mirror of
https://github.com/webmproject/libwebp.git
synced 2025-04-05 00:16:50 +02:00
c63c5df618
after: 1432ebba Refactor palette sorting computation. fixes: src\utils\palette.c(384): warning C4028: formal parameter 2 different from declaration src\utils\palette.c(384): warning C4028: formal parameter 3 different from declaration src\utils\palette.c(384): warning C4028: formal parameter 5 different from declaration Change-Id: If29205f346e674108646045b7a3d90f078fed9b0
61 lines
2.5 KiB
C
61 lines
2.5 KiB
C
// Copyright 2023 Google Inc. All Rights Reserved.
|
|
//
|
|
// Use of this source code is governed by a BSD-style license
|
|
// that can be found in the COPYING file in the root of the source
|
|
// tree. An additional intellectual property rights grant can be found
|
|
// in the file PATENTS. All contributing project authors may
|
|
// be found in the AUTHORS file in the root of the source tree.
|
|
// -----------------------------------------------------------------------------
|
|
//
|
|
// Utilities for palette analysis.
|
|
//
|
|
// Author: Vincent Rabaud (vrabaud@google.com)
|
|
|
|
#ifndef WEBP_UTILS_PALETTE_H_
|
|
#define WEBP_UTILS_PALETTE_H_
|
|
|
|
#include "src/webp/types.h"
|
|
|
|
struct WebPPicture;
|
|
|
|
// The different ways a palette can be sorted.
|
|
typedef enum PaletteSorting {
|
|
kSortedDefault = 0,
|
|
// Sorts by minimizing L1 deltas between consecutive colors, giving more
|
|
// weight to RGB colors.
|
|
kMinimizeDelta = 1,
|
|
// Implements the modified Zeng method from "A Survey on Palette Reordering
|
|
// Methods for Improving the Compression of Color-Indexed Images" by Armando
|
|
// J. Pinho and Antonio J. R. Neves.
|
|
kModifiedZeng = 2,
|
|
kUnusedPalette = 3,
|
|
kPaletteSortingNum = 4
|
|
} PaletteSorting;
|
|
|
|
// Returns the index of 'color' in the sorted palette 'sorted' of size
|
|
// 'num_colors'.
|
|
int SearchColorNoIdx(const uint32_t sorted[], uint32_t color, int num_colors);
|
|
|
|
// Sort palette in increasing order and prepare an inverse mapping array.
|
|
void PrepareMapToPalette(const uint32_t palette[], uint32_t num_colors,
|
|
uint32_t sorted[], uint32_t idx_map[]);
|
|
|
|
// Returns count of unique colors in 'pic', assuming pic->use_argb is true.
|
|
// If the unique color count is more than MAX_PALETTE_SIZE, returns
|
|
// MAX_PALETTE_SIZE+1.
|
|
// If 'palette' is not NULL and the number of unique colors is less than or
|
|
// equal to MAX_PALETTE_SIZE, also outputs the actual unique colors into
|
|
// 'palette' in a sorted order. Note: 'palette' is assumed to be an array
|
|
// already allocated with at least MAX_PALETTE_SIZE elements.
|
|
int GetColorPalette(const struct WebPPicture* const pic,
|
|
uint32_t* const palette);
|
|
|
|
// Sorts the palette according to the criterion defined by 'method'.
|
|
// 'palette_sorted' is the input palette sorted lexicographically, as done in
|
|
// PrepareMapToPalette. Returns 0 on memory allocation error.
|
|
int PaletteSort(PaletteSorting method, const struct WebPPicture* const pic,
|
|
const uint32_t* const palette_sorted, uint32_t num_colors,
|
|
uint32_t* const palette);
|
|
|
|
#endif // WEBP_UTILS_PALETTE_H_
|