I updated my app to OpenCV Android 2.4.2 and wanted to use SURF as before in version 2.4.0, but I can't find the required package anymore. Neither can I find the nonfree package within sdk\native\jni\include\opencv2. Are SURF and SIFT moved to another package again or are they completely missing within the new version 2.4.2?
SURF and SIFT are still in the nonfree package, but this package is excluded from OpenCV4Android distribution. The problem is that these algorithms are patented, so you should prefer Orb or FREAK. For those who really need to have SURF we will create an instruction on how to build the nonfree module from OpenCV sources. But this way will be incompatible with Android OpenCV Manager and you can't distribute you application on Google Play Market (technically you can, but you'll meet some difficulties).
So, we suggest to use Orb or FREAK (latter is not available in Java at the moment), because there are no legal issues with them, they are much faster, and it is usually possible to achieve the same quality.
Thanks for the clarification! Actually I'm trying to use FREAK, but I still need a Feature Detector. Since the demo code for FREAK used SURF (http://code.opencv.org/projects/opencv/repository/entry/trunk/opencv/samples/cpp/freak_demo.cpp) I wanted to try it as well. I have now tested FREAK with a FAST Feature Detector, but my approach is slower than my previous approach with SURF (SURF for both detection & extraction). Don't really now why, I thought FAST+FREAK would be faster. Maybe it's because I'm using BFMatcher for FREAK, I used Flann for SURF. Is it possible to use Flann for FREAK (since is a binary descriptor I thought this would not be possible)?
You should ask your questions in a separate "question". They are good enough for a wider audience :)
Thanks! Done: http://answers.opencv.org/question/489/freak-vs-surf/
Let's track this request in OpenCV tracker: http://code.opencv.org/issues/2825
There is a tutorial about building nonfree module for OpenCV for Android. Version OpenCV 2.4.5. https://sites.google.com/site/wghsite/technical-notes/sift_surf_opencv_android Hope this helps.
Asked: 2012-07-17 06:01:05 -0600
Seen: 8,906 times
Last updated: Jul 17 '12
