In: Paparoditis N., Pierrot-Deseilligny M., Mallet C, Tournaire O. (Eds). IAPRS. Vol. XXXVIII, Part ЗА - Saint-Mandé, France. September 1-3, 2010 
5. DISCUSSION 
The main part of the concept presented in this paper consists of 
texture selection using weighted quality measure. The 
introduced equation for calculating the quality q allows 
reducing and increasing of the influence of particular 
component, such as distance, occlusion and viewing direction. 
On the examples from the Chapter 4.2 can be observed, that the 
large viewing angle makes the texture unreadable. Furthermore, 
often in such textures the difference in resolution along x and y 
axis is significant. To avoid this effect which is disrupting for 
observer, the influence of the viewing direction should be 
increased. For this reason the weight a 3 in the equation (7) 
should be set higher than a, and a 2 . It can be noticed that the 
results for qij-2 are intuitively better than for q^.jand q,j. 3 . 
Comparing textures from Fig. 6a and 7b having the almost 
equal quality q^.j by dj=a 2 can be noticed, that the wall texture 
(Fig. 6a) is much more useful than the roof surface from Fig. 
7b. Considering the quality qij. 2 where a 3 >a 2 we see that the 
quality of the wall texture has significantly higher value which 
correspond to our perception. 
In Fig. 7b we can also observe mismatch between image and the 
projected model, which is especially remarkable by narrow 
polygons seen under large angle. As result of a disadvantageous 
orientation the texture depicted in the Fig. 6c is completely 
useless for object extraction, which is also represented in q,j. 2 
better than in q^.j and q^. 
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ACKNOWLEADGMENTS 
The authors would like to thank FGAN-FOM, Ettlingen, for 
providing images of the flight campaign.