SAR图像斑点噪声滤除方法应用研究

Study on the application of speckle noise filtering methods in SAR images

SAR图像中相干斑点噪声的滤除方法很多,在不同情况下选择不同滤波方法的研究急待进行。分别利用常用空间域滤波方法和数种小波系数滤波算法对4幅不同的SAR图像进行斑点噪声的滤除,分析了各自在不同图像滤波中的优缺点,为在不同情况下使用不同的滤波算法提供了一种经验性分析结果。在大量实验的基础上,得到了小波滤波阈值系数比例值为1 5时的较好的滤波效果,利用小波变换细节子图间的近似比例关系,提高了运算的速度。

There are many methods in the field of speckle noise filtering in SAR images, however, it is necessary to study how the methods are selected in different ATR missions. Speckle noise filtering in space and wavelet based methods are used to reduce the speckle in four different SAR images. Analysis is done to compare the merits of different methods. On the basis of experiments, it is observed that the favorable threshold coefficent is 1.5. According to the approximate scale relation of wavelet detailed coefficient sub-images, a new algorithm is proposed to get a higher speed.