Renata Jedryczka 
  
  
  
  
  
  
  
  
  
235500 
235400 
s SS : i 235339 
390000 290100 
| | | ; N scale 1:2000 
16 17 19 20 22 23 25 
5 CONCLUSIONS 
In this paper we present the way of DEM production in urban zones for orthoimage which assumes to generate first 
DEM on the ground and then add the building- DEM. We generate DEM straight from images. The proposition 
concerned using the existing vector data in the most possible automatic way and in that way decreasing manual 
measurements. The main idea was to short the time needed for generation a dense DEM for orthoimage generation. 
We have shown this on the fragment of the whole area because this work should be done on small fragments of the 
image. That gives the possibility to control visually successive results. 
In dense build-up zones the fully automatic method doesn’t seem to be realistic. Automatic extraction of buildings from 
images is necessary if we have not enough rich outer data information and it can serve as a good source of bringing 
them up to date. To have really good (in accuracy) DEM of built-up areas we first need good ground-DEM in regular 
grid (for example collected systematically from various kinds of information not only from images) and good data bases 
of man made objects. The combination of these two in interactive process can give expected results. 
6 REFERENCES 
Ackermann F., 1996. Techniques and Strategies for DEM Generation, Digital Photogrammetry: An Addendum to the 
Manual of Photogrammetry, ASPRS, ed. C. Greve, Maryland. 
Jedryczka R., Semi-automatic exterior orientation using existing vector map data, OEEPE- European Organization for 
Experimental Photogrametric Research, Publication no. 36, pp. 133-137. 
Krzystek P., Wild D., 1998, Generation of Digital Elevation Models, The 3-rd Course in Digital Photogrammetry, 
Bonn, 1998. 
Pasko M., Gruber M., 1996. Fusion of 2D Data and Aerial Images for 3D Building Reconstruction, International. 
Archives of Photogrammetry and Remote Sensing, Vienna, Vol.31,Part.B3, pp.257-260. 
Roux M., Lopez-Krahe J., Maitre H., 1996. Automatic Digital Terrain Model Generation Using Aerial Images and 
Maps, International. Archives of Photogrammetry and Remote Sensing, Vienna, Vol.31,Part.B3, pp.697-702. 
  
456 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B3. Amsterdam 2000.