if (space == COLORSPACE_XYZ) {
return Matrix3d::Identity();
}
+ if (space == COLORSPACE_sRGB) {
+ // sRGB is not defined by the color primaries, but by concrete
+ // forward and inverse matrices that are rounded-off versions
+ // of the Rec. 709 color space (see
+ // https://photosauce.net/blog/post/what-makes-srgb-a-special-color-space).
+ // We're not compliant with the inverse matrix, since we'd be
+ // too accurate (sRGB is specified for 8-bit only); however,
+ // results should be very close in practice (and even closer to
+ // scRGB's inverse matrix, which is a higher-accuracy inversion of
+ // the same forward matrix).
+ return Matrix3d{
+ { 0.4124, 0.3576, 0.1805 },
+ { 0.2126, 0.7152, 0.0722 },
+ { 0.0193, 0.1192, 0.9505 }
+ };
+ }
double x_R, x_G, x_B;
double y_R, y_G, y_B;
switch (space) {
- case COLORSPACE_REC_709: // And sRGB.
+ case COLORSPACE_REC_709:
x_R = rec709_x_R; x_G = rec709_x_G; x_B = rec709_x_B;
y_R = rec709_y_R; y_G = rec709_y_G; y_B = rec709_y_B;
break;