Xiaolin Wu
Professor
NSERC-DALSA
Industrial Research Chair in Digital Cinema
Department of Electrical &
Computer Engineering
ITB A315
McMaster University
Hamilton, Ontario,
Canada, L8G 4K1
phone: 905 525-9140 ext 24190
fax: 905 521-2922
email: xwu at ece.mcmaster.ca
COURSES:
Data Structures and Algorithms (2SI4)
Image
Processing (4TN3)
RESEARCH:
My general research activities are in
visual/multimedia computing and communications. I have published numerous
algorithms for computer graphics and image processing (image coding in
particular), some of which are being used by practitioners, such as a fast optimal color quantizer,
and a Context-based Adaptive Lossless Image Codec (CALIC)
which was developed jointly with Nasir Memon as a candidate algorithm for the
new JPEG lossless standard. CALIC(executable) is widely
used as a benchmark in performance evaluation of lossless image codecs.
I and my students have also developed
·
The best color demosaicking technique so far in
the literature: Primary-Consistent Soft-Decision (PCSD executable: pcsd.rar) color demosaicking
algorithm.
·
The best image interpolation technique so far in
the literature: Soft-decision Adaptive Interpolation (SAI executable: sai.rar) algorithm.
·
Model-based Adaptive Recovery of Compressive Sensing:
MARX algorithm (executable: marx.rar).
I have also been active in JPEG standardization
process, and proposed new techniques for context modeling and Embedded
Conditional Entropy Coding of Wavelet coefficients (ECECOW). My new L-cube
(Layered Low-complexity Lossless) codec was ranked the first in compression
performance among seven proposals submitted to MPEG for digital cinema
archival.
_____________________________________________________________________________________________________________________
Ongoing Government-funded Research Projects:
·
Network-aware Multimedia Coding and Communication
(funded by NSERC)
·
High-fidelity 2D and 3D image compression (NSERC
Collaborative Health Research Project)
·
Joint compression and classification of
hyperspectral images (funded by Center for Research in Earth and Space
Technology)
·
Real-time lossless/near-lossless coding of digital cinema
contents (by NSERC-DALSA Industrial Research Chair Project and CFI)
·
Color demosaicking for digital movie cameras (funded
by NSERC-DALSA Industrial Research Chair Project and CFI)
Research Positions
Research topics:
Optimization algorithms for designing
codes used in communications and data compression, and for problems in digital
cinema or biomedical image processing.
Qualifications:
Ph.D or equivalent in Computer Science, Electrical
Engineering, or Mathematics. Strengths in discrete optimization, graph theory,
and algorithms are highly valued.
Duration:
One
year and renewable.
Annual salary:
$35,000
to $60,000, depending on qualifications and experiences.
*********************************************************************************************
Our Research Group (Multimedia Computing and
Communications Laboratory)
·
Xiaohan Wang
(Ph.D student)
·
Xiangjun
Zhang (Ph.D student)
·
Mingkai Shao (Ph.D student)
·
Amin Behnad (M.A.Sc. student)
·
Reza Pournaghi (M.A.Sc. student)
·
Hauzhong Wang (M.A.Sc. student)
·
Jie Cao (M.A.Sc. student)
·
Heng Wang (M.A.Sc. student)
·
Yong Zhao (M.A.Sc. student)
·
Cindy
Kwan (M.A.Sc. student, now with Microsoft)
·
Nima Sarshar (Ph.D student, now with Univ. of Regina)
·
Marko Slyz (postdoctoral fellow)
·
Zhe Wang (Ph.D student, now with Google)
·
Lei Zhang (postdoctoral fellow, now with HK Poly.
Tech. Univ.)
·
Ning Zhang (research associate, now with IMAX Corp.)
________________________________________________________________________________________________________
Selected Publications:
Joint source-channel and network coding
- X. Wu, B. Ma and N.
Sarshar, “Rainbow network problems and multiple description coding”, IEEE Trans. on Information Theory,
vol. 54, no. 10, pp. 4565-4574, Oct. 2008.
- X. Wu, X. Wang, and Z.
