by Stefan Krüger, Andrew Calway.
“This report describes a novel method for estimating motion in image sequences. The approach is based on a multiresolution model in which the motion field is considered to consist of a collage of different size regions with different local motions associated with them. The local motions are defined in terms of an affine model. The estimation procedure consists of a local component in which the affine motion parameters are estimated using a generalised correlation technique and a global component”

http://citeseer.ist.psu.edu/kruger96multiresolution.html