1// Copyright 2022 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// Gamma correction utilities.
11
12#ifndef WEBP_SHARPYUV_SHARPYUV_GAMMA_H_
13#define WEBP_SHARPYUV_SHARPYUV_GAMMA_H_
14
15#include "src/webp/types.h"
16
17#ifdef __cplusplus
18extern "C" {
19#endif
20
21// Initializes precomputed tables. Must be called once before calling
22// SharpYuvGammaToLinear or SharpYuvLinearToGamma.
23void SharpYuvInitGammaTables(void);
24
25// Converts a gamma color value on 'bit_depth' bits to a 16 bit linear value.
26uint32_t SharpYuvGammaToLinear(uint16_t v, int bit_depth);
27
28// Converts a 16 bit linear color value to a gamma value on 'bit_depth' bits.
29uint16_t SharpYuvLinearToGamma(uint32_t value, int bit_depth);
30
31#ifdef __cplusplus
32} // extern "C"
33#endif
34
35#endif // WEBP_SHARPYUV_SHARPYUV_GAMMA_H_
36