Change search
ReferencesLink to record
Permanent link

Direct link
Model Based Coding: Initialization, Parameter Extraction and Evaluation
Umeå University, Faculty of Science and Technology, Applied Physics and Electronics.
2005 (English)Doctoral thesis, monograph (Other academic)
Abstract [en]

This thesis covers topics relevant to model-based coding. Model-based coding is a promising very low bit rate video coding technique. The idea behind this technique is to parameterize a talking head and to extract and transmit the parameters describing facial movements. At the receiver, the parameters are used to reconstruct the talking head. Since only high-level animation parameters are transmitted, very high compression can be achieved with this coding scheme. This thesis covers the following three key problems.

Although it is a fundamental problem, the initialization problem, has been neglected some extent in the literature. In this thesis, we pay particular attention to the study of this problem. We propose a pseudo-automatic initialization scheme: an Analysis-by-Synthesis scheme based on Simulated Annealing. It has been proved to be an efficient scheme.

Owing to technical advance today and the newly emerged MPEG-4 standard, new schemes of performing texture mapping and motion estimation are suggested which use sample based direct texture mapping; the feasibility of using active motion estimation is explored which proves to be able to give more than 10 times tracking resolution. Based on the matured face detection technique, Dynamic Programming is introduced to face detection module and work for face tracking.

Another important problem addressed in this thesis is how to evaluate the face tracking techniques. We studied the evaluation problems by examining the commonly used method, which employs a physical magnetic sensor to provide "ground truth". In this thesis we point out that it is quite misleading to use such a method.

Place, publisher, year, edition, pages
Umeå: Tillämpad fysik och elektronik , 2005. , 164 p.
Keyword [en]
Signalbehandling, Model-based coding, Motion estimation, Vision based tracking, Initialization, Analysis-by-Synthesis, Texture mapping, Active tracking.
Keyword [sv]
National Category
Signal Processing
Research subject
Signal Processing
URN: urn:nbn:se:umu:diva-434ISBN: 91-7305-800-9OAI: diva2:143446
Public defence
2005-02-28, N420, Naturvetarhuset, Umeå university, Umeå, 10:15
Available from: 2005-01-26 Created: 2005-01-26Bibliographically approved

Open Access in DiVA

fulltext(6056 kB)2057 downloads
File information
File name FULLTEXT01.pdfFile size 6056 kBChecksum MD5
Type fulltextMimetype application/pdf

By organisation
Applied Physics and Electronics
Signal Processing

Search outside of DiVA

GoogleGoogle Scholar
Total: 2057 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 897 hits
ReferencesLink to record
Permanent link

Direct link