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Sorina Dumitrescu (Ph.D., Univ. of Bucharest)

Associate Professor

Department of Electrical & Computer Engineering
ITB A222
McMaster University
Hamilton, Ontario, Canada, L8S 4K1

phone: 905 525-9140 ext 26486

fax: 905 521-2922

email: sorina@mail.ece.mcmaster.ca

RESEARCH INTERESTS

Data compression

Robust multimedia coding

Image compression and transmission

Joint source-channel coding/decoding

Data compression for networks

Multiple-description source coding

Quantization

Network coding

Steganography, steganalysis

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AWARDS

NSERC University Faculty Award (2007-2012)

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GRADUATE STUDENTS

Ph. D.

· Ying Zhang

· completed in 2011; currently with ViXS, Toronto

· thesis: „Practical LDGM-based Multiple Description Coding”

· Xiaohan Wang

· completed in 2009, co-supervised with Prof. Xiaolin Wu; currently with Google, Kirkland

· thesis: „New Advances in Joint Source-channel and Multiple Description Coding”

Master

· Zhouyang Gao

· in progress

· Yinghan Wan

· completed in 2011; currently with Genband, Ottawa

· thesis: „Index Assignment for Robust Multiple Description Scalar Quantizer”

· Jiayi Xu

· completed in 2011; currently with Microsoft, Redmond, WA

· thesis: „Fast Rate-Distortion Optimal Packetization of Embedded Bitstreams into Independent Source Packets”

· Dong Xia

· completed in 2011; co-supervised with Prof. Jian-Kang Zhang, currently with Amazon, Seattle;

· thesis: „Full Diversity Noncoherent Space-time Block Code Designs via Unique factorizations of Signals”

· Heng Wang

· completed in 2010; co-supervised with Prof. Xiaolin Wu; currently with Evertz Microsystems, Burlington

· thesis: „High-fidelity Image Compression for High-throughput and Energy-efficient Cameras”

· Gang Xue

· completed in 2009; co-supervised with Prof. Xiaolin Wu; currently with RIM, Waterloo

· thesis: „Temporal Denoising of High Resolution Video”

· Geoffrey Rivers

· completed in 2009; co-supervised with Prof. Shahram Shirani; currently with Evertz Microsystems, Burlington

· thesis: „Unequal Erasure Protection Techniques for Scalable Multi-streams”

· Ting Zheng

· completed in 2008; currently with IBM China, Beijing

· thesis: „Two Techniques for Symmetric Multiple Description Coding with Reduced Storage Space Decoder”

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BIO

Sorina Dumitrescu received the M.A.Sc. and Ph. D. degrees in mathematics from the University of Bucharest, Romania, in 1990 and 1997, respectively. From 2000 to 2002 she was a Postdoctoral Fellow in the Department of Computer Science at the University of Western Ontario, London, Canada. Since 2002 she has been with the Department of Electrical and Computer Engineering at McMaster University, Hamilton, Canada, where she held a postdoctoral position (2002-2004), a Research Associate position (2004-2005), and an Assistant Professor position (2005-2011), and where she is currently an Associate Professor. Her current research interests include multimedia coding and communications, robust image coding, network-aware data compression, multiple description codes, quantization, joint source-channel coding, steganalysis. Her earlier research interests were in formal languages and automata theory. Dr. Dumitrescu held an NSERC University Faculty Award (April 2007- March 2012).

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PUBLICATIONS

Book

N. Sarshar, X. Wu, J. Wang, S. Dumitrescu, „Network-aware Source Coding and Communication”, Cambridge University Press, Sept. 2011, ISBN – 13:9780521888400, http://www.cambridge.org/aus/catalogue/catalogue.asp?isbn=9780521888400

Refereed Journal Papers

D. Xia, J.-K. Zhang, S. Dumitrescu, “Energy-Efficient Full Diversity Collaborative Unitary Space-Time Block Code Design via Unique Factorization of Signals”, IEEE Trans. on Information Theory, vol. 59, no. 3, pp. 1678—1703, Mar. 2013.

