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Diffstat (limited to 'third_party/jpeg-xl/lib/jxl/alpha_test.cc')
| -rw-r--r-- | third_party/jpeg-xl/lib/jxl/alpha_test.cc | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/third_party/jpeg-xl/lib/jxl/alpha_test.cc b/third_party/jpeg-xl/lib/jxl/alpha_test.cc new file mode 100644 index 0000000000..ddafd829ec --- /dev/null +++ b/third_party/jpeg-xl/lib/jxl/alpha_test.cc @@ -0,0 +1,134 @@ +// 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/alpha.h" + +#include "lib/jxl/test_utils.h" +#include "lib/jxl/testing.h" + +namespace jxl { +namespace { + +using ::testing::_; +using ::testing::ElementsAre; +using ::testing::FloatNear; + +TEST(AlphaTest, BlendingWithNonPremultiplied) { + const float bg_rgb[3] = {100, 110, 120}; + const float bg_a = 180.f / 255; + const float fg_rgb[3] = {25, 21, 23}; + const float fg_a = 15420.f / 65535; + const float fg_a2 = 2.0f; + float out_rgb[3]; + float out_a; + PerformAlphaBlending( + /*bg=*/{&bg_rgb[0], &bg_rgb[1], &bg_rgb[2], &bg_a}, + /*fg=*/{&fg_rgb[0], &fg_rgb[1], &fg_rgb[2], &fg_a}, + /*out=*/{&out_rgb[0], &out_rgb[1], &out_rgb[2], &out_a}, 1, + /*alpha_is_premultiplied=*/false, /*clamp=*/false); + EXPECT_THAT(out_rgb, + ElementsAre(FloatNear(77.2f, .05f), FloatNear(83.0f, .05f), + FloatNear(90.6f, .05f))); + EXPECT_NEAR(out_a, 3174.f / 4095, 1e-5); + PerformAlphaBlending( + /*bg=*/{&bg_rgb[0], &bg_rgb[1], &bg_rgb[2], &bg_a}, + /*fg=*/{&fg_rgb[0], &fg_rgb[1], &fg_rgb[2], &fg_a2}, + /*out=*/{&out_rgb[0], &out_rgb[1], &out_rgb[2], &out_a}, 1, + /*alpha_is_premultiplied=*/false, /*clamp=*/true); + EXPECT_THAT(out_rgb, ElementsAre(FloatNear(fg_rgb[0], .05f), + FloatNear(fg_rgb[1], .05f), + FloatNear(fg_rgb[2], .05f))); + EXPECT_NEAR(out_a, 1.0f, 1e-5); +} + +TEST(AlphaTest, BlendingWithPremultiplied) { + const float bg_rgb[3] = {100, 110, 120}; + const float bg_a = 180.f / 255; + const float fg_rgb[3] = {25, 21, 23}; + const float fg_a = 15420.f / 65535; + const float fg_a2 = 2.0f; + float out_rgb[3]; + float out_a; + PerformAlphaBlending( + /*bg=*/{&bg_rgb[0], &bg_rgb[1], &bg_rgb[2], &bg_a}, + /*fg=*/{&fg_rgb[0], &fg_rgb[1], &fg_rgb[2], &fg_a}, + /*out=*/{&out_rgb[0], &out_rgb[1], &out_rgb[2], &out_a}, 1, + /*alpha_is_premultiplied=*/true, /*clamp=*/false); + EXPECT_THAT(out_rgb, + ElementsAre(FloatNear(101.5f, .05f), FloatNear(105.1f, .05f), + FloatNear(114.8f, .05f))); + EXPECT_NEAR(out_a, 3174.f / 4095, 1e-5); + PerformAlphaBlending( + /*bg=*/{&bg_rgb[0], &bg_rgb[1], &bg_rgb[2], &bg_a}, + /*fg=*/{&fg_rgb[0], &fg_rgb[1], &fg_rgb[2], &fg_a2}, + /*out=*/{&out_rgb[0], &out_rgb[1], &out_rgb[2], &out_a}, 