protected static Matrix GetRGBToXYZMatrix(IRGBWorkingSpace workingSpace)
{
if (workingSpace == null)
{
throw new ArgumentNullException("workingSpace");
}
// for more info, see: http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html
RGBPrimariesChromaticityCoordinates chromaticity = workingSpace.ChromaticityCoordinates;
double xr = chromaticity.R.x, xg = chromaticity.G.x, xb = chromaticity.B.x,
yr = chromaticity.R.y, yg = chromaticity.G.y, yb = chromaticity.B.y;
double Sr, Sg, Sb;
double Xr = xr / yr;
const double Yr = 1;
double Zr = (1 - xr - yr) / yr;
double Xg = xg / yg;
const double Yg = 1;
double Zg = (1 - xg - yg) / yg;
double Xb = xb / yb;
const double Yb = 1;
double Zb = (1 - xb - yb) / yb;
var S = new []
{
new[] { Xr, Xg, Xb },
new[] { Yr, Yg, Yb },
new[] { Zr, Zg, Zb },
}.Inverse();
Vector W = workingSpace.WhitePoint.Vector;
(S.MultiplyBy(W)).AssignVariables(out Sr, out Sg, out Sb);
var M = new []
{
new[] { Sr *Xr, Sg *Xg, Sb *Xb },
new[] { Sr *Yr, Sg *Yg, Sb *Yb },
new[] { Sr *Zr, Sg *Zg, Sb *Zb },
};
return(M);
}
/// <summary>
/// Constructs RGB working space using a reference white, companding, and chromacity coordinates.
/// </summary>
public RGBWorkingSpace(XYZColor referenceWhite, ICompanding companding, RGBPrimariesChromaticityCoordinates chromaticityCoordinates)
{
WhitePoint = referenceWhite;
Companding = companding;
ChromaticityCoordinates = chromaticityCoordinates;
}
/// <inheritdoc cref="object" /> public bool Equals(RGBPrimariesChromaticityCoordinates other) => R.Equals(other.R) && G.Equals(other.G) && B.Equals(other.B);