极化SAR改进Lee滤波相干斑抑制研究

Speckle Reduction for Polarimetric SAR Images by Improved Lee Filter

针对Lee滤波总存在降低相干斑与有效保持细节信息这一矛盾,将自适应窗引入极化SAR滤波。该方法首先在span图像中根据窗内像素与窗边缘像素分布特性决定是否扩大窗口,在均质区域选择较大窗口,保证了一定的相干斑抑制能力,而在细节信息比较丰富的区域则选择较小窗口,避免细节信息被滤除,然后在选定的窗口中利用极化Lee滤波对数据进行相干斑抑制,在保证相干斑抑制能力的同时保留了细节信息。

An improved speckle reduction algorithm for polarimetric SAR image based on the local adaptive processing is proposed. This algorithm automatically adjusts the size of the filter window according to distributed characteristic of the pixels in and around the window in the span image. The window size is expanded in the homogeneous area to suppress speckle noises, while the window size is reduced in the area that contains abundant details. This algorithm has the advantages of effectively reducing the speckle noise and keeping the detail. Experiments demonstrate the effectiveness of the proposed method.