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/*
* Copyright 2017 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkColorSpacePriv.h"
#include "SkImage.h"
#include "SkPngEncoder.h"
#include "Resources.h"
/**
* Create a color space that swaps the red, green, and blue channels.
*/
static sk_sp<SkColorSpace> gbr_color_space() {
float gbr[9];
gbr[0] = gSRGB_toXYZD50[1];
gbr[1] = gSRGB_toXYZD50[2];
gbr[2] = gSRGB_toXYZD50[0];
gbr[3] = gSRGB_toXYZD50[4];
gbr[4] = gSRGB_toXYZD50[5];
gbr[5] = gSRGB_toXYZD50[3];
gbr[6] = gSRGB_toXYZD50[7];
gbr[7] = gSRGB_toXYZD50[8];
gbr[8] = gSRGB_toXYZD50[6];
SkMatrix44 toXYZD50(SkMatrix44::kUninitialized_Constructor);
toXYZD50.set3x3RowMajorf(gbr);
return SkColorSpace::MakeRGB(SkColorSpace::kSRGB_RenderTargetGamma, toXYZD50);
}
/**
* Create a color space with a steep transfer function.
*/
static sk_sp<SkColorSpace> tf_color_space() {
SkColorSpaceTransferFn fn;
fn.fA = 1.f; fn.fB = 0.f; fn.fC = 0.f; fn.fD = 0.f; fn.fE = 0.f; fn.fF = 0.f; fn.fG = 50.f;
return SkColorSpace::MakeRGB(fn, SkColorSpace::kSRGB_Gamut);
}
/**
* Create a wide gamut color space.
*/
static sk_sp<SkColorSpace> wide_gamut_color_space() {
return SkColorSpace::MakeRGB(SkColorSpace::kSRGB_RenderTargetGamma,
SkColorSpace::kRec2020_Gamut);
}
int main(int argc, char** argv) {
sk_sp<SkImage> image = GetResourceAsImage("flutter_logo.jpg");
if (!image) {
SkDebugf("Cannot find flutter_logo.jpg in resources.\n");
return 1;
}
// Encode an image with a gbr color space.
SkImageInfo info = SkImageInfo::MakeN32(image->width(), image->height(), kOpaque_SkAlphaType,
gbr_color_space());
size_t rowBytes = info.minRowBytes();
SkAutoTMalloc<uint8_t> storage(rowBytes * image->height());
SkPixmap src(info, storage.get(), rowBytes);
image->readPixels(src, 0, 0, SkImage::kDisallow_CachingHint);
SkFILEWStream dst0("gbr.png");
SkPngEncoder::Options opts;
opts.fUnpremulBehavior = SkTransferFunctionBehavior::kIgnore; // Does not matter for opaque src
SkAssertResult(SkPngEncoder::Encode(&dst0, src, opts));
// Encode an image with steep transfer function.
src.setColorSpace(tf_color_space());
image->readPixels(src, 0, 0, SkImage::kDisallow_CachingHint);
SkFILEWStream dst1("tf.png");
SkAssertResult(SkPngEncoder::Encode(&dst1, src, opts));
// Encode a wide gamut image.
src.setColorSpace(wide_gamut_color_space());
image->readPixels(src, 0, 0, SkImage::kDisallow_CachingHint);
SkFILEWStream dst2("wide-gamut.png");
SkAssertResult(SkPngEncoder::Encode(&dst2, src, opts));
return 0;
}
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