SURF and BRISK in OpenCV

Today I spent half a day to compare the two feature detector and descriptor SURF and BRISK.

The conclusion is

• SURF is more accurate but takes much longer
• BRISK is 10 times faster with comparable accuracy. 

One thing to notice:

when using Brute-force matcher, mind the normType. See HERE

C++: BFMatcher::BFMatcher(int normType=NORM_L2, bool crossCheck=false )

Parameters:

* normType – One of NORM_L1, NORM_L2, NORM_HAMMING,NORM_HAMMING2. L1 and L2 norms are preferable choices for SIFT and SURF descriptors, 

* NORM_HAMMING should be used with ORB, BRISK and BRIEF, NORM_HAMMING2 should be used with ORB when WTA_K==3 or 4.

The other thing to notice is the threshold used to select good matches. Maybe RANSAC should be used.

SURF feature

BRISK feature