Campuses:

Characterizing Local Features of Illuminated Objects

Thursday, March 9, 2006 - 9:00am - 10:00am
EE/CS 3-180
James Damon (University of North Carolina, Chapel Hill)
The perceived shapes of objects in images result from a
collection
of visual clues.
These clues follow from the interplay of geometric features
such as
perceived boundaries,
edges and corners, delineating curves on object surfaces, and
features
resulting from
illumination such as shadow curves and specularity.
Furthermore, a
viewer gains such
information not just from static images but also from perceived
changes
resulting from
change in viewing direction.



In this talk, we explain how it is possible to determine a
catalog
of possible local
models for the generic interplay between geometric features and
shadow
curves. This
catalogue can be expanded to included the expected changes in
such
models under
movement in viewing direction.

Such a catalog is constructed through the use of
singularity theory,
which is a
mathematical theory that allows construction of such
classifications
based on stability and possible perturbations. We explain the
general features of the
classification and
indicate how it is obtained.


This is the result of joint work carried out with Peter
Giblin and
Gareth Haslinger.