Perceptually Organized EM: A Framework for Motion Segmentation that Combines Information about Form and
Yair Weiss and Edward H. Adelson
MIT Media Lab Perceptual Computing Section Technical Report #315(1994).
Recent progress in motion analysis has been achieved with systems that estimate global parameterized motion by
integrating multiple constraints. The success of these approaches depends critically on the ability to segment
constraints derived from different motions. Hence the problems of motion estimation and segmentattion are tightly
coupled. We believe it is impossible to solve these problems solely in the motion domain, and that mechanisms of
spatial form analysis must be incorporated into the motion estimation procedure.
We present a new framework which allows the incorporation of form information in a graceful manner. It combines
concepts from perceptual organization with the powerful optimization technique of EM. We show that the algorithm is
guaranteed to decrease a cost function at every iteration, and that in the absence of form information the cost
function reduces to the one minimized by EM. We demonstrate that the approach can achieve good motion estimation and
segmentation with challenging motion sequences.