Seminars/Colloquia/Invited Talks

Seminars

Robert Pless

Learning Image Manifolds = Manifold Learning

PLACE:	Clark 314
EVENT:	CIS Seminar Series
DATE:	May 02, 2006
TIME:	1:00 - 2:00

Abstract

This talk will detail my explorations in applying Manifold Learning techniques to real problems in image processing. Initial experiments with natural image sets (What is the intrinsic dimension of a Charlie Chaplin video clip?... Do cardio-pulmonary MR-images have a natural 2D parameterization?) illuminate several limitations of existing algorithms. First, using Euclidean (sum-of-squared pixel intensity difference) distance is usually a poor choice of image distance functions for natural images. Second, many natural image manifolds have a cyclic topology (and thus cannot be cleanly embedding into a Euclidean space). Third, natural data sets often include unlabeled examples from multiple, intersecting low-dimensional manifolds.
I will talk about several heuristic (and occasionally well founded) algorithms for choosing effective local image distance measures, finding minimal parameterizations for cyclic manifolds, and simultaneously clustering and parameterizing data from multiple intersecting manifolds. These have been brought together in an end-to-end application which automatically learns the 2D manifold structure of (ungated, free-breathing) cardiac MRI images of a patient, and uses the manifold structure of the images to regularize the segmentation of the left ventricle simultaneously in all frames.

Brief Biography

Robert Pless is an Associate Professor of Computer Science and founder of the Media and Machines Laboratory at Washington University in St. Louis. His research focus is the statistics and geometry of video, including anomaly detection and motion pattern analysis with applications to surveillance video and MR-imagery. Dr. Pless is active on the program committees of the International Conference on Computer Vision (ICCV) and the IEEE Conference on Computer Vision and Pattern Recognition (CVPR), and chaired the IEEE workshop on Omnidirectional Vision and Camera Networks (Omnivis 2003). In 2006 he received the NSF CAREER award. Dr. Pless has a Bachelors Degree in Computer Science from Cornell University in 1994 and a PhD from the University of Maryland, College Park in 2000.