//================================================================================
/// @brief HLS <====> RGB
///
/// [1]H是色相，代表了6种颜色，分成0～6区域，用一个模型来表述就是一个双(六)棱椎，其中的L是HSL立方体的主对角线。
//     RGB立方体的顶点：红、黄、绿、青、蓝和品红就成为HSL六角形的顶点,0-360度的范围内有6种颜色,但是它不是平均分布的,如绿色最多.
///    H是0-360，L和S是0.00%-100.00%  
//================================================================================
//HLS ---> RGB
void RGBtoHLS (int rgb, double& H, double& L, double& S)
{Color color(rgb);RGBtoHLS(color.R, color.G, color.B, H, L, S);
}//HLS ---> RGB
void RGBtoHLS (int r, int g, int b, double& H, double& L, double& S)
{int   n_cmax = max(r, max(g, b));int   n_cmin = min(r, min(g, b));double Delta = 0;double Max = 0, Min = 0;double Redf = 0, Greenf = 0, Bluef = 0;Redf    = (r / 255.0f);Greenf  = (g / 255.0f);Bluef   = (b / 255.0f); Max     = max(max(Redf, Greenf), Bluef);Min     = min(min(Redf, Greenf), Bluef);H = 0;L = (Max + Min) / 2.0f;S = 0;if (Max == Min){return;}Delta = (Max - Min);if (L < 0.5)S = Delta / (Max + Min);elseS = Delta / (2.0 - Max - Min);if (Redf == Max){if (Greenf >= Bluef){H = (Greenf - Bluef) / Delta;}else{H = 6.0 + (Greenf - Bluef) / Delta;}}		else if (Greenf == Max)H = 2.0 + (Bluef - Redf) / Delta;elseH = 4.0 + (Redf - Greenf) / Delta;H /= 6.0; //除以6，表示在那个部分。if (H < 0.0)H += 1.0;   if (H > 1)H -= 1;H = (int)(H * 360); //转成[0, 360]
}void Color_HueToRgb(double p, double q, double Ht, double *Channel)
{if (Ht < 0.0)Ht += 1.0;else if (Ht > 1.0)Ht -= 1.0;if ((6.0 * Ht) < 1.0)*Channel = (p + (q - p) * Ht * 6.0);else if ((2.0 * Ht) < 1.0)*Channel = (q);else if ((3.0 * Ht) < 2.0)*Channel = (p + (q - p) * ((2.0F / 3.0F) - Ht) * 6.0);else*Channel = (p);
}//RGB ---> HLS
void HLStoRGB (double H, double L, double S, BYTE &r, BYTE &g, BYTE &b)
{double M1 = 0, M2 = 0;double Redf = 0, Greenf = 0, Bluef = 0;double hue = H / 360;if (S == 0)//灰色{Redf    = L;Greenf  = L;Bluef   = L;}else{if (L <= 0.5)M2 = L * (1.0 + S);elseM2 = L + S - L * S;M1 = (2.0 * L - M2);Color_HueToRgb(M1, M2, hue + (1.0F / 3.0F), &Redf);Color_HueToRgb(M1, M2, hue, &Greenf);Color_HueToRgb(M1, M2, hue - (1.0F / 3.0F), &Bluef);}r = (BYTE)(Redf * 255);g = (BYTE)(Bluef * 255);b = (BYTE)(Greenf * 255);
}

<span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);">参考文档： http://blog.csdn.net/idfaya/article/details/6770414</span>