SAR图像去噪方法研究论文

河南理工大学本科毕业论文I摘要合成孔径雷达(SAR)图像的相干斑噪声严重降低了图像的可解译度，影响了后续目标检测、分类和识别等应用。SAR图像的相干斑噪声是成像过程中出现的原理性缺陷。在过去的二十年里，国内外的诸多学者提出了大量抑制图像相干斑噪声的方法。其中大多数方法是利用一个定义好的滤波器窗口来估计相干斑图像局部噪声方差，然后在局部分别作滤波处理。结果表明这些方法在均匀的区域内能够大大削减相干斑噪声，而在非均匀区域内图像变得模糊或过于平滑而失去细节信息，降低了图像的空间分辨率，图像的解译性因此变差。理想的降噪方法是能在很好地保留边缘和细节信息的前提下抑制相干斑噪声。本论文的研究内容：（1）首先介绍了SAR图像及其噪声的国内外研究动态，然后简述了SAR图像噪声的形成机理。（2）重点对SAR图像斑点噪声的抑制算法进行了研究，对经典斑点噪声抑制算法(卷积滤波中的中值滤波；还有基于统计估计理论的Lee滤波算法及其增强算法、Kuan滤波算法、Frost滤波算法、小波滤波算法、均值滤波算法等)进行了原理说明。（3）结合实例，将各种算法的处理结果进行了分析和比较，对其效果和优缺点进行了评价。关键词：合成孔径雷达；噪声抑制；效果评价河南理工大学本科毕业论文IIABSTRACTThepresenceofspecklenoiseinthesyntheticapertureradar(SAR)images。severelyrestrictstheapplicationofthecoherentimages．Specklenoiseisgeneratedbythecoherentprocessingofradarsignals．Duringthepasttwodecades，manyspecklereductiontechniqueshavebeendevelopedforremovingospeckle．Anidealalgorithmshouldsmooththespecklewithoutblurrededgesandfinedetail．Butmostalgorithmscannotsatisfythesetwodemandsverywell．Thispapertheresearchcontent:(1)FirstintroducedtheSARandthenoiseoftheimageresearchdynamic,thenbrieflyintroducedtheformationmechanismoftheSARimagenoise.(2)FocusonstudyingthealgorithmofimagenoisesuppressionofSARspots,introducedtheprincipleoftheclassicspotsnoisesuppressionalgorithm(theconvolutionfiltermedianfiltering,andbasedonthestatisticalestimationtheoryoffilteralgorithmanditsenhancementalgorithmLeeKuan,filteralgorithm,Frostfilteralgorithm,waveletfilteralgorithm,averagefilteringalgorithm,etc).(3)Combinedwithanexample,allwiththeresultofthealgorithmisanalyzedandcompared,evaluatedtheireffects,advantagesanddisadvantages.Keywords:SAR;Noiseinhibition;Effectevaluation河南理工大学本科毕业论文III目录1绪论.........................................................................................................................................11.1SAR图像噪声抑制研究背景及其意义......................................................................11.2SAR图像纹斑噪声抑制的研究现状..........................................................................21.3本论文的研究内容.......................................................................................................62SAR图像常用去噪方法介绍................................................................................................82.1SAR图像噪声产生机理..............................................................................................82.2传统的SAR图像去噪方法.........................................................................................92.2.1均值滤波.............................................................................................................92.2.2中值滤波...........................................................................................................102.3基于自适应滤波的SAR图像去噪方法...................................................................102.3.1Lee滤波...........................................................................................................112.3.2增强Lee滤波..................................................................................................112.3.3Kuan滤波.........................................................................................................112.3.4Frost滤波..........................................................................................................112.3.5增强Frost滤波器.............................................................................................122.3.6Sigma滤波........................................................................................................122.3.7GammaMAP滤波............................................................................................132.3.8BitErros滤波...................................................................................................132.4其它的SAR图像去噪方法.......................................................................................142.4.1连续小波变换滤波...........................................................................................142.4.2离散小波变换滤波...........................................................................................153去噪实现与评价...................................................................................................................163.1各种去噪方法的实现.................................................................................................163.1.1SAR图像数据介绍...........................................................................................163.1.2图像的滤波结果...............................................................................................173.2图像滤波效果评价.....................................................................................................233.2.1相干斑噪声滤波算法的评价标准...................................................................233.2.2不同去噪方法的对比分析...............................................................................254结论展望...............................................................................................................................284.1论文研究内容总结.....................................................................................................284.2研究展望................................................