1 // Copyright 2011 Google Inc. All Rights Reserved. 2 // 3 // Use of this source code is governed by a BSD-style license 4 // that can be found in the COPYING file in the root of the source 5 // tree. An additional intellectual property rights grant can be found 6 // in the file PATENTS. All contributing project authors may 7 // be found in the AUTHORS file in the root of the source tree. 8 // ----------------------------------------------------------------------------- 9 // 10 // Spatial prediction using various filters 11 // 12 // Author: Urvang (urvang (at) google.com) 13 14 #ifndef WEBP_UTILS_FILTERS_H_ 15 #define WEBP_UTILS_FILTERS_H_ 16 17 #include "../webp/types.h" 18 19 #if defined(__cplusplus) || defined(c_plusplus) 20 extern "C" { 21 #endif 22 23 // Filters. 24 typedef enum { 25 WEBP_FILTER_NONE = 0, 26 WEBP_FILTER_HORIZONTAL, 27 WEBP_FILTER_VERTICAL, 28 WEBP_FILTER_GRADIENT, 29 WEBP_FILTER_LAST = WEBP_FILTER_GRADIENT + 1, // end marker 30 WEBP_FILTER_BEST, 31 WEBP_FILTER_FAST 32 } WEBP_FILTER_TYPE; 33 34 typedef void (*WebPFilterFunc)(const uint8_t* in, int width, int height, 35 int stride, uint8_t* out); 36 typedef void (*WebPUnfilterFunc)(int width, int height, int stride, 37 uint8_t* data); 38 39 // Filter the given data using the given predictor. 40 // 'in' corresponds to a 2-dimensional pixel array of size (stride * height) 41 // in raster order. 42 // 'stride' is number of bytes per scan line (with possible padding). 43 // 'out' should be pre-allocated. 44 extern const WebPFilterFunc WebPFilters[WEBP_FILTER_LAST]; 45 46 // In-place reconstruct the original data from the given filtered data. 47 extern const WebPUnfilterFunc WebPUnfilters[WEBP_FILTER_LAST]; 48 49 // Fast estimate of a potentially good filter. 50 extern WEBP_FILTER_TYPE EstimateBestFilter(const uint8_t* data, 51 int width, int height, int stride); 52 53 #if defined(__cplusplus) || defined(c_plusplus) 54 } // extern "C" 55 #endif 56 57 #endif /* WEBP_UTILS_FILTERS_H_ */ 58
