Renata Jedryczka 
  
  
cy for 
nual or 
Tom Figure 1. The dots represent the places with Z value generated in the automatic process of DEM generation: 
on the left-white dots are projected on the left image, on the right- black dots are projected on XY plane of the object 
space with scale dependent of size of user window and original image pixel size. 
The most Z values calculated on the roofs of the buildings and in the areas of shadows are wrong. Very often we have 
additional data with measurements of various objects like buildings, roads, paths etc. . We used such set of data to add 
lack height information and correct the wrong ones. Only the roofs of the buildings have been taken into account. 
: These data stored in the file have been visualised on the screen both on the image (using projection and Z value) and 
metric à : 
on the XY plane. You can see in the Figure 2 that some of Z values are wrong. 
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Figure 2. The projection of the vector data : on the left on the image (Z values were used), on the right on the XY 
plane with results of automatic Z generation. 
ion of 
  
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B3. Amsterdam 2000. 453