“…Therefore prior to classification, methods of balancing a numerous features vector, feature selection or extraction are studied to speed up the learning process and minimize the curse of dimensionality problem [ 29 , 30 ]. Emotion classification is generally performed using standard techniques such as SVM [ 31 , 32 , 33 ], various types of artificial neural networks (NN) [ 34 , 35 , 36 , 37 ], different types of the k-NN classifier [ 19 , 38 ] or using Hidden Markov Model (HMM) and its variations [ 39 ]. However, it is a complex task with many unresolved issues.…”