IEEE Circuits
and Systems Society Joint Chapter of the Vancouver/Victoria Sections
IEEE Circuits and Systems Society Distinguished
Lecturer Program
Simplified
Fast Motion Estimation:
Simplified and Unified Multi-Hexagon Search (SUMH) with Context Adaptive
Lagrange Multiplier (CALM)
Speaker: Dr. Nam LING
IEEE CAS Society Distinguished Lecturer
IEEE Circuits and Systems Society Distinguished Lecturer
Professor,
Department of Computer Engineering
Associate
Dean, School of Engineering
Santa Clara
University, Santa Clara, California 95053 USA
Date and Location
Thursday,
June 21, 2007, 4:00 pm - 5:00 pm
ASB 10900:
IRMACS Presentation Studio
Simon Fraser University, Burnaby, BC V5A 1S6
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PDF version of the presentation: Part 1
PDF version of the presentation: Part 2
Abstract
1.
Fast motion
estimations are especially important to speed up the time-consuming encoding
processes for H.264 video encoding. In this talk, we first present our
simplified fast motion estimation method, called Simplified and Unified Multi-Hexagon Search (SUMH), that produces
a significant speed-up as compared with today’s fast motion estimations, yet
encounters only a small PSNR degradation when compared to that of full search.
In addition, we present a novel method to refine the Lagrange multiplier,
called Context Adaptive Lagrange Multiplier (CALM), for rate-constrained motion
estimation. Both our
methods were recently adopted into the
H.264/MPEG-4 AVC video coding international standard (including the text
document and the JM reference software). Our SUMH method was adopted as
JVT-P021 and our CALM method as JVT-T046.
Our SUMH is based on two principles,
partial distortion search (PDS) and dual-halfway-stop (DHS) algorithms. PDS
generally produces less video quality degradation of the predicted images than
those of conventional fast block matching algorithms (BMAs). However, the
speedup gain of PDS algorithms is usually limited. In this talk, we present an
enhancement over a normalized PDS (NPDS) algorithm to further reduce block
matching motion estimation complexity and improve video fidelity. The novelty
of our algorithm is that, in addition to the halfway-stop technique in NPDS, a
dual-halfway-stop (DHS) method, which is based on a dynamic threshold, is
proposed so that block matching is not performed against all searching points.
The dynamic threshold is obtained via a linear model utilizing already computed
distortion statistics. An adaptive search range mechanism based on inter block
distortion further constrains the searching process. Experimental results show
that our proposed method reduces the encoding time by about 55% on the average
when compared to those of the state-of-the-art methods, with similar
rate-distortion performances. Our SUMH algorithm, making use of DHS-NPDS,
consists of two parts, an integer-pel fast search and a sub-pel fast search.
To extend motion estimation further, we
propose a new simple and efficient method to adjust Lagrange multipliers based
on the context (CALM), which improves the accuracy for the detection of true
motion vectors as well as the most efficient encoding modes for luma, which are
used for deriving the motion vectors and modes for chroma. Simulation results
show that the chroma bit rates can be reduced by 4.36% and 4.80% (on the
average) for U- and V- chroma components, respectively, when compared with that
of the JM 10.2 reference software. In addition, the coding efficiency
improvement is comparable to the more complicated rate-distortion optimized
(RDO) mode decision techniques.
A demo will be given in the talk.
Prof. Nam LING received a B.Eng. degree in Electrical Engineering
from the National University of Singapore
(NUS). He received M.S. and Ph.D. degrees, both in Computer Engineering, from the University of Louisiana at Lafayette, U.S.A.
Prof. Ling is currently a full Professor with the Department of Computer Engineering
and the Associate Dean (Research and Faculty Development) for the School of
Engineering at Santa Clara University (SCU), California, U.S.A. He is also a
Consulting Professor and Honorary Advisor to the National University of
Singapore (NUS Overseas Colleges) and a Guest Professor of Shanghai Jiao Tong
University (China). He has served as Visiting
Professor/Consultant/Scientist/Scholar to institutions such as the Institute for Infocomm Research (I2R) (Singapore), Nanyang Technological University (Singapore), National Dong Hwa
University (Taiwan), and National Chiao Tung University (Taiwan).
Prof.
Ling has more than 130 publications in the fields of video/image coding, video
decoder design, video communications, and systolic arrays. He is the primary
author of the book entitled Specification and Verification of Systolic Arrays.
Prof. Ling received the Arthur Vining Davis Junior Faculty Fellowship in 1991
and the SCU Outstanding Achievement Award in Teaching, Research, and Service,
in 1992. Prof. Ling was named 1999 Researcher of the Year by SCU Engineering.
He received the SCU Award for Recent Achievement in Scholarship in 2002 and the
SCU President’s Recognition Award in 2005. He was named IEEE Distinguished
Lecturer (Circuits and Systems) for 2002-2003 and 2007-2008. Prof. Ling also received the 2003 IEEE ICCE Best
Paper Award (First Place Winner) for his work on MPEG-4 face animation. He and
his team’s proposal on simplified fast motion estimation, Simplified and Unified Multi-Hexagon Search (SUMH) method,
was adopted in 2005, and their context adaptive Lagrange multiplier (CALM)
method was adopted in 2006, both into the H.264/MPEG-4 AVC video coding
international standard.
Prof.
Ling served as an Associate Editor for the IEEE Transactions on Circuits and
Systems - I in 2002-03. He was a Guest Editor for the Journal of VLSI Signal
Processing Systems special issue in 2006. In 1993 - 1995, Prof. Ling served as
the Chair of the IEEE Computer Society Technical Committee (TC) on
Microprocessors and Microcomputers. Currently, he serves as the Chair of
the IEEE Circuits and Systems Society Circuits and Systems for Communications
Technical Committee. He is also a member of the VSPC TC (IEEE Circuits and
Systems Society) and a member of the DISPS TC (IEEE Signal Processing Society).
Prof. Ling was the General Chair for the IEEE Hot Chips Symposium in 1995. He
is currently Technical Program Co-Chair for ISCAS’07 and Program Co-Chair for
SiPS’07. He served as Program Chair/Co-Chair for DCV’02 and SiPS’00. He was Track
Co-Chair for ISCAS’04, ISCAS’05, and ISCAS’06. Prof. Ling served in program
committees, organizing committees, and as session chairs for many IEEE
conferences. He has delivered more than 70 invited/distinguished/keynote
colloquia in six different countries.
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Contact
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