最速梯度法工具箱，可以在matlab上进行应用，非常方便-Toolbox steepest gradient method can be applied on the matlab is very convenient

两个代码一个是demo, demo是它的小样例子, 另外一个是它的源代码. - - This is the matlab implementation of following noise level estimation: Xinhao Liu, Masayuki Tanaka and Masatoshi Okutomi Noise Level Estimation Using Weak Textur