Table 2.

The types of information that can be extracted out of image sequences and the related visual clues that can provide this information.

Information	Related Visual Clues
Who is the person? (identity)	Face
	Hair
	Skin
	Height
	Clothes
	Gait
How is the person displayed? (e.g., the appearance)	Face expressions
	Hair (e.g., hairstyle, colour, etc.)
	Body (e.g., nudity)
	Posture
	Shape
	Colour
Where is the person? (location)	Room
	Spatial position (e.g., on the floor, on the bed, etc.)
	Room signs
What is the person doing? (ongoing activity)	Behaviour (i.e., movement, gesture, action, activity)
	Gaze
	Spatial position
	Objects and interactions
When is the activity taking place? (time)	Temporal clues (e.g., a wall clock)