This paper deals with estimation of dense optical flow
and ego-motion in a generalized imaging system by exploiting
probabilistic linear subspace constraints on the flow.
We deal with the extended motion of the imaging system
through an environment that we assume to have some degree
of statistical regularity. For example, in autonomous
ground vehicles the structure of the environment around the
vehicle is far from arbitrary, and the depth at each pixel
is often approximately constant. The subspace constraints
hold not only for perspective cameras, but in fact for a
very general class of imaging systems, including catadioptric
and multiple-view systems. Using minimal assumptions
about the imaging system, we learn a probabilistic
subspace constraint that captures the statistical regularity
of the scene geometry relative to an imaging system. We
propose an extension to probabilistic PCA (Tipping and
Bishop, 1999) as a way to robustly learn this subspace
from recorded imag...