Automatic Object Extraction from Aerial Imagery – A Survey Focusing on Buildings Helmut Mayer Chair for Photogrammetry and Remote Sensing, <s> Outstanding Issues for Model and Strategy <s> Applications such as landscape planning, environmental monitoring, and flight and driving simulators have a high demand for realistic landscape models. Quantity, precision and the type of models ask for methods which automate the model generation by evaluation of remote sensing data. The presented modelling system AIDA tackles the demand for efficient representation and high realism by integrating a priori knowledge about the appearance of the objects in the scene to drive object specific constraints for 3D reconstruction. This requires an image interpretation to assign a meaning to the objects in the scene. For explicit representation of the declarative and procedural knowledge a problem independent formalism based on semantic nets and rules is used. It provides both a data driven and model driven control strategy. <s> BIB001 </s> Automatic Object Extraction from Aerial Imagery – A Survey Focusing on Buildings Helmut Mayer Chair for Photogrammetry and Remote Sensing, <s> Outstanding Issues for Model and Strategy <s> Abstract Abstraction, which is defined here as the increase of the degree of simplification and emphasis, is of major importance for object extraction. In this paper it is shown theoretically as well as empirically, how so-called scale-space events for lines define multiple abstraction levels for roads in images. The investigations are based on different scale-spaces as well as on a sophisticated model for line extraction for which the scales where events occur can be determined analytically. As one result of the investigations, a model is derived which is used in a multi-scale, multi-abstraction level road extraction system. <s> BIB002 </s> Automatic Object Extraction from Aerial Imagery – A Survey Focusing on Buildings Helmut Mayer Chair for Photogrammetry and Remote Sensing, <s> Outstanding Issues for Model and Strategy <s> Thank you very much for downloading semantic modeling for the acquisition of topographic information from images and maps smati97. Maybe you have knowledge that, people have search hundreds times for their chosen readings like this semantic modeling for the acquisition of topographic information from images and maps smati97, but end up in malicious downloads. Rather than enjoying a good book with a cup of tea in the afternoon, instead they juggled with some harmful virus inside their computer. <s> BIB003
The importance of three outstanding issues has become clear only recently. First, scale or resolution of an image are not only important due to their link to the observability of objects or parts of objects. More importantly, by the abstraction in the coarse scales generated by scale-spaces, features in the image such as lines can be linked directly to objects like roads   BIB002 . Second, the context and its spatial organization renders a highly effective means to impose structure on the knowledge BIB001  BIB003 . This makes it possible to construct large consistent models and strategies tackling the complexity of the objects. Third, the 3D-structure of objects such as vegetation and especially buildings is the key to their recognition. There are two ways which ideally should be combined: DSM are quite effective for detecting vegetation and buildings    . The reliability is improved considerably if a DSM from active laser scanning is used    .