preview

Recognizing the Temporal Dynamics of the Face

Good Essays

Fig. 1.1 Universal Emotions

Most of the developed methods try to recognize the basic expressions and some attempts at recognizing non-basic expressions. However, there have been very few attempts at recognizing the temporal dynamics of the face. Temporal dynamics denotes to the timing and time length of facial actions. The significant terms that are used in joining with temporal dynamics are: onset, apex and offset. These are known as the temporal segments of an expression [40]. Onset is the instance when the facial expression starts, apex is the point when the expression is at its peak and offset is when the expression fades away (start-of-offset is when the expression starts to fade, and the end-of-offset is when the expression completely fades out). Similarly, onset-time is defined as the time taken from start to the peak, apex-time is defined as the complete time at the peak and offset-time is defined as the total time from a peak to the stop. Pantic and Patras have reported successful recognition of facial AUs and their temporal segments [2]. By doing so, they have been able to recognize a much larger range of expressions.
Another very important type of expression classification is ‘posed’ and ‘spontaneous’. Posed expressions are the artificial expressions that a subject will produce when he or she is requested to do so. This is commonly the case when the subject is under normal test condition or under observation in a laboratory.
In contrast, natural expressions are

Get Access