“…Gao et al presented a scheme for facial expression recognition from a single facial image using line based caricatures [53]. Among other significant contributions in emotion recognition, the works presented in [6], [8], [9], [11], [12], [15]- [17], [23]- [28], [30]- [32], [35], [40], [46], [56], [57], [60], [70], [72], [77]- [80] need special mention. For a more complete literature survey, which cannot be given here for space restriction, readers may refer to two outstanding papers by Pantic et al [57], [67].…”