Invariants in visual motion
Daniel Raviv · 1991
This paper deals with new and simple representations of 3-D points in a movingobserver coordinate system.Assuming rectilinear motion with no rotation of an observer where the optical axis coincides with the direction of motion, and a stationary scene, points in 3-D space that lie on a particular 3-D surface produce constant value of some nonlinear function of the measurable image optical flow.Five sets of different surfaces are introduced and there is one optical-flow based constant value for each sur- face.We called these values "invariants".It is shown how to extract these invariants and how to use them for representing 3-D space.Ill