Speckle Filtering by Generalized Gamma Distribution

Synthetic aperture radar (SAR) image contains undesired artifacts in the form of a granular look, which is called speckle. Methods previously proposed for speckle noise filtering suffer from two major limitations: 1) noise attenuation is not sufficient, especially in the smooth and background areas; 2) existing methods do not preserve or enhance edges sufficiently-they only inhibit smoothing near edges. The proposed method is capable of reducing the speckle more effectively than previous methods and jointly enhancing the edge information, rather than just inhibiting smoothing. Our method employs the generalized gamma distribution (GGD) to model the SAR images and adopts maximum-likelihood method to estimate GGD´s parameters, which use for constructing the speckle filter. Finally, the proposed method is evaluated and compared to well-accepted methods through real data.