public static Color1931XYZ ToXYZ(this ColorRGB RGB, ColorTransformMatrix RGBtoXYZ)
{
Color1931XYZ XYZ = default(Color1931XYZ);
RGBtoXYZ.Transform(RGB.R, RGB.G, RGB.B, out XYZ.X, out XYZ.Y, out XYZ.Z);
return(XYZ);
}
public static ColorRGB ToRGB(this Color1931XYZ XYZ, ColorTransformMatrix XYZtoRGB)
{
ColorRGB RGB = default(ColorRGB);
XYZtoRGB.Transform(XYZ.X, XYZ.Y, XYZ.Z, out RGB.R, out RGB.G, out RGB.B);
return(RGB);
}
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));
}
internal static ColorLMS ToLMS(this Color1931XYZ XYZ, ref ColorTransformMatrix XYZtoLMS)
{
ColorLMS LMS;
XYZtoLMS.Transform(XYZ.X, XYZ.Y, XYZ.Z, out LMS.L, out LMS.M, out LMS.S);
return(LMS);
}
internal static void XYZtoDKL(Color1931XYZ stimulus, ColorLMS backgroundLMS, ref ColorTransformMatrix XYZtoLMS, ref ColorTransformMatrix LMStoDKL, out ColorDKL dkl)
{
ColorLMS stimulusLMS;
XYZtoLMS.Transform(stimulus.X, stimulus.Y, stimulus.Z, out stimulusLMS.L, out stimulusLMS.M, out stimulusLMS.S);
ColorLMS deltaLMS = stimulusLMS - backgroundLMS;
LMStoDKL.Transform(deltaLMS.L, deltaLMS.M, deltaLMS.S, out dkl.Isochromatic, out dkl.RGisoluminant, out dkl.Sisoluminant);
}
internal static void DKLtoXYZ(ColorDKL dkl, ColorLMS backgroundLMS, ref ColorTransformMatrix DKLtoLMS, ref ColorTransformMatrix LMStoXYZ, out Color1931XYZ xyz)
{
ColorLMS diffLMS;
DKLtoLMS.Transform(dkl.Isochromatic, dkl.RGisoluminant, dkl.Sisoluminant, out diffLMS.L, out diffLMS.M, out diffLMS.S);
ColorLMS stimulusLMS = diffLMS + backgroundLMS;
LMStoXYZ.Transform(stimulusLMS.L, stimulusLMS.M, stimulusLMS.S, out xyz.X, out xyz.Y, out xyz.Z);
}
public ColorTransformMatrix Invert(int iterations)
{
ColorTransformMatrix inverse = Invert();
for (int i = 0; i < iterations; i++)
{
inverse = inverse * (2 * Identity - this * inverse);
}
return(inverse);
}
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);
}
private static void Solve(float x1, float x2, float x3, ColorRGB rgb1, ColorRGB rgb2, ColorRGB rgb3, out float m1, out float m2, out float m3)
{
// Cramer's rule
ColorTransformMatrix A = new ColorTransformMatrix
(
rgb1.R, rgb1.G, rgb1.B,
rgb2.R, rgb2.G, rgb2.B,
rgb3.R, rgb3.G, rgb3.B
);
ColorTransformMatrix A1 = new ColorTransformMatrix
(
x1, rgb1.G, rgb1.B,
x2, rgb2.G, rgb2.B,
x3, rgb3.G, rgb3.B
);
ColorTransformMatrix A2 = new ColorTransformMatrix
(
rgb1.R, x1, rgb1.B,
rgb2.R, x2, rgb2.B,
rgb3.R, x3, rgb3.B
);
ColorTransformMatrix A3 = new ColorTransformMatrix
(
rgb1.R, rgb1.G, x1,
rgb2.R, rgb2.G, x2,
rgb3.R, rgb3.G, x3
);
float det = A.Determinant;
m1 = A1.Determinant / det;
m2 = A2.Determinant / det;
m3 = A3.Determinant / det;
}
public static Color1931XYZ ToXYZ(this ColorHSV HSV, ColorTransformMatrix RGBtoXYZ)
{
ColorRGB RGB = ToRGB(HSV);
return(ToXYZ(HSV, RGBtoXYZ));
}
public static unsafe ImageSource RenderLinearGamutLuv(int width, int height, ColorTransformMatrix XYZtoRGB, float leftU, float rightU, float topV, float bottomV)
{
if (width == 0 || height == 0)
{
return(null);
}
const float minVisibleU = 0.001423f;
const float maxVisibleU = 0.6234f;
const float minVisibleV = 0.01592f;
const float maxVisibleV = 0.5868f;
float widthU = rightU - leftU;
float heightV = bottomV - topV;
float uPerPixel = widthU / width;
float vPerPixel = heightV / height;
int pxMinVisibleU = 0; if (uPerPixel != 0)
{
