基于非局部分类处理的SAR图像降斑

发布时间：2019-07-13 20:36

【摘要】：针对合成孔径雷达(synthetic aperture radar,SAR)图像不同内容间的统计特性差距较大以及采用非局部降斑方法处理SAR图像时会产生图像细节丢失及伪影等现象,提出了一种基于非局部分类处理的SAR图像降斑方法。首先对相似块方差系数的均值采用阈值比较的方法将图像分为同质区和异质区,在寻找目标块对应的相似块时,根据图像块中心像素点所属的类别选择合适的参数进行块匹配,并在获得相似块后分别使用加权平均的方法处理同质区目标块和3D变换域硬阈值收缩方法处理异质区目标块。该方法不仅能在块匹配过程中选择不同的块尺寸和搜索范围以提高块匹配的精度,而且使用不同方法处理同质区和异质区时能够在图像降斑与细节保持的权衡中达到更好的平衡。实验结果表明,该方法充分利用同质区和异质区的特点,结合不同的方法进行分类处理可有效提高图像降斑性能,在SAR图像降斑性能指标和视觉效果方面均达到了较高水平。
[Abstract]:Aiming at the large difference of statistical characteristics between different contents of synthetic aperture radar (synthetic aperture radar,SAR) images and the loss of image details and artifacts when SAR images are processed by nonlocal speckle reduction method, a SAR image speckle reduction method based on non-local classification processing is proposed. Firstly, the mean value of similarity block variance coefficient is divided into homogeneous region and heterogeneous region by threshold comparison. When finding the similar block corresponding to the target block, the appropriate parameters are selected according to the category of the central pixel point of the image block to carry out block matching, and after obtaining the similar block, the weighted average method is used to deal with the homogeneous region target block and the 3D transform domain hard threshold contraction method to deal with the heterogeneous target block. This method can not only select different block sizes and search ranges in the process of block matching to improve the accuracy of block matching, but also achieve a better balance in the tradeoff between image speckle reduction and detail maintenance when different methods are used to deal with homogeneous and heterogeneous regions. The experimental results show that this method can effectively improve the image speckle reduction performance by making full use of the characteristics of homogeneous region and heterogeneous region, and can effectively improve the image speckle reduction performance by combining different methods, and the SAR image speckle reduction performance index and visual effect have reached a high level.
【作者单位】：重庆大学通信工程学院;
【基金】：国家自然科学基金(61301224) 中央高校基本科研业务费(CDJZR11160003;CDJZR10160003;CDJZR12160014;CDJZR13160008) 重庆市自然科学基金(cstc2012jjA40001) 重庆市科技攻关计划(cstc2012gg-yyjs0572)资助课题
【分类号】：TN957.52

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