3-D reconstruction of urban scenes from aerial stereo imagery: A focusing strategy

A contribution to the automatic 3-D reconstruction of complex urban scenes from aerial stereo pairs is proposed. It consists of segmenting the scene i nto two different kinds of components: the ground and the above-ground obje cts. The above-ground objects are classified either as buildings or as vege tation. The idea is to define appropriate regions of interest in order to a chieve a relevant 3-D reconstruction. For that purpose, a digital elevation model of the scene is first computed and segmented into above-ground regio ns using a Markov random field model. Then a radiometric analysis is used t o classify above-ground regions as building or vegetation, leading to the d etermination of the final above-ground objects. The originality of the meth od is its ability to cope with extended above-ground areas, even in case of a sloping ground surface. This characteristic is necessary in a urban envi ronment. Results are very robust to image and scene variability, and they e nable the utilization of appropriate local 3-D reconstruction algorithms. ( C) 1999 Academic Press.