Mat& img;
IplImage pImg= IplImage(img);
IplImage * src = &pImg;
IplImage* xx=cvCreateImage(cvGetSize(src),8,3);
cvCopyImage(src,xx);
cvNamedWindow("xx",0);
cvShowImage("xx",xx);
cvWaitKey(0);
Mat& img;
IplImage pImg= IplImage(img);
IplImage * src = &pImg;
IplImage* xx=cvCreateImage(cvGetSize(src),8,3);
cvCopyImage(src,xx);
cvNamedWindow("xx",0);
cvShowImage("xx",xx);
cvWaitKey(0);