A Trilateral Filter for Video SAR Speckle Noise Reduction

This letter proposes a trilateral filtering algorithm for speckle reduction in video synthetic aperture radar (video SAR). The novel filter takes traditional bilateral filter as the basic framework, so as to fully exploit the similarities of gray levels and the spatial location of neighboring pixels. Moreover, the proposed trilateral filter additionally exploits the temporal correlation information among adjacent image frames of the SAR videos and effectively reduces the interference of redundant information by using an adaptive similar frame selection technology. Comprehensively considering the three-dimensional (3-D) correlation information of spatial, temporal, and gray scale, a triple-similarity kernel is specifically developed for video SAR despeckling. The proposed trilateral filter can effectively smooth the speckle noise while greatly sustain the details of each image frame of the SAR videos. Experiments show that the proposed algorithm has better despeckling performance compared with other algorithms.