Denoising Via Block Wiener Filtering in Wavelet Domain

Abstract

In this paper we describe a new method for image denoising. Weanalyze statistical properties of the wavelet coecients of natural images. Itturns out that there is a strong local covariance structure introduced by theedges. We suggest a model for this covariance which allows us to estimate itfrom the noisy image. Then Wiener lter is employed in order to remove thenoise.We compare our approach to other noise removal techniques. Wienerwaveletdenoising produces superior results both visually and in terms of meansquare error.1. IntroductionA good model of the signal statistics is essential in many applications. This paperdescribes a simple and eective model for the covariance structure of naturalimages. We use this model for noise removal.There are two powerful techniques to reduce the noise level in a signal: Wienerltering [3] and wavelet thresholding [2]. Wiener ltering is a linear procedure.Wavelet thresholding is nonlinear. Classical versions of both meth...