Despeckling SAR images using stationary wavelet transform combining with directional filter banks

摘要

Synthetic aperture radar (SAR) images are inherently affected by multiplicative speckle noise, which is due to the coherent nature of scattering phenomena. This paper presents a depeckling method for SAR images based on stationary wavelet transform combining with directional filter banks. In particular, the traditional thresholding method is substituted by a novel and efficient method, Bayesian maximum a posteriori (MAP) estimation, to achieve more satisfying results. The performances of stationary wavelet transform, contourlet transform and stationary wavelet combining with directional filter banks for despeckling SAR images are compared through an experiment. Experiment results show this method not only suppresses the speckle noise effectively, but also preserves as many target characteristics of original images as possible. Besides, the recovered SAR image's visual effect is satisfying. (C) 2008 Elsevier Inc. All rights reserved.