Global image registration aimed at finding a transformation aligning two images can be approximated by estimating parameters of affine deformations. Some of the existing methods are inapplicable to binary images. The burden of computation process in other methods is more expensive. In this paper

we modified the definition of centroid for images and proposed the concept of generalized centroid. By combining the generalized centroid

we proposed an algorithm to achieve the estimation for parameters of affine deformations. Unlike the traditional centroid

the generalized centroid is defined by a modified repeated integral. The traditional centroid is only a special case of the proposed generalized centroid. To maintain the affine deformation relation

we present the condition in which the generalized centroid needs to be satisfied. We propose an algorithm to achieve the estimation for parameters of affine deformations. The basic idea of the algorithm is that we should find three sets of corresponding points in the original image and corresponding deformation image using these three pairs of points and establish equations to determine the parameters of affine deformations. The proposed centroids are applicable not only to gray images but also to binary images. Compared with the cross-weighted moment method to estimate the parameters of affine deformations

the proposed method requires less calculation and the recovery effect of the two methods is not significantly different. Compared with the method of constructing a nonlinear equation group using the image moment

the proposed method has a good ability to estimate the parameters of affine deformations. By combining the generalized centroid

we proposed an algorithm to achieve the estimation for parameters of affine deformations. The proposed method is applicable to gray images and binary images. Moreover

the recovery effect is better and the calculation is less.