利用经验模态分解方法抑制SAR斑点噪声  

Speckle Suppression Using the Empirical Mode Decomposition

作　　者：韩春明[1] 郭华东[1] 王长林[1] 

机构地区：[1]中国科学院遥感应用研究所遥感信息科学重点实验室,北京100101

出　　处：《遥感学报》2002年第4期266-271,共6页NATIONAL REMOTE SENSING BULLETIN

基　　金：国家自然科学基金重点项目 ( 4 99890 0 1) ;中国科学院知识创新工程重要方向项目 (KZCX2_312 )的支持

摘　　要：提出了一种利用经验模态分解 (EMD)方法抑制SAR斑点噪声的方法。利用经验模态分解方法 ,可以将SAR图像分解为一系列的以空间周期尺度不同为特征的模态 ,定义空间特征周期尺度不大于 4的为噪声。通过从图像中减掉噪声成分使SAR斑点噪声得以抑制。用这种方法处理SAR图像在斑点抑制和纹理信息保持两方面取得了令人满意的结果。An effective algorithm for suppressing speckle in synthetic aperture radar(SAR)images utilizing the empirical mode decomposition(EMD)method is presented in this paper.The EMD was proposed by Norden E Huang et al .,with which any complicated data set can be decomposed into a finite and often small number of intrinsic mode functions.Contrary to almost all previous methods,this new method is intuitive,direct,a posterior and adaptive,with the basis of the decomposition based on,and derived from,the data.So EMD is quite suitable for analyzing nonlinear and non_stationary data.A line of digital SAR images can be decomposed into a series of modes whose characteristic space scale defined by the space lapse between the extrema is different.The speckle noise is defined by the mode whose space scale is not more than 4.The SAR speckle suppression is implemented by smearing short space scale component in the spatial domain via the EMD.As the EMD is one_dimensional method,we use EMD in the following way.First we process each horizontal row of pixels,then process each column pixel of image. EMD is based on and derived from the data,thus it is adaptive and can preserve the edge information.Application to SAR images has shown that the performance of the algorithm is satisfactory in both smoothing and edge preservation.

关 键 词：经验模态分解方法 斑点噪声 SAR EMD 空间特征周期尺度 遥感图像 

分 类 号：TN957.52[电子电信—信号与信息处理]