Introduction - If you have any usage issues, please Google them yourself
The non-local means is an algorithm introduced by A. Buades, B. Coll, J.M Morel.
The main reference for the algorithm is
A. Buades, B. Coll, J.M Morel,
A review of image denoising algorithms, with a new one ,
Multiscale Modeling and Simulation (SIAM interdisciplinary journal), Vol 4 (2), pp: 490-530, 2005.
This toolbox implements the algorithm in a fairly general way in a C file that can be called Matlab. It allows to perform the traditional NL-means for denoising (for both B&W and color images) but also to use an arbitrary set of patches to perform the denoising.