Edge Preserving Wavelet Speckle Filtering

A new edge preserving wavelet filtering is proposed and it is applied to real SAR images that are generally affected by a multiplicative noise, called speckle, which degrades the quality of these images. The new approach attempts to look for the neighborhood area in the detail images of a wavelet decomposition, that identifies homogeneous areas and edge information by using masks in order to reduce speckle while edges are preserved. The improved filtering method uses the Nagao & Matsuyama and Tomita & Tsuji masks to detect edges locations in wavelet subspaces. The information provided by the masks is used to distinguish which of the detail coefficients are to be shrunk.