Merge branch 'master' into release

1 files changed, 74 insertions, 0 deletions

diff --git a/media/libjxl/src/lib/jxl/opsin_params.h b/media/libjxl/src/lib/jxl/opsin_params.h
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+++ b/media/libjxl/src/lib/jxl/opsin_params.h
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+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_JXL_OPSIN_PARAMS_H_
+#define LIB_JXL_OPSIN_PARAMS_H_
+
+// Constants that define the XYB color space.
+
+#include <stdlib.h>
+
+#include <cmath>
+
+#include "lib/jxl/base/compiler_specific.h"
+
+namespace jxl {
+
+// Parameters for opsin absorbance.
+static const float kM02 = 0.078f;
+static const float kM00 = 0.30f;
+static const float kM01 = 1.0f - kM02 - kM00;
+
+static const float kM12 = 0.078f;
+static const float kM10 = 0.23f;
+static const float kM11 = 1.0f - kM12 - kM10;
+
+static const float kM20 = 0.24342268924547819f;
+static const float kM21 = 0.20476744424496821f;
+static const float kM22 = 1.0f - kM20 - kM21;
+
+static const float kBScale = 1.0f;
+static const float kYToBRatio = 1.0f;  // works better with 0.50017729543783418
+static const float kBToYRatio = 1.0f / kYToBRatio;
+
+static const float kB0 = 0.0037930732552754493f;
+static const float kB1 = kB0;
+static const float kB2 = kB0;
+
+// Opsin absorbance matrix is now frozen.
+static const float kOpsinAbsorbanceMatrix[9] = {
+    kM00, kM01, kM02, kM10, kM11, kM12, kM20, kM21, kM22,
+};
+
+// Must be the inverse matrix of kOpsinAbsorbanceMatrix and match the spec.
+static inline const float* DefaultInverseOpsinAbsorbanceMatrix() {
+  static float kDefaultInverseOpsinAbsorbanceMatrix[9] = {
+      11.031566901960783f,  -9.866943921568629f, -0.16462299647058826f,
+      -3.254147380392157f,  4.418770392156863f,  -0.16462299647058826f,
+      -3.6588512862745097f, 2.7129230470588235f, 1.9459282392156863f};
+  return kDefaultInverseOpsinAbsorbanceMatrix;
+}
+
+// Returns 3x3 row-major matrix inverse of kOpsinAbsorbanceMatrix.
+// opsin_image_test verifies this is actually the inverse.
+const float* GetOpsinAbsorbanceInverseMatrix();
+
+void InitSIMDInverseMatrix(const float* JXL_RESTRICT inverse,
+                           float* JXL_RESTRICT simd_inverse,
+                           float intensity_target);
+
+static const float kOpsinAbsorbanceBias[3] = {
+    kB0,
+    kB1,
+    kB2,
+};
+
+static const float kNegOpsinAbsorbanceBiasRGB[4] = {
+    -kOpsinAbsorbanceBias[0], -kOpsinAbsorbanceBias[1],
+    -kOpsinAbsorbanceBias[2], 1.0f};
+
+}  // namespace jxl
+
+#endif  // LIB_JXL_OPSIN_PARAMS_H_