The Robotics Institute

RI | Seminar | March 22

Robotics Institute Seminar, March 22
Time and Place | Seminar Abstract | Speaker Biography | Speaker Appointments

Statistics of the Geometry of Object Populations

Stephen M. Pizer

Kenan Professor

Medical Image Display & Analysis Group

University of North Carolina


Co-authors: P. Thomas Fletcher, Conglin Lu, Sarang Joshi, Erik Dam, Roland Pilgram


Time and Place

Mauldin Auditorium (NSH 1305)
Talk 10:30 am



Probability distributions on geometric representations of objects or multi-object complexes are useful as priors in segmentation via posterior optimization of deformable models, for characterization of geometric differences between populations, e.g., of healthy and diseased anatomy, and for a variety of other objectives. These applications require localization, accurate estimation of probabilities from a few tens of sample cases, rich and intuitive characterization of geometric effects, and null probabilities for geometrically illegal objects. I will present an implemented mechanism for achieving these aims that is based on Markov random fields of geometric residues through multiple scale levels, considering objects as geometric transformations in symmetric spaces, finding means and principal geodesic components on these abstract curved spaces, and medial primitives. Probability distributions for a few anatomic objects and multi-object ensembles will be presented. While the mathematical level of this material is deep, the presentation level will be accessible to users and developers of image analysis methods.


Speaker Biography

PhD, Harvard, 1967. Dissertation work done at MGH is perhaps the first dissertation in medical image computing.

On faculty in Computer Science, Radiology, Radiation Oncology, and Biomedical Engineering at UNC since 1967.

Kenan Professor

Advisee of about 45 dissertations.

Head of MIDAG, the UNC Medical Image Display & Analysis Group, a group of over 110 from 11 departments.


Stephen M. Pizer, Kenan Professor of Computer Science,

Radiology, Radiation Oncology, and Biomedical Engineering,

Head of Medical Image Display and Analysis Group, Univ of NC


Phone: +1 919 962-1785

Admin. Asst.:+1 919 962-1768

Fax: +1 919 962-1799



222 Sitterson Hall, CB # 3175

Computer Science Department

University of North Carolina

Chapel Hill, NC 27599-3175



Speaker Appointments

For appointments, please contact George Stetten.

The Robotics Institute is part of the School of Computer Science, Carnegie Mellon University.