891
detection of those fields in which two or more crop types are
grown. Based on updated DFBM this way, two classification schemes
have been developed (Csornai et al, 1988). The first one is a
simple reclassification[REC] of a per point classification (e.g.
maximum likelihood CMXLj) on the basis of majority of classified
pixels within the field boundaries, the second incurs information
on boundaries at the very beginning of the classification,
collecting the statistics based on pixels each field (Table 3).
Categories
#FieIds
Area (Ha)
Accuracy
CMXLj
in percent
CRECj
Winter wheat
9
746
84.4
100
Alfalfa
1
54
60.6
60.6
Corn
14
764
69.5
87.6
Sugar-beet
3
168
60.2
71.7
Peas
3
88
86.6
100
Pasture
4
749
64.4
86.7
Settlement
1
187
71
100
Total
3b
2756
72
90.7
Table 3. Table of accuracy in classification for a sample
co—operative (Foldes)
Both these two schemes proved to be effective. Based on some
preliminary results (Csornai et al, 1989) it can be
concluded that in inventory type of surveys the basic
classification accuracy can increase by 10—12 percent
(Table 4).
Categories
# p i x e 1 s
Per—point
CPPC)
Reclass.
CREC]
Per—field
CPFC]
Wheat
41150
87 7.
91 7.
98 7.
Maize
37442
73 7.
78 7.
90 7.
Sugar—beet
12485
65 7.
83 7.
81 7.
Potato
4186
67 7.
83 7.
77 7.
Alfalfa
3687
65 7.
B5 7.
96 7.
Soil
2026
87 7.
91 7.
45 7.
Water
3568
71 7.
100 7.
76 7.
Average PCC
80.1 7.
86.8 7.
91.6 7.
Table 4. Comparison of the classification accuracies on a
small area.