SURF and SIFT algorithms doesn't work in OpenCV 3.0 Java

Question

I am using OpenCV 3.0 (the latest version) in Java, but when I use SURF algorithm or SIFT algorithm it doesn\'t work and throws Exception which says: OpenCV Error: Bad

Answer 1

That is because they are not free in newer versions of OpenCV (3+). I faced that problem few time ago. You have to:

1. Download OpenCV (if you have not)
2. Download the nonfree part from opencv github repo
3. Generate the makefiles with cmake -DBUILD_SHARED_LIBS=OFF specifying the nonfree part with DOPENCV_EXTRA_MODULES_PATH=../opencv_contrib/modules option and build with make -j8 (or whatever Java version you use)
4. Edit features2d_manual.hpp file, including opencv2/xfeatures2d.hpp and including the necessary code for SIFT and SURF case, which are commented and not defined: fd=xfeatures2d::SIFT::create(); for SIFT descriptor andde = xfeatures2d::SIFT::create(); for SIFT extractor. Do the same for SURF if you want to use it too.

I wrote this post explaining step by step how to compile the nonfree OpenCV part in order to use privative tools like SIFT or SURF. Compile OpenCV nonfree part