[Colloquium] TTI-C Colloquium: David Forsyth, UIUC

[Julia MacGlashan]

When:              Monday, November 3 @ 2:00pm

 

Where:            TTI-C Conference Room: 1427 E. 60th St, 2nd Floor

 

Who:                David Forsyth, University of Illinois at
Urbana-Champaign

 

Title:                 Looking at People

 

 

There is a great need for programs that can describe what people are doing
from video.   This is difficult to do, because it is hard to identify and
track people in video sequences, because we have no canonical vocabulary for
describing what people are doing, and because phenomena such as aspect and
individual variation greatly affect the appearance of what people are doing.
Recent work in kinematic tracking has produced methods that can report the
kinematic configuration of the body fairly accurately and fully
automatically.

 

The problem of vocabulary is more difficult.  I will discuss a generative
activity model that allows activities to be assembled from a set of distinct
spatial and temporal components.  The models themselves are learned from
labelled motion capture data and are assembled in a way that makes it
possible to learn very complex finite automata without estimating large
numbers of parameters. The advantage of such a model is that one can search
videos for examples of activities specified with a simple query language,
without possessing any example of the activity sought.  In this case, aspect
is dealt with by explicit 3D reasoning.

 

An alternative strategy for dealing with aspect and individual variation is
to build discriminative methods applied to appearance features.  The
difficulty here is that activities look different when seen from different
directions.  I will describe recent methods that make it possible to
transfer models --- that is, to learn a model of an activity from one view,
then recognize it in a completely different view.

 

 

Contact:          Greg Shakhnarovich, TTI-C         greg at tti-c.org
834-2572

 

 

 

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