[QT] How to covert QT QImage into OpenCV IplImage and vise-versa.

IplImage* QImage2IplImage(QImage *qimg)
{
    IplImage *imgHeader = cvCreateImageHeader( cvSize(qimg->width(), qimg->height()), IPL_DEPTH_8U, 4);
    imgHeader->imageData = (char*) qimg->bits();
    uchar* newdata = (uchar*) malloc(sizeof(uchar) * qimg->byteCount());
    memcpy(newdata, qimg->bits(), qimg->byteCount());
    imgHeader->imageData = (char*) newdata;
    //cvClo
    return imgHeader;
}
//---
QImage*  IplImage2QImage(IplImage *iplImg)
{
    int h = iplImg->height;
    int w = iplImg->width;
    int channels = iplImg->nChannels;
    QImage *qimg = new QImage(w, h, QImage::Format_ARGB32);
    char *data = iplImg->imageData;
    for (int y = 0; y < h; y++, data += iplImg->widthStep)
    {
        for (int x = 0; x < w; x++)
        {
            char r, g, b, a = 0;
            if (channels == 1)
            {
                r = data[x * channels];
               g = data[x * channels];
               b = data[x * channels];
            }
           else if (channels == 3 || channels == 4)
           {
               r = data[x * channels + 2];
               g = data[x * channels + 1];
               b = data[x * channels];
           }
            if (channels == 4)
            {
                a = data[x * channels + 3];
                qimg->setPixel(x, y, qRgba(r, g, b, a));
            }
            else
            {
                qimg->setPixel(x, y, qRgb(r, g, b));
            }
        }
    }
    return qimg;
}