“…Recent surveys [2,3] detail the research into FER over past decades. Deep CNNs have recently achieved good FER results [4,5,6,7,8,9,10,11,12,1,13,14,15,16,17,18,19,20], but they may also learn identity-related features that are irrelevant to expression and suffer from high intra-class variations and inter-class similarities, leading to a drop in FER performance on unseen subjects. Wen et al [21] introduced a center loss for face recognition to reduce intra-class variations, without explicitly considering inter-class similarity.…”