1、将Mat转换为IplImage
//! converts header to IplImage; no data is copied
operator IplImage() const;
举例:Mat img;
IplImage *src;
src=&IplImage(img);
2、将IplImage转换为Mat
//! converts old-style IplImage to the new matrix; the data is not copied by default
Mat(const IplImage* img, bool copyData=false);