关键词: 图像配准, Sobel算子, Keren改进算法

Abstract: In order to obtain high accurate，high stable registration core image，a registration method based on the edge characters and Keren algorithm is proposed.Firstly，the edges of reference images and images requiring registration are extracted.Then，these images are decomposed into Gauss pyramid structure.Finaly，the Keren algorithm is applied to core image registration from coarse to fine accuracy.The experiment shows that the method compared with Keren algorithm，they both have high registration accuracy in the case of a small rotation angle，but the former has lower absolute error in the case of a large rotation angle，and makes the absolute error of translation parameters under 0.1 pixel and under 0.1 degree in the case of a large rotation angle.So，the proposed method improves the accuracy of registration of the core images.

Key words: image registration, Sobel operator, Keren improvement algorithm