libwebp/src/utils/quant_levels.h
Pascal Massimino d39177b74c make QuantizeLevels() store the sum of squared error
(instead of MSE).
Useful for directly storing the alpha-PSNR (in another patch)

Change-Id: I4072864f9c53eb4f38366e8025a2816eb14f504e
2012-07-24 15:06:18 -07:00

40 lines
1.4 KiB
C

// Copyright 2011 Google Inc. All Rights Reserved.
//
// This code is licensed under the same terms as WebM:
// Software License Agreement: http://www.webmproject.org/license/software/
// Additional IP Rights Grant: http://www.webmproject.org/license/additional/
// -----------------------------------------------------------------------------
//
// Alpha plane quantization utility
//
// Author: Vikas Arora (vikasa@google.com)
#ifndef WEBP_UTILS_QUANT_LEVELS_H_
#define WEBP_UTILS_QUANT_LEVELS_H_
#include <stdlib.h>
#include "../webp/types.h"
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif
// Replace the input 'data' of size 'width'x'height' with 'num-levels'
// quantized values. If not NULL, 'sse' will contain the sum of squared error.
// Valid range for 'num_levels' is [2, 256].
// Returns false in case of error (data is NULL, or parameters are invalid).
int QuantizeLevels(uint8_t* const data, int width, int height, int num_levels,
uint64_t* const sse);
// Apply post-processing to input 'data' of size 'width'x'height' assuming
// that the source was quantized to a reduced number of levels.
// Returns false in case of error (data is NULL, invalid parameters, ...).
int DequantizeLevels(uint8_t* const data, int width, int height);
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
#endif
#endif /* WEBP_UTILS_QUANT_LEVELS_H_ */