c - YUV420到RGB颜色转换错误

我将converting格式的图像YUV420转换为RGB的opencv图像，但是我在Orange之后得到了conversion.彩色图像，我使用以下代码来做到这一点。我的代码有什么问题吗？

 int step = origImage->widthStep;
 uchar *data = (uchar *)origImage->imageData;
 int size = origImage->width * origImage->height;
 IplImage* img1 = cvCreateImage(cvGetSize(origImage), IPL_DEPTH_8U, 3);

for (int i = 0; i<origImage->height; i++)
{
  for (int j=0; j<origImage->width; j++)
  {
    float Y = data[i*step + j];
    float U = data[ (int)(size + (i/2)*(step/2)  + j/2) ];
    float V = data[ (int)(size*1.25 + (i/2)*(step/2) + j/2)];

    float R = Y + (int)(1.772f*V);
    float G = Y - (int)(0.344f*V + 0.714f*U);
    float B = Y + (int)(1.402f*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; }

    cvSet2D(img1, i, j,cvScalar(B,G,R));
  }
}

origImage-> YUV图片，
img1-> RGB图像，

http://upload.wikimedia.org/wikipedia/en/0/0d/Yuv420.svg

是否有任何opencv函数可以将YUV420格式的pixel转换为相应的RGB像素？ (不是整个图像)

最佳答案

通过修改用于计算R G B值的公式，我得到了答案，
该代码工作正常

 int step = origImage->widthStep;
 uchar *data = (uchar *)origImage->imageData;
 int size = origImage->width * origImage->height;
 IplImage* img1 = cvCreateImage(cvGetSize(origImage), IPL_DEPTH_8U, 3);

for (int i = 0; i<origImage->height; i++)
{
  for (int j=0; j<origImage->width; j++)
  {
    float Y = data[i*step + j];
    float U = data[ (int)(size + (i/2)*(step/2)  + j/2) ];
    float V = data[ (int)(size*1.25 + (i/2)*(step/2) + j/2)];

    float R = Y + 1.402 * (V - 128);
    float G = Y - 0.344 * (U - 128) - 0.714 * (V - 128);
    float B = Y + 1.772 * (U - 128);


    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; }

    cvSet2D(img1, i, j,cvScalar(B,G,R));
  }
}