I'm very new to OpenCV (started using it two days ago), I'm trying to cut a hand image from a depth image got from Kinect, I need the hand image for gesture recognition. I have the image as a `cv::Mat` type. My questions are:

1. Is there a way to convert `cv::Mat` to `cvMat` so that I can use `cvGetSubRect` method to get the Region of interest?
2. Are there any methods in `cv::Mat` that I can use for getting the part of the image?

I wanted to use `IplImage` but I read somewhere that `cv::Mat` is the preferred way now.