FLANN is a library for performing fast approximate nearest neighbor searches in high dimensional spaces. It contains a collection of algorithms we found to work best for nearest neighbor search and a system for automatically choosing the best algorithm and optimum parameters depending on the dataset. FLANN is written in C++ and contains bindings for the following languages: C, MATLAB and Python. The Python bindings will need numpy, and the MATLAB bindings will need MATLAB installed and with its binaries directory set into the PATH. If you want to build the MATLAB bindings, set the environment variable WITH_MATLAB to 1.