+TEST(YCbCrTest, WikipediaRec601ForwardMatrix) {
+ YCbCrFormat ycbcr_format;
+ ycbcr_format.luma_coefficients = YCBCR_REC_601;
+ ycbcr_format.full_range = false;
+ ycbcr_format.num_levels = 256;
+
+ float offset[3];
+ Eigen::Matrix3d ycbcr_to_rgb;
+ compute_ycbcr_matrix(ycbcr_format, offset, &ycbcr_to_rgb);
+
+ Eigen::Matrix3d rgb_to_ycbcr = ycbcr_to_rgb.inverse() * 255.0;
+
+ // Values from https://en.wikipedia.org/wiki/YCbCr#ITU-R_BT.601_conversion.
+ EXPECT_NEAR( 65.481, rgb_to_ycbcr(0,0), 1e-3);
+ EXPECT_NEAR( 128.553, rgb_to_ycbcr(0,1), 1e-3);
+ EXPECT_NEAR( 24.966, rgb_to_ycbcr(0,2), 1e-3);
+
+ EXPECT_NEAR( -37.797, rgb_to_ycbcr(1,0), 1e-3);
+ EXPECT_NEAR( -74.203, rgb_to_ycbcr(1,1), 1e-3);
+ EXPECT_NEAR( 112.000, rgb_to_ycbcr(1,2), 1e-3);
+
+ EXPECT_NEAR( 112.000, rgb_to_ycbcr(2,0), 1e-3);
+ EXPECT_NEAR( -93.786, rgb_to_ycbcr(2,1), 1e-3);
+ EXPECT_NEAR( -18.214, rgb_to_ycbcr(2,2), 1e-3);
+
+ EXPECT_NEAR( 16.0, offset[0] * 255.0, 1e-3);
+ EXPECT_NEAR(128.0, offset[1] * 255.0, 1e-3);
+ EXPECT_NEAR(128.0, offset[2] * 255.0, 1e-3);
+}
+
+TEST(YCbCrTest, WikipediaJPEGMatrices) {
+ YCbCrFormat ycbcr_format;
+ ycbcr_format.luma_coefficients = YCBCR_REC_601;
+ ycbcr_format.full_range = true;
+ ycbcr_format.num_levels = 256;
+
+ float offset[3];
+ Eigen::Matrix3d ycbcr_to_rgb;
+ compute_ycbcr_matrix(ycbcr_format, offset, &ycbcr_to_rgb);
+
+ // Values from https://en.wikipedia.org/wiki/YCbCr#JPEG_conversion.
+ EXPECT_NEAR( 1.00000, ycbcr_to_rgb(0,0), 1e-5);
+ EXPECT_NEAR( 0.00000, ycbcr_to_rgb(0,1), 1e-5);
+ EXPECT_NEAR( 1.40200, ycbcr_to_rgb(0,2), 1e-5);
+
+ EXPECT_NEAR( 1.00000, ycbcr_to_rgb(1,0), 1e-5);
+ EXPECT_NEAR(-0.34414, ycbcr_to_rgb(1,1), 1e-5);
+ EXPECT_NEAR(-0.71414, ycbcr_to_rgb(1,2), 1e-5);
+
+ EXPECT_NEAR( 1.00000, ycbcr_to_rgb(2,0), 1e-5);
+ EXPECT_NEAR( 1.77200, ycbcr_to_rgb(2,1), 1e-5);
+ EXPECT_NEAR( 0.00000, ycbcr_to_rgb(2,2), 1e-5);
+
+ Eigen::Matrix3d rgb_to_ycbcr = ycbcr_to_rgb.inverse();
+
+ // Same.
+ EXPECT_NEAR( 0.299000, rgb_to_ycbcr(0,0), 1e-6);
+ EXPECT_NEAR( 0.587000, rgb_to_ycbcr(0,1), 1e-6);
+ EXPECT_NEAR( 0.114000, rgb_to_ycbcr(0,2), 1e-6);
+
+ EXPECT_NEAR(-0.168736, rgb_to_ycbcr(1,0), 1e-6);
+ EXPECT_NEAR(-0.331264, rgb_to_ycbcr(1,1), 1e-6);
+ EXPECT_NEAR( 0.500000, rgb_to_ycbcr(1,2), 1e-6);
+
+ EXPECT_NEAR( 0.500000, rgb_to_ycbcr(2,0), 1e-6);
+ EXPECT_NEAR(-0.418688, rgb_to_ycbcr(2,1), 1e-6);
+ EXPECT_NEAR(-0.081312, rgb_to_ycbcr(2,2), 1e-6);
+
+ EXPECT_NEAR( 0.0, offset[0] * 255.0, 1e-3);
+ EXPECT_NEAR(128.0, offset[1] * 255.0, 1e-3);
+ EXPECT_NEAR(128.0, offset[2] * 255.0, 1e-3);
+}
+