pxMinVisibleU = Math.Max(0, (int)((minVisibleU - leftU) / uPerPixel));
}
int pxMaxVisibleU = width; if (uPerPixel != 0)
{
pxMaxVisibleU = Math.Min(width, (int)((maxVisibleU - leftU) / uPerPixel));
}
int pxMinVisibleV = height; if (vPerPixel != 0)
{
pxMinVisibleV = Math.Min(height, (int)((minVisibleV - topV) / vPerPixel));
}
int pxMaxVisibleV = 0; if (uPerPixel != 0)
{
pxMaxVisibleV = Math.Max(0, (int)((maxVisibleV - topV) / vPerPixel));
}
byte[] data = new byte[width * height * 4];
float R, G, B;
float u, v, x, y;
float X, Y = 1f, Z;
fixed(byte *pData = data)
{
for (int pxV = pxMaxVisibleV; pxV <= pxMinVisibleV; pxV++)
{
for (int pxU = pxMinVisibleU; pxU <= pxMaxVisibleU; pxU++)
{
u = leftU + pxU * uPerPixel;
v = topV + pxV * vPerPixel;
ConvertColor.Fastuv2xy(u, v, out x, out y);
ConvertColor.FastxyY2XYZ(x, y, Y, out X, out Z);
XYZtoRGB.Transform(X, Y, Z, out R, out G, out B);
if (R >= 0 && G >= 0 && B >= 0)
{
byte *pBGR = pData + (pxV * width + pxU) * 4;
pBGR[0] = (byte)Math.Min(255, ConvertColor.scRGBtosRGB(B) * 255); // TODO: handle negative
pBGR[1] = (byte)Math.Min(255, ConvertColor.scRGBtosRGB(G) * 255);
pBGR[2] = (byte)Math.Min(255, ConvertColor.scRGBtosRGB(R) * 255);
pBGR[3] = 255;
}
}
}
}
return(BitmapSource.Create(width, height, 96, 96, PixelFormats.Pbgra32, null, data, width * 4));
}
public static ColorRGB ToRGB(this Chromaticity1976uv uv, ColorTransformMatrix XYZtoRGB)
{
Chromaticity1931xy xy = Toxy(uv);
return(ToRGB(xy, XYZtoRGB));
}
public static ColorRGB ToRGB(this Chromaticity1931xy xy, ColorTransformMatrix XYZtoRGB)
{
Color1931XYZ XYZ = ToXYZ(xy, 1f);
return(ToRGB(XYZ, XYZtoRGB));
}
public static ColorRGB ToRGB(this Color1976LCh LCh, ColorTransformMatrix XYZtoRGB, Color1931XYZ white)
{
return(ToRGB((Color1976Lab)LCh, XYZtoRGB, white));
}
public static ColorRGB ToRGB(this Color1976Lab Lab, ColorTransformMatrix XYZtoRGB, Color1931XYZ white)
{
Color1931XYZ XYZ = ToXYZ(Lab, white);
return(ToRGB(XYZ, XYZtoRGB));
}
public static Color1976Luv ToLuv(this ColorRGB RGB, ColorTransformMatrix RGBtoXYZ, Color1931XYZ whiteLuv)
{
Color1931XYZ XYZ = ToXYZ(RGB, RGBtoXYZ);
return(ToLuv(XYZ, whiteLuv));
}
public static Color1931xyY ToxyY(this ColorRGB RGB, ColorTransformMatrix RGBtoXYZ)
{
Color1931XYZ XYZ = ToXYZ(RGB, RGBtoXYZ);
return(ToxyY(XYZ));
}
public static ColorRGB ToRGB(int nm, ColorTransformMatrix XYZtoRGB)
{
Color1931XYZ XYZ = ToXYZ(nm);
return(ToRGB(XYZ, XYZtoRGB));
}
public static Chromaticity1976uv Touv(this ColorHSV HSV, ColorTransformMatrix RGBtoXYZ)
{
Color1931XYZ XYZ = ToXYZ(HSV, RGBtoXYZ);
return(Touv(XYZ));
}
public static Chromaticity1931xy Toxy(this ColorRGB RGB, ColorTransformMatrix RGBtoXYZ)
{
Color1931XYZ XYZ = ToXYZ(RGB, RGBtoXYZ);
return(Toxy(XYZ));
}
internal static ColorLMS ToLMS(this Color1931xyY xyY, ref ColorTransformMatrix XYZtoLMS) => xyY.ToXYZ().ToLMS(ref XYZtoLMS);
public static ColorRGB ToRGB(this Color1931xyY xyY, ColorTransformMatrix XYZtoRGB)
{
Color1931XYZ XYZ = ToXYZ(xyY);
return(ToRGB(XYZ, XYZtoRGB));
}
public static Chromaticity1931xy Toxy(this ColorHSV HSV, ColorTransformMatrix RGBtoXYZ)
{
ColorRGB RGB = ToRGB(HSV);
return(Toxy(RGB, RGBtoXYZ));
}
public static Color1976Lab ToLab(this ColorHSV HSV, ColorTransformMatrix RGBtoXYZ, Color1931XYZ whiteLab)
{
Color1931XYZ XYZ = ToXYZ(HSV, RGBtoXYZ);
return(ToLab(XYZ, whiteLab));
}
