/src/libjxl/lib/jxl/dec_xyb.cc

Source
// 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/dec_xyb.h"

#include <algorithm>
#include <cmath>
#include <cstdint>
#include <cstdlib>
#include <cstring>
#include <iterator>

#include "lib/jxl/base/data_parallel.h"
#include "lib/jxl/image_metadata.h"
#include "lib/jxl/image_ops.h"

#undef HWY_TARGET_INCLUDE
#define HWY_TARGET_INCLUDE "lib/jxl/dec_xyb.cc"
#include <hwy/foreach_target.h>
#include <hwy/highway.h>

#include "lib/jxl/base/compiler_specific.h"
#include "lib/jxl/base/matrix_ops.h"
#include "lib/jxl/base/rect.h"
#include "lib/jxl/base/sanitizers.h"
#include "lib/jxl/base/status.h"
#include "lib/jxl/cms/color_encoding_cms.h"
#include "lib/jxl/cms/jxl_cms_internal.h"
#include "lib/jxl/cms/opsin_params.h"
#include "lib/jxl/color_encoding_internal.h"
#include "lib/jxl/common.h"
#include "lib/jxl/dec_xyb-inl.h"
#include "lib/jxl/image.h"
#include "lib/jxl/opsin_params.h"
#include "lib/jxl/quantizer.h"
HWY_BEFORE_NAMESPACE();
namespace jxl {
namespace HWY_NAMESPACE {

// These templates are not found via ADL.
using hwy::HWY_NAMESPACE::MulAdd;

// Same, but not in-place.
Status OpsinToLinear(const Image3F& opsin, const Rect& rect, ThreadPool* pool,
                     Image3F* JXL_RESTRICT linear,
                     const OpsinParams& opsin_params) {
  JXL_ENSURE(SameSize(rect, *linear));
  JXL_CHECK_IMAGE_INITIALIZED(opsin, rect);

  const auto process_row = [&](const uint32_t task,
                               size_t /*thread*/) -> Status {
    const size_t y = static_cast<size_t>(task);

    // Faster than adding via ByteOffset at end of loop.
    const float* JXL_RESTRICT row_opsin_0 = rect.ConstPlaneRow(opsin, 0, y);
    const float* JXL_RESTRICT row_opsin_1 = rect.ConstPlaneRow(opsin, 1, y);
    const float* JXL_RESTRICT row_opsin_2 = rect.ConstPlaneRow(opsin, 2, y);
    float* JXL_RESTRICT row_linear_0 = linear->PlaneRow(0, y);
    float* JXL_RESTRICT row_linear_1 = linear->PlaneRow(1, y);
    float* JXL_RESTRICT row_linear_2 = linear->PlaneRow(2, y);

    const HWY_FULL(float) d;

    for (size_t x = 0; x < rect.xsize(); x += Lanes(d)) {
      const auto in_opsin_x = Load(d, row_opsin_0 + x);
      const auto in_opsin_y = Load(d, row_opsin_1 + x);
      const auto in_opsin_b = Load(d, row_opsin_2 + x);
      auto linear_r = Undefined(d);
      auto linear_g = Undefined(d);
      auto linear_b = Undefined(d);
      XybToRgb(d, in_opsin_x, in_opsin_y, in_opsin_b, opsin_params, &linear_r,
               &linear_g, &linear_b);

      Store(linear_r, d, row_linear_0 + x);
      Store(linear_g, d, row_linear_1 + x);
      Store(linear_b, d, row_linear_2 + x);
    }
    return true;
  };
  JXL_RETURN_IF_ERROR(RunOnPool(pool, 0, static_cast<int>(rect.ysize()),
                                ThreadPool::NoInit, process_row,
                                "OpsinToLinear(Rect)"));
  JXL_CHECK_IMAGE_INITIALIZED(*linear, rect);
  return true;
}

// NOLINTNEXTLINE(google-readability-namespace-comments)
}  // namespace HWY_NAMESPACE
}  // namespace jxl
HWY_AFTER_NAMESPACE();

#if HWY_ONCE
namespace jxl {

HWY_EXPORT(OpsinToLinear);
Status OpsinToLinear(const Image3F& opsin, const Rect& rect, ThreadPool* pool,
                     Image3F* JXL_RESTRICT linear,
                     const OpsinParams& opsin_params) {
  return HWY_DYNAMIC_DISPATCH(OpsinToLinear)(opsin, rect, pool, linear,
                                             opsin_params);
}

