1. In a computer, a method of non-rigid image registration between a fixed image and a moving image, comprising the steps of: (a) detecting feature points on the fixed image and feature points on the moving image; (b) assigning a feature vector to each feature point; (c) calculating the dissimilarity of each pair of feature vectors for feature pairs on the fixed image and the moving image; (d) calculating the correspondence between feature pairs based on dissimilarity measure: Xi and Xi′; (e) solving for a dense deformation field P using a closed form free form deformation (FFD) model; and (f) transforming the moving image and the feature points on the moving image using a current FFD deformation field estimate.