Structural similar patches for nonlocal-means with modified robust M-estimator and residual images

Nonlocal-means provides a powerful framework for denoising. However, there are some issues of it. In this letters, we proposed some improvements for solve or alleviating the influence of the issues. First, we show the connection between the NL-means and robust M-estimator framework, and propose a modified robust M-estimator function for NL-means. Then, we introduced the structure similar for searching the similar patches. And then, we propose a iterative theme for using it to improve the quality. Finally, extensive simulation results reveal that the proposed improvements are useful for denoising procedure.