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Evaluation of conventional digital camera scenes for Thematic Information Extraction



Figure 4: The classified image obtained using Maximum Likelihood classifier for Merbok River estuary (Green = Forest, Blue = Water, Orange = Land, and Light Blue = Turbid Water)

(B) Area B
The Kappa coefficient and overall accuracy value for the three-classification technique are shown in Table 4. The others accuracy assessment results are presented in Tables 5 and 6, where the Kappa coefficient, the confusion matrix and the accuracy of each class using Maximum Likelihood, minimum distance-to-mean and parallelepiped classification are given, respectively. From the present analysis, one can see that the Maximum Likelihood classifier produced the best image classification accuracy with the highest overall accuracy and Kappa coefficient. The overall classification accuracies achieved by the proposed Maximum Likelihood classifier on the digital image is 95.00 %. This followed by the Minimum Distance-to-Mean with the overall classification accuracy of 73.00%, and Parallelepiped resulted in the overall classification accuracy of 1.00%. A classified image using Maximum Likelihood classifier is shown in Figure 5.

Table 4: The overall classification accuracy and Kappa coefficient
Classification method Overall classification accuracy (%) Kappa coefficient
Maximum Likelihood 95.000 0.866
Minimum Distance-to-Mean 73.000 0.457
Parallelepiped 1.000 0.008

Table 5: The confusion matrix results
Classified Data Reference Data
Grass Water Land Urban Total
Grass 21 1 0 0 22
Water 0 154 1 0 155
Land 2 2 12 4 20
Urban 0 0 0 3 3
Total 23 157 13 7 200

Table 6: The accuracy of each class using Maximum Likelihood classification.
Class Maximum Likelihood
Producer Accuracy (%) User Accuracy (%)
Grass 91.304 95.455
Water 98.089 99.355
Land 92.308 60.000
Urban 42.857 100.000

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