This is a fast and robust implementation of the popular Nonlocal Means for MRI-Rician denoising. It works by computing the non-local weights based on distances in a features space comprising the local mean value and gradients of the image.

It can reach an acceleration factor of 20x over the original implementation, with an improved performance for medium-low SNR images.

We use a bias correction step for Rician noise based on the well-known Conventional Approach.

This software can be compiled either as a Slicer module or a stand-alone:

http://www.nitrc.org/snapshots.php?group...

For diffusion MRI volumes, see also: http://www.nitrc.org/projects/jalmmse_dw...

Key words: nonlocal (non-local) means, NLM, C++, ITK