Wang, "Resource-scalable joint source-channel MAP and MMSE estimation
of multiple descriptions", IEEE
Trans. on Signal Processing, vol. 57, no. 1, pp. 279-288, Jan. 2009.
- S. Dumitrescu and X. Wu,
“On the complexity of joint source-channel decoding of Markov sequences
over memoryless channels”, IEEE Trans. on Communications, vol. 56,
no. 6, pp. 877-885, June 2008.
- S. Dumitrescu, X. Wu,
and Z. Wang, “Efficient algorithms for optimal uneven protection of single
and multiple scalable code streams against packet erasures”, IEEE
Trans. on Multimedia, vol. 9, no. 7, pp. 1466-1474, Nov. 2007.
- X. Wu, S. Dumitrescu, and Z.
Wang, “Monotonicity-based fast algorithm for MAP estimation of Markov
sequences over noisy channels”, IEEE
Trans. on Information Theory, vol.50, no.7, pp.1539-1544, July 2004.
- Z. Wang and X. Wu, “Length-constrained MAP decoding of variable
length encoded Markov sequences”, IEEE
Trans. on Communications, vol.54, no.7, pp.1259-1266, July, 2006.
- S. Dumitrescu, X. Wu,
and Z. Wang, ”Globally optimal uneven error protected packetization of
scalable code streams”, IEEE Trans. on Multimedia, vol. 6, no. 2,
pp. 230-239, Apr. 2004.
- N. Sarshar and X. Wu, “A practical approach to joint
network-source coding”, Proc. of DCC
2006 (dcc06.pdf).
- X. Huang and X. Wu, “Optimal index assignment for multiple
description lattice vector quantization”, Proc. of DCC 2006 (IAMDLVQ.pdf).
- X. Wu, X. Wang, and J. Wang, “Joint source-channel decoding of
multiple description quantized Markov sequences”, Proc. of DCC 2006 (MDQMAP.pdf).
- B. Ma and X. Wu, “Maximum network flow of multiple description codes”, Proc. of NetCod 2005, Apr. 2005.
- N. Sarshar and X. Wu, “Statistical mechanics of optimal networked
source coding”, Proc. of NetCod 2005,
Apr. 2005.
- X. Wu, S. Cheng and Z. Xiong, ``On packetization of embedded
multimedia bitstreams'', IEEE Trans. on Multimedia, 2001, vol. 3,
pp. 132-140, 2001.
Signal quantization and source
coding
- S. Dumitrescu and X. Wu,
“Lagrangian optimization of two-description scalar quantizers”, IEEE Trans. on Information Theory, vol. 53, no. 11, pp. 3990-4012, Nov. 2007.
- M. Xue, X. Wu, P. Franti, “Context quantization by kernel Fisher
discriminant”, IEEE
Trans. on Image Processing, vol. 15, no. 1, pp. 169-177,
Jan. 2006.
- S. Dumitrescu and X. Wu,
“Optimal two-description scalar quantizer design”, Algorithmica, vol. 41, no. 4, pp. 269-287, Feb. 2005.
- S. Dumitrescu and X. Wu,
“Algorithms for optimal multi-resolution quantization", Journal of Algorithms, vol. 50, no.
1, pp. 1-22, Jan. 2004.
- D. Chen, Y. Chiang, N. Memon, X.
Wu, “Alphabet partitioning techniques for semi-adaptive Huffman coding of
large alphabets”, IEEE Trans. on
Communications, vol. 55, no. 3, March 2007.
- S. Forchhammer, X. Wu,
and J. D. Andersen, "Optimal
context quantization in lossless compression of image data
sequences", IEEE Trans. on
Image Processing, vol. 13, no. 4, pp. 509-517, Apr. 2004.
- X. Wu, ``Optimal binary vector quantization via enumeration of
covering codes'', IEEE Trans. on Information Theory, vol. 43, no.
2, pp. 638-645, March 1997.
- X. Wu, "YIQ vector quantization in a new color palette architecture",
IEEE Trans. on Image Processing, vol. 5. no. 2, pp. 321-329, 1996.
- X. Wu and K. Zhang, "Quantizer monotonicities and quantizer
design algorithms", IEEE Trans. on Information Theory, vol.
39, no. 3, pp. 1049-1053, May 1993.
