Emotional facial expression analysis in the time domain
Emotions have been studied for a long time and results show that they play an important role in human cognitive functions. In fact, emotions play an extremely important role during the communication between people. And the human face is the most communicative part of the body for expressing emotions; it is recognized that a link exists between facial activity and emotional states. In order to make computer applications more believable and friendly, giving them the ability to recognize and/or express emotions are research fields which have been much focused on. Being able to perform these tasks, firstly, we need to have knowledge about the relationship between emotion and facial activity. Up to now, there have been proposed researches on this relationship. However, almost all these researches focused on analyzing the relationship without taking into account time factors. They analyzed the relationship but did not examined it in the time domain. In this paper, we propose a work on analyzing the relationship between emotions and facial activity in the time domain. Our goal is finding the temporal patterns of facial activity of six basic emotions (happy, sad, angry, fear, surprise, disgust). To perform this task, we analyzed a spontaneous video database in order to consider how facial activities which are related to the six basic emotions happen temporally. From there, we bring out the general temporal patterns for facial expressions of each of the six emotions.