rving 
ew, it 
  
er. (c). 
. Kuan 
Frost 
's with 
actors, 
ftware 
e. The 
S, we 
conclude that speckle noise decreases as the window 
size increases. The damping factor influences the sharp 
edges. The larger the damping factor, the sharper the 
edges are preserved. The number of looks also 
influence the final filtered image(Ref.Fig.5(g),(h)). 
  
Fig.5, (a). window size 3X3, (b), window size 5X5,(c), 
window size 7X7, (d). window size 11X11, (e) window size 
7X7, damp=0.1, (f). window size 7X7,damp=10.(g). window 
size 11X11, damp=10. (h). window size 11X11, damp=5. 
5. Conclusion 
In this paper, the primary results of evaluating filtering 
techniques have been made by using PCI software. The 
results indicate the performances of these filter are 
dependent on the window size, the number of looks, 
and the filtered areas. The performances of the Lee 
Filter, Frost Filter, Kuan Filter are similar. The GMAP 
filter is superior to the other filters in terms og visual 
interpretation. The further research will focus on 
detailed evaluation and design of speckle filters. 
169 
6. Acknowledgment 
The authors gratefully thank the support of the 
European Space Agency in supporting ITC's research 
on SAR speckle reduction techniques. 
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International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B2. Vienna 1996