Y. Zhang, S. Dumitrescu, J. Chen, Z. Sun, „LDGM-based Multiple Description Coding for Finite Alphabet Sources”, pdf, Trans. on Communications, vol. 60, no. 12, pp. 3671--3682, Dec. 2012.

D. Xia, J.-K. Zhang, S. Dumitrescu, F.-K. Gong “Full Diversity Non-Coherent Alamouti-Based Toeplitz Space-Time Block Codes”, IEEE Trans. on Signal Processing, vol. 60, no. 10, pp. 5241 – 5253, Oct. 2012.

S. Dumitrescu, J. Xu, „Efficient Rate-Distortion Optimal Packetization of Embedded Bitstreams into Independent Source Packets”, pdf, IEEE Trans. Image Processing, vol. 21, no. 5, pp. 2653—2666, May 2012.

J. Chen, Y. Zhang, S. Dumitrescu, "Gaussian Multiple Description Coding with Low-Density Generator Matrix Codes", pdf, IEEE Trans. on Communications, vol. 60, no. 3, pp. 676—687, Mar. 2012.

S. Dumitrescu, „Fast Encoder Optimization in Multi-resolution Scalar Quantizer Design”, pdf, IEEE Trans. on Inform. Theory, vol. 57, no. 3, pp. 1520 – 1529, Mar. 2011.

M. Shao, S. Dumitrescu, X. Wu, “Layered Multicast with Inter-layer Network Coding for Multimedia Streaming”, pdf, IEEE Trans. on Multimedia, vol. 13, no. 2, pp. 353—365, Apr. 2011.

M. Omoomi, S. Samavi, S. Dumitrescu, “An efficient high payload +/-1 data embedding scheme”, Multimedia Tools and Applications, vol. 54, no. 2, pp. 201—218, Aug. 2011.

J. Chen, S. Dumitrescu, Y. Zhang, J. Wang, „Robust Multiresolution Coding”, pdf, IEEE Trans. on Communications, vol. 58, no. 11, pp. 3186 – 3195, Nov. 2010.

M. Mahdavi, S. Samavi, S. Dumitrescu, F. Aalamifar, P. Abedikhoozani, “Real-time steganalysis of LSB-replacement in digital audio streams”, Journal of Circuits, Systems, and Computers, vol. 19, no. 7, pp. 1399-1421, Nov. 2010.

S. Dumitrescu, G. Rivers, S. Shirani, “Unequal Erasure Protection Technique for Scalable Multi-streams”, pdf, IEEE Trans. on Image Processing, vol. 19, no. 2, pp. 422 – 434, Feb. 2010.

S. Dumitrescu, „Fast Joint Source-Channel Decoding of Convolutional Coded Markov Sequences with Monge Property”, pdf, IEEE Trans. on Communications, vol. 58, no. 1, pp. 128-135, Jan. 2010.

S. Dumitrescu, X. Wu, „On Properties of Locally Optimal Multiple Description Scalar Quantizers with Convex Cells”, pdf, IEEE Trans. on Information Theory, vol. 55, no. 12, pp. 5591 – 5606, Dec. 2009.

X. Wang, X. Wu, S. Dumitrescu, „On Explicit Formulas for Bandwidth and Anti-bandwith of Hypercubes”, Discrete Applied Mathematics, vol. 157, no. 8, pp. 1947-1952, April 2009.

S. Dumitrescu, „Comments on Optimal Erasure Protection for Scalably Compressed Video Streams with Limited Retransmission”, IEEE Trans. on Image Processing, vol. 18, no. 1, pp. 214-216, Jan. 2009.

S. Dumitrescu and X. Wu, „On the Complexity of Joint Source-Channel Decoding of Markov Sequences over Memoryless Channels”, pdf, IEEE Trans. on Communications, vol. 56, no. 6, pp. 877—885, June 2008.

