“…Most commonly used techniques for feature selection in the emotion recognition problem include principal component analysis (PCA) [59], independent component analysis [60], rough sets [42], [61], Gabor filter [62], and Fourier descriptors [25]. Among the popularly used techniques for emotion classification, neural net-based mapping [3], [4], [18], fuzzy relational approach [14], linear discriminate analysis [60], support vector machine (SVM) [8], and hidden Markov model [59], [62] need special mention. A brief overview of the existing research on emotion recognition is given next.…”