ROBUST TECHNIQUES FOR ESTIMATING PARAMETERS OF 3D BUILDING PRIMITIVES

A semi-automatic building extraction system using two or more digitized overlapping aerial images has been enhanced by increased automation for the measurement of saddleback-roof (lopsided and symmetric) buildings, hip-roof buildings and flatroof building (boxes) . The goal is to minimize the interaction an operator has to do for measuring the form and pose parameters of 3D building models of the above mentioned types. The automated tasks are computed on-line and fully integrated in the work flow. Thus accepting or correcting the results or adapting the automated calculation is possible. The used methods are grey value correlation for absolute heights and the robust estimation techniques RANSAC and Clustering for the determination of heights and the other form parameters of the building primitives. These methods work on automatically extracted line segments. The automated modules have been empirically evaluated on more than 250 buildings in two datasets with different image quality and different densities of built-up areas. The results of these tests show a success rate of up to 88% for a form parameter estimation module and the height measurement.