In this paper, a new method of 2D inhomogeneous and non-parametric image registration with sub-pixel accuracy is proposed. The method is based on the invocation of deformation operators which imitate the deformations expected to be observed when a landslide occurs. The similarity between two images is measured by a similarity function which takes into consideration grey level value correlation and geometric deformation. The geometric deformation term ensures that the minimum necessary deformation compatible with the two images is employed. An extra term, ensuring maximum overlap between the two images is also incorporated, in order to avoid the pitfall of finding maximum correlation coefficient with minimum overlap. Sub-pixel accuracy is achieved by manipulating lists of pixels (real valued positions and corresponding grey values) rather than integer grid positions conventionally used to represent images. Landsat 5 TM images of southern Italy are used for the experiments.