SN 
ul | 
I | 
i il il 
  
  
  
M 
     
(e) 
  
Figure 3. Detected humps and grouping examples. (a) Gray-value DEM image for the DEM surface in Figure 
2(c). (b) Elevation contours for (a), the contour interval is 4 meters. (c) Detected humps for the scene in Figure 
2(a). Each hump corresponds to one complete building in the scene. (d) and (e) Two hump DEM surfaces 
generated after grouping. The two humps are University Hall and library in OSU campus respectively. (f) The 
topographic surface after all humps were removed. 
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