关键词: 医学图像配准, 互信息, 灰度压缩

Abstract: The medical image registration based on mutual information can reach sub-pixel accuracy and don’t need to extract anatomical features from images，is a high-precision sound registration way.But frequent involving a large number of floating-point calculation of the mutual information，the registration rate is slow，can not meet the demands of real-time.This paper presents a statistical gray histogram mutual information compression method can significantly reduce the amount of computation mutual information，thus speeding up the registration rate.The experiments show that the method can reduce the registration time under the premise not affect the accuracy of registration.

Key words: medical image registration, mutual information, gray-scale compression