#if !JXL_HIGH_PRECISION
HWY_EXPORT(HasFastXYBTosRGB8);
bool HasFastXYBTosRGB8() { return HWY_DYNAMIC_DISPATCH(HasFastXYBTosRGB8)(); }

HWY_EXPORT(FastXYBTosRGB8);
Status FastXYBTosRGB8(const float* input[4], uint8_t* output, bool is_rgba,
                      size_t xsize) {
  return HWY_DYNAMIC_DISPATCH(FastXYBTosRGB8)(input, output, is_rgba, xsize);
}
#endif  // !JXL_HIGH_PRECISION

void OpsinParams::Init(float intensity_target) {
  InitSIMDInverseMatrix(GetOpsinAbsorbanceInverseMatrix(), inverse_opsin_matrix,
                        intensity_target);
  memcpy(opsin_biases, jxl::cms::kNegOpsinAbsorbanceBiasRGB.data(),
         sizeof(jxl::cms::kNegOpsinAbsorbanceBiasRGB));
  memcpy(quant_biases, kDefaultQuantBias, sizeof(kDefaultQuantBias));
  for (size_t c = 0; c < 4; c++) {
    opsin_biases_cbrt[c] = cbrtf(opsin_biases[c]);
  }
}

bool CanOutputToColorEncoding(const ColorEncoding& c_desired) {
  if (!c_desired.HaveFields()) {
    return false;
  }
  // TODO(veluca): keep in sync with dec_reconstruct.cc
  const auto& tf = c_desired.Tf();
  if (!tf.IsPQ() && !tf.IsSRGB() && !tf.have_gamma && !tf.IsLinear() &&
      !tf.IsHLG() && !tf.IsDCI() && !tf.Is709()) {
    return false;
  }
  if (c_desired.IsGray() && c_desired.GetWhitePointType() != WhitePoint::kD65) {
    // TODO(veluca): figure out what should happen here.
    return false;
  }
  return true;
}

Status OutputEncodingInfo::SetFromMetadata(const CodecMetadata& metadata) {
  orig_color_encoding = metadata.m.color_encoding;
  orig_intensity_target = metadata.m.IntensityTarget();
  desired_intensity_target = orig_intensity_target;
  const auto& im = metadata.transform_data.opsin_inverse_matrix;
  orig_inverse_matrix = im.inverse_matrix;
  default_transform = im.all_default;
  xyb_encoded = metadata.m.xyb_encoded;
  std::copy(std::begin(im.opsin_biases), std::end(im.opsin_biases),
            opsin_params.opsin_biases);
  for (int i = 0; i < 3; ++i) {
    opsin_params.opsin_biases_cbrt[i] = cbrtf(opsin_params.opsin_biases[i]);
  }
  opsin_params.opsin_biases_cbrt[3] = opsin_params.opsin_biases[3] = 1;
  std::copy(std::begin(im.quant_biases), std::end(im.quant_biases),
            opsin_params.quant_biases);
  bool orig_ok = CanOutputToColorEncoding(orig_color_encoding);
  bool orig_grey = orig_color_encoding.IsGray();
  return SetColorEncoding(!xyb_encoded || orig_ok
                              ? orig_color_encoding
                              : ColorEncoding::LinearSRGB(orig_grey));
}

Status OutputEncodingInfo::MaybeSetColorEncoding(
    const ColorEncoding& c_desired) {
  if (c_desired.GetColorSpace() == ColorSpace::kXYB &&
      ((color_encoding.GetColorSpace() == ColorSpace::kRGB &&
        color_encoding.GetPrimariesType() != Primaries::kSRGB) ||
       color_encoding.Tf().IsPQ())) {
    return false;
  }
  if (!xyb_encoded && !CanOutputToColorEncoding(c_desired)) {
    return false;
  }
  return SetColorEncoding(c_desired);
}

Status OutputEncodingInfo::SetColorEncoding(const ColorEncoding& c_desired) {
  color_encoding = c_desired;
  linear_color_encoding = color_encoding;
  linear_color_encoding.Tf().SetTransferFunction(TransferFunction::kLinear);
  color_encoding_is_original = orig_color_encoding.SameColorEncoding(c_desired);

