Delta-Sigma Analysis of Image Halftoning by Error Diffusion
Prof. Brian L. Evans
Laboratory for Vision Systems
Dept. of Electrical and Computer Engineering
The University of Texas at Austin
bevans@ece.utexas.edu
research conducted in collaboration with
Mr. Thomas D. Kite (UT Austin), Prof. Alan C. Bovik (UT Austin), and
Dr. Terry Sculley (Crystal Semiconductor Corp.)
The error diffusion algorithm is an efficient way of converting
grayscale images into high quality halftones. However, its operation
is not well understood. We will show that error diffusion is a
non-separable two-dimensional extension of delta-sigma modulation.
Delta-sigma modulation analysis techniques explain features in
halftones produced by classical error diffusion schemes, and allow
the optimization of these schemes for high visual quality.
Biography
Brian L. Evans is an Assistant Professor in the
Department of Electrical and
Computer Engineering at
The University of Texas at Austin,
and the Associate Director of the
Laboratory for Vision Systems
within the
Center for Vision and
Image Sciences.
His research interests include
real-time software, embedded systems, heterogeneous systems,
image and video processing systems, system-level design,
symbolic computation, and computer-aided design.
He has developed numerous computer-aided design tools to prototype
and test research ideas.
His B.S.E.E.C.S. (1987) degree is from the
Rose-Hulman Institute of Technology,
and his M.S.E.E. (1988) and Ph.D.E.E. (1993) degrees are from the
Georgia Institute of Technology.
From 1993 to 1996, he was a post-doctoral researcher at the
University of California at
Berkeley with the
Ptolemy Project.
Ptolemy is a
research
project and
software
environment focused on design methodology for signal processing,
communications, and controls systems.
He is the recipient of a 1997
NSF CAREER Award.