/// <summary>
/// A color difference algorithm to get the difference in visible color, and not just the integer difference in RGB values.
/// NOTE: The JND (Just Noticible Difference) between two colors is about 2.3.
/// </summary>
public static double GetEDeltaColorDifference(this Color c, Color color)
{
LAB a = c.GetLAB();
LAB b = color.GetLAB();
return(Math.Sqrt(Math.Pow(a.L - b.L, 2) + Math.Pow(a.a - b.a, 2) + Math.Pow(a.b - b.b, 2)));
}
public static LAB GetLAB(this XYZ c)
{
// Adapted from http://www.easyrgb.com/index.php?X=MATH&H=07#text7
double var_X = c.X / 95.047;
double var_Y = c.Y / 100.000;
double var_Z = c.Z / 108.883;
if (var_X > 0.008856)
{
var_X = Math.Pow(var_X, (1.0 / 3));
}
else
{
var_X = (7.787 * var_X) + (16.0 / 116);
}
if (var_Y > 0.008856)
{
var_Y = Math.Pow(var_Y, (1.0 / 3));
}
else
{
var_Y = (7.787 * var_Y) + (16.0 / 116);
}
if (var_Z > 0.008856)
{
var_Z = Math.Pow(var_Z, (1.0 / 3));
}
else
{
var_Z = (7.787 * var_Z) + (16.0 / 116);
}
LAB lab = new LAB();
lab.L = (116 * var_Y) - 16;
lab.a = 500 * (var_X - var_Y);
lab.b = 200 * (var_Y - var_Z);
return(lab);
}
public static LAB GetLAB(this XYZ c)
{
// Adapted from http://www.easyrgb.com/index.php?X=MATH&H=07#text7
double var_X = c.X / 95.047;
double var_Y = c.Y / 100.000;
double var_Z = c.Z / 108.883;
if (var_X > 0.008856) var_X = Math.Pow(var_X, (1.0 / 3));
else var_X = (7.787 * var_X) + (16.0 / 116);
if (var_Y > 0.008856) var_Y = Math.Pow(var_Y, (1.0 / 3));
else var_Y = (7.787 * var_Y) + (16.0 / 116);
if (var_Z > 0.008856) var_Z = Math.Pow(var_Z, (1.0 / 3));
else var_Z = (7.787 * var_Z) + (16.0 / 116);
LAB lab = new LAB();
lab.L = (116 * var_Y) - 16;
lab.a = 500 * (var_X - var_Y);
lab.b = 200 * (var_Y - var_Z);
return lab;
}