Abstract: An operator based on Mexican hat function was used for image local area and feature point detection．Then an image registration algorithm using the two kinds of features was proposed．The Mexican hat operator combining zero-crossing is used for local areas detection,and the feature points are detected by the operator on the different scale space．The image is partitioned into several regions by the local areas and the regions are matched．Then the points are grouped by the regions and matched in each group respectively．At last the image transaction function is gotten by the grouped random sample consensus．The algorithm in this work is based on two kinds of image feature detection and matching using the Mexican hat function,and the experimental results show that the proposed algorithm has high alignment accuracy and small computational volume．

Key words: Mexican hat,Feature detection,Feature matching,Image registration