Eberhard Gülch and Hardo Müller and Thomas Läbe, "Integration of Automatic Processes Into Semi-Automatic Building Extraction", In Proceedings of ISPRS Conference "Automatic Extraction Of GIS Objects From Digital Imagery". 1999.

• Abstract
• BibTeX
• Download

The modeling of three-dimensional objects is a current topic in digital photogrammetric research. The modeling of buildings in digital imagery or digital surface models involving automation processes has reached a level where it can compete with classical photogrammetric stereo measurements. There are many different ways on how to integrate automation. We describe our system and its automated features that support the operator in the adaption of parametric models to multiple overlapping images. There do exist tools to automate the measurement of heights, to automate the estimation of the form parameters or for the handling of building aggregates. With such tools we can reach about 20 seconds for the modeling of a volumetric primitive which is fully comparable to the currently used photogrammetric methods.

@inproceedings{Gulch1999Integration,
  author = {G\"ulch, Eberhard and M\"uller, Hardo and L\"abe, Thomas},
  title = {Integration of Automatic Processes Into Semi-Automatic Building Extraction},
  booktitle = {Proceedings of ISPRS Conference "Automatic Extraction Of GIS Objects From Digital Imagery"},
  year = {1999}
}

Ansgar Brunn and Felicitas Lang and Eberhard Gülch and Wolfgang Förstner, "A Hybrid concept for 3D Building Acquisition", In Journal for Photogrammetry & Remote Sensing. Vol. 53, pp. 119-129. 1998.

• Abstract
• BibTeX
• DOI
• Download

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 semiautomatic reconstruction of object parts and complete buildings.

@inproceedings{Brunn1998Hybrid,
  author = {Brunn, Ansgar and Lang, Felicitas and G\"ulch, Eberhard and F\"orstner, Wolfgang},
  title = {A Hybrid concept for 3D Building Acquisition},
  booktitle = {Journal for Photogrammetry \& Remote Sensing},
  year = {1998},
  volume = {53},
  pages = {119--129},
  doi = {10.1016/S0924-2716(97)00039-7}
}

Eberhard Gülch and Hardo Müller and Thomas Läbe and Lemonia Ragia, "On the performance of semi-automatic building extraction", In Proceedings of ISPRS Commission III Symposium. Columbus, Ohio 1998.

• Abstract
• BibTeX
• Download

A Semi-Automatic Building Extraction system using two or more digitized overlapping aerial images has been enhanced by increased automation for the measurement of saddle-back-roof buildings, hip-roof buildings and boxes. All newly developed modules have been incorporated in the object oriented design of the system. The new methods consist of a ground-point and roof-top matching tool and a robust determination of shape parameters, like e.g. gutter length and width. The current performance of building extraction is quantitatively and qualitatively evaluated. We examine the increased efficiency using the automated tools, the success rate of individual modules and the overall success rate using a combination of methods. A methodology for quantitative comparison is tested on footprints of buildings from classical stereo measurements and from semi-automatic measurements. A qualitative comparison in 3D of multiple measurements of complete buildings is performed on three different datasets.

@inproceedings{Gulch1998performance,
  author = {G\"ulch, Eberhard and M\"uller, Hardo and L\"abe, Thomas and Ragia, Lemonia},
  title = {On the performance of semi-automatic building extraction},
  booktitle = {Proceedings of ISPRS Commission III Symposium},
  year = {1998}
}

Eberhard Gülch and Hardo Müller, "Virtuelle Staedte aus digitalen Bildern", In Proceedings of Virtual GIS. Rostock 1998.

• Abstract
• BibTeX
• Download

Der Übergang von der klassischen Photogrammetrie mit analogen Bildern zur Digitalen Photogrammetrie mit digitalen Bildern und der Automation von Messprozessen eröffnet vielfältige Möglichkeiten zur effizienten Erfassung von 3D-Information in urbanen Gebieten. Es ist ein zunehmender Bedarf an realen 3D-Daten für eine Vielfalt von Anwendungen zu beobachten. Diese reichen von Managementaufgaben in Stadtplanung und Städtebau bis hin zu Funknetzsimulationen, Werbung und Spieleindustrie. 3D-Stadtmodelle eignen sich nicht nur zur Analyse und Simulation, sondern auch zur computeranimierten Darstellung bis hin zur Virtuellen Realität. Das hier vorgestellte System wird zur geometrischen Modellierung aus Mono-, Stereo- oder mehrfachüberdeckenden Luftbildern eingesetzt. Verschiedene automatisierte Module unterstützen den Operateur. Neben einer detaillierten geometrischen Erfassung spielt die Visualisierung von Texturen eine immer größere Rolle. Mit dem hier vorgestellten System können orientierte Luft- und Nahbereichsaufnahmen gleichermaßen zur automatischen Texturierung von erfaßten 3D-Objektmodellen eingesetzt werden. Integraler Bestandteil ist eine Entzerrung und die Wahl der Texturelementgröße im Objektraum, womit verschiedene Detaillierungsgrade (Level-of-Detail) der virtuellen Darstellung erzeugt werden können.

