OpenCV C++, getting Region Of Interest (ROI) using cv::Mat

c++, opencv, roi

Solution

You can use the overloaded function call operator on the `cv::Mat`:

cv::Mat img = ...;
cv::Mat subImg = img(cv::Range(0, 100), cv::Range(0, 100));

Check the OpenCV documentation for more information and for the overloaded function that takes a `cv::Rect`. Note that using this form of slicing creates a new matrix header, but does not copy the data.

Problem

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: - Is there a way to convert `cv::Mat` to `cvMat` so that I can use `cvGetSubRect` method to get the Region of interest? - 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.

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