Data Co-Reduction for Fast Multimedia Similarity Search
Dr Heng Tao SHEN (School of Information Technology & Electrical Engineering, The University of Queensland)
COMPUTER SCIENCE SEMINARDATE: 2011-03-18
TIME: 11:00:00 - 12:00:00
LOCATION: Ian Ross Seminar Room
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ABSTRACT:
Multimedia similarity search has been playing a critical role in many novel applications. Typically, multimedia objects are described by high-dimensional feature vectors (or points) which are organized in databases for retrieval. Although many high-dimensional indexing methods have been proposed to facilitate the search process, efficient retrieval over large, sparse and extremely high-dimensional databases remains challenging due to the continuous increases in data size and feature dimensionality. In this talk, we discuss the first framework for Data Co-Reduction (DCR) on both data size and feature dimensionality. By utilizing recently developed co-clustering methods, DCR simultaneously reduces both size and dimensionality of the original data into a compact subspace, where lower bounds of the actual distances in the original space can be efficiently established to achieve fast and lossless similarity search in the filter-and-refine approach. Particularly, DCR considers the duality between size and dimensionality, and achieves the optimal co-reduction which generates the least number of candidates for actual distance computations. We conduct an extensive experimental study on large and real-life multimedia datasets. Our results demonstrate that DCR outperforms existing methods significantly for lossless retrieval, especially in the presence of extremely high dimensionality.
BIO:
Dr Heng Tao SHEN is currently an Associate Professor and Reader in School of Information Technology & Electrical Engineering, The University of Queensland. He obtained his BSc (with 1st class Honours) and PhD from Department of Computer Science, National University of Singapore in 2000 and 2004 respectively, then joined The University of Queensland as a Lecturer in June 2004 and Senior Lecturer in March 2007. His research interests include Multimedia/Mobile/Web Search, Database Management, P2P/Cloud Computing, etc. Heng Tao has published about 60 papers in A*/A ranked journals and conferences. He has served on program committees in all leading database and multimedia conferences, including ACM SIGMOD, ACM Multimedia, VLDB, ICDE, etc. He is the winner of Chris Wallace Award for outstanding Research Contribution in 2010 conferred by Computing Research and Education Association of Australasia.
