@incollection{BrunnDrauschkeKulschewskietal., author = {Brunn, Ansgar and Drauschke, Martin and Kulschewski, Kai and F{\"o}rstner, Wolfgang}, title = {Automatic Dodging of Aerial Images}, series = {Publikationen der DGPF, Band 16: Von der Medizintechnik bis zur Planetenforschung - Photogrammetrie und Fernerkundung f{\"u}r das 21. Jahrhundert}, booktitle = {Publikationen der DGPF, Band 16: Von der Medizintechnik bis zur Planetenforschung - Photogrammetrie und Fernerkundung f{\"u}r das 21. Jahrhundert}, address = {Muttenz (Schweiz)}, pages = {173 -- 180}, abstract = {We present an automated approach for the dodging of images, with which we edit digital images as it is usually done with analogue images in dark-rooms. Millions of aerial images of all battle fields were taken during the Second World War. They were intensively used, e.g. for the observation of military movements, the documentation of success and failure of military operations and further planning. Today, the information of these images supports the removal of explosives of the Second World War and the identi- fication of dangerous waste in the soil. In North Rhine-Westphalia, approximately 300.000 aerial images are scanned to handle the huge amount of available data efficiently. The scanning is done with a gray value depth of 12 bits and a pixel size of 21 μm to gain both, a high radiometric and a high geometric resolution of the images. Due to the photographic process used in the 1930s and 1940s and several reproductions, the digitized images are exposed locally very differently. Therefore, the images shall be improved by automated dodging. Global approaches mostly returned unsatisfying results. Therefore, we present a new approach, which is based on local histogram equalization. Other methods as spreading the histogram or linear transformations of the histogram manipulate the images either too much or not enough. For the implementation of our approach, we focus not only on the quality of the resulting images, but also on robustness and performance of the algorithm. Thus, the technique can also be used for other applications concerning image improvements.}, language = {en} } @phdthesis{Brunn, author = {Brunn, Ansgar}, title = {Semantik-basierte Geb{\"a}udeerfassung mit verkoppelten Markoff-Zufallsfeldern}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:5n-01394}, abstract = {In dieser Arbeit wird ein neues automatisches Verfahren zur Erfassung von Geb{\"a}uden aus Digitalen Oberfl{\"a}chenmodellen entwickelt. Im Gegensatz zu den meisten bisher in der Literatur beschriebenen Verfahren wird in diesem Ansatz die Rekonstruktion der Geb{\"a}ude eng mit der Interpretation verkn{\"u}pft. Es wird ein topologischer Ansatz zur Geb{\"a}uderekonstruktion gew{\"a}hlt, der die integrierte Auswertung von unterschiedlichen Datenquellen erm{\"o}glicht. Die Topologie eines Objektes l{\"a}sst sich durch einen CW-Komplex repr{\"a}sentieren. In dieser Arbeit werden CW-Komplexe zur Repr{\"a}sentation der Topologie der Geb{\"a}udeoberfl{\"a}che genutzt. Die Bestandteile des CW-Komplexes, die Zellen (Punkte, Kanten und Fl{\"a}chen), werden lokal klassifiziert. Zur Verbesserung der lokalen Klassifikationen werden Nachbarschaftsbedingungen mittels bedingter Wahrscheinlichkeiten ber{\"u}cksichtigt. Dazu wird eine Nachbarschaftsordnung auf dem CW-Komplex definiert und ein verkoppeltes Markoff-Zufallsfeld formuliert. Wir lernen die Geb{\"a}udemodelle automatisch aus repr{\"a}sentativen Interpretationen. Die Geb{\"a}ude werden lokal -aufgrund der Klassifikation der Zellen - mittels robuster Sch{\"a}tzverfahren rekonstruiert. Die Geb{\"a}udetypen der rekonstruierten Geb{\"a}ude werden durch das Markoff-Zufallsfeld klassifiziert. Zur Veranschaulichung des Potentials und Beurteilung des Verfahrens werden synthetische und reale Beispiele in einem verallgemeinerten geometrischem Modellraum angef{\"u}hrt und diskutiert.}, language = {de} } @inproceedings{FoerstnerHeuelBrunn, author = {F{\"o}rstner, Wolfgang and Heuel, Stephan and Brunn, Ansgar}, title = {Testing Uncertain Geometric Relations}, series = {Mustererkennung 2000, Proceedings of the DAGM 2000 in Kiel}, booktitle = {Mustererkennung 2000, Proceedings of the DAGM 2000 in Kiel}, publisher = {Springer}, pages = {17 -- 27}, abstract = {This paper integrates statistical reasoning and Grassmann-Cayly algebra for making 2D and 3D geometric reasoning practical. The multi-linearity of the forms allows rigorous error propagation and statistical testing of geometric relations. This is archieved by representing all objects in homogeneous coordinates and expressing all relations using standard matrix calculus.}, language = {en} } @article{Brunn, author = {Brunn, Ansgar}, title = {Analyse von Laserscannerdaten f{\"u}r die Geb{\"a}udeextraktion}, series = {Zeitschrift f{\"u}r Photogrammetrie, Fernerkundung und Geoinformation}, volume = {3}, journal = {Zeitschrift f{\"u}r Photogrammetrie, Fernerkundung und Geoinformation}, language = {de} } @article{BrunnWeidner, author = {Brunn, Ansgar and Weidner, Uwe}, title = {Hierarchical Bayesian Nets for Building Extraction Using Dense Digital Surface Models}, series = {ISPRS Journal for Photogrammetry \& Remote Sensing}, volume = {53}, journal = {ISPRS Journal for Photogrammetry \& Remote Sensing}, number = {5}, doi = {10.1016/S0924-2716(98)00012-4}, pages = {296 -- 307}, abstract = {During the last years an increasing demand for 3D data of urban scenes can be recognized. Techniques for automatic acquisition of buildings are needed to satisfy this demand in an economic way. This paper describes an approach for building extraction using digital surface models (DSM) as input data. The first task is the detection of areas within the DSM which describe buildings. The second task is the reconstruction of geometric building descriptions. In this paper we focus on new extensions of our approach. The first extension is the detection of buildings using two alternative classification schemes: a binary or a statistical classification based on Bayesian nets, both using local geometric properties. The second extension is the extraction of roof structures as a first step towards the reconstruction of polyhedral building descriptions.