sRGB XYZ Lab颜色空间相互转换及相关计算的类
using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
namespace CRS
{
/// <完成sRGB XYZ Lab颜色空间相互转换及相关计算的类>
///
/// </summary>
internal class ColorSpaceTransform
{
public static double[] sRGB2XYZ(double [] sRGB)
{
double[] XYZ = new double[3];
double sR, sG, sB;
sR = sRGB[0];
sG = sRGB[1];
sB = sRGB[2];
sR /= 255;
sG /= 255;
sB /= 255;
if (sR<=0.04045)
{
sR = sR / 12.92;
}
else
{
sR = Math.Pow(((sR + 0.055) / 1.055), 2.4);
}
if (sG <= 0.04045)
{
sG = sG / 12.92;
}
else
{
sG = Math.Pow(((sG + 0.055) / 1.055), 2.4);
}
if (sB <= 0.04045)
{
sB = sB / 12.92;
}
else
{
sB = Math.Pow(((sB + 0.055) / 1.055), 2.4);
}
XYZ[0] = 41.24 * sR + 35.76 * sG + 18.05 * sB;
XYZ[1] = 21.26 * sR + 71.52 * sG + 7.2 * sB;
XYZ[2] = 1.93 * sR + 11.92 * sG + 95.05 * sB;
return XYZ;
}
public static int[] XYZ2sRGB(double [] XYZ)
{
int[] sRGB = new int[3];
double X, Y, Z;
double dr, dg, db;
X = XYZ[0];
Y = XYZ[1];
Z = XYZ[2];
dr = 0.032406 * X - 0.015371 * Y - 0.0049895 * Z;
dg = -0.0096891 * X + 0.018757 * Y + 0.00041914 * Z;
db = 0.00055708 * X - 0.0020401 * Y + 0.01057 * Z;
if (dr<=0.00313)
{
dr = dr * 12.92;
}
else
{
dr = Math.Exp(Math.Log(dr) / 2.4) * 1.055 - 0.055;
}
if (dg <= 0.00313)
{
dg = dg * 12.92;
}
else
{
dg = Math.Exp(Math.Log(dg) / 2.4) * 1.055 - 0.055;
}
if (db <= 0.00313)
{
db = db * 12.92;
}
else
{
db = Math.Exp(Math.Log(db) / 2.4) * 1.055 - 0.055;
}
dr = dr * 255;
dg = dg * 255;
db = db * 255;
dr = Math.Min(255, dr);
dg = Math.Min(255, dg);
db = Math.Min(255, db);
sRGB[0] = (int)(dr + 0.5);
sRGB[1] = (int)(dg + 0.5);
sRGB[2] = (int)(db + 0.5);
return sRGB;
}
public static double[] XYZ2Lab(double[] XYZ,double Xw,double Yw,double Zw)
{
double[] Lab = new double[3];
double X, Y, Z;
X = XYZ[0];
Y = XYZ[1];
Z = XYZ[2];
double Xn, Yn, Zn;
Xn = Xw;
Yn = Yw;
Zn = Zw;
double XXn, YYn, ZZn;
XXn = X / Xn;
YYn = Y / Yn;
ZZn = Z / Zn;
double fx, fy, fz;
if (XXn > 0.008856)
{
fx = Math.Pow(XXn, 0.333333);
}
else
{
fx = 7.787 * XXn + 0.137931;
}
if (YYn > 0.008856)
{
fy = Math.Pow(YYn, 0.333333);
}
else
{
fy = 7.787 * YYn + 0.137931;
}
if (ZZn > 0.008856)
{
fz = Math.Pow(ZZn, 0.333333);
}
else
{
fz = 7.787 * ZZn + 0.137931;
}
Lab[0] = 116 * fy - 16;
Lab[1] = 500 * (fx - fy);
Lab[2] = 200 * (fy - fz);
return Lab;
}
public static double[] Lab2XYZ(double[] Lab)
{
double[] XYZ = new double[3];
double L, a, b;
double fx, fy, fz;
double Xn, Yn, Zn;
Xn = 95.04;
Yn = 100;
Zn = 108.89;
L = Lab[0];
a = Lab[1];
b = Lab[2];
fy = (L + 16) / 116;
fx = a / 500 + fy;
fz = fy - b / 200;
if (fx>0.2069)
{
XYZ[0] = Xn * Math.Pow(fx, 3);
}
else
{
XYZ[0] = Xn * (fx - 0.1379) * 0.1284;
}
if ((fy > 0.2069) || (L>8))
{
XYZ[1] = Yn * Math.Pow(fy, 3);
}
else
{
XYZ[1] = Yn * (fy - 0.1379) * 0.1284;
}
if (fz > 0.2069)
{
XYZ[2] = Zn * Math.Pow(fz, 3);
}
else
{
XYZ[2] = Zn * (fz - 0.1379) * 0.1284;
}
return XYZ;
}
}
}
此类时我的CRS工程的一部分，用于常用的色度空间的转换计算。在VS08下经过测试，计算结果正确。
我写代码只为了完成功能，很少考虑复杂度，内存开销等问题，请大家谅解！
本文出自 “moto” 博客，谢绝转载！