Matching based on local brightness is quite limited, because
small changes on local appearance invalidate the
constancy in brightness. The root of this limitation is its
treatment regardless of the information from the spatial contexts.
This papers leaps from brightness constancy to context
constancy, and thus from optical flow to contextual flow.
It presents a new approach that incorporates contexts to
constrain motion estimation for target tracking. In this approach,
one individual spatial context of a given pixel is
represented by the posterior density of the associated feature
class in its contextual domain. Each individual context
gives a linear contextual flow constraint to the motion,
so that the motion can be estimated in an over-determined
contextual system. Based on this contextual flow model, this
paper presents a new and powerful target tracking method
that integrates the processes of salient contextual point selection,
robust contextual matching, and dynami...