  // Compute the opsin inverse matrix and luminances based on primaries and
  // white point.
  Matrix3x3 inverse_matrix;
  bool inverse_matrix_is_default = default_transform;
  inverse_matrix = orig_inverse_matrix;
  constexpr Vector3 kSRGBLuminances{0.2126, 0.7152, 0.0722};
  luminances = kSRGBLuminances;
  if ((c_desired.GetPrimariesType() != Primaries::kSRGB ||
       c_desired.GetWhitePointType() != WhitePoint::kD65) &&
      !c_desired.IsGray()) {
    Matrix3x3 srgb_to_xyzd50;
    const auto& srgb = ColorEncoding::SRGB(/*is_gray=*/false);
    PrimariesCIExy p;
    JXL_RETURN_IF_ERROR(srgb.GetPrimaries(p));
    CIExy w = srgb.GetWhitePoint();
    JXL_RETURN_IF_ERROR(PrimariesToXYZD50(p.r.x, p.r.y, p.g.x, p.g.y, p.b.x,
                                          p.b.y, w.x, w.y, srgb_to_xyzd50));
    Matrix3x3 original_to_xyz;
    JXL_RETURN_IF_ERROR(c_desired.GetPrimaries(p));
    w = c_desired.GetWhitePoint();
    if (!PrimariesToXYZ(p.r.x, p.r.y, p.g.x, p.g.y, p.b.x, p.b.y, w.x, w.y,
                        original_to_xyz)) {
      return JXL_FAILURE("PrimariesToXYZ failed");
    }
    luminances = original_to_xyz[1];
    if (xyb_encoded) {
      Matrix3x3 adapt_to_d50;
      if (!AdaptToXYZD50(c_desired.GetWhitePoint().x,
                         c_desired.GetWhitePoint().y, adapt_to_d50)) {
        return JXL_FAILURE("AdaptToXYZD50 failed");
      }
      Matrix3x3 xyzd50_to_original;
      Mul3x3Matrix(adapt_to_d50, original_to_xyz, xyzd50_to_original);
      JXL_RETURN_IF_ERROR(Inv3x3Matrix(xyzd50_to_original));
      Matrix3x3 srgb_to_original;
      Mul3x3Matrix(xyzd50_to_original, srgb_to_xyzd50, srgb_to_original);
      Mul3x3Matrix(srgb_to_original, orig_inverse_matrix, inverse_matrix);
      inverse_matrix_is_default = false;
    }
  }

  if (c_desired.IsGray()) {
    Matrix3x3 tmp_inv_matrix = inverse_matrix;
    Matrix3x3 srgb_to_luma{luminances, luminances, luminances};
    Mul3x3Matrix(srgb_to_luma, tmp_inv_matrix, inverse_matrix);
  }

  // The internal XYB color space uses absolute luminance, so we scale back the
  // opsin inverse matrix to relative luminance where 1.0 corresponds to the
  // original intensity target.
  if (xyb_encoded) {
    InitSIMDInverseMatrix(inverse_matrix, opsin_params.inverse_opsin_matrix,
                          orig_intensity_target);
    all_default_opsin = (std::abs(orig_intensity_target - 255.0) <= 0.1f &&
                         inverse_matrix_is_default);
  }

  // Set the inverse gamma based on color space transfer function.
  const auto& tf = c_desired.Tf();
  inverse_gamma = (tf.have_gamma ? tf.GetGamma()
                   : tf.IsDCI()  ? 1.0f / 2.6f
                                 : 1.0);
  return true;
}

