SPECKLE FILTERING IN SAR IMAGES BY CONTRAST MODIFICATION, COMPARISON WITH A LARGE CLASS OF FILTERS

Speckle appearing in synthetic aperture radar (SAR) images is generate d by coherent processing of radar signals. Basically the speckle has t he nature of multiplicative noise. Recently, several methods have been proposed to remove speckle in SAR images, among them, Lee's methods, Frost's method and Zamperoni's method. In this paper, we propose an ef fective method for smoothing speckle-corrupted images. Digital process ing is introduced, based on a contrast modification in a multiresoluti on pyramid image representation. The contrast modification is realized by a median filter or an adaptive order filter giving a reconstructed image. For assessing this new method, we realized a comparative study with several noise-smoothing algorithms.