Various Techniques Involved in Facial Expression Recognition-Review

Facial expressions transfers non-verbal clues, which play an imperative role in interpersonal relations. Automatic appreciation of facial expressions can be a central component of ordinary human-machine interfaces; it may also be used in communication science and in scientific practice. Although humans recognize facial expressions nearly without effort or delay, reliable expression recognition by appliance is still a challenge. A system that performs these operations more accurately and in real time would be crucial to achieve a human like interaction between man and machine. This paper presents a high-level outline of unconscious expression recognition; it highlights the key system components and some research contests. This paper reviews the past work done in solving these problems for image sequences and a number of methodological approaches relative to facial expression recognition systems and proposes further research areas that require more attention towards the successful implementation of a more efficient channel for machine-emotion interaction.