本代码是利用互信息法进行配准，多分辨率优化地刚性配准。-The code is the use of mutual information registration method, multi-resolution optimization to rigid registration.

从国外找到的matlab信息论工具箱，比较实用，可以求随机变量的互信息和熵。-Matlab information toolbox, including m files for computing multual information and entropy.