SAR Image Despeckling Based on Local Homogeneous-Region Segmentation by Using Pixel-Relativity Measurement
SAR Image Despeckling Based on Local Homogeneous-Region Segmentation by Using Pixel-Relativity Measurement
复制标题
基于像素相关性测量的局部均匀区域分割SAR图像去斑
DOI：
10.1109/tgrs.2011.2107915
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发表时间：
2011-07-01
影响因子：
8.2
通讯作者：
Gong, Maoguo
中科院分区：
文献类型：
--
作者：
Feng, Hongxiao;Hou, Biao;Gong, Maoguo
提出了一种基于像素相关性度量的局部邻域分割的逐点自适应散斑滤波算法。提出了一种比距离来度量两个散斑图像块之间的距离。从理论上证明了比率距离对乘性散斑的有效性，而传统的欧氏距离在这种情况下是无效的。推导了比值距离的概率密度函数，将比值距离映射为相对值。与基于高斯核投影的相对论测量方法相比，这种新的相对论测量方法无需参数设置，功能更强大。该方法成功地应用于对每个像素分割出一个局部形状自适应的均匀区域，并给出了一种简化的分割实现策略。分割后，最大似然准则被引入到估计每个均匀区域内的真实信号。提出了一种新的基于平均值比值的边缘保持度评价方法，可以对边缘保持度进行更精确的定量评价。视觉和数值实验结果表明，该滤波器优于现有的最先进的去斑滤波器。
This paper provides a novel pointwise-adaptive speckle filter based on local homogeneous-region segmentation with pixel-relativity measurement. A ratio distance is proposed to measure the distance between two speckled-image patches. The theoretical proofs indicate that the ratio distance is valid for multiplicative speckle, while the traditional Euclidean distance failed in this case. The probability density function of the ratio distance is deduced to map the distance into a relativity value. This new relativity-measurement method is free of parameter setting and more functional compared with the Gaussian kernel-projection-based ones. The new measurement method is successfully applied to segment a local shape-adaptive homogeneous region for each pixel, and a simplified strategy for the segmentation implementation is given in this paper. After segmentation, the maximum likelihood rule is introduced to estimate the true signal within every homogeneous region. A novel evaluation metric of edge-preservation degree based on ratio of average is also provided for more precise quantitative assessment. The visual and numerical experimental results show that the proposed filter outperforms the existing state-of-the-art despeckling filters.