xref: /aosp_15_r20/external/webp/extras/sharpyuv_risk_table.h (revision b2055c353e87c8814eb2b6b1b11112a1562253bd)
1 // Copyright 2023 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 // Precomputed data for 420 risk estimation.
11 
12 #ifndef WEBP_EXTRAS_SHARPYUV_RISK_TABLE_H_
13 #define WEBP_EXTRAS_SHARPYUV_RISK_TABLE_H_
14 
15 #include "src/webp/types.h"
16 
17 extern const int kSharpYuvPrecomputedRiskYuvSampling;
18 // Table of precomputed risk scores when chroma subsampling images with two
19 // given colors.
20 // Since precomputing values for all possible YUV colors would create a huge
21 // table, the YUV space (i.e. [0, 255]^3) is reduced to
22 // [0, kSharpYuvPrecomputedRiskYuvSampling-1]^3
23 // where 255 maps to kSharpYuvPrecomputedRiskYuvSampling-1.
24 // Table size: kSharpYuvPrecomputedRiskYuvSampling^6 bytes or 114 KiB
25 extern const uint8_t kSharpYuvPrecomputedRisk[];
26 
27 #endif  // WEBP_EXTRAS_SHARPYUV_RISK_TABLE_H_
28