Hi , I am try to match object using Features2D + Homography module. and try to run the code from opencv documentation . Here is that
www.docs.opencv.org/2.4/doc/tutorials/features2d/feature_homography/feature_homography.html
www.github.com/opencv/opencv/blob/2.4/samples/cpp/tutorial_code/features2D/SURF_Homography.cpp
But error code is showing as "The sample requires nonfree module that is not available in your OpenCV distribution I have downloaded opencv 3.1 with contrib on ubuntu 16.04 OS
Please tell how to run the code .