Figure 10. Boundary representation of the test model. 
free form object were also determined by image matching. 
This geometric information was used as input to a B-rep based 
geometric modeler. Figure 10 illustrates the resulted B-rep of 
the test model by the geometric modeler. 
5. CONCLUSIONS 
Digital photogrammetry can be applied to acquire 3D 
geometric data for the generation of object representations in 
CAD/CAM. The method which uses both area and edge based 
image matching for reconstruction of digital surface models is 
very efficient, especially for objects with surface 
discontinuities. The interface between digital image matching 
and CAD/CAM systems makes it possible to transform the 
acquired digital surface model directly into 3D object 
representations. The presented method may be applied in the 
fields of design and manufacturing in mechanical engineering, 
automobile industry, robot technology and others. 
Further efforts should be made in automatic recognition of 
Primitives of B-rep and CSG representations from digital 
images. Conversion from octree representation to other object 
representations is also an interesting topic. 
ACKNOWLEDGEMENTS 
The research work was in part done when the author was with 
the Department of Photogrammetry and Cartography, and the 
Institute for Machine tools and Manufacturing Technology of 
the Technical University of Berlin, Germany. 
The author would like to thank Prof. Dr.-Ing. J. Albertz for his 
encouragement. The Volkswagen Foundation, ZTZ of the 
Technical University of Berlin and the Pacific International 
Center for High Technology Research are acknowledged for 
supporting a part of the research work. 
REFERENCES 
Ackermann, F., 1984. High Precision Digital Image 
Correlation. Schriftenreihe Institut fuer Photogrammetrie, 
University of Stuttgart, No. 9, Stuttgart 1984. 
Albertz, J. (edit), 1989. Interpretation von 
Oberflaechenstrukturen und -veraenderungen auf Grund 
digitaler stereophotogrammetrischer  Bilddatenauswertung. 
Technical Report for the Research Project IFP 7/2, Technical 
University of Berlin. 
Cogan, L. and D. Hunter, 1984. DTM Collection and the 
Kern Correlator. Kern & Co. Ltd., April 1984. 
Claus, M., 1983. Korrelationsrechnung in Stereobildpaaren 
Zur automatischen Gewinnung von digitalen 
Gelaendemodellen, Orthophotos und Hoehenlinienplaenen. 
German Geodetic Commission (DGK), Series C, No.283. 
Foerstner, W., 1986. Beispiele zur automatischen Erfassung 
von digitalen Oberflaechenmodellen. Photogrammetrie und 
Fernerkundung/BuL, 54 Heft 2, pp 71- 79. 
Helava, U. V., 1988. Object-Space Least-Squares Correlation. 
Photogrammetric Engineering and Remote Sensing, Vol.54, 
No.6, pp. 711 - 714. 
Kreiling, 'W., 1976. Automatische Herstellung von 
Hoehenmodellen und Orthophotos aus Stereobildern durch 
digitale Korrelation. Dissertation, University of Karlsruhe, 
Karlsruhe. 
Li, R., 1988. Erstellung digitaler Oberflaechenmodelle durch 
Flaechen- und  Kantenkorrelation. Photogrammetrie und 
Fernerkundung/BuL, 56 Heft 4, pp. 119 - 130. 
Li, R., 1990. Reconstruction of Discontinuous Surface Models 
Using Digital Images by Area and Edge Based Digital Image 
Matching. German Geodetic Commission (DGK), Series C, 
No.364. 
Li, R., 1991. An Algorithm for Building Octree from 
Boundary Representation. PED-Vol.50, ASME, Intelligent 
Design And Manufacturing For Prototyping, edited by A. 
Bagchi and J.J. Beaman, pp.13-23. 
Marr, D., 1982. Vision. W.H. Freeman and Company. 
Morthenson, M.E., 1985. Geometric Modeling. John Wiley & 
Sons. 
Ohta, Y. and T., Kanade, 1985. Stereo by Intra- and 
Inter-Scanline Search Using Dynamic Programming. IEEE 
Transaction on Pattern Analysis and Machine Intelligence, 
PAMI - 7, No. 2, pp. 139 - 154. 
Ohta, Y. and K., Ikeda, 1988. Collinear Trinocular Stereo 
Using Two Level Dynamic Programming. 9th Int. Conf. on 
Pattern Recognition, Rome, Italy, pp. 658 - 662. 
Samet, H., 1990. The Design and Analysis of Spatial Data 
Structures. Addison-Wesley Publishing Company, Inc., 
Reading, Massachusetts. 
Spur, G. and F.-L. Krause, 1984. CAD-Technik. Carl 
Hanser Verlag, Muenchen Wien. 
Spur, G., F.-L., Krause, H., Hayka and R., Li, 1989. 
Common Project IWF-CMSR Intermediate Report, Technical 
University of Berlin. 
Spur, G., F.-L., Krause, R., Li, E., Lenz, M., Shpitalni and 
A., Fischer, 1990. Multirepresentation Based Geometrical 
Modeler. CIRP Annals - Vol.39/1, pp. 141-144. 
Terzopoulos, D., 1986. Regularization of Inverse Visual 
Problems Involving Discomtinuieties. IEEE Transaction on 
Pattern Analysis and Machine Intelligence, PAMI - 7, No.4, 
pp.413-424. 
VW-GEDAS, 1989. AUDIMESS-An Interactive Graphic 
System for Generating Measuring Programs for CNC 
Measuring Machines. VW-Gesellschaft fuer Technische 
Datenverarbeitungssysteme mbH, Berlin. 
Wong, K. W. and Wei-Hsin Ho, 1986. Close-Range 
Mapping with a Solid State Camera. Photogrammetric 
Engineering and Remote Sensing, Vol.52, No.1, pp. 67 - 74. 
Wrobel, B., 1987. Digitale Bildzuordnung durch Facetten mit 
Hilfe von  Objektraummodellen. Photogrammetrie und 
Fernerkundung/Bul, 55 Heft 3, pp.93-101. 
ZEISS, 1987. InduSURF-Photogrammetrisches System zur 
Automatischen Oberflaechenmessung von Industrie-Objekten. 
Carl Zeiss, Oberkochen, Germany.