Coverage Report

Created: 2025-06-22 08:04

/src/libjxl/lib/jxl/cms/tone_mapping-inl.h
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// Copyright (c) the JPEG XL Project Authors. All rights reserved.
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//
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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#if defined(LIB_JXL_CMS_TONE_MAPPING_INL_H_) == defined(HWY_TARGET_TOGGLE)
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#ifdef LIB_JXL_CMS_TONE_MAPPING_INL_H_
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#undef LIB_JXL_CMS_TONE_MAPPING_INL_H_
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#else
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#define LIB_JXL_CMS_TONE_MAPPING_INL_H_
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#endif
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#include <hwy/highway.h>
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#include "lib/jxl/cms/tone_mapping.h"
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#include "lib/jxl/cms/transfer_functions-inl.h"
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HWY_BEFORE_NAMESPACE();
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namespace jxl {
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namespace HWY_NAMESPACE {
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namespace {
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// These templates are not found via ADL.
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using hwy::HWY_NAMESPACE::Clamp;
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using hwy::HWY_NAMESPACE::Max;
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using hwy::HWY_NAMESPACE::ZeroIfNegative;
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template <typename D>
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class Rec2408ToneMapper : Rec2408ToneMapperBase {
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 private:
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  using V = hwy::HWY_NAMESPACE::Vec<D>;
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 public:
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  using Rec2408ToneMapperBase::Rec2408ToneMapperBase;
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  void ToneMap(V* red, V* green, V* blue) const {
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    const V luminance = Mul(Set(df_, source_range_.second),
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                            (MulAdd(Set(df_, red_Y_), *red,
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                                    MulAdd(Set(df_, green_Y_), *green,
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                                           Mul(Set(df_, blue_Y_), *blue)))));
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    const V pq_mastering_min = Set(df_, pq_mastering_min_);
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    const V inv_pq_mastering_range = Set(df_, inv_pq_mastering_range_);
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    const V normalized_pq = Min(
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        Set(df_, 1.f),
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        Mul(Sub(InvEOTF(luminance), pq_mastering_min), inv_pq_mastering_range));
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    const V ks = Set(df_, ks_);
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    const V e2 =
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        IfThenElse(Lt(normalized_pq, ks), normalized_pq, P(normalized_pq));
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    const V one_minus_e2 = Sub(Set(df_, 1), e2);
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    const V one_minus_e2_2 = Mul(one_minus_e2, one_minus_e2);
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    const V one_minus_e2_4 = Mul(one_minus_e2_2, one_minus_e2_2);
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    const V b = Set(df_, min_lum_);
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    const V e3 = MulAdd(b, one_minus_e2_4, e2);
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    const V pq_mastering_range = Set(df_, pq_mastering_range_);
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    const V e4 = MulAdd(e3, pq_mastering_range, pq_mastering_min);
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    const V new_luminance =
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        Min(Set(df_, target_range_.second),
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            ZeroIfNegative(tf_pq_.DisplayFromEncoded(df_, e4)));
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    const V min_luminance = Set(df_, 1e-6f);
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    const auto use_cap = Le(luminance, min_luminance);
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    const V ratio = Div(new_luminance, Max(luminance, min_luminance));
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    const V cap = Mul(new_luminance, Set(df_, inv_target_peak_));
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    const V normalizer = Set(df_, normalizer_);
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    const V multiplier = Mul(ratio, normalizer);
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    for (V* const val : {red, green, blue}) {
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      *val = IfThenElse(use_cap, cap, Mul(*val, multiplier));
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    }
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  }
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 private:
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  V InvEOTF(const V luminance) const {
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    return tf_pq_.EncodedFromDisplay(df_, luminance);
