All Direction Enhancement Adaptive Filter and Its Application in Smoothing Speckle Noise of SAR Images

doi:10.11834/jig.19960232

Views : 0 下载量: 53 CSCD: 0

PDF
Export
Share
Collection
Album

All Direction Enhancement Adaptive Filter and Its Application in Smoothing Speckle Noise of SAR Images
Vol. 1, Issue 2, Pages: 115(1996)
Published Online：20 March 2012，

Published：1996
DOI： 10.11834/jig.19960232
稿件说明：

移动端阅览

DOI：

All Direction Enhancement Adaptive Filter and Its Application in Smoothing Speckle Noise of SAR Images[J]. Journal of Image and Graphics, 1996, 1(2): 115. DOI： 10.11834/jig.19960232.

摘要

合成孔径雷达图象的斑点噪声是由于合成孔径雷达（SAR）发射的相干干涉波产生的，它严重地影响了合成孔径雷达图象的质量和应用。为了更好地平滑噪声，保护边界和纹理信息，本文在分析和实现适应于SAR图象的各种局域自适应滤波器的基础上，实现了一种新的改进的全方向增强的局域自适应滤波器，它是把（2N＋1）＊（2N＋1）的滤波子窗口分成4N个子窗口，根据不同的子窗口中的局域变化系数来进行滤波，结果表明，这种全方向增强的局域自适应滤波器在保护地物的辐射特性和图象的纹理信息以及增强图象的微细节等方面，均比以前的滤波器有较大的提高。

Abstract

peckle noise

which originates physically from coherent interference of back-scattered electromagnetic radiation from the multiple scattering elements in a ground illumination cell

makes the radiometric and textural aspects less efficient for application of SAR image. In order to average speckle in the homogeneous areas

preserve edges and linear features

many adaptive filters are analyzed in this paper.A new modified adaptive filter-all direction enhancement adaptive filter are developed in which the (2N *2N) sliding window is divided into 4N subwindows

and the filter works according to the local coefficient of variation of the subwindows. The experiment results indicated that the modified filter performs better than the older ones. It reduces speckles and preserve structural features

edges and small details in all directions in the meanwhile.