Semi-automatic generation of highly detailed textured building models

• Applicant: Professor Dr.-Ing. Wolfgang Förstner
• Subject Area: Geodesy, Photogrammetry, Remote Sensing, Geoinformatics, Cartography
• Term: from 2005 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5457183

The aim of the project is to develop of models, methods, and tools for the semi-automatic, interactive refinement of 3D city models. Starting from models of level of detail 2 (LOD 2), consisting of simple detailed building models with ground edges, stairs, balconies, windows, doors, and textures. Focus ison 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 ofambiguities 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. The novelty of the approach is (1) the specification of highresolution object models which cope with the inherent inconsistencies between the high resolution image data and the envisaged level of detail in a 3D GIS with respect to a plausible visualisation, and (2) the reconstruction of the instantiated object model from crudely geo-referenced possibly uncalibrated images and its generalization according to the model specification. In the first two years we develop the 3D object model integrating vector and raster data, and demonstrate the fusion ofdigital elevation model data, 3D building data and image data for achieving a consistent and visually plausible object description in the context of building collars. We restrict to scenes with a low degree of occlusion. In the last year we increase efficiency of the interpretation process and increase the complexity of the tackled scenes, especially with respect to occlusions.

• DFG Programme: Research Grants
• International Connection: China
• Participating Persons: Professor Dr. Jun Chen; Professor Dr. Thomas H. Kolbe; Professor Dr. Lutz Plümer