说明：  比较了软阈值，硬阈值及当今各种阈值计算方法,sar图像去噪的几种新的方法，计算互信息非常有用的一组程序。
( Comparison of soft threshold and hard threshold and today various threshold calculation method, Several new methods sar image denoising, Mutual information is useful to calculate a set of procedures.)