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利用经验模态分解和主成分分析的SAR图像相干斑抑制

王文波1,赵攀1,张晓东2   

  1. 1. 武汉科技大学
    2. 武汉大学
  • 收稿日期:2011-10-10 修回日期:2012-07-11 出版日期:2012-12-25 发布日期:2013-04-17
  • 通讯作者: 王文波

Research on SAR Image Speckle Reduction Using EMD and Principle Component Analysis

  • Received:2011-10-10 Revised:2012-07-11 Online:2012-12-25 Published:2013-04-17

摘要:

对SAR图像应用对数加性噪声模型,将经验模态分解(Empirical mode decomposition, EMD)与主成分分析(Principal Component Analysis, PCA)相结合,提出了一种基于PCA的EMD相干斑抑制算法。根据对数SAR图像中相干斑噪声的统计特性和高斯白噪声经EMD分解后的能量分布模型,近似估算SAR图像经EMD分解后各层内蕴模态函数中所含噪声的能量;将内蕴模态函数利用PCA进行分解,根据PCA对含噪信号的分解特性和内蕴模态函数中噪声能量所占的比例,选择合适的成分分量重构内蕴模态函数,以进一步去除噪声保留有用的细节信息。仿真实验结果表明,本文方法在有效抑制相干斑噪声的同时可以较好地保持边缘纹理细节的清晰。

关键词: 经验模态分解, SAR图像, 相干斑抑制, 主成分分析

Abstract:

By combining the empirical mode decomposition(EMD) and principle component analysis(PCA), a new speckle reduction method based EMD is proposed for logarithmic SAR images. Based on the Statistical properties of logarithmically transformed speckle and energy distribution model of decomposed Gaussian white noise by EMD, the noise energy in each intrinsic mode function is approximately calculated. After the intrinsic mode function is decomposed by PCA, to further remove the noise and keep useful details, we select the appropriate principal components according to the noise energy proportion in intrinsic mode function and the decomposition characteristics of PCA, then reconstruct the intrinsic mode function by the selected principal components. The experimental results show that the SAR image edges are retained better and the speckles are removed effectively with the proposed method.

Key words: empirical mode decomposition, SAR image, speckle reduction, principle component analysis