1, + /*alpha_is_premultiplied=*/true, /*clamp=*/true); + EXPECT_THAT(out_rgb, ElementsAre(FloatNear(fg_rgb[0], .05f), + FloatNear(fg_rgb[1], .05f), + FloatNear(fg_rgb[2], .05f))); + EXPECT_NEAR(out_a, 1.0f, 1e-5); +} + +TEST(AlphaTest, Mul) { + const float bg = 100; + const float fg = 25; + float out; + PerformMulBlending(&bg, &fg, &out, 1, /*clamp=*/false); + EXPECT_THAT(out, FloatNear(fg * bg, .05f)); + PerformMulBlending(&bg, &fg, &out, 1, /*clamp=*/true); + EXPECT_THAT(out, FloatNear(bg, .05f)); +} + +TEST(AlphaTest, PremultiplyAndUnpremultiply) { + const float alpha[] = {0.f, 63.f / 255, 127.f / 255, 1.f}; + float r[] = {120, 130, 140, 150}; + float g[] = {124, 134, 144, 154}; + float b[] = {127, 137, 147, 157}; + + PremultiplyAlpha(r, g, b, alpha, 4); + EXPECT_THAT( + r, ElementsAre(FloatNear(0.f, 1e-5f), FloatNear(130 * 63.f / 255, 1e-5f), + FloatNear(140 * 127.f / 255, 1e-5f), 150)); + EXPECT_THAT( + g, ElementsAre(FloatNear(0.f, 1e-5f), FloatNear(134 * 63.f / 255, 1e-5f), + FloatNear(144 * 127.f / 255, 1e-5f), 154)); + EXPECT_THAT( + b, ElementsAre(FloatNear(0.f, 1e-5f), FloatNear(137 * 63.f / 255, 1e-5f), + FloatNear(147 * 127.f / 255, 1e-5f), 157)); + + UnpremultiplyAlpha(r, g, b, alpha, 4); + EXPECT_THAT(r, ElementsAre(FloatNear(120, 1e-4f), FloatNear(130, 1e-4f), + FloatNear(140, 1e-4f), FloatNear(150, 1e-4f))); + EXPECT_THAT(g, ElementsAre(FloatNear(124, 1e-4f), FloatNear(134, 1e-4f), + FloatNear(144, 1e-4f), FloatNear(154, 1e-4f))); + EXPECT_THAT(b, ElementsAre(FloatNear(127, 1e-4f), FloatNear(137, 1e-4f), + FloatNear(147, 1e-4f), FloatNear(157, 1e-4f))); +} + +TEST(AlphaTest, UnpremultiplyAndPremultiply) { + const float alpha[] = {0.f, 63.f / 255, 127.f / 255, 1.f}; + float r[] = {50, 60, 70, 80}; + float g[] = {54, 64, 74, 84}; + float b[] = {57, 67, 77, 87}; + + UnpremultiplyAlpha(r, g, b, alpha, 4); + EXPECT_THAT(r, ElementsAre(_, FloatNear(60 * 255.f / 63, 1e-4f), + FloatNear(70 * 255.f / 127, 1e-4f), 80)); + EXPECT_THAT(g, ElementsAre(_, FloatNear(64 * 255.f / 63, 1e-4f), + FloatNear(74 * 255.f / 127, 1e-4f), 84)); + EXPECT_THAT(b, ElementsAre(_, FloatNear(67 * 255.f / 63, 1e-4f), + FloatNear(77 * 255.f / 127, 1e-4f), 87)); + + PremultiplyAlpha(r, g, b, alpha, 4); + EXPECT_THAT(r, ElementsAre(FloatNear(50, 1e-4f), FloatNear(60, 1e-4f), + FloatNear(70, 1e-4f), FloatNear(80, 1e-4f))); + EXPECT_THAT(g, ElementsAre(FloatNear(54, 1e-4f), FloatNear(64, 1e-4f), + FloatNear(74, 1e-4f), FloatNear(84, 1e-4f))); + EXPECT_THAT(b, ElementsAre(FloatNear(57, 1e-4f), FloatNear(67, 1e-4f), + FloatNear(77, 1e-4f), FloatNear(87, 1e-4f))); +} + +} // namespace +} // namespace jxl |