public static RGBColor XYZtoRGB(XYZColor xyz)
{
float x, y, z;
x = xyz.X / 100; //X from 0 to 95.047 (Observer = 2°, Illuminant = D65)
y = xyz.Y / 100; //Y from 0 to 100.000
z = xyz.Z / 100; //Z from 0 to 108.883
float r, g, b;
r = x * 3.2406f + y * -1.5372f + z * -0.4986f;
g = x * -0.9689f + y * 1.8758f + z * 0.0415f;
b = x * 0.0557f + y * -0.2040f + z * 1.0570f;
if (r > 0.0031308f)
{
r = 1.055f * (float)Math.Pow(r, (1 / 2.4f)) - 0.055f;
}
else
{
r = 12.92f * r;
}
if (g > 0.0031308f)
{
g = 1.055f * (float)Math.Pow(g, (1 / 2.4f)) - 0.055f;
}
else
{
g = 12.92f * g;
}
if (b > 0.0031308f)
{
b = 1.055f * (float)Math.Pow(b, (1 / 2.4f)) - 0.055f;
}
else
{
b = 12.92f * b;
}
//clamp values before making it a RGBColor
r = MathHelper.Clamp(r, 0, 1);
g = MathHelper.Clamp(g, 0, 1);
b = MathHelper.Clamp(b, 0, 1);
return(new RGBColor(r, g, b, xyz.Alpha));
}
public static XYZColor RGBtoXYZ(RGBColor rgb)
{
XYZColor xyz = new XYZColor();
float r, g, b;
r = rgb.R;
g = rgb.G;
b = rgb.B;
if (r > 0.04045f)
{
r = (float)Math.Pow((r + 0.055) / 1.055, 2.4);
}
else
{
r = r / 12.92f;
}
if (g > 0.04045)
{
g = (float)Math.Pow((g + 0.055f) / 1.055f, 2.4f);
}
else
{
g = g / 12.92f;
}
if (b > 0.04045f)
{
b = (float)Math.Pow((b + 0.055f) / 1.055f, 2.4f);
}
else
{
b = b / 12.92f;
}
r *= 100;
g *= 100;
b *= 100;
xyz.X = r * 0.4124f + g * 0.3576f + b * 0.1805f;
xyz.Y = r * 0.2126f + g * 0.7152f + b * 0.0722f;
xyz.Z = r * 0.0193f + g * 0.1192f + b * 0.9505f;
xyz.Alpha = rgb.Alpha;
return(xyz);
}
//TODO: Test XYZtoLAB
public static CieLabColor XYZtoLAB(XYZColor xyz)
{
float var_x = xyz.X / XYZColor.XLIMIT;
float var_y = xyz.Y / XYZColor.YLIMIT;
float var_z = xyz.Z / XYZColor.ZLIMIT;
if (var_x > 0.008856)
{
var_x = (float)Math.Pow(var_x, (1 / 3f));
}
else
{
var_x = (7.787f * var_x) + (16f / 116f);
}
if (var_y > 0.008856)
{
var_y = (float)Math.Pow(var_y, (1 / 3f));
}
else
{
var_y = (7.787f * var_y) + (16f / 116f);
}
if (var_z > 0.008856)
{
var_z = (float)Math.Pow(var_z, (1 / 3f));
}
else
{
var_z = (7.787f * var_z) + (16f / 116f);
}
float var_l = (116f * var_y) - 16f;
float var_a = 500 * (var_x - var_y);
float var_b = 200 * (var_y - var_z);
return(new CieLabColor(var_l, var_a, var_b)
{
Alpha = xyz.Alpha
});
}
public static RGBColor XYZtoRGB(XYZColor xyz)
{
float x, y, z;
x = xyz.X/100; //X from 0 to 95.047 (Observer = 2°, Illuminant = D65)
y = xyz.Y/100; //Y from 0 to 100.000
z = xyz.Z/100; //Z from 0 to 108.883
float r, g, b;
r = x*3.2406f + y*-1.5372f + z*-0.4986f;
g = x*-0.9689f + y*1.8758f + z*0.0415f;
b = x*0.0557f + y*-0.2040f + z*1.0570f;
if (r > 0.0031308f) r = 1.055f*(float)Math.Pow(r, (1/2.4f)) - 0.055f;
else r = 12.92f*r;
if (g > 0.0031308f) g = 1.055f*(float)Math.Pow(g ,(1/2.4f)) - 0.055f;
else g = 12.92f*g;
if (b > 0.0031308f) b = 1.055f*(float)Math.Pow(b, (1/2.4f)) - 0.055f;
else b = 12.92f*b;
//clamp values before making it a RGBColor
r = MathHelper.Clamp(r, 0, 1);
g = MathHelper.Clamp(g, 0, 1);
b = MathHelper.Clamp(b, 0, 1);
return new RGBColor(r,g,b,xyz.Alpha);
}
//TODO: Test XYZtoLAB
public static CieLabColor XYZtoLAB(XYZColor xyz)
{
float var_x = xyz.X/XYZColor.XLIMIT;
float var_y = xyz.Y/XYZColor.YLIMIT;
float var_z = xyz.Z/XYZColor.ZLIMIT;
if (var_x > 0.008856) var_x = (float) Math.Pow(var_x, (1/3f));
else var_x = (7.787f*var_x) + (16f/116f);
if (var_y > 0.008856) var_y = (float)Math.Pow(var_y, (1 / 3f));
else var_y = (7.787f * var_y) + (16f / 116f);
if (var_z > 0.008856) var_z = (float)Math.Pow(var_z, (1 / 3f));
else var_z = (7.787f * var_z) + (16f / 116f);
float var_l = (116f * var_y) - 16f;
float var_a = 500 * (var_x - var_y);
float var_b = 200 * (var_y - var_z);
return new CieLabColor(var_l, var_a, var_b) { Alpha = xyz.Alpha};
}
public static XYZColor RGBtoXYZ(RGBColor rgb)
{
XYZColor xyz = new XYZColor();
float r, g, b;
r = rgb.R;
g = rgb.G;
b = rgb.B;
if (r > 0.04045f) r = (float)Math.Pow((r + 0.055)/1.055, 2.4);
else r = r / 12.92f;
if (g > 0.04045) g =(float)Math.Pow((g + 0.055f)/1.055f , 2.4f);
else g = g/12.92f;
if (b > 0.04045f) b = (float)Math.Pow((b + 0.055f)/1.055f , 2.4f);
else b = b/12.92f;
r *= 100;
g *= 100;
b *= 100;
xyz.X = r*0.4124f + g*0.3576f + b*0.1805f;
xyz.Y = r*0.2126f + g*0.7152f + b*0.0722f;
xyz.Z = r*0.0193f + g*0.1192f + b*0.9505f;
xyz.Alpha = rgb.Alpha;
return xyz;
}
