Nonlocal Filtering for Polarimetric SAR Data: A Pretest Approach.

A pretest approach based on the complex Wishart distribution in polarimetric synthetic aperture radar (POLSAR) speckle filtering is proposed in this paper. The main principle is to select homogeneous pixels in a large-scale area in the filtering process, which is called pretesting. To preserve details and fine structures while despeckling, the homogeneous pixels are selected by comparing their 3 ×...