suitably dense grid of points. In a further step, the
points were used as reference data for surface ap-
proximation by the finite element method (Ebner et
al., 1988). Finally, the filtered gridded DSM was con-
verted into a dense raster DSM by bilinear interpola-
tion, from which raster products were generated.
Figure 6 shows an image of elevation layers of the part
of the cylinder and Figure 7 is a perspective view
correspondingly.
Fig. 6. Elevation layers image.
Fig. 7. A perspective image coverred by elevation
layers.
4. CONCLUSIONS
In most cases, TINs are suitable for surface descrip-
tion in architecture. However, TIN filtering by grid
approximation is also necessary in case of smooth ob-
jects. Computer-generated images not only provide
opportunities for better understanging of the architec-
ture but also make it possible to detect measuring er-
rors in the data acquisition sensitively (cf. Fig. 4). An
architecture information system will certainly contrib-
ute to documentations in architecture a great deal.
REFERENCES
De Floriani, L. and Puppo, E., 1988: Constrained De-
launay Triangulation for Multiresolution Surface De-
scription. Proceedings of 9th International
Conference on Pattern Recognition, Rome, Italy, pp.
566-569.
Ebner, H., Reinhardt, W., Hóssler, R., 1988: Gener-
ation, Management and Utilization of High Fidelity
Digital Terrain Models. International Archives of
Photogrammetry and Remote Sensing, Vol. 27, Part B
11, pp. 111/556-566.
Hell, G., Peipe, J. and Stephani, M., 1988: Photo-
grammetric Documentation of the DOME OF THE
ROCK. Proceeding of XI. International Symposium of
CIPA, pp. 103-113.
Mayr, W. and Stephani, M., 1988: Digitally Generated
Orthophotos - A Step Towards Digital Architectural
Photogrammetry (DAP). XI. International Sympo-
sium of CIPA, Sofia, Bulgaria.
Rinaudo, F., 1988: New Forms of Architectural Rep-
resentation and Documentation: Non Plane Projec-
tions and Specific Information Systems. Proceeding of
XI. International Symposium of CIPA, pp. 155-163.
Stephani, M. and Tang, L., 1990: Experiences with vis-
ualization of architectural objects. Int. arch. of photo-
gramm. and rem. sens., Vol. 28, Part 5/1, pp. 191-196.
Tang, L., 1989: Surface Modelling and Visualization
Based On Digital Image Processing Techniques. In:
Optical 3-D Measurement Techniques (Ed.
A.Grün/H.Kahmen), Wichmann, pp. 317-325.
Tang, L., 1991: Einsatz der Rasterdatenverarbeitung
zum Aufbau digitaler Gelándemodelle. Mitteilungen
der geodátischen Institute der Technischen Universi-
tát Graz, Folge 73, 100 pp.
Tang, L., 1992: Raster algorithms for surface modell-
ing. International Archives of Photogrammetry and
Remote Sensing, Vol. 29, Commission III (to be pub-
lished).
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