Exploring Human Body Shape and Motion
James Davis - University of California, Santa Cruz

Directly sensing the shape and motion of people would enable many new
applications. Unfortunately no such sensor yet exists. We hypothesize that a
high quality surface prior model of human shape will be sufficient to enable
sensing using todays inadequate sensors. We introduce a data-driven method for
building a human shape model that spans variation in both subject shape and
pose.  The method is based on a representation that incorporates both
articulated and nonrigid deformations.  We learn a pose deformation model that
derives the nonrigid surface deformation as a function of the pose of the
articulated skeleton.  We also learn a separate model of variation based on
body shape.  Our two models can be combined to produce 3D surface models with
realistic muscle deformation for different people in different poses, when
neither appear in the training set. We show how the model can be used for shape
completion  --- generating a complete surface mesh given a limited set of
markers specifying the target shape.  We present applications of shape
completion to partial view completion and motion capture animation. In
particular, our method is capable of constructing a high-quality animated
surface model of a moving person, with realistic muscle deformation, using just
a single static scan of that person. We also show results using this model to
recover shape and motion from traditional cameras.

James Davis is an Assistant Professor in Computer Science at the University of
California, Santa Cruz.  He received his PhD from Stanford University in 2002,
and was previously a senior research scientist at Honda Research Institute. His
research expertise is in computer graphics, machine vision, and sensing systems
for building digital models of the real world, work that has resulted in over
25 patents and peer-reviewed publications, recieved an ICRA 2003 Best Vision
Paper, and an NSF CAREER award. His research has been commercialization by
companies including Sony, PrenticeHall, and Apple Computer, and he now sits on
advisory councils for a handful of startups and nonprofits. He is additionally
interested in applying technology to address global social issues, and has
developed an award winning course around this theme.