Building acquisition, textured building models, integration of GIS-technology and image analysis

• Applicant: Professor Dr.-Ing. Wolfgang Förstner
• Subject Area: Geophysics
• Term: from 2007 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 62011057

The aim of the project is to develop models, methods, and tools for the semi-automatic, interactive refinement of 3D city models. Starting from models of level of detail 2 (LOD2), consisting of simple building blocks and roof structures, the refinement leads to models of LOD3, namely detailed building models with ground edges, stairs, balconies, windows, doors and textures. Focus is on the transition between building facades and the digital elevation model, the so-called building collar. The main component is a 3D spatial database which integrates vector building models and aerial and terrestrial raster images. A carefully designed user interface supports the interactive resolution of ambiguities in the interpretation of the images. For the integration of geometry and texture an evaluation function will be developed which balances the inextricable conflict between model and image with respect to visual plausibility. In the first phase we have developed an ontology, work flow scenarios, generic models and procedures for reconstructing stairs as the main link between the terrain and a building. In the second phase we focus on more general parts of the building collar, on the integration into an interactive system, especially using stochastic grammars, Bayesian networks, possibly also Markov-Random fields and Monte Carlo techniques for a reliable recovery of essential structures. The novelty of the approach is (1) the specification of high resolution object models, (2) the reconstruction of the instantiated object model from geo-referenced point clouds and its generalization according to the model specification. (3) the integrated use of stochastic attribute grammars and graphical models for image interpretation.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Lutz Plümer