Systems Seminar
Higher-Order Active Contours
Ian Jermyn
Ariana
INRIA, Sophia Antipolis
Abstract
This talk will describe a new class of active contour models, higher-order
polynomial energies, that hold great promise for region and shape
modelling. The distinctive feature of the new class of models is that
different points of the contour interact with each other in ways that
depend on the contour geometry, and that may depend on the data. The result
is that the new energies can incorporate non-trivial prior information
about geometry, their minima representing families of contours sharing
complex geometric properties. However, unlike most current attempts to
incorporate geometric information into contour energies, these models do
not describe only small, tangential variations around a 'mean' shape, and
they are automatically translation and rotation invariant. In addition, new
data energies can correlate the contour with the data in ways that are
impossible using classical models.
Off-the-shelf contour energy minimization methods do not apply directly to
the new models, necessitating an extension of existing level set methods to
deal with the non-local forces that arise.
An example of an energy in this class, consisting of a prior term whose
minima bear a strong resemblance to networks of interest in several types
of imagery, and a data term illustrating the possibilities inherent in the
new energies, will be described. A number of results will be shown, some
illustrating the prior behaviour of the contour in the absence of data, and
others showing the results obtained so far in the extraction of road
networks from optical satellite images.
This is joint work with Marie Rochery and Josiane Zerubia.
Time and Place: Mon., Aug. 23, at 3:30 pm in 4610 Engr. Hall.
*** NOTE SPECIAL DAY ***
SYSTEMS SEMINAR WEB PAGE:
http://homepages.cae.wisc.edu/~gubner/seminar/