}  // namespace jxl
#endif  // HWY_ONCE

Coverage Report

Created: 2026-06-16 07:20

Line	Count	Source
1		// Copyright (c) the JPEG XL Project Authors. All rights reserved.
2		//
3		// Use of this source code is governed by a BSD-style
4		// license that can be found in the LICENSE file.
5
6		#include "lib/jxl/dec_xyb.h"
7
8		#include <algorithm>
9		#include <cmath>
10		#include <cstdint>
11		#include <cstdlib>
12		#include <cstring>
13		#include <iterator>
14
15		#include "lib/jxl/base/data_parallel.h"
16		#include "lib/jxl/image_metadata.h"
17		#include "lib/jxl/image_ops.h"
18
19		#undef HWY_TARGET_INCLUDE
20		#define HWY_TARGET_INCLUDE "lib/jxl/dec_xyb.cc"
21		#include <hwy/foreach_target.h>
22		#include <hwy/highway.h>
23
24		#include "lib/jxl/base/compiler_specific.h"
25		#include "lib/jxl/base/matrix_ops.h"
26		#include "lib/jxl/base/rect.h"
27		#include "lib/jxl/base/sanitizers.h"
28		#include "lib/jxl/base/status.h"
29		#include "lib/jxl/cms/color_encoding_cms.h"
30		#include "lib/jxl/cms/jxl_cms_internal.h"
31		#include "lib/jxl/cms/opsin_params.h"
32		#include "lib/jxl/color_encoding_internal.h"
33		#include "lib/jxl/common.h"
34		#include "lib/jxl/dec_xyb-inl.h"
35		#include "lib/jxl/image.h"
36		#include "lib/jxl/opsin_params.h"
37		#include "lib/jxl/quantizer.h"
38		HWY_BEFORE_NAMESPACE();
39		namespace jxl {
40		namespace HWY_NAMESPACE {
41
42		// These templates are not found via ADL.
43		using hwy::HWY_NAMESPACE::MulAdd;
44
45		// Same, but not in-place.
46		Status OpsinToLinear(const Image3F& opsin, const Rect& rect, ThreadPool* pool,
47		Image3F* JXL_RESTRICT linear,
48	0	const OpsinParams& opsin_params) {
49	0	JXL_ENSURE(SameSize(rect, *linear));
50	0	JXL_CHECK_IMAGE_INITIALIZED(opsin, rect);
51
52	0	const auto process_row = [&](const uint32_t task,
53	0	size_t /thread/) -> Status {
54	0	const size_t y = static_cast<size_t>(task);
55
56		// Faster than adding via ByteOffset at end of loop.
57	0	const float* JXL_RESTRICT row_opsin_0 = rect.ConstPlaneRow(opsin, 0, y);
58	0	const float* JXL_RESTRICT row_opsin_1 = rect.ConstPlaneRow(opsin, 1, y);
59	0	const float* JXL_RESTRICT row_opsin_2 = rect.ConstPlaneRow(opsin, 2, y);
60	0	float* JXL_RESTRICT row_linear_0 = linear->PlaneRow(0, y);
61	0	float* JXL_RESTRICT row_linear_1 = linear->PlaneRow(1, y);
62	0	float* JXL_RESTRICT row_linear_2 = linear->PlaneRow(2, y);
63
64	0	const HWY_FULL(float) d;
65
66	0	for (size_t x = 0; x < rect.xsize(); x += Lanes(d)) {
67	0	const auto in_opsin_x = Load(d, row_opsin_0 + x);
68	0	const auto in_opsin_y = Load(d, row_opsin_1 + x);
69	0	const auto in_opsin_b = Load(d, row_opsin_2 + x);
70	0	auto linear_r = Undefined(d);
71	0	auto linear_g = Undefined(d);
72	0	auto linear_b = Undefined(d);
73	0	XybToRgb(d, in_opsin_x, in_opsin_y, in_opsin_b, opsin_params, &linear_r,
74	0	&linear_g, &linear_b);
75
76	0	Store(linear_r, d, row_linear_0 + x);
77	0	Store(linear_g, d, row_linear_1 + x);
78	0	Store(linear_b, d, row_linear_2 + x);
79	0	}
80	0	return true;
