public static XYZColor lab2xyz(LabColor lab)
{
const double REF_X = 95.047; // Observer= 2°, Illuminant= D65
const double REF_Y = 100.000;
const double REF_Z = 108.883;
double y = (lab.l + 16.0) / 116.0;
double x = lab.a / 500.0 + y;
double z = y - lab.b / 200.0;
if (Math.Pow(y, 3) > 0.008856)
{
y = Math.Pow(y, 3);
}
else
{
y = (y - 16.0 / 116.0) / 7.787;
}
if (Math.Pow(x, 3) > 0.008856)
{
x = Math.Pow(x, 3);
}
else
{
x = (x - 16.0 / 116.0) / 7.787;
}
if (Math.Pow(z, 3) > 0.008856)
{
z = Math.Pow(z, 3);
}
else
{
z = (z - 16.0 / 116.0) / 7.787;
}
XYZColor xyz = new XYZColor(0, 0, 0);
xyz.x = REF_X * x;
xyz.y = REF_Y * y;
xyz.z = REF_Z * z;
return(xyz);
}
public static LabColor xyz2lab(XYZColor xyz)
{
const double REF_X = 95.047; // Observer= 2°, Illuminant= D65
const double REF_Y = 100.000;
const double REF_Z = 108.883;
double x = xyz.x / REF_X;
double y = xyz.y / REF_Y;
double z = xyz.z / REF_Z;
if (x > 0.008856)
{
x = Math.Pow(x, 1.0 / 3.0);
}
else
{
x = (7.787 * x) + (16.0 / 116.0);
}
if (y > 0.008856)
{
y = Math.Pow(y, 1.0 / 3.0);
}
else
{
y = (7.787 * y) + (16.0 / 116.0);
}
if (z > 0.008856)
{
z = Math.Pow(z, 1.0 / 3.0);
}
else
{
z = (7.787 * z) + (16.0 / 116.0);
}
LabColor lab = new LabColor(0, 0, 0);
lab.l = (int)(116 * y) - 16;
lab.a = (int)(500 * (x - y));
lab.b = (int)(200 * (y - z));
return(lab);
}
public static RGBColor lab2rgb(LabColor lab)
{
XYZColor xyz = ColorConversor.lab2xyz(lab);
return(ColorConversor.xyz2rgb(xyz));
}
public static int toRGB(LabColor c)
{
return(0);
}