In this paper we present a novel face classification system
where we represent face images as a spatial arrangement
of image patches, and seek a smooth non-linear functional
mapping for the corresponding patches such that in
the range space, patches of the same face are close to one
another, while patches from different faces are far apart,
in L2 sense. We accomplish this using Volterra kernels,
which can generate successively better approximations to
any smooth non-linear functional. During learning, for
each set of corresponding patches we recover a Volterra
kernel by minimizing a goodness functional defined over
the range space of the sought functional. We show that
for our definition of the goodness functional, which minimizes
the ratio between intra-class distances and inter-class
distances, the problem of generating Volterra approximations,
to any order, can be posed as a generalized eigenvalue
problem. During testing, each patch from the test image
that is class...
Ritwik Kumar, Arunava Banerjee, Baba C. Vemuri