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Robotics Institute Seminar,
February 24, 2006
Time and Place | Seminar Abstract | Speaker Biography | Speaker Appointments
A Frequency Analysis
of Light Transport
Fredo Durand
Massachusetts Institute of Technology
Computer Science and
Artificial Intelligence Laboratory
Mauldin
Auditorium (NSH 1305)
Refreshments 3:15 pm
Talk 3:30 pm
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Abstract |
We present a signal-processing
framework for light transport. We study the frequency content of radiance and
how it is affected by phenomena such as shading, occlusion, and travel in free
space. This extends previous work that considered either spatial or angular
dimensions, and offers a comprehensive treatment of both space and angle.
We
characterize how the radiance signal is modified as light propagates and
interacts with objects. In particular, we show that occlusion (a multiplication
in the primal space) amounts in the Fourier domain to a convolution by the
frequency content of the blocker. Propagation in free space corresponds to a
shear in the space-angle frequency domain, while reflection on curved objects
performs a different shear along the angular frequency axis. As described by
previous work, reflection is a convolution in the primal space, and therefore
amounts to a multiplication in the Fourier domain. Our extension shows how the
spatial components of lighting are affected by this angular convolution.
We
show that our signal-processing framework predicts the characteristics of
interactions such as caustics, and the disappearance of the shadows of small features.
Predictions on the frequency spectrum of the radiance function can then be used
to control sampling rates or the choice of reconstruction kernels for
rendering. Other potential applications include pre-computed radiance transfer
and inverse rendering.
http://people.csail.mit.edu/fredo/PUBLI/Fourier/
In
collaboration with Nicolas Holzschuch, Cyril Soler, Eric Chan & Franois Sillion
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Speaker Biography |
Frédo Durand is an
assistant professor in the Electrical Engineering and Computer Science
Department of the Massachusetts Institute of Technology, and a member of the
Computer Science and Artificial Intelligence Laboratory. He received his PhD
from
His
research interests span most aspects of picture generation and creation. This
includes realistic graphics, real-time rendering ,
non-photorealistic rendering, as well as computational photography. His recent
emphasis is on the use of tools from signal processing and inspiration from
perceptual sciences. He co-organized the first Symposium on Computational Photography and Video in 2005.
He received a Eurographics Young Researcher Award in 2004, an NSF
CAREER award in 2005 and a Microsoft Research New Faculty Fellowship in 2005.
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Speaker Appointments |
For
appointments, please contact Janice Brochetti (janiceb@cs.cmu.edu).
The Robotics Institute is part of the School of Computer Science, Carnegie Mellon University.