- X. Wu, "Color quantization by dynamic programming and
principal analysis", ACM Trans. on Graphics, vol. 11, no. 4
(TOG special issue on color), pp. 348-372, Oct. 1992.
- X. Wu, "On convergence of Lloyd's method I", IEEE
Trans. on Information Theory, vol. 38, no. 1, pp. 171-174, Jan. 1992.
- X. Wu, "Optimal quantization by
matrix-searching," Journal of Algorithms, vol. 12, no. 4, pp.
663-673, Dec. 1991.
Image Coding
- X. Wu, S. Dumitrescu, and N.
Zhang, "On multirate optimality of JPEG 2000 code streams", IEEE Trans. on Image Processing,
vol. 14, no. 12, pp. 2012-2023, Dec. 2005.
- N. Sarshar and X. Wu, “On rate-distortion models for natural
images”, IEEE Trans. on Image
Processing, vol. 16, no. 5, pp. 1383-1394, May 2007.
- N. Zhang and X. Wu, “Lossless compression of color mosaic images”,
IEEE Trans. on Image Processing,
vol. 15, no. 6, pp. 1379-1388, June 2006.
- W. Ding, F. Wu, X. Wu, and S. Li, “Adaptive directional
lifting-based wavelet transform for image coding ”, IEEE Trans. on Image Processing, vol. 16, no. 2, Feb. 2007.
- X. Xue and X. Wu,
“Directly operable image representation of multiscale primal sketch”, IEEE
Trans. on Multimedia, vol. 7, no. 5, pp. 805-816, Oct. 2005
- S. Cheng, Z. Xiong, and
X. Wu, ``Fast trellis coded color quantization of images'', Real-Time
Imaging, vol. 8, pp. 265-275,
August 2002.
- X. Wu and N. Memon, "Lossless interframe image compression
via context modeling", IEEE Trans. on Image Processing, vol.
9, no. 5, pp. 994-1001, May 2000.
- X. Wu and P. Bao, "-constrained high-fidelity image compression
via adaptive context modeling", IEEE Trans. on Image Processing,
vol. 9, no. 4, pp. 536-542, April 2000.
- X. Wu, J. Wen, and W-H Wong, "Conditional entropy coding of
VQ indexes for image compression", IEEE Trans. on Image Processing,
vol. 8, no. 8, pp. 1005-1013, Aug. 1999.
- Z. Xiong and X. Wu, "Wavelet image coding using trellis coded
space-frequency quantization", IEEE Signal Processing Letters,
pp. 158-161, July 1999.
- P. Bao and X. Wu, ``-constrained near-lossless image compression
using weighted finite automata encoding'', Computers and Graphics,
vol. 22, no. 2, pp. 217-223, June 1998.
- X. Wu, "Lossless compression of continuous-tone images via
context selection, quantization, and modeling'', IEEE Trans. on Image
Processing, vol. 6, no. 5, pp. 656-664, May 1997.
- X. Wu and N. Memon, ``Context-based, adaptive, lossless image
codec'', IEEE Trans. on Communications, vol. 45, no. 4, pp.
437-444, April 1997.
- N. Memon and X. Wu, ``Recent developments in context-based
predictive techniques for lossless image compression'', The Computer
Journal, vol. 40, no. 2/3, pp. 127-136, 1997.
- X. Wu and Y. Fang, "A segmentation-based predictive
multiresolution image coder", IEEE Trans. on Image Processing,
vol. 4, no. 1, pp. 34-47, 1995.
- X. Wu, "Image coding by adaptive tree-structured
segmentation", IEEE Trans. on Information Theory, vol. 38, no.
6, pp. 1755-1767, Nov. 1992.
Image and Signal Processing
- X. Zhang, X. Wu, “Image
interpolation by adaptive 2D autoregressive modeling and soft-decision estimation”,
IEEE
Trans. on Image Processing, vol.
17, no. 6, pp. 887-896, June 2008.
- L. Zhang, X. Wu and D.
Zhang, “Color reproduction from noisy CFA data of single sensor digital
cameras”, IEEE Trans. on Image Processing, vol. 16, no. 9, pp. 2184-2197, Sept. 2007.
