10 // Utilities for palette analysis.
14 #include "src/utils/palette.h"
27 // Palette reordering for smaller sum of deltas (and for smaller storage).
41 // palette entry diff.
80 void PrepareMapToPalette(const uint32_t palette[], uint32_t num_colors,  in PrepareMapToPalette()  argument
83   memcpy(sorted, palette, num_colors * sizeof(*sorted));  in PrepareMapToPalette()
86     idx_map[SearchColorNoIdx(sorted, palette[i], num_colors)] = i;  in PrepareMapToPalette()
95 int GetColorPalette(const WebPPicture* const pic, uint32_t* const palette) {  in GetColorPalette()  argument
137   if (palette != NULL) {  // Fill the colors into palette.  in GetColorPalette()
141         palette[num_colors] = colors[i];  in GetColorPalette()
145     qsort(palette, num_colors, sizeof(*palette), PaletteCompareColorsForQsort);  in GetColorPalette()
155 // The palette has been sorted by alpha. This function checks if the other
156 // components of the palette have a monotonic development with regards to
157 // position in the palette. If all have monotonic development, there is
161 static int PaletteHasNonMonotonousDeltas(const uint32_t* const palette,  in PaletteHasNonMonotonousDeltas()  argument
167     const uint32_t diff = VP8LSubPixels(palette[i], predict);  in PaletteHasNonMonotonousDeltas()
180     predict = palette[i];  in PaletteHasNonMonotonousDeltas()
186                                       int num_colors, uint32_t* const palette) {  in PaletteSortMinimizeDeltas()
189   memcpy(palette, palette_sorted, num_colors * sizeof(*palette));  in PaletteSortMinimizeDeltas()
192   // deltas in the palette. This reduces storage needs since the  in PaletteSortMinimizeDeltas()
193   // palette is stored with delta encoding.  in PaletteSortMinimizeDeltas()
198       const uint32_t cur_score = PaletteColorDistance(palette[k], predict);  in PaletteSortMinimizeDeltas()
204     SwapColor(&palette[best_ix], &palette[i]);  in PaletteSortMinimizeDeltas()
205     predict = palette[i];  in PaletteSortMinimizeDeltas()
210 // Modified Zeng method from "A Survey on Palette Reordering
245                              const uint32_t* const palette, uint32_t num_colors,  in CoOccurrenceBuild()  argument
260   PrepareMapToPalette(palette, num_colors, palette_sorted, idx_map);  in CoOccurrenceBuild()
270       // between Memon's and the modified Zeng's palette reordering methods".  in CoOccurrenceBuild()
299                                    uint32_t* const palette) {  in PaletteSortModifiedZeng()  argument
306   // TODO(vrabaud) check whether one color images should use palette or not.  in PaletteSortModifiedZeng()
373   // Re-map the palette.  in PaletteSortModifiedZeng()
375     palette[i] = palette_in[remapping[(first + i) % num_colors]];  in PaletteSortModifiedZeng()
384                 uint32_t* const palette) {  in PaletteSort()  argument
387       // Nothing to do, we have already sorted the palette.  in PaletteSort()
388       memcpy(palette, palette_sorted, num_colors * sizeof(*palette));  in PaletteSort()
391       PaletteSortMinimizeDeltas(palette_sorted, num_colors, palette);  in PaletteSort()
394       return PaletteSortModifiedZeng(pic, palette_sorted, num_colors, palette);  in PaletteSort()