XVIIIth Congress: XVIIIth Congress

Kraus, Karl; Waldhäusl, Peter

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Multivolume work

Persistent identifier:: 1667435949

Title:: XVIIIth Congress

Sub title:: Vienna, Austria 1996

Year of publication:: 1996

Place of publication:: Vienna

Publisher of the original:: Austrian Society of Surveying and Geoinformation

Identifier (digital):: 1667435949

Language:: English

Editor:: Kraus, Karl; Waldhäusl, Peter

Corporations:: International Society for Photogrammetry and Remote Sensing, Congress, 18., 1996, Wien; International Society for Photogrammetry and Remote Sensing

Adapter:: International Society for Photogrammetry and Remote Sensing, Congress, 18., 1996, Wien; International Society for Photogrammetry and Remote Sensing

Founder of work:: International Society for Photogrammetry and Remote Sensing, Congress, 18., 1996, Wien; International Society for Photogrammetry and Remote Sensing

Other corporate:: International Society for Photogrammetry and Remote Sensing, Congress, 18., 1996, Wien; International Society for Photogrammetry and Remote Sensing

Document type:: Multivolume work

Volume

Persistent identifier:: 1667438379

Title:: XVIIIth Congress

Scope:: 449 Seiten

Year of publication:: 1996

Place of publication:: Vienna

Publisher of the original:: Austrian Society of Surveying and Geoinformation

Identifier (digital):: 1667438379

Illustration:: Illustrationen, Diagramme

Signature of the source:: ZS 312(31,B2)

Language:: English

Additional Notes:: Erscheinungsdatum des Originals ist anhand des Copyrightjahrs ermittelt.

Usage licence:: Attribution 4.0 International (CC BY 4.0)

Editor:: Kraus, Karl; Waldhäusl, Peter

Corporations:: International Society for Photogrammetry and Remote Sensing, Congress, 18., 1996, Wien; International Society for Photogrammetry and Remote Sensing; International Society for Photogrammetry and Remote Sensing, Commission Instrumentation for Data Reduction and Analysis

Adapter:: International Society for Photogrammetry and Remote Sensing, Congress, 18., 1996, Wien; International Society for Photogrammetry and Remote Sensing; International Society for Photogrammetry and Remote Sensing, Commission Instrumentation for Data Reduction and Analysis

Founder of work:: International Society for Photogrammetry and Remote Sensing, Congress, 18., 1996, Wien; International Society for Photogrammetry and Remote Sensing; International Society for Photogrammetry and Remote Sensing, Commission Instrumentation for Data Reduction and Analysis

Other corporate:: International Society for Photogrammetry and Remote Sensing, Congress, 18., 1996, Wien; International Society for Photogrammetry and Remote Sensing; International Society for Photogrammetry and Remote Sensing, Commission Instrumentation for Data Reduction and Analysis

Publisher of the digital copy:: Technische Informationsbibliothek Hannover

Place of publication of the digital copy:: Hannover

Year of publication of the original:: 2019

Document type:: Volume

Collection:: Earth sciences

Chapter

Title:: 3D-WIREFRAME MODELS AS GROUND CONTROL POINTS FOR THE AUTOMATIC EXTERIOR ORIENTATION Thomas Läbe, Karl Heiko Ellenbeck

Document type:: Multivolume work

Structure type:: Chapter

3D-WIREFRAME MODELS AS GROUND CONTROL POINTS FOR THE AUTOMATIC EXTERIOR ORIENTATION Thomas Läbe, Karl Heiko Ellenbeck Institute of Photogrammetry University of Bonn laebe@ipb.uni-bonn.de Commission ll, Working Group 5 KEY WORDS: Automation, Orientation, Database, Control point model, Building extraction ABSTRACT The bottleneck of today's automation of image orientation is the identification of control points for exterior orientation. A solution for this problem is presented. It is based on 3D-wireframe models of buildings as ground control points. The paper describes the setup of a database of such control points and the use of the data for an automatic exterior orientation. 1 INTRODUCTION Today we are on the way towards the regular use of digi- tal photogrammetric workstations progressively allowing au- tomation of in principle all steps of image analysis. In nearly every case one needs the orientation parameters of the im- ages. Examples of actually available automatic orientation tasks are the interior orientation, the relative orientation and aerotriangulation. Regarding the different matching tasks of the orientation processes one finds out why solutions for the exterior orientation are rare. The following list gives an overview: e matching between simple 2D-objects and images cer- tainly is the most simple task in case the object can be described by its intensity image. Interior orientation for example can be automized by using classical template matching techniques. e matching between images and images is of similar simplicity due to the already identical representation. Quite a number of matching techniques are available which may be used for relative orientation or for point transfer in aerial triangulation. e matching between complex 3D-objects and images is used for image interpretation, e. g. for building detec- tion but also for the important task of control point identification and mensuration necessary for determin- ing the exterior orientation. Solutions which have been proposed for the automation of the exterior orientation are 1.) the use of signalized control points and 2.) the use of old image templates of natural control points. Putting the signals on the ground by hand is costly. Signals also have to be larger for automatic procedures than for man- ual measurements due to the lack of adequate identification procedures which can compensate for varying background. Different templates may be used for different scales of the images. Approach 2), i. e. using image templates, has to cope with many problems such as different illumination, veg- etation, scales and perspective of the images used for the setup of the control points and the images which have to be orientated. We propose to use 3D-control point models as a solution for the matching task. In most cases the problems mentioned 218 above do not occur. Our module for the automatic exterior orientation uses sets of 3D-edges as control point models. When one sets up a database of control point models for this approach, one could in principle use all 3D-objects which are projected in the images as straight lines. But in most cases one wants to use one model for many different areal photographs, which have been taken at different times. Be- cause of this, the 3D-edges have to be time invariant. Edges at roads or buildings are such structures. Sometimes the edges of roads, especially of small ones without any mark- ings, vary slightly because of different seasons or weather. Our approach, therefore, uses 3D-wireframe models of build- ings as ground control features, though actually only the 3D- edges of these wireframes are used for the orientation. Using wireframes eases the acquisition of the 3D-structures. Other possibilities are also conceivable. 2 MOTIVATION The motivation for the development of a module for au- tomatic exterior orientation (AMOR) and the setup of a database of 3D-control point models was the change of the orthophoto production from an analytical to a digital system at the Landesvermessungsamt (State Survey Department) North-Rhine-Westfalia in Bonn. For nearly 30 years each map sheet of the orthophoto base map 1:5000 was updated at least every 5 years with a new orthophoto from an actual photo flight with an image scale of about 1:12500. With the beginning of this renewal program a database of time invariant control points was established to provide the necessary control points for each spatial resection at the orthophoto projector. These time invariant control points consist of two points on roofs (gables) of a building. In the area of North-Rhine-Westfalia, about 70% of the more than 8000 orthophoto map sheets can be oriented by a spatial resection using these roof points. For the digital production process we proposed to enhance the control points (2 roof points) to contol point models consist- ing of wireframe models of the houses or groups of houses. À module for automatic exterior orientation then has at first to detect automatically the control point models in the image, secondly to match the 2D image edges with the corresponding wireframe edges and lastly to compute the spatial resection. The building of the new database is at work at our Institute and this paper reports on this for the first time. Besides the International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B2. Vienna 1996 ho ho the Th wa foll

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