Extraction for Map Revision, ISPRS XVII Congress, 
Commission IV, pp. 569 - 575. 
3. Stokes, John, Parsing Segmented Digital Images, 
1992, ISPRS XVII Congress, 1992, Commission III, 
pp. 727 - 734. 
4. Yeu, B.M. et al, A Study in Geo-Spatial System for 
Urban Change Detection by Digital Image 
Processing of Aerial Photographs FIG XX 
International Congress, 1994, Commission 3, SGS 
352 4 
symbol to represent an automatically 
detected building 
symbol without an enclosing polygon 
implies new buildings detected 
  
symbol within enclosed polygon implies 
Fig. 5.5 Result of detecting building changes a detected existing building 
  
polygons without symbols implies a 
The figures are illustrated to show what is expected after building that has been removed 
a very optimistic implementation of the system. For 
example in Fig. 5.5, symbols without an enclosing 
polygon could also imply a false detection and polygons 
without symbols could imply a missed detection. Much 
refinements is expected before a practical system can be 
developed, but it is hopeful because the utilization of 
existing database provides plenty of accurate a priori 
knowledge as well as an evaluation capability. 
6. REFERENCES 
  
  
1. Ballard and Brown, 1982, Computer Vision, 
Prentice-Hall, Englewood Cliffs, NJ. 
2. Murakami, H., Welch, R., 1992, Automatic Feature 
991 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996