Well-annotated (emotion-tagged) media content of facial behavior is essential for training, testing, and validation of algorithms for the development of expression recognition systems.
Most of the databases are usually based on the basic emotions theory (by Paul Ekman) which assumes the existence of six discrete basic emotions (anger, fear, disgust, surprise, joy, sadness).
Spontaneous expressions differ from posed ones remarkably in terms of intensity, configuration, and duration.
Therefore, in most cases, the posed expressions are exaggerated, while the spontaneous ones are subtle and differ in appearance.
Song: Calm, happy, sad, angry, fearful, and neutral.