Speaker: Mary Pugh
Title: Image Segmentation and Energy Dissipation.
Affiliation: University of Pennsylvania.
Date: Friday, April 13, 2001.
Place and Time: Room 101 - Love Building, 3:35-4:35 pm.
Refreshments: Room 204 - Love Building, 3:00 pm.

Abstract. In this talk I will present some work in progress in vision research. We consider the problem of recognizing what parts of an image are perceived as being in the foreground. We use a variant of the Pao-Geiger-Rubin model, which uses an energy dissipation approach to this problem. The model is surface-based, rather than contour-based. Specifically, the edges in the image are not viewed as isolated contours, but are viewed as bounding a surface. Each local edge has a local hypothesis; for example, a north-south edge might think "the region immediately to the left of me is part of the figure". The model then uses energy dissipation methods to seek assignments of local hypotheses that are mutually agreeable, yielding a segmentation of the image that might be perceived. We test the model on various images to address questions like: does the model "perceive" objects to be in the foreground (the way we do)? how does it perform on optical illusions that viewers report to have two different segmentations?
     This is joint work with Nava Rubin of the Center for Neural Science, NYU and Davi Geiger of the Courant Institute, NYU. I thank Anita Disney (CNS, NYU), Dave McLaughlin (Courant, NYU) and Bob Shapley (CNS, NYU) for useful discussions.