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Adaptive Fusion of Spectral Bands MSS4 to MSS7
and Out-Image Data


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Table 29: Adaptive fusion of spectral bands MSS4 to MSS7 and of out-image data: distance to roads, plateaux, valleys, slope orientation, slope steepness, crests, irrigation, DEM and distance to urban areas

Rates of classification obtained
$\mbox{\ }$Class Number of pixels  

correctly classified

(A)             

Number of pixels

in samples     

(B)            

Rate of pixels    

correctly classified

(A/B)         

       1 342 459 74.51%
       2 251 459 54.68%
       3 84 306 27.45%
       4 84 391 21.48%
       5 146 459 31.81%
       6 185 459 40.31%
       7 62 459 13.51%
       8 37 459 8.06%
       9 237 459 51.63%
TOTAL 1428 3910 36.52%




The results are quite different from those of simple conjunctive fusion. The mean rate of recognition was 36.52% (against 22.89% for conjunctive fusion). In fact mainly classes 1 and 2 benefit from a significant improvement of their rate of recognition. That is the effect of disjunctive fusion. As we noticed in the previous chapter, disjunctive fusion often attributes after fusion the same degrees of membership for a pixel to several classes. In such an approach, our implementation assigns the pixel concerned, to the first of the candidate classes.

Let us notice that the problem of pixels unclassified with conjunctive fusion disappeared. Moreover, the rates of recognition of each class are better than in the case of simple disjunctive fusion. Thus, the conjunctive part of the adaptive rule worked when it was possible.

However, the image obtained is very unsatisfactory because the adaptive rule, in the presence of conflict, often used disjunctive fusion. In fact, if there is conflict between the sources and that the unanimity cannot be reached to assign a pixel to a class (unclassified pixels for simple conjunctive fusion), the disjunctive part of the adaptive rule is used. That occurs in 93.03% of the cases for the whole of the image during the fusion of the spectral bands and the out-image data.



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