高分辨率SAR图像相干斑噪声抑制方法

Approach for Coherent Speckle Reduction in High Resolution SAR Images

文章主要提出了一种新的基于小波变换对高分辨率合成孔径雷达(SAR)图像相干斑噪声抑制的算法。首先从SAR图像相干斑噪声产生的机理出发,论述了通过传统的滤波方法,在抑制高分辨率SAR图像的相干斑噪声的同时损失了大量的边缘信息和纹理细节而采用小波变换降噪的优越性和必要性;其次详细地论述了在小波域中如何利用高频局部的统计特性和分解尺度大小来选取滤波窗口尺寸进行滤波;最后通过实验结果说明了此方法比采用传统的固定窗来实现对高分辨率SAR图像的降噪、保留边缘信息和纹理细节有着更好的性能。

This paper mainly deal with a new speckle reduction algorithm in high resolution SAR images based on wavelet transform. First of all, the reason of generating speckle in SAR image is interpreted, A great deal of edge and texture were damaged when the speckle of high resolution SAR images were reduced by some traditional methods , the advantage and the necessity of speckle reduction based on wavelet transform for reducing speckle are discussed ; Secondly, it is expounded in detail how to select the size of a filter window which based on local statistics in each subband and the scale of decomposition for reducing speckle in wavelet transform domain; Finally, Experimental results show that proposed method has better reducing speckle and edge preservation performance over the conventional filter with a window of fixed size.