- X. Wu and L. Zhang,
“Color video demosaicking via motion estimation and data fusion”, IEEE Trans. on Circuit and Syst. for
Video Tech., vol. 16, no.2, pp. 231-240, Feb. 2006.
- X. Wu
and L. Zhang, “Improvement
of color video demosaicking in temporal domain,” IEEE Trans. Image Processing, vol.15, no.10, Oct. 2006.
- L. Zhang and X. Wu, “Image
interpolation via directional filtering and data fusion,” IEEE Trans.
Image Processing, vol.15,
no.8, pp. 2226-2238, Aug. 2006.
- X. Wu and N. Zhang, “Primary-consistent soft-decision color
demosaicking for digital cameras", IEEE
Trans. on Image Processing, vol. 13, no. 9, pp. 1263-1274, Sept. 2004.
- L. Zhang and X. Wu, "Color demosaicking via directional
linear minimum mean square-error estimation", IEEE Trans. on Image Processing, vol. 14, no. 12, pp.
2167-2178, Dec. 2005.
- P. Bao, L. Zhang and X.
Wu, “Canny edge detection enhancement by scale multiplication,” IEEE
Trans. Pattern Analysis and Machine Intelligence, vol. 27, no. 9, pp. 1485-1490,
Sept. 2005.
- L. Zhang, P. Bao, and X.Wu, “Multiscale-LMMSE-based image
denoising with optimal wavelet selection”, IEEE
Trans. on Circuit and Syst. for Video Tech., vol. 15, no. 4, pp. 496-481, Apr. 2005.
- L. Zhang, X. Wu, Q. Pan
and H. Zhang, "Multiresolution modeling and estimation of multisensor
data", IEEE Trans. on Signal
Processing, pp. 3170-3182, Nov. 2004.
- L. Zhang, P. Bao, and X.
Wu, "Wavelet-based estimation of fractional Brownian motion embedded
in noisy environment", IEEE
Trans. on Information Theory, vol. 50, no. 9, pp. 2194-2200, Sept. 2004.
- L. Zhang, X. Wu, and P. Bao, "Noisy signal compression by
wavelet transform with optimal downsampling", International Journal of Wavelets, Multiresolution and Information
Processing, vol. 1, no. 4, pp. 407-423, Dec. 2003.
- L. Zhang, P. Bao, and
X.Wu, ”Hybrid inter- and intra-wavelet scale image restoration”, Pattern
Recognition, p. 1737-1746, vol. 36 (8), Aug. 2003.
Biomedical Imaging
- X. Wu and T. Qiu, “Wavelet coding of volumetric medical images for
high throughput and operability”, IEEE
Trans. on Medical Imaging, vol. 24, no. 6, pp. 719-727, June 2005.
- X. Wu, S. Dumitrescu, P. Biyani, and Q. Wu, “Fast chromosome
karyotyping by auction algorithm”, Int.
J. of Bioinformatics and Applications, vol. 2, no. 3, 2006.
- P. Biyani, X. Wu and A. Sinha, “Joint classification and pairing
of human chromosomes”, IEEE/ACM
Trans. on Computational Biology and Bioinformatics, vol. 2, no. 2, pp.
102-109, Apr. 2005.
- Z. Xiong, X. Wu, S.
Cheng, and J. Hua, "Lossy-to-lossless compression of medical
volumetric data using 3D integer wavelet transforms", IEEE
Transactions on Medical Imaging, vol. 22, pp. 459-470, March 2003.
Steganalysis and Watermarking
- S. Dumitrescu and X. Wu, “A new framework of LSB steganalysis of
digital media”, IEEE Trans. on
Signal Processing, vol. 53, no. 10, pp. 3923-3935, Oct., 2005.
- S. Dumitrescu, X. Wu, and
Z. Wang, "Detection of LSB steganography via sample pair
analysis", IEEE Transactions on Signal Processing, pp. 1995-2007, July 2003.
- X. Wu, "Semantically
transparent fingerprinting for copyright protection of digital
cinema", Proc. of 2003 SPIE
Conference on Electronic Imaging, Santa Clara, CA., vol. 5020, pp.
574-579, Feb. 2003.