A Survey on: Facial Emotion Recognition Invariant to Pose, Illumination and Age

Facial Emotion Recognition (FER) gained considerable interest among scientists working in areas like medical diagnosis, forensics and communication technology. Numerous studies have already been conducted on facial emotion recognition (FER) but none seems to deal with pose, illumination and age invariance simultaneously. This paper reviews several challenges for pose, illumination and age invariance for FER. Here we also provide a survey on deep learning methodologies used in FER. It is noted that deep learning algorithms provide greater accuracy than all other algorithms previously used.