81	0	}; Unexecuted instantiation: dec_xyb.cc:jxl::N_SSE4::OpsinToLinear(jxl::Image3<float> const&, jxl::RectT<unsigned long> const&, jxl::ThreadPool, jxl::Image3<float>, jxl::OpsinParams const&)::$_0::operator()(unsigned int, unsigned long) const Unexecuted instantiation: dec_xyb.cc:jxl::N_AVX2::OpsinToLinear(jxl::Image3<float> const&, jxl::RectT<unsigned long> const&, jxl::ThreadPool, jxl::Image3<float>, jxl::OpsinParams const&)::$_0::operator()(unsigned int, unsigned long) const Unexecuted instantiation: dec_xyb.cc:jxl::N_AVX3::OpsinToLinear(jxl::Image3<float> const&, jxl::RectT<unsigned long> const&, jxl::ThreadPool, jxl::Image3<float>, jxl::OpsinParams const&)::$_0::operator()(unsigned int, unsigned long) const Unexecuted instantiation: dec_xyb.cc:jxl::N_AVX3_ZEN4::OpsinToLinear(jxl::Image3<float> const&, jxl::RectT<unsigned long> const&, jxl::ThreadPool, jxl::Image3<float>, jxl::OpsinParams const&)::$_0::operator()(unsigned int, unsigned long) const Unexecuted instantiation: dec_xyb.cc:jxl::N_AVX3_SPR::OpsinToLinear(jxl::Image3<float> const&, jxl::RectT<unsigned long> const&, jxl::ThreadPool, jxl::Image3<float>, jxl::OpsinParams const&)::$_0::operator()(unsigned int, unsigned long) const Unexecuted instantiation: dec_xyb.cc:jxl::N_SSE2::OpsinToLinear(jxl::Image3<float> const&, jxl::RectT<unsigned long> const&, jxl::ThreadPool, jxl::Image3<float>, jxl::OpsinParams const&)::$_0::operator()(unsigned int, unsigned long) const
82	0	JXL_RETURN_IF_ERROR(RunOnPool(pool, 0, static_cast<int>(rect.ysize()),
83	0	ThreadPool::NoInit, process_row,
84	0	"OpsinToLinear(Rect)"));
85	0	JXL_CHECK_IMAGE_INITIALIZED(*linear, rect);
86	0	return true;
87	0	} Unexecuted instantiation: jxl::N_SSE4::OpsinToLinear(jxl::Image3<float> const&, jxl::RectT<unsigned long> const&, jxl::ThreadPool, jxl::Image3<float>, jxl::OpsinParams const&) Unexecuted instantiation: jxl::N_AVX2::OpsinToLinear(jxl::Image3<float> const&, jxl::RectT<unsigned long> const&, jxl::ThreadPool, jxl::Image3<float>, jxl::OpsinParams const&) Unexecuted instantiation: jxl::N_AVX3::OpsinToLinear(jxl::Image3<float> const&, jxl::RectT<unsigned long> const&, jxl::ThreadPool, jxl::Image3<float>, jxl::OpsinParams const&) Unexecuted instantiation: jxl::N_AVX3_ZEN4::OpsinToLinear(jxl::Image3<float> const&, jxl::RectT<unsigned long> const&, jxl::ThreadPool, jxl::Image3<float>, jxl::OpsinParams const&) Unexecuted instantiation: jxl::N_AVX3_SPR::OpsinToLinear(jxl::Image3<float> const&, jxl::RectT<unsigned long> const&, jxl::ThreadPool, jxl::Image3<float>, jxl::OpsinParams const&) Unexecuted instantiation: jxl::N_SSE2::OpsinToLinear(jxl::Image3<float> const&, jxl::RectT<unsigned long> const&, jxl::ThreadPool, jxl::Image3<float>, jxl::OpsinParams const&)
88
89		// NOLINTNEXTLINE(google-readability-namespace-comments)
90		} // namespace HWY_NAMESPACE
91		} // namespace jxl
92		HWY_AFTER_NAMESPACE();
93
94		#if HWY_ONCE
95		namespace jxl {
96
97		HWY_EXPORT(OpsinToLinear);
98		Status OpsinToLinear(const Image3F& opsin, const Rect& rect, ThreadPool* pool,
99		Image3F* JXL_RESTRICT linear,
100	0	const OpsinParams& opsin_params) {
101	0	return HWY_DYNAMIC_DISPATCH(OpsinToLinear)(opsin, rect, pool, linear,
102	0	opsin_params);
103	0	}
104
105		#if !JXL_HIGH_PRECISION
106		HWY_EXPORT(HasFastXYBTosRGB8);
107		bool HasFastXYBTosRGB8() { return HWY_DYNAMIC_DISPATCH(HasFastXYBTosRGB8)(); }
