@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} } @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} } @inproceedings{ChizhovaBrunn, author = {Chizhova, Maria and Brunn, Ansgar}, title = {Aufbau wissenschaftlicher Partnerschaften nach Osteuropa - ein aktueller Erfahrungsbericht}, series = {DGPF-Tagung, K{\"o}ln, 2015}, booktitle = {DGPF-Tagung, K{\"o}ln, 2015}, abstract = {Der Aufbau internationaler Partnerschaften nach Osteuropa ist aktuell ein Thema f{\"u}r viele Hochschulen im deutschsprachigen Raum. Gerade die Studieng{\"a}nge der Vermessung und Geoinformatik haben oftmals Schwierigkeiten Partner im Ausland zu finden, da das Fach in vielen L{\"a}ndern nicht in der gleichen Form gelehrt wird. Dieser Beitrag zeigt aktuelle M{\"o}glichkeiten des Aufbaus von Partnerschaften nach Russland anhand der Erfahrungen der Hochschule f{\"u}r angewandte Wissenschaften W{\"u}rzburg-Schweinfurt auf. Dazu werden die aktuelle fachspezifische Situation in der Hochschulausbildung wie auch die Struktur der Ausbildung in Russland vorgestellt, kurz mit der Situation an der Hochschule f{\"u}r angewandte Wissenschaften W{\"u}rzburg-Schweinfurt verglichen sowie die M{\"o}glichkeiten der Zusammenarbeit aufgezeigt.}, language = {de} }