}, language = {en} } @article{BrunnLangGuelchetal., author = {Brunn, Ansgar and Lang, Felicitas and G{\"u}lch, Eberhard and F{\"o}rstner, Wolfgang}, title = {A hybrid concept for 3D building acquisition}, series = {ISPRS Journal of Photogrammetry and Remote Sensing}, volume = {53}, journal = {ISPRS Journal of Photogrammetry and Remote Sensing}, number = {2}, doi = {10.1016/S0924-2716(97)00039-7}, pages = {119 -- 129}, abstract = {This paper presents a hybrid concept of interaction between scene and sensors for image interpretation. We present a strategy for 3D building acquisition which combines different approaches based on different levels of description and different sensors: the detection of regions of interest, and the automatic and semi-automatic reconstruction of object parts and complete buildings.}, language = {en} } @inproceedings{BrunnLangFoerstner, author = {Brunn, Ansgar and Lang, Felicitas and F{\"o}rstner, Wolfgang}, title = {A Procedure for Segmenting Surfaces by Symbolic and Iconic Image Fusion}, series = {Mustererkennung 96, Proceedings of the DAGM 96 in Heidelberg}, booktitle = {Mustererkennung 96, Proceedings of the DAGM 96 in Heidelberg}, publisher = {Springer-Verlag}, doi = {10.1007/978-3-642-80294-2_2}, pages = {11 -- 20}, abstract = {This paper deals with the derivation of a symbolic surface description exploiting the information of multiple images while using a minimum of domain knowledge. We present a new concept for segmenting surfaces by fusing multiple images both on the iconic and on the symbolic description level. In a first step a local 3D-reconstruction and interpretation is derived based on the result of a polymorphic feature ex-traction. It serves as prior information for a second step which refines the initial segmentation using the radiometric image content. Examples of the proposed procedure are presented for the application of 3D-building reconstruction from aerial images.}, language = {en} } @inproceedings{BrunnWeidnerFoerstner, author = {Brunn, Ansgar and Weidner, Uwe and F{\"o}rstner, Wolfgang}, title = {Model-based 2D-Shape-Recovery}, series = {Mustererkennung 1995, Proceedings of the DAGM 95 in Bielefeld}, booktitle = {Mustererkennung 1995, Proceedings of the DAGM 95 in Bielefeld}, publisher = {Springer}, pages = {260 -- 268}, abstract = {This paper presents a new approach for the reconstruction of polygons using local and global constraints. THe MDL-based solution is shown to be useful for analysing range and image data of buildungs.}, language = {en} } @misc{Brunn, author = {Brunn, Ansgar}, title = {Parametersch{\"a}tzung in dynamischen Systemen}, language = {de} } @inproceedings{DizbadiTaghipourArastooetal., author = {Dizbadi, Mehran and Taghipour, Majid and Arastoo, Behrooz and Brunn, Ansgar}, title = {Land-use changes in coastal areas of Using Multi-Time satellite data}, series = {Euro-Mediterranean Journal for Environmental Integration University of Sfax, Tunisia}, booktitle = {Euro-Mediterranean Journal for Environmental Integration University of Sfax, Tunisia}, editor = {Ksibi, Prof. Mohamed}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:863-opus-44800}, abstract = {The use of coastal lands is constantly changing due to the regression and progress of water 10 areas. This coastal Land use changes the need for continuous monitoring at regular intervals to 11 efficiently manage coastal resources. In this study, the effect of Gorgan gulf ( is location in the 12 southeastern part of the Caspian Sea in Golestan province of IRAN country ) progress and re-13 gression on land-use change in the surrounding lands has been modeled and estimated using 14 remote sensing images. For this purpose, two satellite images of Landsat 5 and Sentinel 2 were 15 taken in 1992 and 2017, respectively, and after preparing and applying the necessary prepro-16 cessing, the most similar classification and land uses of the study area were extracted. Overall 17 accuracy values of 0.94 and kappa coefficient of 0.92 indicated the appropriate accuracy of land 18 use maps. The classified images and the topographic maps, and the network of passages of the 19 study area were designated as land modeling inputs to detect land-use changes over 25 years. The 20 study results showed that the water area of the Gorgan gulf had faced a water level decline of 21 150 square kilometers, which has led to an increase in the area of wastelands. Also, agriculture 22 and garden, and rangelands have been significantly reduced during the study period 23 Keywords: Change Detection, Landsat 5, Sentinel 2, Remote Sensing, Gorgan gulf}, language = {en} } @article{BrunnDegenWeberetal., author = {Brunn, Ansgar and Degen, Isabella and Weber, Linda and Freibott, Maximilian}, title = {3D-Vermessung der Zoolithenh{\"o}hle in der Fr{\"a}nkischen Schweiz - Eine Tropfsteinh{\"o}hle virtuell in 3D}, series = {VDV Magazin - Zeitschrift f{\"u}r Geod{\"a}sie und Geoinformatik}, journal = {VDV Magazin - Zeitschrift f{\"u}r Geod{\"a}sie und Geoinformatik}, number = {1}, publisher = {Chmielorz GmbH}, address = {Wiesbaden}, language = {de} }