I was doing testing of OpenCV background subtraction algorithms. After recompiling OpenCV (from github, tagged as 3.1) and adding CUDA and EIGEN, I've noticed that MOG2 became about 30% faster but KNN became 4 times slower. I also have OPENCL, IPP, TBB and SSE/AVX enabled. I usually use one universal include file (opencv2/opencv.hpp)
Is there a way to find out what acceleration method OpenCV have used in its functions?
Or is there a way to control what acceleration method will be used?