瑞利分布，主要实现锐利分布的某些特征，非常的不错。-Rayleigh distribution, mainly the distribution of certain characteristics to achieve sharp, very good.

ContourletSD: MATLAB code implementing the new contourlet transform with sharp frequency localization as described in the following paper. Y. Lu and M. N. Do A new contourlet transform with sharp frequency localization. Proc. IEEE Internatio