Apart from being the channel used to identify other members of the species, the human face provides a number of signals essential for interpersonal communication in our social life. The face houses the speech production center and is used to regulate the conversation by gazing or nodding, and to interpret what is being said by lip reading. It is our direct and naturally preeminent means of communicating and understanding someone’s affective state and intentions solely based on a displayed facial expression is being shown.
The face is a multi-signal sender/receiver, capable of tremendous flexibility and specificity. In turn, automating the analysis of facial signals can be highly beneficial in many different fields such as behavioral science, market research, communication, education, and human-machine interaction.





