之前做紫边处理的时候介绍到过一些颜色转换的算法，这里详细列出几种颜色之间转换的代码，以备以后使用：
//RGB to CMYk
int* rgb2cmyk(int R,int G,int B)
{
int cmyk [4];
cmyk[3]=(int)(min(min(255-R,255-G),255-B)/2.55);//cmykK
int MyR = (int)(R/2.55);
int Div = 100-cmyk[3];
if (Div == 0)Div = 1;
cmyk[0] = ((100-MyR-cmyk[3])/Div)*100;//cmykC
int MyG = (int)(G/2.55);
cmyk[1] = ((100-MyG-cmyk[3])/Div)*100;
int MyB = (int)(B/2.55);
cmyk[2] = ((100-MyB-cmyk[3])/Div)*100;
return cmyk;
}
//CMYK to RGB
int* cmyk2rgb(int C,int M,int Y,int K)
{
int rgb[3];
int *R=&rgb[0];
int *G=&rgb[1];
int *B=&rgb[2];
float MyC = C/100;
float MyM = M/100;
float MyY = Y/100;
float MyK = K/100;
int *R = (int)((1-(MyC*(1-MyK)+MyK))*255);
int *G = (int)((1-(MyM*(1-MyK)+MyK))*255);
int *B = (int)((1-(MyY*(1-MyK)+MyK))*255);
if (*R<0) *R=0;
if (*G<0) *G=0;
if (*B<0) *B=0;
if (*R>255) *R=255;
if (*G>255) *G=255;
if (*B>255) *B=255;
return rgb;
}
//RGB to YUV
int* rgb2yuv(int R,int G,int B)
{
int yuv[3];
yuv[0] = (int)(0.299*R+0.587*G+0.114*B);
yuv[1] = (int)(-0.147*R-0.289*G+0.437*B);
yuv[2] = (int)(0.615*R-0.515*G-0.1*B);
return yuv;
}
//YUV to RGB
int* yuv2rgb(int y,int u,int v)
{
int rgb[3];
int *R=&rgb[0];
int *G=&rgb[1];
int *B=&rgb[2];
*R = (int)(y+1.14*v);
*G = (int)(y-0.394*u-0.581*v);
*B = (int)(y+2.028*u);
if (*R<0) *R=0;
if (*G<0) *G=0;
if (*B<0) *B=0;
if (*R>255) *R=255;
if (*G>255) *G=255;
if (*B>255) *B=255;
return rgb;
}
//RGB to YIQ
int* rgb2yiq(int R,int G,int B)
{
int yiq[3];
yiq[0] = (int)(0.299*R+0.587*G+0.114*B);
yiq[1] = (int)(0.596*R-0.274*G-0.322*B);
yiq[2] = (int)(0.212*R-0.523*G+0.311*B);
return yiq;
}
//YIQ to RGB
int* yiq2rgb(float y,float i,float q)
{
int rgb[3];
int *R=&rgb[0];
int *G=&rgb[1];
int *B=&rgb[2];
*R = (int)(y+0.956*i+0.621*q);
*G = (int)(y-0.272*i-0.647*q);
*B = (int)(y-1.105*i+1.702*q);
if (*R<0) *R=0;
if (*G<0) *G=0;
if (*B<0) *B=0;
if (*R>255) *R=255;
if (*G>255) *G=255;
if (*B>255) *B=255;
return rgb;
}
//RGB to YCbCr
int* rgb2ycbcr(int R, int G,int B)
{
int ycbcr[3];
ycbcr[0] = (int)(0.299*R+0.587*G+0.114*B);
ycbcr[1] = (int)(-0.1687*R-0.3313*G+0.5*B+128);
if (ycbcr[1] > 255) ycbcr[1] = 255;
ycbcr[2] = (int)(0.5*R-0.4187*G-0.0813*B+128);
if (ycbcr[2] > 255) ycbcr[2] = 255;
return ycbcr;
}
//YCbCr to RGB
int* ycbcr2rgb(int Y,int Cb,int Cr)
{
int rgb[3];
int *R=&rgb[0];
int *G=&rgb[1];
int *B=&rgb[2];
*R = (int)(Y + 1.402 * (Cr -128));
*G = (int)(Y - 0.34414 * (Cb - 128) - 0.71414 * (Cr - 128));
*B = (int)(Y + 1.772 * (Cb -128));
if (*R > 255) *R = 255;
if (*G > 255) *G = 255;
if (*B > 255) *B = 255;
if (*R < 0) *R =0;
if (*G < 0) *G =0;
if (*B < 0) *B =0;
return rgb;
}