Systems for data processing, anaylsis and representation

Allam, Mosaad; Plunkett, Gordon

Bibliographic data

Monograph

Persistent identifier:: 1067490280

Title:: Systems for data processing, anaylsis and representation

Sub title:: ISPRS Commission II Symposium : June 6 - 10, Ottawa, Canada

Scope:: 1 Online-Ressource (XX, 530 Seiten)

Year of publication:: 1994

Place of publication:: Ottawa

Publisher of the original:: The Surveys, Mapping and Remote Sensing, Natural Resources Canada

Identifier (digital):: 1067490280

Illustration:: Illustrationen

Signature of the source:: ZS 312(30,2)

Language:: English

Additional Notes:: Erscheinungsdatum des Originals ist aus dem Copyrightjahr ermittelt.

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

Editor:: Allam, Mosaad; Plunkett, Gordon

Corporations:: Symposium Systems for Data Processing, Analysis and Representation, 1994, Ottawa; International Society for Photogrammetry and Remote Sensing; International Society for Photogrammetry and Remote Sensing, Commission Instrumentation for Data Reduction and Analysis; Kanada, Surveys, Mapping and Remote Sensing Sector

Adapter:: Symposium Systems for Data Processing, Analysis and Representation, 1994, Ottawa; International Society for Photogrammetry and Remote Sensing; International Society for Photogrammetry and Remote Sensing, Commission Instrumentation for Data Reduction and Analysis; Kanada, Surveys, Mapping and Remote Sensing Sector

Founder of work:: Symposium Systems for Data Processing, Analysis and Representation, 1994, Ottawa; International Society for Photogrammetry and Remote Sensing; International Society for Photogrammetry and Remote Sensing, Commission Instrumentation for Data Reduction and Analysis; Kanada, Surveys, Mapping and Remote Sensing Sector

Other corporate:: Symposium Systems for Data Processing, Analysis and Representation, 1994, Ottawa; International Society for Photogrammetry and Remote Sensing; International Society for Photogrammetry and Remote Sensing, Commission Instrumentation for Data Reduction and Analysis; Kanada, Surveys, Mapping and Remote Sensing Sector

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:: Monograph

Collection:: Earth sciences

Chapter

Title:: [Wednesday, June 8, 1994]

Document type:: Monograph

Structure type:: Chapter

Chapter

Title:: [Session F-1 WG II/1 - Real-Time Mapping Technologies - Automatic Orientation of Sensors]

Document type:: Monograph

Structure type:: Chapter

Chapter

Title:: THE EXTERIOR ORIENTATION OF DIGITAL IMAGES BY ROAD MATCHING FAYEZ SHAHIN & KURT NOVAK

Document type:: Monograph

Structure type:: Chapter

ic orienta- om digital blishes the ddress the utomation ‘his proce- mented at about the on the van are math- 1e ground. extracted age space. the roads nd. Thus, ientataion mall scale 'erlapping 'chniques, d feature ccessfully 1 between 991, Ack- the exte- gistration of images, and the mapping from orthoim- ages, have not reached advanced levels of au- tomation. Operator intervention is still nec- essary in these tasks. This group of tasks has to be solved by determining the corre- spondence between an image and a model of the object space; for example, for the exterior orientation of an aerial photograph one has to determine a match between ground con- trol points and their conjugate locations in the image. Finding such a match is a very difficult problem, because it requires match- ing the 3-D ground representation of control points, which is in vector form, to the 2-D im- age representation of the same points, which is in raster form. In photogrammetric practice, the correspon- dence between image and object spaces is es- tablished by identifying and measuring con- trol points in images manually In many cases, such as in satellite images or small scale aerial photographs, it is very difficult to iden- tify control points due to the low resolution of the images. This paper presents a general procedure for exterior orientation of images by matching features in the image with those on the ground. This approach is extremely ef- ficient for orienting satellite images and small scale aerial photos. Thus, it has a great po- tential for real time mapping applications. During the past three years a mobile map- ping system has been developed and imple- mented by the Center for Mapping at The Ohio State University. It collects informa- tion about the environment of highways from a driving van. The GPS receiver mounted on the vehicle (GPSVan) determines the road alignment in a ground coordinate system [No- vak 1991]. These road alignments provide a model of the road in object space. Digital images of the same area can be analyzed to extract roads automatically. By comparing roads on the ground and in the images, a cor- respondence between linear features in object and image spaces can be established auto- matically. Consequently, the automatic exte- rior orientation of digital images using linear features as control can be solved [Tankovich 1991, Mikhail 1993]. The system implemented for solving the cor- respondence problem between linear features in images and on the ground consists of three modules. These modules are the ground mod- ule, the image module, and the matching module. They are discussed in the follow- ing sections. Practical results are presented in section 5 of this paper. 2. THE GROUND MODULE The GPSVan captures a huge number of dis- crete 3-D ground coordinates representing the centerline of a road. The goal of this ground module is to segment road centerlines and de- scribe them mathematically. The first step is the detection of the critical (important) points of the road alignment. Next, the co- efficients of the B-splines are computed such that the critical points serve as break points of the piecewise polynomials. 2.1 Detection of Critical Points The detection of critical points for B-spline representation is a crucial step, because these points are representative of the original data. Redundant points should be deleted, and im- portant features of the original data should be maintained. The method implemented by the authors is based on the local properties of the curve. It depends on calculating the angles between two line segments P; ,P; and P;P;,,. All points P; for which this angle is less than a threshold are deleted. This method has the advantage of keeping only a few points for a straight line, and many points for lines of high curvature [Ballard and Brown 1982]. 2.2 Cubic B-splines Representation Splines are named after the draftman's de- vice for drawing fair curves between specific 175

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