BRIEF and FREAK without SIFT and SURF

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I was wondering if it is possible to compile opencv with the xfeatures2d features while excluding SIFT and SURF features.

this is already the default behaviour (as of 3.4.x or so)

SIFT and SURF (as well as some patented denoising algos) will only be enabled / compiled into your lib/exe if

OPENCV_ENABLE_NONFREE=ON

was set in cmake, when buildng the opencv libs.