基于自适应非局部均值的SAR图像相干斑抑制  

SAR image despeckling based on adaptive non-local means

作　　者：陈世媛 李小将 CHEN Shiyuan;LlX iaojiang(Colledge of Postgraduate , Academy of Equipment, Beijing 101416 , China;DeprrLmenL of Space Equipment, Academy of Equipment, Beijing 101416 , China)

机构地区：[1]装备学院研究生院,北京101416 [2]装备学院航天装备系,北京101416

出　　处：《系统工程与电子技术》2017年第12期2683-2690,共8页Systems Engineering and Electronics

基　　金：国家高技术研究发展计划(863计划)资助课题

摘　　要：针对在利用非局部均值方法对合成孔径雷达(synthetic aperture radar,SAR)图像降斑时,存在的图像块相似性度量不准确、鲁棒性不高等问题,提出了一种基于自适应非局部均值的SAR图像相干斑抑制方法。首先,定义平滑度以刻画图像不同区域的纹理复杂程度,并设计自适应匹配函数,自适应地确定图像块和搜索窗口的大小,以提高块相似性度量的准确性,并在此基础上提出了自适应非局部均值算法框架。然后,利用Gabor滤波器对图像块的相似性进行度量,以增强块相似性度量的鲁棒性,并以所提框架为依据,设计了基于Gabor滤波器的自适应非局部均值算法。实验结果表明,所提算法不仅能够有效去除相干斑噪声,而且较好地保持了图像的纹理、边缘、点目标等信息,为后期SAR图像的理解与解译奠定了良好的基础。To deal with the shortage of inaccuracy and low-level robustness of block similarity measure for synthetic aperture radar（SAR）image despeckling using the traditional non-local means method,a new SAR image despeckling method based on adaptive non-local means is proposed.Firstly,the smoothness which is defined to measure image texture complexity is used to design the matching functions,and on the basis of those functions the size of image block and search window can be adjusted adaptively in order to improve the accuracy of block similarity measure.As a result,a framework of the adaptive non-local algorithm is proposed.Secondly,the block similarity is measured by the Gabor filter for enhancing the robustness of block similarity measure,and an adaptive non-local means method based on Gabor filter is presented when combined with the proposed framework.The experiment results show that the proposed method can not only reduce speckle efficiently,but also preserve the texture,edges and targets well,which lies the foundations for the understanding and interpretation of SAR images.

关 键 词：合成孔径雷达 自适应块匹配 块相似性度量 GABOR滤波器 

分 类 号：TP751.1[自动化与计算机技术—检测技术与自动化装置]