Attribute, Mean values 
(60), (70), (80) 
(+3) 
Uniformity ; Variance 
Knowledge ; The spectral 
  
knowledge (gray level) 
    
a segmentation quadtre 
30 
31 
32 33 
Transformation 
Attribute ; Form 
  
Homogeneity ; Regular polygon 
  
Knowledge; The geometric 
knowledge of objects 
  
  
  
  
b Homogeneous region quadtree 
Figure 3. The elements of segmentation quadtree and homogeneous 
region quadtree ,and their transformation. 
4. QUADTREE INTERPRETATION AND 
SPATIAL RELATION EXTRACTION BASED ON 
DG. 
After a homogeneous region quadtree is formed by 
using the above technique the correspondence between 
objects and the regions quadtree shall be determined 
based on DGs ,and a class interpretation quadtree 
shall be obtained 
For this purpose, the spatial relations and constraints 
among the class interpretation quadtree are extracted. 
Sets of mutually consistent interpretation that share 
similar function or are spatial decompositions of the 
scene are formed, which may further help us to 
interpret the quadtrees based on DGs. 
If,after the above processes ,some interpretation class 
560 
is still ambiguous ,the previous processes may be 
repeated by using the current best interpretation. At 
each repetition ,the regions quadtree and the projected 
objects may be put into a 
more accurate 
correspondence in the discrimination graphs way. 
4. 1 Interpretation of homogeneous region quadtree 
  
Assuming that we can obtain different image 
attributes and the result of each attribute is a finite 
number of categories;as well as there is only a finite 
number of scene objects whose image appearance falls 
in a particular category . In accordance with these 
assume, we introduce the quadtree interpretation based 
on discrimination graphs (DGs),i.e. we may assign 
the quadtrees to same interpretation if they belong to 
same the categories of the image attributes. The 
interpretation may be an abstract objects class, or be 
an elementary object class(see Figure 4). 
  
  
  
  
  
Arid/ sou 
Irrigation > = HE Re 
/Bare land E N 
  
  
  
  
  
  
a Homogeneous region 
one based on DGs. 
quadtree intepretation from abstract to specific 
sizezz 60 
saturation «0. 7 
(Bare land Rj) 
Sizezz60 Sizezz 60 
CArid/Irrigation Saturationzz 0. 8 
/Bare land) Hue;30—90 
ME d (Irrigation land R2) 
Size >60 Size >60 
Saturationzz 0. 8 
(Arid/Irrigation land) 
Saturationzz 0. 8 
Hue;90—120 (Arid land R,) 
(b) DGs 
Figure 4. An example of discrimination graphs and homogeneous region 
quadtree. 
The interpretation of a homogeneous region quadtree 
is done by assigning the quadtrees to a class based on 
how closely the observed set of the region attributes