How to crop circles (found with Hough Transform) in OpenCV?

Question

I\'m using the code from the page. It works very well and I get a circle that I am looking for. All my image have only 1 circle and I have modified parameters of HoughCirc

Answer 1

You can define a Region of Interest (ROI) on your image based on the coordinates of the circle, then imwrite will only save the cropped portion:

cv::Rect roi(x, y, w, h); // I let you do the math ;)
cv::Mat cropped = original(roi);
cv::imwrite("cropped.png", cropped);