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  }
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  V T(const V a) const {
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    const V ks = Set(df_, ks_);
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    const V inv_one_minus_ks = Set(df_, inv_one_minus_ks_);
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    return Mul(Sub(a, ks), inv_one_minus_ks);
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  }
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  V P(const V b) const {
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    const V t_b = T(b);
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    const V t_b_2 = Mul(t_b, t_b);
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    const V t_b_3 = Mul(t_b_2, t_b);
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    const V ks = Set(df_, ks_);
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    const V max_lum = Set(df_, max_lum_);
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    return MulAdd(
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        MulAdd(Set(df_, 2), t_b_3, MulAdd(Set(df_, -3), t_b_2, Set(df_, 1))),
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        ks,
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        MulAdd(Add(t_b_3, MulAdd(Set(df_, -2), t_b_2, t_b)),
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               Sub(Set(df_, 1), ks),
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               Mul(MulAdd(Set(df_, -2), t_b_3, Mul(Set(df_, 3), t_b_2)),
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                   max_lum)));
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  }
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  D df_;
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  const TF_PQ tf_pq_ = TF_PQ(/*display_intensity_target=*/1.0);
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};
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class HlgOOTF : HlgOOTF_Base {
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 public:
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  using HlgOOTF_Base::HlgOOTF_Base;
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  static HlgOOTF FromSceneLight(float display_luminance,
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                                const Vector3& primaries_luminances) {
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    return HlgOOTF(/*gamma=*/1.2f *
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                       std::pow(1.111f, std::log2(display_luminance / 1000.f)),
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                   primaries_luminances);
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  }
Unexecuted instantiation: stage_from_linear.cc:jxl::N_SCALAR::(anonymous namespace)::HlgOOTF::FromSceneLight(float, std::__1::array<float, 3ul> const&)
Unexecuted instantiation: stage_to_linear.cc:jxl::N_SCALAR::(anonymous namespace)::HlgOOTF::FromSceneLight(float, std::__1::array<float, 3ul> const&)
Unexecuted instantiation: stage_tone_mapping.cc:jxl::N_SCALAR::(anonymous namespace)::HlgOOTF::FromSceneLight(float, std::__1::array<float, 3ul> const&)
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  static HlgOOTF ToSceneLight(float display_luminance,
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                              const Vector3& primaries_luminances) {
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    return HlgOOTF(
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        /*gamma=*/(1 / 1.2f) *
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            std::pow(1.111f, -std::log2(display_luminance / 1000.f)),
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        primaries_luminances);
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  }
Unexecuted instantiation: stage_from_linear.cc:jxl::N_SCALAR::(anonymous namespace)::HlgOOTF::ToSceneLight(float, std::__1::array<float, 3ul> const&)
Unexecuted instantiation: stage_to_linear.cc:jxl::N_SCALAR::(anonymous namespace)::HlgOOTF::ToSceneLight(float, std::__1::array<float, 3ul> const&)
Unexecuted instantiation: stage_tone_mapping.cc:jxl::N_SCALAR::(anonymous namespace)::HlgOOTF::ToSceneLight(float, std::__1::array<float, 3ul> const&)
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  template <typename V>
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  void Apply(V* red, V* green, V* blue) const {
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    hwy::HWY_NAMESPACE::DFromV<V> df;
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    if (!apply_ootf_) return;
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    const V luminance =
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        MulAdd(Set(df, red_Y_), *red,
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               MulAdd(Set(df, green_Y_), *green, Mul(Set(df, blue_Y_), *blue)));
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    const V ratio =
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        Min(FastPowf(df, luminance, Set(df, exponent_)), Set(df, 1e9));
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    *red = Mul(*red, ratio);
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    *green = Mul(*green, ratio);
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    *blue = Mul(*blue, ratio);
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  }
Unexecuted instantiation: stage_from_linear.cc:void jxl::N_SCALAR::(anonymous namespace)::HlgOOTF::Apply<hwy::N_SCALAR::Vec1<float> >(hwy::N_SCALAR::Vec1<float>*, hwy::N_SCALAR::Vec1<float>*, hwy::N_SCALAR::Vec1<float>*) const
Unexecuted instantiation: stage_to_linear.cc:void jxl::N_SCALAR::(anonymous namespace)::HlgOOTF::Apply<hwy::N_SCALAR::Vec1<float> >(hwy::N_SCALAR::Vec1<float>*, hwy::N_SCALAR::Vec1<float>*, hwy::N_SCALAR::Vec1<float>*) const
