| Event Perception from Motion
P657 | 3440 | Bingham G.
Gunnar Johansson's seminal studies on event perception in the 1950's and
60's led to two subsequent areas of study: visual event perception and
structure-from-motion. In structure-from-motion research, one investigates
how object shape is perceived on the basis of information in optic flow
characterized in terms of a momentary vector field. In these studies,
object motion is assumed to be very simple, rotation about the center of
mass at constant angular velocity. In event perception research, one
investigates how events are recognized on the basis of information in
optic flow characterized in terms of the extended trajectories. Motion in
events can be relatively complex (e.g. a bouncing ball, falling leaves,
splashing water, a person walking). More structure-from-motion studies
have been performed in recent years yielding more technical advances and
more progress. Numerous studies report that the visual system can only use
the information made available over two sequential frames in a movie (i.e.
the momentary vector field), not more. But this cannot be enough to
recognize events, which we can clearly do. In this seminar, we will review
these developments and compare these two areas of research.