yuv转opencv中的IplImage

http://www.2cto.com/kf/201208/145559.html

http://www.opencv.org.cn/forum.php?mod=viewthread&tid=645&extra=

第一个是很笨的办法：

yuv三个分量分别写在3个矩阵下，然后合并之后转换为rgb分量的图片格式就可以了；

代码如下：

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IplImage *image,*rgbimg,*yimg,*uimg,*vimg,*uuimg,*vvimg; 
     
    rgbimg = cvCreateImage(cvSize(nWidth, nHeight),IPL_DEPTH_8U,3); 
    image = cvCreateImage(cvSize(nWidth, nHeight),IPL_DEPTH_8U,3); 
     
    yimg = cvCreateImageHeader(cvSize(nWidth, nHeight),IPL_DEPTH_8U,1); 
    uimg = cvCreateImageHeader(cvSize(nWidth/2, nHeight/2),IPL_DEPTH_8U,1); 
    vimg = cvCreateImageHeader(cvSize(nWidth/2, nHeight/2),IPL_DEPTH_8U,1); 
     
    uuimg = cvCreateImage(cvSize(nWidth, nHeight),IPL_DEPTH_8U,1); 
    vvimg = cvCreateImage(cvSize(nWidth, nHeight),IPL_DEPTH_8U,1); 
     
    cvSetData(yimg,pBuf, nWidth); 
    cvSetData(uimg,pBuf+nWidth*nHeight, nWidth/2); 
    cvSetData(vimg,pBuf+long(nWidth*nHeight*1.25), nWidth/2); 
    cvResize(uimg,uuimg,CV_INTER_LINEAR); 
    cvResize(vimg,vvimg,CV_INTER_LINEAR); 
     
    cvMerge(yimg,uuimg,vvimg,NULL,image); 
    cvCvtColor(image,rgbimg,CV_YCrCb2BGR); 

还有一个方法就比较负载
首先自己根据原理转换为rgb格式

然后利用cvSetData（）函数写入数据生成IplImage格式的图片

首先定义转换的公式：

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#define MR(Y,U,V) (Y + (1.403)*(V-128)) 
#define MG(Y,U,V) (Y - (0.344) * (U-128) - (0.714) * (V-128) )  
#define MB(Y,U,V) (Y + ((1.773) * (U-128))) 

yuv转rgb的函数：
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void YUV420_C_RGB( char* pYUV, unsigned char* pRGB, int height, int width) 
{ 
    char* pY = pYUV; 
    char* pU = pYUV+height*width; 
    char* pV = pU+(height*width/4); 
 
 
    unsigned char* pBGR = NULL; 
    unsigned char R = 0; 
    unsigned char G = 0; 
    unsigned char B = 0; 
    char Y = 0; 
    char U = 0; 
    char V = 0; 
    double tmp = 0; 
    for ( int i = 0; i < height; ++i ) 
    { 
        for ( int j = 0; j < width; ++j ) 
        { 
            pBGR = pRGB+ i*width*3+j*3; 
 
            Y = *(pY+i*width+j); 
            U = *pU; 
            V = *pV; 
 
            //B 
            tmp = MB(Y, U, V); 
            //B = (tmp > 255) ? 255 : (char)tmp; 
            //B = (B<0) ? 0 : B; 
            B = (unsigned char)tmp; 
            //G 
            tmp = MG(Y, U, V); 
            //G = (tmp > 255) ? 255 : (char)tmp; 
           // G = (G<0) ? 0 : G; 
            G = (unsigned char)tmp; 
            //R 
            tmp = MR(Y, U, V); 
            //R = (tmp > 255) ? 255 : (char)tmp; 
            //R = (R<0) ? 0 : R; 
            R = (unsigned char)tmp; 
 
 
            *pBGR     = R;             
            *(pBGR+1) = G;         
            *(pBGR+2) = B; 
         
 
            if ( i%2 == 0 && j%2 == 0) 
            { 
                *pU++; 
                //*pV++; 
            } 
            else 
            { 
                if ( j%2 == 0 ) 
                { 
                    *pV++ ; 
                } 
            } 
        } 
     
    } 
} 

最后是写入IplImage的代码：
[html] 
unsigned char* pRGB = NULL; 
 
pRGB = (unsigned char*)malloc(nSize*sizeof(unsigned char*)*2); 
     
YUV420_C_RGB(pBuf,pRGB,nWidth,nHeight); 
     
IplImage *image; www.2cto.com
image = cvCreateImageHeader(cvSize(nWidth, nHeight),IPL_DEPTH_8U,3); 
cvSetData(image,pRGB,nWidth*3); 
程序都运行过
编译环境为vs2008

作者：xuhongwei0411