Eigenmethod for feature matching of pre- and post-event images exploiting adjacency

With the continuing increase in the number of images collected every day from different sensors, automated registration of multisensor/multispectral images has become a very important issue. This is especially true when pre- and post-event image comparison is concerned: for this particular application, the requirement of obtaining the earliest possible post-event image imposes the use of data potentially possessing significantly different characteristics with respect to the pre-event image. Strongly inhomogeneous image pairs require robust automatic registration techniques, preferably based on resolution-independent, feature-based registration. In a previous paper we proposed a mode-based feature matching scheme, mutated from the computer vision domain and adapted to pre- and post-event feature matching. Some of the weakpoints highlighted in that first version are addressed in this paper, where a new version of the method is proposed which exploits a new piece of information, i.e. the adjacency between feature points, generally preserved across the disaster event. Extensive generation of synthetic cases allowed obtaining significant feedback and consequently tuning the algorithm. Three real cases of pre-post event feature matching on high resolution satellite images are shown and discussed.