Salami, Ayobami T.
The individual is assigned to the class for which the probability value is greatest. In an operational context,
the observed means, variances and covariances are substituted using the log form of equation (1):
Ln[Q(X;)] - -1/21n(D)-U2(X;-M) Dy (X;-My) ............... eq.(2)
Where:
M, = Mean vector associated with a sample of observations belonging to the kth class; taken as an
estimator of U,.
Dx = p by p dispersion matrix associated with a sample of observations belonging to the kth class; taken as
an estimator of 7.
A simple decision rule, R;, can be derived from the equation (2) by estimating constants:
R;: Choose K which minimises.
FLK(X)- Lo(DO (Xx -M m OM... eennereretnenece eq.(3)
4 RESULTS AND DISCUSSION
The results of the analysis are presented in three parts. These are the levels of divergence among the
classes, the confusion matrix and output of the final supervised classification.
4.1 Level of Divergence
The divergence matrix (Table 1) shows the extent of separation among the vegetal classes mapped from the
imagery. Table 2 which expresses the level of separability in percentages, was derived from Table 1. The
former shows that tree crop/mature secondary regrowth and young secondary regrowth (CS and C6) are the
most similar classes. There is only 27.93% separation between the two classes. This result depicts the
extent of similarity between the two vegetal types. The reason for this is explained later in the discussion.
Apart from this high level of similarity between C5 and C6, there is generally, a high level of
discrimination among the classes. This shows that generally, the variances between are much higher than
variances within the classes or vegetal types.
Table 1: Divergence Matrix of Cover Types
Cl c C3 C4 C5 C6
Ci 0.0000
C2 0.9988 0.0000
C3 0.9987 0.8381 0.0000
C4 0.8979 0.8315 0.8469 0.0000
Cs 1.0000 1.0000 0.9999 0.9958 0.0000
C6 1.0000 0.9996 0.9975 0.9679 0.2793 0.0000
KEY
C1: Burnt Patches (BP)
C2: Arable Cropland/Fallow Complex (ACFC)
C3: Exposed Land/Settlement (ELS)
C4: Mixed Grassland (MG)
C5: Tree Cropland/Mature Secondary Regrowth Complex (TMSRC)
C6: Young Secondary Regrowth (YSR)
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000. 1303