108
109		HWY_EXPORT(FastXYBTosRGB8);
110		Status FastXYBTosRGB8(const float* input[4], uint8_t* output, bool is_rgba,
111		size_t xsize) {
112		return HWY_DYNAMIC_DISPATCH(FastXYBTosRGB8)(input, output, is_rgba, xsize);
113		}
114		#endif // !JXL_HIGH_PRECISION
115
116	0	void OpsinParams::Init(float intensity_target) {
117	0	InitSIMDInverseMatrix(GetOpsinAbsorbanceInverseMatrix(), inverse_opsin_matrix,
118	0	intensity_target);
119	0	memcpy(opsin_biases, jxl::cms::kNegOpsinAbsorbanceBiasRGB.data(),
120	0	sizeof(jxl::cms::kNegOpsinAbsorbanceBiasRGB));
121	0	memcpy(quant_biases, kDefaultQuantBias, sizeof(kDefaultQuantBias));
122	0	for (size_t c = 0; c < 4; c++) {
123	0	opsin_biases_cbrt[c] = cbrtf(opsin_biases[c]);
124	0	}
125	0	}
126
127	264k	bool CanOutputToColorEncoding(const ColorEncoding& c_desired) {
128	264k	if (!c_desired.HaveFields()) {
129	90	return false;
130	90	}
131		// TODO(veluca): keep in sync with dec_reconstruct.cc
132	263k	const auto& tf = c_desired.Tf();
133	263k	if (!tf.IsPQ() && !tf.IsSRGB() && !tf.have_gamma && !tf.IsLinear() &&
134	3.92k	!tf.IsHLG() && !tf.IsDCI() && !tf.Is709()) {
135	0	return false;
136	0	}
137	263k	if (c_desired.IsGray() && c_desired.GetWhitePointType() != WhitePoint::kD65) {
138		// TODO(veluca): figure out what should happen here.
139	533	return false;
140	533	}
141	263k	return true;
142	263k	}
143
144	264k	Status OutputEncodingInfo::SetFromMetadata(const CodecMetadata& metadata) {
145	264k	orig_color_encoding = metadata.m.color_encoding;
146	264k	orig_intensity_target = metadata.m.IntensityTarget();
147	264k	desired_intensity_target = orig_intensity_target;
148	264k	const auto& im = metadata.transform_data.opsin_inverse_matrix;
149	264k	orig_inverse_matrix = im.inverse_matrix;
150	264k	default_transform = im.all_default;
151	264k	xyb_encoded = metadata.m.xyb_encoded;
152	264k	std::copy(std::begin(im.opsin_biases), std::end(im.opsin_biases),
153	264k	opsin_params.opsin_biases);
154	1.05M	for (int i = 0; i < 3; ++i) {
155	792k	opsin_params.opsin_biases_cbrt[i] = cbrtf(opsin_params.opsin_biases[i]);
156	792k	}
157	264k	opsin_params.opsin_biases_cbrt[3] = opsin_params.opsin_biases[3] = 1;
158	264k	std::copy(std::begin(im.quant_biases), std::end(im.quant_biases),
159	264k	opsin_params.quant_biases);
160	264k	bool orig_ok = CanOutputToColorEncoding(orig_color_encoding);
161	264k	bool orig_grey = orig_color_encoding.IsGray();
162	264k	return SetColorEncoding(!xyb_encoded \|\| orig_ok
163	264k	? orig_color_encoding
164	264k	: ColorEncoding::LinearSRGB(orig_grey));
165	264k	}
166
167		Status OutputEncodingInfo::MaybeSetColorEncoding(
168	13.4k	const ColorEncoding& c_desired) {
169	13.4k	if (c_desired.GetColorSpace() == ColorSpace::kXYB &&
170	0	((color_encoding.GetColorSpace() == ColorSpace::kRGB &&
171	0	color_encoding.GetPrimariesType() != Primaries::kSRGB) \|\|
172	0	color_encoding.Tf().IsPQ())) {
173	0	return false;
174	0	}
175	13.4k	if (!xyb_encoded && !CanOutputToColorEncoding(c_desired)) {
176	0	return false;
177	0	}
178	13.4k	return SetColorEncoding(c_desired);
179	13.4k	}
180
181	277k	Status OutputEncodingInfo::SetColorEncoding(const ColorEncoding& c_desired) {
