skia2/tests/ColorSpaceTest.cpp
msarett 2c3eca38c9 Approximate common gamma tables as single values
This should improve performance of gamma conversion in
software (we can use vector math instead of table look
ups).

Additionally this allows us to quickly and easily
identify sRGB-like gammas.

On gpu, identifying sRGB gamma improves performance/memory,
because the hardware may support gamma conversion.

This will help us identify situations where gamma
conversion is not necessary.
Ex: sRGB input -> sRGB display

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1950183006

Review-Url: https://codereview.chromium.org/1950183006
2016-05-09 14:27:49 -07:00

122 lines
4.1 KiB
C++

/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "Resources.h"
#include "SkCodec.h"
#include "SkColorSpace.h"
#include "Test.h"
#include "png.h"
static bool almost_equal(float a, float b) {
return SkTAbs(a - b) < 0.001f;
}
static void test_space(skiatest::Reporter* r, SkColorSpace* space,
const float red[], const float green[], const float blue[],
const float expectedGammas[]) {
#ifdef SK_DEBUG
const SkColorSpace::SkGammas& gammas = space->gammas();
REPORTER_ASSERT(r, almost_equal(expectedGammas[0], gammas.red()));
REPORTER_ASSERT(r, almost_equal(expectedGammas[1], gammas.green()));
REPORTER_ASSERT(r, almost_equal(expectedGammas[2], gammas.blue()));
#endif
SkMatrix44 mat = space->xyz();
const float src[] = {
1, 0, 0, 1,
0, 1, 0, 1,
0, 0, 1, 1,
};
float dst[4];
for (int i = 0; i < 3; ++i) {
mat.mapScalars(&src[i*4], dst);
REPORTER_ASSERT(r, almost_equal(red[i], dst[0]));
REPORTER_ASSERT(r, almost_equal(green[i], dst[1]));
REPORTER_ASSERT(r, almost_equal(blue[i], dst[2]));
}
}
const float g_sRGB_XYZ[] = { 0.4358f, 0.2224f, 0.0139f, // R
0.3853f, 0.7170f, 0.0971f, // G
0.1430f, 0.0606f, 0.7139f }; // B
DEF_TEST(ColorSpace_sRGB, r) {
const float srgb_gamma[] = { 2.2f, 2.2f, 2.2f };
test_space(r, SkColorSpace::NewNamed(SkColorSpace::kSRGB_Named).get(),
g_sRGB_XYZ, &g_sRGB_XYZ[3], &g_sRGB_XYZ[6], srgb_gamma);
}
static SkStreamAsset* resource(const char path[]) {
SkString fullPath = GetResourcePath(path);
return SkStream::NewFromFile(fullPath.c_str());
}
DEF_TEST(ColorSpaceParsePngICCProfile, r) {
SkAutoTDelete<SkStream> stream(resource("color_wheel_with_profile.png"));
REPORTER_ASSERT(r, nullptr != stream);
if (!stream) {
return;
}
SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream.release()));
REPORTER_ASSERT(r, nullptr != codec);
#if (PNG_LIBPNG_VER_MAJOR > 1) || (PNG_LIBPNG_VER_MAJOR == 1 && PNG_LIBPNG_VER_MINOR >= 6)
SkColorSpace* colorSpace = codec->getColorSpace();
REPORTER_ASSERT(r, nullptr != colorSpace);
const float red[] = { 0.436066f, 0.222488f, 0.013916f };
const float green[] = { 0.385147f, 0.716873f, 0.0970764f };
const float blue[] = { 0.143066f, 0.0606079f, 0.714096f };
const float gamma[] = { 2.2f, 2.2f, 2.2f };
test_space(r, colorSpace, red, green, blue, gamma);
#endif
}
DEF_TEST(ColorSpaceParseJpegICCProfile, r) {
SkAutoTDelete<SkStream> stream(resource("icc-v2-gbr.jpg"));
REPORTER_ASSERT(r, nullptr != stream);
if (!stream) {
return;
}
SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream.release()));
REPORTER_ASSERT(r, nullptr != codec);
if (!codec) {
return;
}
SkColorSpace* colorSpace = codec->getColorSpace();
REPORTER_ASSERT(r, nullptr != colorSpace);
const float red[] = { 0.385117f, 0.716904f, 0.0970612f };
const float green[] = { 0.143051f, 0.0606079f, 0.713913f };
const float blue[] = { 0.436035f, 0.222488f, 0.013916f };
const float gamma[] = { 2.2f, 2.2f, 2.2f };
test_space(r, colorSpace, red, green, blue, gamma);
}
DEF_TEST(ColorSpaceSRGBCompare, r) {
// Create an sRGB color space by name
sk_sp<SkColorSpace> namedColorSpace = SkColorSpace::NewNamed(SkColorSpace::kSRGB_Named);
// Create an sRGB color space by value
SkMatrix44 srgbToxyzD50(SkMatrix44::kUninitialized_Constructor);
srgbToxyzD50.set3x3ColMajorf(g_sRGB_XYZ);
sk_sp<SkColorSpace> rgbColorSpace = SkColorSpace::NewRGB(
SkColorSpace::SkGammas(2.2f, 2.2f, 2.2f), srgbToxyzD50);
REPORTER_ASSERT(r, namedColorSpace == namedColorSpace);
// Change a single value from the sRGB matrix
srgbToxyzD50.set(2, 2, 0.5f);
sk_sp<SkColorSpace> strangeColorSpace = SkColorSpace::NewRGB(
SkColorSpace::SkGammas(2.2f, 2.2f, 2.2f), srgbToxyzD50);
REPORTER_ASSERT(r, strangeColorSpace != namedColorSpace);
}