5the 
iffe- 
1s all 
For 
es of 
ada- 
argin 
>; the 
work 
ation 
grid 
rela- 
their 
idary 
t: the 
tively 
sive) 
rres- 
und- 
idary 
stone 
lings, 
s and 
ecial- 
other 
      
    
      
Cadastral 
Objects 
Parcel 
Corresponding 
Number 
  
Boundary 
Stone 
Fig. 2: The cadastral objects 
(the objects below are parts of the objects above) 
The roads as well as all other objects that can be consi- 
dered as areas consist of an identifier and an area. All 
these areas are built up from the object general area. 
This object is surrounded by boundary lines and topo- 
graphic lines (lines that separate different topographic 
objects). 
An example for a concept of the semantic network is the 
parcel area (PA) consisting of the concept boundary line 
(BL). Another example is the concept general area 
(GA) consisting of BL and the concept topographic line 
(TL). The parts of PA and GA bound the area. The 
concept boundary stone (BS) is part of the concept BL. 
Topographic 
Opes 
T 
Two boundary stones are situated at the ends of the 
boundary line. 
The second level is called "graphics and text". The ob- 
jects in this level include graphics objects (eg points, 
straight and curved lines, circles, arrows, hatched and 
screened areas and other kinds of map symbols) as well 
as text objects (characters and digits). In this level mainly 
neighbourhood relations are used and operations ana- 
lyse eg the thickness, position, size or the orientation of 
objects. 
Some examples for concepts are point, circle_1.9mm, 
polygon, polygon_0.35mm, polygon_0.18mm and re- 
maining object (RO). The remaining objects are candi- 
dates for text, numbers or symbols that at present we do 
not investigate any further. The concepts poly- 
gon_0.35mm and polygon_0.18mm are specialisations of 
the concept polygon (their thickness is known from the 
map legend). They are exhaustively and exclusively spe- 
cialised according to their thickness. The concept point 
is used to preserve the information, which polygons are 
connected and which are not. The concept circle_1.9mm 
(line thickness is 0.18mm and radius is 1.9mm) preserves 
the topology of the polygons in the same way as the 
concept point but the junction of the polygons is marked 
with a symbol. The symbol consists of a circle bounding 
an area that conceals the junction and a part of the 
polygons. 
The third level is called the "image graph". It consists of 
a number of separated attributed graphs, each corres- 
Building (Forest ) EX Waterbody qm 
SR 
p 
  
PE) 
Building \ (Building m Main Forest Forest 
Identifier Area uilding (Building) (Identifier / \ Area 
Identifier: General 
House Number Area 
Boundary \{Topographic Boundary || Topographic 
Line Line Line Line 
  
  
General 
Area 
Topographic 
Line 
   
Boundary 
Line 
  
   
  
  
Road Road Main 
Area ) (Identifier / ( Street 
General 
Area 
    
  
  
Fig. 3: The topographic objects 
(lines: the objects below are parts of the objects above; 
dashed lines: the object at the end of the arrow is a 
specialization of the object at the beginning) 
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