Convect QImage to IplImage

static IplImage* qImage2IplImage(const QImage& qImage)
  {
    int width = qImage.width();
    int height = qImage.height();

    // Creates a iplImage with 3 channels
    IplImage *img = cvCreateImage(cvSize(width, height), IPL_DEPTH_8U, 3);
    char * imgBuffer = img->imageData;

    //Remove alpha channel
    int jump = (qImage.hasAlphaChannel()) ? 4 : 3;

    for (int y=0;y<img->height;y++){
      QByteArray a((const char*)qImage.scanLine(y), qImage.bytesPerLine());
      for (int i=0; i<a.size(); i+=jump){
          //Swap from RGB to BGR
          imgBuffer[2] = a[i];
          imgBuffer[1] = a[i+1];
          imgBuffer[0] = a[i+2];
          imgBuffer+=3;
      }
  }

  return img;
  }