UMI  
ProQuest® Dissertations & Theses
The world's most comprehensive collection of dissertations and theses. Learn more...
ProQuest  
 
 
Cluster sampling and its applications to segmentation, stereo and motion
by Barbu, Adrian Gheorghe, PhD, UNIVERSITY OF CALIFORNIA, LOS ANGELES, 2005, 0 pages; 3316974
 

Abstract: Many computer vision problems can be formulated as graph partition problems that minimize energy functions. Generally applicable algorithms like the Gibbs sampler can perform the minimization task, but they are very slow to converge, especially since the graphs in vision tasks are large (105–10 6 nodes). On the other hand, computationally effective algorithms like Graph Cuts and Belief Propagation are specialized to particular forms of energy functions, and they cannot be applied for complex statistical models using generative models and high-order priors. In this thesis, a new stochastic algorithm capable of sampling arbitrary energy functions defined on graph partitions is presented. To increase efficiency, the algorithm uses the image information to make informed jumps in the search space. The image information is given in the form of edge weights and represents an empirical probability that the nodes connected by the edge belong to the same object. At each step, the algorithm creates clusters of nodes by turning on/off the edges randomly according to their weights, and changes the label of all nodes in one cluster (connected component) in a single move. Each move is accepted or rejected according to an acceptance probability given by a simple and explicit equation. The algorithm is applied to 4 important problems in computer vision: image segmentation, perceptual organization, stereo matching and motion segmentation. To address different computational or representational issues, multi-grid, multi-level and multi-cue variants of the algorithm are presented. In image segmentation, the algorithm's performance is compared to the Gibbs sampler, while in stereo matching, it is compared to Graph Cuts and Belief Propagation.

 
Advisor: Zhu, Song-Chun
School: UNIVERSITY OF CALIFORNIA, LOS ANGELES
Source: DAI-B 69/07, p. 4253, Jan 2009
Source Type: PhD
Subjects: Computer science
Publication Number: 3316974
     
Adobe PDF Access the complete dissertation:
 

» Find an electronic copy at your library.
  Use the link below to access a full citation record of this graduate work:
  http://gateway.proquest.com/openurl%3furl_ver=Z39.88-2004%26res_dat=xri:pqdiss%26rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation%26rft_dat=xri:pqdiss:3316974
  If your library subscribes to the ProQuest Dissertations & Theses (PQDT) database, you may be entitled to a free electronic version of this graduate work. If not, you will have the option to purchase one, and access a 24 page preview for free (if available).

 
 
 

About ProQuest Dissertations & Theses
With over 2.3 million records, the ProQuest Dissertations & Theses (PQDT) database is the most comprehensive collection of dissertations and theses in the world. It is the database of record for graduate research.

The database includes citations of graduate works ranging from the first U.S. dissertation, accepted in 1861, to those accepted as recently as last semester. Of the 2.3 million graduate works included in the database, ProQuest offers more than 1.9 million in full text formats. Of those, over 860,000 are available in PDF format. More than 60,000 dissertations and theses are added to the database each year.

If you have questions, please feel free to visit the ProQuest Web site - http://www.il.proquest.com - or call ProQuest Hotline Customer Support at 1-800-521-3042.



Copyright © 2007 ProQuest. All rights reserved. Terms and Conditions

ProQuest