I’ve search long time for having result on this problem. I want to use the object of IplImage, which data should be filled from Mat. If you using the simple solution found on stackoverflow, then you can’t access the methods of the IplImage object.

Mat matImage;
IplImage iplImage;

iplImage = cvCreateImage(cvSize(640,480), IPL_DEPTH_8U, 1);
iplImage->imageData = (char *) matImage.data;