[4eyes] ECE Vision Research Lab seminar tomorrow

[Matthew Turk]

FYI

 

 

The following is the announcement for a seminar given by Julian Yarkony from
UC Irvine tomorrow. The duration will be for an hour.

 

"Planarity Matters:  Variational inference in Planar Markov Random Fields
and Variational Approach to Planar Correlation Clustering"
Julian Yarkony, PhD Student ICS, UC, Irvine

Feb 23 (Thu) 11:00am
HFH Rm 4164

ABSTRACT:
Variational inference in Planar Markov Random Fields: MAP Inference in
Markov random fields (MRFs) is of great importance for many vision
applications.  MRFs which appear in computer vision tend to be planar in
structure.  We demonstrate various means to take advantage of reductions of
MAP estimation to perfect matching in a dual decomposition framework.  We
show how this can be applied to binary MRFs  and non-binary MRFs  when
planarity is present.    Our algorithms provide upper and lower bounds on
the MAP which can be tightened iteratively and can be interpreted with
regard to the marginal polytope.

Variational Approach to Planar Correlation Clustering: Grouping pixels in an
image into regions is a key problem in computer vision research. We frame
the problem as a correlation clustering problem on a planar graph. In this
talk a new algorithm for computing the ground state (MAP) for planar
correlation clustering problems is introduced. Our algorithm substitutes an
intractable minimization for a tractable maximization of a variational lower
bound then maps the lower bound to a solution. In practice our lower bound
and the energy of the final solution have the same value providing a
guarantee of global optimality. The key advantage to our work is that  the
algorithm will produce clustering of the super-pixels in an image without
receiving the number of clusters as input.

BIO:
Julian Yarkony is a 5th year PhD student under Professors Fowlkes and Ihler
at the University of California at Irvine.  His research focuses on the
development of  approximation algorithms for applications in image analysis.
He is currently focusing on hierarchical clustering in images under a
variational framework.  His published results concern the creation of
effective MAP estimators for Markov random fields especially planar Markov
random fields.   In his spare time he enjoys fine arts, and the ocean.

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cs.ucsb.edu/pipermail/ilab-users/attachments/20120222/3e37aa52/attachment.html>