Unexecuted instantiation: stage_tone_mapping.cc:void jxl::N_SCALAR::(anonymous namespace)::HlgOOTF::Apply<hwy::N_SCALAR::Vec1<float> >(hwy::N_SCALAR::Vec1<float>*, hwy::N_SCALAR::Vec1<float>*, hwy::N_SCALAR::Vec1<float>*) const
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  bool WarrantsGamutMapping() const { return apply_ootf_ && exponent_ < 0; }
Unexecuted instantiation: stage_from_linear.cc:jxl::N_SCALAR::(anonymous namespace)::HlgOOTF::WarrantsGamutMapping() const
Unexecuted instantiation: stage_to_linear.cc:jxl::N_SCALAR::(anonymous namespace)::HlgOOTF::WarrantsGamutMapping() const
Unexecuted instantiation: stage_tone_mapping.cc:jxl::N_SCALAR::(anonymous namespace)::HlgOOTF::WarrantsGamutMapping() const
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};
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template <typename V>
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void GamutMap(V* red, V* green, V* blue, const Vector3& primaries_luminances,
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              float preserve_saturation = 0.1f) {
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  hwy::HWY_NAMESPACE::DFromV<V> df;
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  const V luminance =
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      MulAdd(Set(df, primaries_luminances[0]), *red,
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             MulAdd(Set(df, primaries_luminances[1]), *green,
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                    Mul(Set(df, primaries_luminances[2]), *blue)));
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  // Desaturate out-of-gamut pixels. This is done by mixing each pixel
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  // with just enough gray of the target luminance to make all
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  // components non-negative.
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  // - For saturation preservation, if a component is still larger than
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  // 1 then the pixel is normalized to have a maximum component of 1.
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  // That will reduce its luminance.
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  // - For luminance preservation, getting all components below 1 is
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  // done by mixing in yet more gray. That will desaturate it further.
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  const V zero = Zero(df);
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  const V one = Set(df, 1);
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  V gray_mix_saturation = zero;
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  V gray_mix_luminance = zero;
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  for (const V* ch : {red, green, blue}) {
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    const V& val = *ch;
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    const V val_minus_gray = Sub(val, luminance);
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    const V inv_val_minus_gray =
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        Div(one, IfThenElse(Eq(val_minus_gray, zero), one, val_minus_gray));
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    const V val_over_val_minus_gray = Mul(val, inv_val_minus_gray);
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    gray_mix_saturation =
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        IfThenElse(Ge(val_minus_gray, zero), gray_mix_saturation,
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                   Max(gray_mix_saturation, val_over_val_minus_gray));
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    gray_mix_luminance =
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        Max(gray_mix_luminance,
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            IfThenElse(Le(val_minus_gray, zero), gray_mix_saturation,
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                       Sub(val_over_val_minus_gray, inv_val_minus_gray)));
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  }
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  const V gray_mix = Clamp(
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      MulAdd(Set(df, preserve_saturation),
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             Sub(gray_mix_saturation, gray_mix_luminance), gray_mix_luminance),
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      zero, one);
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  for (V* const ch : {red, green, blue}) {
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    V& val = *ch;
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    val = MulAdd(gray_mix, Sub(luminance, val), val);
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  }
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  const V max_clr = Max(Max(one, *red), Max(*green, *blue));
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  const V normalizer = Div(one, max_clr);
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  for (V* const ch : {red, green, blue}) {
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    V& val = *ch;
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    val = Mul(val, normalizer);
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  }
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}
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}  // namespace
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// NOLINTNEXTLINE(google-readability-namespace-comments)
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}  // namespace HWY_NAMESPACE
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}  // namespace jxl
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HWY_AFTER_NAMESPACE();
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#endif  // LIB_JXL_CMS_TONE_MAPPING_INL_H_