#include <assert.h>
-
+#include <Eigen/Core>
#include <Eigen/LU>
#include "colorspace_conversion_effect.h"
+#include "d65.h"
#include "util.h"
using namespace Eigen;
+using namespace std;
// Color coordinates from Rec. 709; sRGB uses the same primaries.
-double rec709_x_R = 0.640, rec709_x_G = 0.300, rec709_x_B = 0.150;
-double rec709_y_R = 0.330, rec709_y_G = 0.600, rec709_y_B = 0.060;
+static const double rec709_x_R = 0.640, rec709_x_G = 0.300, rec709_x_B = 0.150;
+static const double rec709_y_R = 0.330, rec709_y_G = 0.600, rec709_y_B = 0.060;
// Color coordinates from Rec. 601. (Separate for 525- and 625-line systems.)
-double rec601_525_x_R = 0.630, rec601_525_x_G = 0.310, rec601_525_x_B = 0.155;
-double rec601_525_y_R = 0.340, rec601_525_y_G = 0.595, rec601_525_y_B = 0.070;
-double rec601_625_x_R = 0.640, rec601_625_x_G = 0.290, rec601_625_x_B = 0.150;
-double rec601_625_y_R = 0.330, rec601_625_y_G = 0.600, rec601_625_y_B = 0.060;
+static const double rec601_525_x_R = 0.630, rec601_525_x_G = 0.310, rec601_525_x_B = 0.155;
+static const double rec601_525_y_R = 0.340, rec601_525_y_G = 0.595, rec601_525_y_B = 0.070;
+static const double rec601_625_x_R = 0.640, rec601_625_x_G = 0.290, rec601_625_x_B = 0.150;
+static const double rec601_625_y_R = 0.330, rec601_625_y_G = 0.600, rec601_625_y_B = 0.060;
-// The D65 white point. Given in both Rec. 601 and 709.
-double d65_x = 0.3127, d65_y = 0.3290;
+// Color coordinates from Rec. 2020.
+static const double rec2020_x_R = 0.708, rec2020_x_G = 0.170, rec2020_x_B = 0.131;
+static const double rec2020_y_R = 0.292, rec2020_y_G = 0.797, rec2020_y_B = 0.046;
ColorspaceConversionEffect::ColorspaceConversionEffect()
: source_space(COLORSPACE_sRGB),
register_int("destination_space", (int *)&destination_space);
}
-Matrix3d get_xyz_matrix(Colorspace space)
+Matrix3d ColorspaceConversionEffect::get_xyz_matrix(Colorspace space)
{
if (space == COLORSPACE_XYZ) {
return Matrix3d::Identity();
x_R = rec601_625_x_R; x_G = rec601_625_x_G; x_B = rec601_625_x_B;
y_R = rec601_625_y_R; y_G = rec601_625_y_G; y_B = rec601_625_y_B;
break;
+ case COLORSPACE_REC_2020:
+ x_R = rec2020_x_R; x_G = rec2020_x_G; x_B = rec2020_x_B;
+ y_R = rec2020_y_R; y_G = rec2020_y_G; y_B = rec2020_y_B;
+ break;
default:
assert(false);
}
double z_G = 1.0 - x_G - y_G;
double z_B = 1.0 - x_B - y_B;
- // Find the XYZ coordinates of D65 (white point for both Rec. 601 and 709),
- // normalized so that Y=1.
- Vector3d d65_XYZ(
- d65_x / d65_y,
- 1.0,
- (1.0 - d65_x - d65_y) / d65_y
- );
-
// We have, for each primary (example is with red):
//
// X_R / (X_R + Y_R + Z_R) = x_R
//
// Some algebraic fiddling yields (unsurprisingly):
//
- // X_R = (x_R / y_R) Y_R
- // Z_R = (z_R / y_R) Y_R
+ // X_R = (x_R / y_R) Y_R (so define k1 = x_R / y_R)
+ // Z_R = (z_R / y_R) Y_R (so define k4 = z_R / y_R)
//
// We also know that since RGB=(1,1,1) should give us the
// D65 illuminant, we must have
// Y_R + Y_G + Y_B = D65_Y
// Z_R + Z_G + Z_B = D65_Z
//
- // But since we already know how to express Y and Z by
- // some constant multiple of X, this reduces to
+ // But since we already know how to express X and Z by
+ // some constant multiple of Y, this reduces to
//
// k1 Y_R + k2 Y_G + k3 Y_B = D65_X
// Y_R + Y_G + Y_B = D65_Y
temp(2,1) = z_G / y_G;
temp(2,2) = z_B / y_B;
+ Vector3d d65_XYZ(d65_X, d65_Y, d65_Z);
Vector3d Y_RGB = temp.inverse() * d65_XYZ;
// Now convert xyY -> XYZ.
return m;
}
-std::string ColorspaceConversionEffect::output_fragment_shader()
+string ColorspaceConversionEffect::output_fragment_shader()
{
// Create a matrix to convert from source space -> XYZ,
// another matrix to convert from XYZ -> destination space,