@inproceedings{Gulch1998Virtuelle,
  author = {G\"ulch, Eberhard and M\"uller, Hardo},
  title = {Virtuelle Staedte aus digitalen Bildern},
  booktitle = {Proceedings of Virtual GIS},
  year = {1998}
}

Thomas Läbe and Eberhard Gülch, "Robust Techniques for Estimating Parameters of 3D Building Primitives", In Proceedings of ISPRS Commission II Symposium. Cambridge, UK 1998.

• Abstract
• BibTeX
• Download

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 flat-roof 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.

@inproceedings{Labe1998Robust,
  author = {L\"abe, Thomas and G\"ulch, Eberhard},
  title = {Robust Techniques for Estimating Parameters of 3D Building Primitives},
  booktitle = {Proceedings of ISPRS Commission II Symposium},
  year = {1998}
}

Wolfgang Förstner and Eberhard Gülch, "Automatic Orientation and Recognition in Highly Structured Scenes", In Proceedings of SPIE Annual Meeting. San Diego 1997.

• Abstract
• BibTeX
• DOI
• Download

The paper discusses the impact of scene and assessment models for videometry. Full automation of calibration and orientation procedures appears to be as necessary for enlarging the field of applications as the use of explicit geometric and semantic scene knowledge. The focus on achieving highest possible accuracy needs to be embedded into a broader context of scene analysis. Examples demonstrate the feasibility of tools from Computer Vision for image metrology.

@inproceedings{Forstner1997Automatic,
  author = {F\"orstner, Wolfgang and G\"ulch, Eberhard},
  title = {Automatic Orientation and Recognition in Highly Structured Scenes},
  booktitle = {Proceedings of SPIE Annual Meeting},
  year = {1997},
  doi = {10.1016/S0924-2716(98)00022-7}
}

Eberhard Gülch, "Application of Semi-Automatic Building Acquisition", In Proceedings of Ascona Workshop 'Automatic Extraction of Man-Made Objects from Aerial and Space Images'. 1997.

• Abstract
• BibTeX
• DOI
• Download

There is an increasing request for 3D data on city objects of all kinds, confirmed by a recent European wide study on 3D city models. To acquire 3D information in urban areas still is costly, only automated or at least semi-automatic methods appear feasible in the long run to reach the cost-effectiveness, necessary for a broad application. The variety of tasks and available sensor data is very large, which puts high requirements on the design of methods and the flexibility of the acquisition process. This paper discusses the requirements we have encountered so far. We present the design and current status of a semi-automatic system for 3D building acquisition. We demonstrate the potential for handling a variety of applications, using different sensor data under different initial conditions.

@inproceedings{Gulch1997Application,
  author = {G\"ulch, Eberhard},
  title = {Application of Semi-Automatic Building Acquisition},
  booktitle = {Proceedings of Ascona Workshop 'Automatic Extraction of Man-Made Objects from Aerial and Space Images'},
  year = {1997},
  doi = {10.1007/978-3-0348-8906-3_13}
}

Eberhard Gülch and Hardo Müller, "Object-oriented software design in semiautomatic building extraction", In Proceedings Integrating Photogrammetric Techniques with Scene Analysis and Machine Vision III. Orlando, USA 1997.

• Abstract
• BibTeX
• DOI
• Download

Developing a system for semiautomatic building acquisition is a complex process, that requires constant integration and updating of software modules and user interfaces. To facilitate these processes we apply an object-oriented design not only for the data but also for the software involved. We use the Unified Modeling Language (UML) to describe the object-oriented modeling of the system in different levels of detail. We can distinguish between use cases from the users point of view, that represent a sequence of actions, yielding in an observable result and the use cases for the programmers, who can use the system as a class library to integrate the acquisition modules in their own software. The structure of the system is based on the Model-View-Controller (MVC) design pattern. An example from the integration of automated texture extraction for the visualization of results demonstrate the feasibility of this approach.

@inproceedings{Gulch1997Object,
  author = {G\"ulch, Eberhard and M\"uller, Hardo},
  title = {Object-oriented software design in semiautomatic building extraction},
  booktitle = {Proceedings Integrating Photogrammetric Techniques with Scene Analysis and Machine Vision III},
  year = {1997},
  doi = {10.1117/12.281043}
}

Ansgar Brunn and Felicitas Lang and G Eberhard and Wolfgang Förstner, "A Multi-Layer Strategy for 3D Building Acquisition", In Proceeding of IAPR-TC7 Workshop. Graz 1996.

