public static double CalDistance_CIE76(ColorSpace color1, ColorSpace color2) { //double deltaE = color1.Compare(color2, new Cie1976Comparison()); double deltaE = 0; Lab c1 = color1.To <Lab>(); Lab c2 = color2.To <Lab>(); double _L = (c1.L - c2.L) * (c1.L - c2.L); double _a = (c1.A - c2.A) * (c1.A - c2.A); double _b = (c1.B - c2.B) * (c1.B - c2.B); deltaE = Math.Sqrt(_L + (_a + _b) * 3); return(deltaE); }