public static unsafe ImageSource RenderLinearGamutLuv(int width, int height, RGBPrimaries <Color1931xyY> primaries, Color1931XYZ white, float leftU, float rightU, float topV, float bottomV)
{
ColorTransformMatrix RGBtoXYZ = ColorTransformMatrix.GetRGBtoXYZ((Color1931XYZ)primaries.Red, (Color1931XYZ)primaries.Green, (Color1931XYZ)primaries.Blue, white);
ColorTransformMatrix XYZtoRGB = RGBtoXYZ.Invert();
return(RenderLinearGamutLuv(width, height, XYZtoRGB, leftU, rightU, topV, bottomV));
}
public static ColorTransformMatrix GetRGBtoXYZ(Color1931XYZ red, Color1931XYZ green, Color1931XYZ blue, Color1931XYZ white)
{
ColorTransformMatrix XYZ = new ColorTransformMatrix(red, green, blue);
ColorTransformMatrix XYZinv = XYZ.Invert();
float Sr, Sg, Sb;
XYZinv.Transform(white.X, white.Y, white.Z, out Sr, out Sg, out Sb);
ColorTransformMatrix M = XYZ;
M.a *= Sr; M.b *= Sg; M.c *= Sb;
M.d *= Sr; M.e *= Sg; M.f *= Sb;
M.g *= Sr; M.h *= Sg; M.i *= Sb;
return(M);
}
// Kaiser, Bonton (1996). Human Color Vision (Second Edition), Appendix, Part IV
public static ColorTransformMatrix GetScaledLMStoDKL(ColorLMS background)
{
ColorTransformMatrix LMStoDKL = new ColorTransformMatrix
(
1, 1, 0,
1, -background.L / background.M, 0,
-1, -1, (background.L + background.M) / background.S
);
ColorTransformMatrix DKLtoLMS = LMStoDKL.Invert();
ColorLMS isolatingIso = new ColorLMS(DKLtoLMS.a, DKLtoLMS.d, DKLtoLMS.g);
float pooledConeContrastIso = (isolatingIso / background).Length;
ColorLMS normalizedIso = isolatingIso / pooledConeContrastIso;
ColorLMS isolatingRGiso = new ColorLMS(DKLtoLMS.b, DKLtoLMS.e, DKLtoLMS.h);
float pooledConeCotnrastRGiso = (isolatingRGiso / background).Length;
ColorLMS normalizedRGiso = isolatingRGiso / pooledConeCotnrastRGiso;
ColorLMS isolatingSiso = new ColorLMS(DKLtoLMS.c, DKLtoLMS.f, DKLtoLMS.i);
float pooledConeContrastSiso = (isolatingSiso / background).Length;
ColorLMS normalizedSiso = isolatingSiso / pooledConeContrastSiso;
ColorDKL unitResponse;
LMStoDKL.Transform(normalizedIso.L, normalizedIso.M, normalizedIso.S, out unitResponse.Isochromatic, out _, out _);
LMStoDKL.Transform(normalizedRGiso.L, normalizedRGiso.M, normalizedRGiso.S, out _, out unitResponse.RGisoluminant, out _);
LMStoDKL.Transform(normalizedSiso.L, normalizedSiso.M, normalizedSiso.S, out _, out _, out unitResponse.Sisoluminant);
ColorTransformMatrix rescaler = new ColorTransformMatrix
(
1 / unitResponse.Isochromatic, 0, 0,
0, 1 / unitResponse.RGisoluminant, 0,
0, 0, 1 / unitResponse.Sisoluminant
);
return(rescaler * LMStoDKL);
}
