Merge "Add color space connection" (c34e059b) · Commits · e / os / platform_frameworks_native

include/ui/ColorSpace.h

+25 −0

Original line number	Diff line number	Diff line
		@@ -20,6 +20,7 @@
		#include <array>
		#include <cmath>
		#include <functional>
		#include <memory>
		#include <string>

		#include <ui/mat3.h>
		@@ -165,6 +166,30 @@ public:
		static const ColorSpace ACES();
		static const ColorSpace ACEScg();

		class Connector {
		public:
		Connector(const ColorSpace& src, const ColorSpace& dst) noexcept;

		constexpr const ColorSpace& getSource() const noexcept { return mSource; }
		constexpr const ColorSpace& getDestination() const noexcept { return mDestination; }

		constexpr const mat3& getTransform() const noexcept { return mTransform; }

		constexpr float3 transform(const float3& v) const noexcept {
		float3 linear = mSource.toLinear(apply(v, mSource.getClamper()));
		return apply(mDestination.fromLinear(mTransform * linear), mDestination.getClamper());
		}

		private:
		const ColorSpace& mSource;
		const ColorSpace& mDestination;
		mat3 mTransform;
		};

		static const Connector connect(const ColorSpace& src, const ColorSpace& dst) {
		return Connector(src, dst);
		}

		private:
		static constexpr mat3 computeXYZMatrix(
		const std::array<float2, 3>& primaries, const float2& whitePoint);

libs/ui/ColorSpace.cpp

+50 −5

Original line number	Diff line number	Diff line
		@@ -96,6 +96,47 @@ constexpr mat3 ColorSpace::computeXYZMatrix(
		};
		}

		static const float2 ILLUMINANT_D50_XY = {0.34567f, 0.35850f};
		static const float3 ILLUMINANT_D50_XYZ = {0.964212f, 1.0f, 0.825188f};
		static const mat3 VON_KRIES = mat3{
		float3{ 0.8951f, -0.7502f, 0.0389f},
		float3{ 0.2664f, 1.7135f, -0.0685f},
		float3{-0.1614f, 0.0367f, 1.0296f}
		};

		static mat3 adaptation(const mat3& matrix, const float3& srcWhitePoint, const float3& dstWhitePoint) {
		float3 srcLMS = matrix * srcWhitePoint;
		float3 dstLMS = matrix * dstWhitePoint;
		return inverse(matrix) * mat3{dstLMS / srcLMS} * matrix;
		}

		ColorSpace::Connector::Connector(
		const ColorSpace& src,
		const ColorSpace& dst) noexcept
		: mSource(src)
		, mDestination(dst) {

		if (all(lessThan(abs(src.getWhitePoint() - dst.getWhitePoint()), float2{1e-3f}))) {
		mTransform = dst.getXYZtoRGB() * src.getRGBtoXYZ();
		} else {
		mat3 rgbToXYZ(src.getRGBtoXYZ());
		mat3 xyzToRGB(dst.getXYZtoRGB());

		float3 srcXYZ = XYZ(float3{src.getWhitePoint(), 1});
		float3 dstXYZ = XYZ(float3{dst.getWhitePoint(), 1});

		if (any(greaterThan(abs(src.getWhitePoint() - ILLUMINANT_D50_XY), float2{1e-3f}))) {
		rgbToXYZ = adaptation(VON_KRIES, srcXYZ, ILLUMINANT_D50_XYZ) * src.getRGBtoXYZ();
		}

		if (any(greaterThan(abs(dst.getWhitePoint() - ILLUMINANT_D50_XY), float2{1e-3f}))) {
		xyzToRGB = inverse(adaptation(VON_KRIES, dstXYZ, ILLUMINANT_D50_XYZ) * dst.getRGBtoXYZ());
		}

		mTransform = xyzToRGB * rgbToXYZ;
		}
		}

		static constexpr float rcpResponse(float x, float g,float a, float b, float c, float d) {
		return x >= d * c ? (std::pow(x, 1.0f / g) - b) / a : x / c;
		}
		@@ -112,6 +153,10 @@ static float absResponse(float x, float g, float a, float b, float c, float d) {
		return std::copysign(response(std::abs(x), g, a, b, c, d), x);
		}

		static float safePow(float x, float e) {
		return powf(x < 0.0f ? 0.0f : x, e);
		}

		const ColorSpace ColorSpace::sRGB() {
		return {
		"sRGB IEC61966-2.1",
		@@ -187,8 +232,8 @@ const ColorSpace ColorSpace::AdobeRGB() {
		"Adobe RGB (1998)",
		{{float2{0.64f, 0.33f}, {0.21f, 0.71f}, {0.15f, 0.06f}}},
		{0.3127f, 0.3290f},
		std::bind(powf, _1, 1.0f / 2.2f),
		std::bind(powf, _1, 2.2f)
		std::bind(safePow, _1, 1.0f / 2.2f),
		std::bind(safePow, _1, 2.2f)
		};
		}

		@@ -196,7 +241,7 @@ const ColorSpace ColorSpace::ProPhotoRGB() {
		return {
		"ROMM RGB ISO 22028-2:2013",
		{{float2{0.7347f, 0.2653f}, {0.1596f, 0.8404f}, {0.0366f, 0.0001f}}},
		{0.3457f, 0.3585f},
		{0.34567f, 0.35850f},
		std::bind(rcpResponse, _1, 1.8f, 1.0f, 0.0f, 1 / 16.0f, 0.031248f),
		std::bind(response, _1, 1.8f, 1.0f, 0.0f, 1 / 16.0f, 0.031248f)
		};
		@@ -217,8 +262,8 @@ const ColorSpace ColorSpace::DCIP3() {
		"SMPTE RP 431-2-2007 DCI (P3)",
		{{float2{0.680f, 0.320f}, {0.265f, 0.690f}, {0.150f, 0.060f}}},
		{0.314f, 0.351f},
		std::bind(powf, _1, 1.0f / 2.6f),
		std::bind(powf, _1, 2.6f)
		std::bind(safePow, _1, 1.0f / 2.6f),
		std::bind(safePow, _1, 2.6f)
		};
		}

libs/ui/tests/colorspace_test.cpp

+12 −0

Original line number	Diff line number	Diff line
		@@ -150,4 +150,16 @@ TEST_F(ColorSpaceTest, Clamping) {
		EXPECT_TRUE(extendedSRGB.g > 1.0f);
		}

		TEST_F(ColorSpaceTest, Connect) {
		// No chromatic adaptation
		auto r = ColorSpace::connect(ColorSpace::sRGB(), ColorSpace::AdobeRGB())
		.transform({1.0f, 0.5f, 0.0f});
		EXPECT_TRUE(all(lessThan(abs(r - float3{0.8912f, 0.4962f, 0.1164f}), float3{1e-4f})));

		// Test with chromatic adaptation
		r = ColorSpace::connect(ColorSpace::sRGB(), ColorSpace::ProPhotoRGB())
		.transform({1.0f, 0.0f, 0.0f});
		EXPECT_TRUE(all(lessThan(abs(r - float3{0.70226f, 0.2757f, 0.1036f}), float3{1e-4f})));
		}

		}; // namespace android