A region-based approach to the estimation of local statistics in adaptive speckle filters

Radar images are inherently degraded by a strong, multiplicative noise known as speckle. The most frequently used speckle filters are adaptive in the sense that the filtering operation depends on estimations of local statistics calculated in a neighbourhood of the considered pixel. The choice of the neighbourhood is consequently an important issue. In this paper we introduce a new method which uses segmentations obtained prior to filtering. This region-based approach is compared to versions using sliding windows. The study is limited to agricultural scenes composed of distinct parcels of relatively homogeneous reflectivity. Without loss of generality, we have restricted ourselves to the LMMSE filter of Kuan et al. (1987).