基于盲估计和双边滤波的SAR图像稀疏降噪  

SAR Image Sparse Denoising Based on Blind Estimation and Bilateral Filtering

作　　者：孙雨 辛志慧 黄鹏辉 王志旭 宣嘉裕 Sun Yu;Xin Zhihui;Huang Penghui;Wang Zhixu;Xuan Jiayu(Yunnan Key Laboratory of Opto-Electronic Information Technology,School of Physics and Electronic Information,Yunnan Normal University,Kunming 650500,Yunnan,China;Department of Electronic Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]云南师范大学物理与电子信息学院云南省光电信息技术重点实验室,云南昆明650500 [2]上海交通大学电子工程系,上海200240

出　　处：《激光与光电子学进展》2023年第16期68-79,共12页Laser & Optoelectronics Progress

基　　金：云南省自然科学基金(202201AT070027);国家自然科学基金(61801419,62171272)。

摘　　要：合成孔径雷达(SAR)在成像过程中由于固有成像机制的缺陷导致图像被乘性噪声污染,图像噪声对后续目标检测识别等处理过程造成了阻碍。现有的去噪算法存在不能自适应估计噪声大小和对边缘保持效果不理想的问题,如何自适应处理不同噪声水平的图像是一个研究难点。提出一种基于盲估计和双边滤波的SAR图像稀疏去噪算法。首先利用双边滤波得到具有良好边缘保持特性的预处理图像;接着利用盲估计获取图像全域噪声水平,将其充当稀疏重建过程中的残差阈值;最后利用稀疏编码和字典学习算法,用尽可能少的原子信息来表示图像,达到图像去噪的目的。实验结果表明,结合了盲估计的稀疏重建算法不仅有效去除了图像噪声,使等效视数获得了显著提升,而且峰值信噪比和边缘保持指数也有良好的表现,有效保留了原图的细节纹理信息。Synthetic aperture radar(SAR)images are contaminated by multiplicative noise during the imaging process because of flaws in SAR’s innate imaging mechanism;the image noise makes it difficult to analyze targets and detect changes.Existing denoising algorithms cannot adaptively estimate the noise size,and the edge preservation effect is not ideal.Additionally,it can be difficult to work out how to adaptively analyze images with different noise sizes.As a result,this work proposes a sparse denoising algorithm for SAR images based on bilateral filtering and blind estimation.First,bilateral filtering was employed to obtain preprocessed images with good edge-preserving properties,and then the blind estimation was utilized to determine the global noise level of the images,which acted as a residual threshold in the sparse reconstruction process.To achieve the goal of image denoising,sparse coding and dictionary learning algorithms were employed for representing the image using the least amount of atomic information possible.The experimental findings demonstrate that the sparse reconstruction algorithm combined with blind estimation not only effectively removes image noise and improves the equivalent numbers of looks,but also performs well for peak signal-to-noise ratio and edgepreserving index,effectively preserving the detailed texture information of the original image.

关 键 词：合成孔径雷达 稀疏表示 图像降噪 盲估计 双边滤波 

分 类 号：TP75[自动化与计算机技术—检测技术与自动化装置]