Two-body Segmentation from Two Perspective Views


Lior Wolf  and  Amnon Shashua 

School of Computer Science and Engineering,

The Hebrew University,

Jerusalem 91904, Israel


We consider a scene containing two independently and generally

moving objects, viewed by two general perspective views. Using

matching points arising from both objects simultaneously we derive a

geometrical constraint, applicable to points from both objects, we

call the segmentation matrix. We then use this constraint in order to

recover the fundamental matrices associated with each object, or

simply to segment the scene into the two objects.  Moreover, when the

two bodies move in pure translation relative to each other we can both

segment the scene and recover the affine calibration (homography at

infinity) of the camera geometry. Unlike algorithms

suggested in the past we need only two images, we work with general

projective cameras (rather than affine or orthographic) and with

general body motion, and no prior information beyond point matches is