• Abstract
• BibTeX
• Download

In various projects we investigate on the extraction of buildings on different type and representation of data. This paper presents a strategy for 3D building acquisition which combines different approaches based on different levels of description. The approach consists of detection of regions of interest and automatic and semiautomatic reconstruction of object parts and complete buildings. We incorporate the approach in a global concept of interaction between scene and sensors for image interpretation.

@inproceedings{Brunn1996Multi,
  author = {Brunn, Ansgar and Lang, Felicitas and G\ulch, Eberhard and F\"orstner, Wolfgang},
  title = {A Multi-Layer Strategy for 3D Building Acquisition},
  booktitle = {Proceeding of IAPR-TC7 Workshop},
  year = {1996}
}

Eberhard Gülch, "Extraction of 3D objects from aerial photographs", In Proceedings COST UCE Action 4 Workshop "Information Systems and Processes for urban civil engineering". Rome, Italy 1996.

• Abstract
• BibTeX
• Download

There is an increasing request for 3D data on city objects of all kinds for urban design, confirmed by a recent European wide study on 3D city models. To acquire 3D information in urban areas still is costly, only automated or at least semi-automatic methods appear feasible in the long run to reach the cost-effectiveness, necessary for a broad application. This paper presents a semi-automatic system for 3D building acquisition from various sensor data, mainly, however, from stereo pairs of digitized aerial images. The operator is supported by various automated modules. Very complex buildings can be modeled by a combination of volumetric primitives. The system does not require stereo-viewing and is such suitable also for non-photogrammetrists. The output of the process are 3D volumetric primitives, ready for further analysis in CAD systems or for visualization purposes in combination with automatically extracted texture. We present results from the acquisition of 3D building information in a suburban area and the centers of two cities and give more details on the acquisition times and the quality of the derived data.

@inproceedings{Gulch1996Extraction,
  author = {G\"ulch, Eberhard},
  title = {Extraction of 3D objects from aerial photographs},
  booktitle = {Proceedings COST UCE Action 4 Workshop "Information Systems and Processes for urban civil engineering"},
  year = {1996}
}

Eberhard Gülch, "One-Eye Stereo System for the Acquisition of Complex 3D Building Descriptions", In GIS. 1996.

• Abstract
• BibTeX
• Download

Summary
An easy usable system for the semi-automatic acquisition of detailed 3D building descriptions from a multitude of images is provided. This approach tackles robustly and efficiently most of the problems of 3D building reconstruction, namely occlusions, inverse mapping, and noise. The 3D modeling is based on Constructive Solid Geometry (CSG) and various automated and supporting tools. Our experiences on the acquisition of an extensive scene are evaluated.
Zusammenfassung
Monokulares Stereo System für die Erfassung komplexer 3D-Gebäudebeschreibungen. Für die semiautomatische Erfassung detaillierter 3D-Gebäudebeschreibungen aus einer Menge von Bildern wird ein einfach handhabbares System vorgestellt. Auf robuste und effiziente Weise werden die meisten Probleme bei der 3D-Gebäuderekonstruktion -- Verdeckungen, inverse Abbildung und Rauschen -- angegangen. Die 3D-Modellierung basiert auf der Constructive Solid Geometry (CSG) und zahlreichen automatisierten und unterstützenden Werkzeugen. Unsere Erfahrungen mit einer grossflächigen Erfassung werden evaluiert.

@inproceedings{Gulch1996One,
  author = {G\"ulch, Eberhard},
  title = {One-Eye Stereo System for the Acquisition of Complex 3D Building Descriptions},
  booktitle = {GIS},
  year = {1996}
}

Wolfgang Förstner and Eberhard Gülch, "A Fast Operator for Detection and Precise Location of Distict Point, Corners and Centres of Circular Features", In Proceedings of the ISPRS Conference on Fast Processing of Photogrammetric Data. Interlaken, pp. 281-305. 1987.

• Abstract
• BibTeX
• Download

Feature extraction is a basic step for image matching and image analysis. The paper describes a fast operator for the detection and precise location of distinct points, corners and centres of circular image features. Distinct points are needed for feature based image matching or for trackong in image sequences. A special class of these distinct points are corners, which, beside edges, are the basic element for the analysis of polyhedra. Finally centres of circular features cover small targeted points and holes, disks or rings, which play an important role in one-dimensional image analysis. The extraction consists of two steps: window selection and feature location. The speed of the non-iterative operator results from parallelism on the arithmetic as well on the process level. Specifically the operator can be split into arithmetic operations on and between imgaes, convolutions, partly with boxfilters, and finally vector and matrix operations. The operator provides a measure for the precision of the location.

@inproceedings{Forstner1987Fast,
  author = {F\"orstner, Wolfgang and G\"ulch, Eberhard},
  title = {A Fast Operator for Detection and Precise Location of Distict Point, Corners and Centres of Circular Features},
  booktitle = {Proceedings of the ISPRS Conference on Fast Processing of Photogrammetric Data},
  year = {1987},
  pages = {281--305}
}