re chosen. 
t data, the 
on with a 
ed heights 
assy-areas 
ayer of the 
is slightly 
ening and 
tor map a 
wk-shaped 
two pixel 
“building 
Ulrich Thoennessen 
b c 
Figure 4: Generating a binary mask: a) Printed Map, b) Aligned Building Layer Superimposed on Intensity, c) Mask | 
In Figure 5a the depth map of the interesting scene detail is shown. Objects with a height of 5m above the ground are 
considered as possible buildings (5b). For a better discrimination of the segments their heights are pseudo-colour coded. 
A comparison with the map indicates that the elevated objects correspond indeed with the buildings and with groups of 
tall trees in the forests at both sides of the highway. The two complementing sets of building candidates are illustrated 
in Figure 5c,d. 
c d 
Figure 5: Scene Detail: a) Detailed Depth Map, b) Objects with Height, c) Masked Objects, d) Complement of c) 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part Bl. Amsterdam 2000. 333