[0].width(),(*this)[0].height(),
                                    filename?filename:"(FILE*)");