Background: Mammogram images are low dose x-ray images which detect the breast
cancer before the women can actually experience it.
Objective: To determine the accurate methodology for feature extraction using different wavelet
families and different classification algorithms.
Methods: Two wavelet families are used namely Daubechies (db8) and Biorthogonal (bior3.7). The
Gray-Level Co-occurrence Matrix is used for extracting 9 features at each sub-band. 27 features are
extracted at three sub-bands of Discrete Wavelet Transform. The features are extracted at three levels
of decomposition and after that the classification algorithm named as Naive Bayes, Multilayer
Perceptron, Fuzzy-NN and Genetic Programming are applied to extracted features. The feature selection
algorithms are applied named as Wavelet and Principle Component Analysis for selecting
the features and then classification accuracy is determined and compared between these.
Results: Mammographic Image Analysis Society, database including 322 mammogram images from
161 patients is used. The classification algorithm without feature selection named as Fuzzy-NN
gives better results at the third level of decomposition having classification accuracy for db8 wavelet
family up to 99.68% and for bior3.7 wavelet family up to 99.98%. Wavelet with Multilayer Perceptron
using feature selection algorithm gives the classification accuracy for db8 wavelet family up
to 96.27% and for bior3.7 up to 93.47%.
Conclusion: Fuzzy-NN algorithm gives highest accuracy of 99.98% for bior3.7 wavelet family. It
indicates that with feature selection and without feature selection, the wavelet families differ as db8
is better consideration for with feature selection and bior3.7 wavelet family for without feature selection.