-// Note: This file does not have its own unit test; it is tested mainly
-// through YCbCrInput's unit tests.
+// Note: These functions are tested in ycbcr_input_test.cpp; both through some
+// direct matrix tests, but most of all through YCbCrInput's unit tests.
#include <Eigen/Core>
#include <Eigen/LU>
rgb_to_ycbcr(0,1) = coeff[1];
rgb_to_ycbcr(0,2) = coeff[2];
- float cb_fac = (224.0 / 219.0) / (coeff[0] + coeff[1] + 1.0f - coeff[2]);
+ float cb_fac = 1.0 / (coeff[0] + coeff[1] + 1.0f - coeff[2]);
rgb_to_ycbcr(1,0) = -coeff[0] * cb_fac;
rgb_to_ycbcr(1,1) = -coeff[1] * cb_fac;
rgb_to_ycbcr(1,2) = (1.0f - coeff[2]) * cb_fac;
- float cr_fac = (224.0 / 219.0) / (1.0f - coeff[0] + coeff[1] + coeff[2]);
+ float cr_fac = 1.0 / (1.0f - coeff[0] + coeff[1] + coeff[2]);
rgb_to_ycbcr(2,0) = (1.0f - coeff[0]) * cr_fac;
rgb_to_ycbcr(2,1) = -coeff[1] * cr_fac;
rgb_to_ycbcr(2,2) = -coeff[2] * cr_fac;
-// Unit tests for YCbCrInput.
+// Unit tests for YCbCrInput. Also tests the matrix functions in ycbcr.cpp directly.
#include <epoxy/gl.h>
#include <stddef.h>
+#include <Eigen/Core>
+#include <Eigen/LU>
+
#include "effect_chain.h"
#include "gtest/gtest.h"
#include "test_util.h"
// Y'CbCr isn't 100% accurate (the input values are rounded),
// so we need some leeway.
- expect_equal(expected_data, out_data, width, height, 0.01, 0.001);
+ expect_equal(expected_data, out_data, width, height, 0.01, 0.0012);
}
// Yes, some 4:2:2 formats actually have this craziness.
expect_equal(expected_data, out_data, 4 * width, height, 0.025, 0.002);
}
+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);
+}
+
} // namespace movit