OpenCV The contour area larger than, eg. 200px

Question

I use the background substraction to detect hand. http://docs.opencv.org/trunk/doc/tutorials/video/background_subtraction/background_subtraction.html Then I would like to outline just a hand. To get rid of imperfections from the background. http://docs.opencv.org/doc/tutorials/imgproc/shapedescriptors/find_contours/find_contours.html But the method is all the contours. I would like to alb contoured those elements which have larger area than, for example. 200px. How to do it? There is a better method to obtain the same hand in the picture?

Answer 1

There are two parameters of contour from which you can extract the info of contour 1.contourArea 2.arcLength

Another way of focus only on hand is Training haar cascade for hand detection. Please refer to the similar question ask before.