how to convert from cv::Mat to CvArr?

Question

i have passed a lot of time searching on how to convert from cv::Mat or CvMat to CvArr but with no gain ,please help me in that,thanks.

Answer 1

Mat img = imread("C:\MyPic.jpg",CV_LOAD_IMAGE_GRAYSCALE);
IplImage tmp=img;
cvErode(&tmp, &tmp, 0, 2);
Mat laser=&tmp;
    imshow("Eroded",laser);

I converted cv::Mat to CvArr by this way. Instead of using tmp directly use &tmp.

Answer 2

When I need to do that I just use :

IplImage tmp = image;

With image a Mat variable.