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.

S. Dumitrescu, X. Wu, Z. Wang, „Efficient Algorithms for Optimal Uneven Protection of Single and Multiple Scalable Code Streams against Packet Erasures”, pdf, IEEE Trans. on Multimedia, vol. 9, no. 7, pp. 1466—1474, Nov. 2007.

S. Dumitrescu, „Faster Algorithm for Designing Optimal Prefix-Free Codes with Unequal Letter Costs”, Fundamenta Informaticae, Special Issue "Trajectories of Language Research", vol. 73, no 1-2, pp. 107-117, Sept. 2006.

X. Wu, S. Dumitrescu, and N. Zhang, "On multirate optimality of JPEG 2000 code stream", IEEE Trans. on Image Processing, vol. 14(12), pp. 2012—2023, Dec. 2005.

S. Dumitrescu and X. Wu, „A new framework of LSB steganalysis of digital media”, IEEE Trans. on Signal Processing, Supplement on Secure Media, vol. 53(10), pp. 3936—3947, Oct. 2005.

X. Wu, S. Dumitrescu, P. Biyani, Q. Wu, „Fast Chromosome Karyotyping by Auction Algorithm”, Int. J. of Bioinformatics Research and Applications, vol. 1, no. 3, pp. 351—362, 2005.

S. Dumitrescu and X. Wu,’’Optimal two-description scalar quantizer design’’, Algorithmica, vol. 41, no. 4, pp. 269-287, Feb. 2005.

S. Dumitrescu, X. Wu, Z. Wang , "Globally optimal uneven error-protected packetization of scalable code streams", IEEE Trans. on Multimedia, Special Issue on Streaming Media, vol. 6 (2), pp. 230-239, April 2004.

X. Wu, S. Dumitrescu, Z. Wang,’’Monotonicity-based fast algorithms for MAP estimation of Markov sequences over noisy channels’’, IEEE Trans. on Information Theory, Special Issue on Problems on Sequences: Information Theory & Computer Science Interface, vol. 50, no.7, pp. 1539—1544, July 2004.

S. Dumitrescu, X. Wu, "Algorithms for Optimal Multi-resolution Quantization", Journal of Algorithms, vol. 50, pp. 1—22, January 2004.

S. Dumitrescu, X. Wu, Z. Wang , "Detection of LSB Steganography via Sample Pair Analysis", pdf, IEEE Trans. on Signal Processing, vol. 51, Issue 7, pp. 1995—2007, July 2003.

Invited Papers

Y. Zhang, S. Dumitrescu, J. Chen, Z. Sun, “LDGM-based Codes for Successive Refinement”, 47^th Annual Allerton Conf. on Communications, Control and Computing, Monticello, IL, Oct. 2009.

S. Dumitrescu, J. Chen, Y. Zhang, „Multiple Description Coding for Binary Sources”, International Conf. on Wireless Communications & Signal Processing (WCSP2009), Nanjing, China, Nov. 2009.

Refereed Conference Papers

S. Dumitrescu, Y. Wan, “Bit-error Resilient Index Assignment for Multiple Description Scalar Quantizers”, IEEE Intern. Symposium Inform. Theory, Istanbul, Turkey, July 2013, accepted.

Y. Wan and S. Dumitrescu, Index Assignment Capable of Detecting One Bit Errors for Multiple Description Scalar Quantizers, Canadian Workshop on Inform. Theory, Toronto, June 2013, accepted.

S. Chuah, S. Dumitrescu, and X. Wu, „L₂optimized predictive image coding with L_∞bound”, ICASSP, Vancouver, Canada, May 2013, accepted.

Y. Zhang, J. Wang, and S. Dumitrescu, „Efficient Motion Estimation Scheme for Downsizing H.264 Homogeneous Transcoding”, IEEE Intern. Conf. on Signal and Image Proc. Appl., Kuala Lumpur, Malaysia, Nov. 2011.

J. