Full text: Proceedings of the Symposium on Global and Environmental Monitoring (Part 1)

396 
Figure 2. t-ratio segmentation of forest stands in a 5x5 km area. Upper left: input composite SPOT XS,PAN 
bands, pixel size 10 meters. Upper right: information on landuse, hydrology and administrative boundaries, 
digitized from public maps at scale of 1:10 000. Lower left: initial regions used (Directed trees 
algorithm). lower right: result of t-ratio segmentation. Average region size: 2.4 hectares. Copyright: SPOT 
image, CUES. 
Algorithm 1. t-ratio region growing. 
Parameters: 
Hires t-ratio threshold. 
Iter Number of iterations. 
Max, Min Maximum and minimum 
region size. 
Functions: 
Nearest(R) Returns the ID of the 
adjacent region 
closest in feature 
space to region R. 
Returns the t-ratio 
for two regions R,N. 
Returns the size of 
region R. 
Returns the total size of 
regions R + N. 
START 
Index = 0 
WHILE Index < Iter DO 
Index = Index + 1 
T = Hires * (Index/Iter) 0,5 
REPEAT 
FOR every region (R) DO 
N = Nearest (R) 
IF (t-ratio(R,N)<T) and (size(R,N)<=Max) THEN 
List R and N for merging 
Merge all pairs of regions listed 
UNTIL no more regions are merged 
END WHIIE 
REPEAT 
FOR every region (R) DO 
IF size(R) < Min THEN 
N = Nearest(R) 
List R and N for merging. 
Merge all regions listed 
UNTIL size of every region >= Min 
STOP 
t-ratio(R,N) 
Size(R) 
Size(R,N)
	        
Waiting...

Note to user

Dear user,

In response to current developments in the web technology used by the Goobi viewer, the software no longer supports your browser.

Please use one of the following browsers to display this page correctly.

Thank you.