[4eyes] Visual Computing Cafe Seminar Friday Nov. 8, 2013

[Pradeep Sen]

UCSB Visual Computing Café Seminar Friday November 8, 2013
12:30pm - 1:30pm, Harold Frank Hall 1132 Auditorium


TITLE:
Capturing the World in High Dynamic Range
by Nima Khademi Kalantari, UC Santa Barbara


ABSTRACT:

The illumination of the world we live in has high dynamic range,
and we must therefore capture it properly in order to reproduce
environments as our eyes perceive them. Unfortunately, standard
digital cameras have low dynamic range and can measure only a
small range of the total illumination of the scene. Recently,
high dynamic range (HDR) imaging has received great attention
because of its tremendous potential in transforming the world
of photography. Approaches have been proposed to generate
high-quality HDR images and videos using specialized camera
systems.  However, because of their high cost and general
unavailability, these cameras are impractical for the average
consumer.

To make high-quality HDR imaging widespread, we must focus on
approaches that use standard digital cameras. The most common
approach is to take sequential LDR images at different exposure
levels (known as bracketed exposures) and then merge them into
an HDR image. Although this technique can produce spectacular
results, the original approaches work only for static scenes
because they typically assume a constant radiance at each pixel
over all exposures. For a dynamic scene, this method produces
ghost-like artifacts from even small misalignments between
exposures. In this talk, I will present our research on this
topic which resulted in two methods for generating high-quality
HDR images and videos from bracketed exposures. Our methods
work by minimizing a patch-based objective function to correct
for the motion between different bracketed exposures in order
to generate ghost-free results.


BIO:
Nima Khademi Kalantari is a Ph.D. student at UCSB working
under the supervision of Dr. Pradeep Sen in the MIRAGE Lab.
His research interests focus on the application of signal
processing to computer graphics and vision. He has published
9 journal papers in different areas including sampling,
rendering, and imaging.




-- 
Pradeep Sen
Associate Professor
UCSB MIRAGE Lab
Dept. of Electrical & Computer Engineering
University of California, Santa Barbara
Santa Barbara, CA 93106-9560