+
+ png_infop end_info = png_create_info_struct(png_ptr);
+ if (!end_info) {
+ png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
+ fclose(fp);
+ return false;
+ }
+
+ if (setjmp(png_ptr->jmpbuf)) {
+ png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
+ fclose(fp);
+ return false;
+ }
+
+ png_init_io(png_ptr, fp);
+ png_set_sig_bytes(png_ptr, 8);
+ png_read_info(png_ptr, info_ptr);
+
+ int width = png_get_image_width (png_ptr, info_ptr);
+ int height = png_get_image_height (png_ptr, info_ptr);
+ int bit_depth = png_get_bit_depth (png_ptr, info_ptr);
+ int color_type = png_get_color_type (png_ptr, info_ptr);
+
+ if (color_type == PNG_COLOR_TYPE_PALETTE && bit_depth <= 8)
+ png_set_expand(png_ptr);
+
+ if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
+ png_set_expand(png_ptr);
+
+ if (bit_depth < 8)
+ png_set_packing(png_ptr);
+
+ if (color_type & PNG_COLOR_MASK_ALPHA)
+ png_set_strip_alpha(png_ptr);
+
+ if (bit_depth == 16)
+ png_set_swap(png_ptr); // convert to little-endian format
+
+ png_read_update_info(png_ptr, info_ptr); // update with transformations
+ int rowbytes = png_get_rowbytes (png_ptr, info_ptr);
+ bit_depth = png_get_bit_depth (png_ptr, info_ptr);
+ color_type = png_get_color_type (png_ptr, info_ptr);
+
+ png_bytep* row_pointers = new png_bytep [height];
+ int i;
+ for (i = 0; i < height; i++)
+ row_pointers[i] = new unsigned char [rowbytes];
+
+ png_read_image(png_ptr, row_pointers);
+
+ setArraySize (width, height);
+ ImageFileArray v = getArray();
+ for (int iy = 0; iy < height; iy++) {
+ for (int ix = 0; ix < width; ix++) {
+ double dV = 0;
+ if (color_type == PNG_COLOR_TYPE_GRAY) {
+ if (bit_depth == 8)
+ dV = row_pointers[iy][ix] / 255.;
+ else if (bit_depth == 16) {
+ int iBase = ix * 2;
+ dV = (row_pointers[iy][iBase] + (row_pointers[iy][iBase+1] << 8)) / 65536.;
+ } else
+ dV = 0;
+ } else if (color_type == PNG_COLOR_TYPE_RGB) {
+ if (bit_depth == 8) {
+ int iBase = ix * 3;
+ double dR = row_pointers[iy][iBase] / 255.;
+ double dG = row_pointers[iy][iBase+1] / 255.;
+ double dB = row_pointers[iy][iBase+2] / 255.;
+ dV = colorToGrayscale (dR, dG, dB);
+ } else
+ dV = 0;
+ }
+ v[ix][height-iy-1] = dV;
+ }
+ }
+
+ png_read_end(png_ptr, end_info);
+ png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
+
+ for (i = 0; i < height; i++)
+ delete row_pointers[i];
+ delete row_pointers;
+
+ fclose (fp);
+ return true;
+}
+#endif
+
+bool
+ImageFile::exportImage (const char* const pszFormat, const char* const pszFilename, int nxcell, int nycell, double densmin, double densmax)
+{
+ int iFormatID = convertExportFormatNameToID (pszFormat);
+
+ if (iFormatID == EXPORT_FORMAT_PGM)