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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.
#include "lib/jxl/opsin_params.h"
#include "lib/jxl/cms/opsin_params.h"
#define INVERSE_OPSIN_FROM_SPEC 1
#include "lib/jxl/base/matrix_ops.h"
namespace jxl {
const Matrix3x3& GetOpsinAbsorbanceInverseMatrix() {
#if INVERSE_OPSIN_FROM_SPEC
return jxl::cms::DefaultInverseOpsinAbsorbanceMatrix();
#else // INVERSE_OPSIN_FROM_SPEC
// Compute the inverse opsin matrix from the forward matrix. Less precise
// than taking the values from the specification, but must be used if the
// forward transform is changed and the spec will require updating.
static const Matrix3x3 const kInverse = [] {
static Matrix3x3 inverse = kOpsinAbsorbanceMatrix;
Inv3x3Matrix(inverse);
return inverse;
}();
return kInverse;
#endif // INVERSE_OPSIN_FROM_SPEC
}
void InitSIMDInverseMatrix(const Matrix3x3& inverse,
float* JXL_RESTRICT simd_inverse,
float intensity_target) {
for (size_t j = 0; j < 3; ++j) {
for (size_t i = 0; i < 3; ++i) {
size_t idx = (j * 3 + i) * 4;
simd_inverse[idx] = simd_inverse[idx + 1] = simd_inverse[idx + 2] =
simd_inverse[idx + 3] = inverse[j][i] * (255.0f / intensity_target);
}
}
}
} // namespace jxl