Building detection and description from a single intensity image

We describe a method to detect buildings and construct 3-D shape descriptions of buildings from a monocular aerial image with a general viewpoint. A grouping process is used to generate 2-D roof hypotheses from fragmented linear features extracted from the input image. Good hypotheses are selected based on 2-D evidence and some local 3-D evidence. These are then verified by searching for 3-D evidence, consisting of shadows cast by the roof and the walls associated with it. This process also helps construct 3-D models of the verified buildings, Overlap and containment relations between 3-D structures are analyzed to resolve conflicts. This method also allows for the integration of results obtained from multiple images. This system has been tested on a large number of real examples with good results, some of which, along with their evaluation, are included in this paper. (C) 1998 Academic Press.