Figure 2. a) Landuse map in GIS b) Color composite of the
bands 5, 4, 3 of TM (RGB 5, 4, 3)
(size is 215 , 340 pixels)
c) MLH classification result — d) A zoomed part of the
classified image shown in Figure. 2(c)
Figure 3 Two samples of the generated likelihood maps for the
selected classes.
a) Likelihood map for class Beans
for class Potatoes
b) Likelihood map
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B4. Istanbul 2004
Polygon
Boundaries
Likelihood map
prob(Cid)
Overlay of the
polygon map
&
Likelihood map
Extracting the
average
probabilities for
each polygon
Thereshold
ing
Binary t
hypothesis
Hypothesis
evaluator
Shape
hypothesis
generation
Figure 4. Schematic diagram of the proposed method for MBIA
of the agricultural areas using the existing boundaries.
On the other hand we need the evidence maps to calculate the
cost. In the first stage, we had generated the likelihood maps for
each class individually. Then if we assume that we have just 7
classes in the image as we used for this data we can calculate
the evidence map for others using a similar formula as it was for
hypothesis maps namely:
B2=1-El (3)
In which El is the evidence map for that particular class which
we are working on it. Performing these calculations now we
have all of the components that we need to estimate the cost of
the specific threshold t; therefore using equation (1) we
calculate the cost. After this we examine that this cost is
minimum or not. If it is not, then we change the threshold value
t to t' and repeat the whole procedure for the new hypothesis
map. The cost graph of the various thresholds for class Onions
have been shown in the Figure 5. Table 1 shows the
corresponding minimum cost for each class. We store the final
result for each class to merge them in the final map by assigning
the relevant IDs to each resulted hypothesis map.
Integration of all of the final hypothesis maps can be seen in the
Figure 6(b). In this map each polygon has a label defined by the
procedure. As it has been shown some unlabeled polygons are
in the final map. This implies that these polygons could not be
categorized into any class. In other words, for all of the classes,
the probabilities have not supported any of them. These
polygons are shown in the Figure 6(c).
1284
Internationc
Cost
Figure ©
Onions ¢
Table 1. T
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