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Nt1310 Unit 3 Test Report

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The training and test samples are selected based on the ground truth of the original image of AVIRIS and HYDICE data. B. Result of Feature Extraction And Selection The goal of the feature extraction and selection is to reduce the dimension of the data. In this experiment the dimension of the AVIRIS and HYDICE images reduced to 20 from 220 and 191 respectively using PCA. From the PCA analysis we can see that image of principal component 1 is brightest and sharpest than other PCA image which is illustrated in figure-2. Fig. 2. Images of some principal components This PCA image is more informative as it has high variance. But principal component 5 contains more information than principal component 3.So this is not always true that high variance image always contains more spatial information than low variance image. To address this problem QMI is applied between class labels and PCA image so that we …show more content…

3. QMI of 1st 20 principal components of AVIRIS The order of the 1st 10 selected features after applying QMI for AVIRIS is 1,3,5,16,7,12,13,6,4,9 and for HYDICE is 1, 8,2,4,3,12,18,5,7. The QMI values for 1st 20th Principal Component is shown in figure-3 for AVIRIS and for HYDICE in figure-3 Fig. 4. QMI of 1st 20 principal components of HYDICE C. Result of Classification We have used support vector machine (SVM) for classification task. We have used RBF kernel for training the classifier. 10 fold cross-validation is used for determining cost parameter C and best kernel width for RBF kernel function. If we perform classification without any feature selection or feature extraction then the accuracy is 48.99% and 65.82% for AVIRIS and HYDICE image respectively which is very poor and it highly motivates us to apply feature reduction technique. In table II we have shown the classification accuracy for each of the pair of class for PCA, MI and PCA-QMI. TABLE II. COMPARISON OF ACCURACY Methods AVIRIS HYDICE MI 82.79 87.19 PCA 98.38 99.32 PCA-QMI 99.02

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