  It was recently demonstrated in [Chaudhury et al.,Non-Local Euclidean
Medians,2012] that the denoising performance of Non-Local Means (NLM) can be
improved at large noise levels by replacing the mean by the robust Euclidean
median. Numerical experiments on synthetic and natural images showed that the
latter consistently performed better than NLM beyond a certain noise level, and
significantly so for images with sharp edges. The Euclidean mean and median can
be put into a common regression (on the patch space) framework, in which the
l_2 norm of the residuals is considered in the former, while the l_1 norm is
considered in the latter. The natural question then is what happens if we
consider l_p (0<p<1) regression? We investigate this possibility in this paper.
