## Soatto et al.1996 : Estimating the
three-dimensional motion of an object from a sequence of projections is of
paramount importance in a variety of applications in control and robotics, such
as autonomous navigation, manipulation, servo, tracking, docking, planning, and
surveillance. Although “visual motion estimation” is an old problem (the first
formulations date back to the beginning of the century), only recently have
tools from nonlinear systems estimation theory hinted at acceptable solutions.
In this paper the authors formulate the visual motion estimation problem in terms
of identification of nonlinear implicit systems with parameters on a
topological manifold and propose a dynamic solution either in the local
coordinates or in the embedding space of the parameter manifold. Such a
formulation has structural advantages over previous recursive schemes, since
the estimation of motion is decoupled from the estimation of the structure of
the object being viewed, and therefore it is possible to handle occlusions in a
principled way.