A Wavelet-Based Filter for SAR Speckle Reduction and the Comparative Evaluation on Its Performance
基于小波分析的SAR图像斑点滤波及其性能比较评价

Speckle noise is a common phenomenon in SAR images. The reduction of Speckle is necessary for any further processing of SAR image such as segmentation, classification and other procedures for information extraction. ln this paper, after a brief review of conventional filters for SAR speckle reduction, a wavelet-based soft-thresholding filter for SAR speckle reduction is presented. To evaluate the performance of this filter, the adaptive local statistics filters, which include Lee, Frost, Enhanced Lee, Enhanced Frost, Kuan, and the Gamma-Map filter, are applied to the speckle reduction for the same type SAR image. The performances are compared in several aspects including Radiometric preservation, feature preservation, speckle reduction in the extended uniform regions and the absence of artifacts. The results show that the wavelet-based speckle reduction filter performs better in every aspect in evaluation than the conventional filters do.