Hybrid deformable image registration using a closed-form free form deformation approach

This paper describes an efficient non-rigid image registration method using a B-spline based Free Form Deformation (FFD) model. The proposed method is very efficient, in that it utilises sparse feature correspondences to estimate an elastic deformation field in a closed form. In a multi-resolution manner, the method is able to recover small to large nonrigid deformations, and the resulting deformation field is globally smooth and guarantees one-to-one mapping between the two registered images.