| Title: | PLUS Factorization of Matrices and its Applications |
| Date: |
August 23, 2006 (Wednesday)
|
| Time: |
11:00 a.m. - 12:00 noon
|
| Venue: |
Room 121, 1/F, Ho Sin-hang Engineering Building,
The Chinese University of Hong Kong, Shatin, N.T. |
| Speaker: |
Dr Pengwei Hao
Department of Computer Science University of London London UK |
PLUS factorization was proposed as a new framework of matrix factorization, A=PLUS, where matrices P, L and U are almost the same as in LU factorization, permutation, unit lower and upper triangular matrices, respectively, and S is a very special matrix, which is unit, lower and triangular, but only with a small number of non- zeros. Different from LU factorization, all the diagonal elements of U in PLUS factorization are customizable, i.e., the elements can be assigned by users almost freely. With PLUS factorization, the matrix A is easily factorized further into a series of special matrices similar to S. The new computational mechanics with PLUS factorization has a few very elegant properties that other factorizations do not have, such as in-place computation and simple inversion. PLUS factorization also allows of transforming integers reversibly and losslessly if the diagonal elements of U are all designated as Gaussian units, 1, -1, i, or - i. So far, it has applications in lossless source coding, reversible data hiding, fast image registration and fast volumetric data rendering. The method has been included in JPEG 2000, the new international standard for image coding.
BIOGRAPHY:
Dr Pengwei Hao received the B.Sc. degree in computer science and the M.Sc. degree in computer graphics from Northwestern Polytechnical University, Xi'an, China, in 1988 and 1994, respectively, and the Ph.D. degree in image processing from the Institute of Remote Sensing Applications, Chinese Academy of Sciences, Beijing, China, in 1997. From 1997 to 1999, he was a Lecturer at the Center for Information Science, Peking University, Beijing, China. In 2000, he was a Visiting Scientist for three months with the Centre for Vision, Speech, and Signal Processing, University of Surrey, Surrey, U.K. In 2002, he was appointed to Lecturer at Queen Mary, University of London, London, U.K. He is also currently an Associate Professor with the Center for Information Science, Peking University, China. He was one of the winners of the National Excellent Doctoral Dissertations, China, by the Academic Degree Committee of the State Council and the Ministry of Education, in 2000.
Enquiries: Miss Temmy So at tel 2609 8444
For more information, please refer to http://www.cse.cuhk.edu.hk/seminar