Abstract
Reduction of mixed noise is an ill posed problem for the occurrence of
contrasting distributions of noise in the image. The mixed noise that is
usually encountered is the simultaneous presence of additive white Gaussian
noise (AWGN) and impulse noise (IN). A standard approach to denoise an image
with such corruption is to apply a rank order filter (ROF) followed by an
efficient linear filter to remove the residual noise. However, ROF cannot
completely remove the heavy tail of the noise distribution originating from the
IN and thus the denoising performance can be suboptimal. In this paper, we
present a variational step to remove the heavy tail of the noise distribution.
Through experiments, it is shown that this approach can significantly improve
the denoising performance of mixed AWGN-IN using well-established methods.