182	277k	color_encoding = c_desired;
183	277k	linear_color_encoding = color_encoding;
184	277k	linear_color_encoding.Tf().SetTransferFunction(TransferFunction::kLinear);
185	277k	color_encoding_is_original = orig_color_encoding.SameColorEncoding(c_desired);
186
187		// Compute the opsin inverse matrix and luminances based on primaries and
188		// white point.
189	277k	Matrix3x3 inverse_matrix;
190	277k	bool inverse_matrix_is_default = default_transform;
191	277k	inverse_matrix = orig_inverse_matrix;
192	277k	constexpr Vector3 kSRGBLuminances{0.2126, 0.7152, 0.0722};
193	277k	luminances = kSRGBLuminances;
194	277k	if ((c_desired.GetPrimariesType() != Primaries::kSRGB \|\|
195	276k	c_desired.GetWhitePointType() != WhitePoint::kD65) &&
196	4.90k	!c_desired.IsGray()) {
197	4.41k	Matrix3x3 srgb_to_xyzd50;
198	4.41k	const auto& srgb = ColorEncoding::SRGB(/is_gray=/false);
199	4.41k	PrimariesCIExy p;
200	4.41k	JXL_RETURN_IF_ERROR(srgb.GetPrimaries(p));
201	4.41k	CIExy w = srgb.GetWhitePoint();
202	4.41k	JXL_RETURN_IF_ERROR(PrimariesToXYZD50(p.r.x, p.r.y, p.g.x, p.g.y, p.b.x,
203	4.41k	p.b.y, w.x, w.y, srgb_to_xyzd50));
204	4.41k	Matrix3x3 original_to_xyz;
205	4.41k	JXL_RETURN_IF_ERROR(c_desired.GetPrimaries(p));
206	4.41k	w = c_desired.GetWhitePoint();
207	4.41k	if (!PrimariesToXYZ(p.r.x, p.r.y, p.g.x, p.g.y, p.b.x, p.b.y, w.x, w.y,
208	4.41k	original_to_xyz)) {
209	0	return JXL_FAILURE("PrimariesToXYZ failed");
210	0	}
211	4.41k	luminances = original_to_xyz[1];
212	4.41k	if (xyb_encoded) {
213	172	Matrix3x3 adapt_to_d50;
214	172	if (!AdaptToXYZD50(c_desired.GetWhitePoint().x,
215	172	c_desired.GetWhitePoint().y, adapt_to_d50)) {
216	0	return JXL_FAILURE("AdaptToXYZD50 failed");
217	0	}
218	172	Matrix3x3 xyzd50_to_original;
219	172	Mul3x3Matrix(adapt_to_d50, original_to_xyz, xyzd50_to_original);
220	172	JXL_RETURN_IF_ERROR(Inv3x3Matrix(xyzd50_to_original));
221	171	Matrix3x3 srgb_to_original;
222	171	Mul3x3Matrix(xyzd50_to_original, srgb_to_xyzd50, srgb_to_original);
223	171	Mul3x3Matrix(srgb_to_original, orig_inverse_matrix, inverse_matrix);
224	171	inverse_matrix_is_default = false;
225	171	}
226	4.41k	}
227
228	277k	if (c_desired.IsGray()) {
229	1.04k	Matrix3x3 tmp_inv_matrix = inverse_matrix;
230	1.04k	Matrix3x3 srgb_to_luma{luminances, luminances, luminances};
231	1.04k	Mul3x3Matrix(srgb_to_luma, tmp_inv_matrix, inverse_matrix);
232	1.04k	}
233
234		// The internal XYB color space uses absolute luminance, so we scale back the
235		// opsin inverse matrix to relative luminance where 1.0 corresponds to the
236		// original intensity target.
237	277k	if (xyb_encoded) {
238	114k	InitSIMDInverseMatrix(inverse_matrix, opsin_params.inverse_opsin_matrix,
239	114k	orig_intensity_target);
240	114k	all_default_opsin = (std::abs(orig_intensity_target - 255.0) <= 0.1f &&
241	114k	inverse_matrix_is_default);
242	114k	}
243
244		// Set the inverse gamma based on color space transfer function.
245	277k	const auto& tf = c_desired.Tf();
246	277k	inverse_gamma = (tf.have_gamma ? tf.GetGamma()
247	277k	: tf.IsDCI() ? 1.0f / 2.6f
248	269k	: 1.0);
249	277k	return true;
250	277k	}
251
252		} // namespace jxl
253		#endif // HWY_ONCE