Improved non-local mean filtering method for PolSAR images

In order to better preserve the structural information and polarization scattering information while suppressing speckle, an adaptive non-local mean filtering algorithm based on coefficient of variance (C.V) is proposed. The algorithm combines the statistical properties of the image sub-blocks with the polarization scattering characteristics of the target points to filter the homogeneous pixels, then introduces the C.V adaptive selection smoothing coefficients to calculate the weights used for filtering, and finally performs non-local mean filtering on the homogeneous pixels. The experimental results of polarimetric synthetic aperture radar data collected by different systems show that compared with the refined LEE filter, NL-Pretest filter and the latest filter, the proposed algorithm can effectively remove the speckle noise, and the edge and polarization scattering characteristics of the image are better maintained. © 2019, Editorial Office of Systems Engineering and Electronics. All right reserved.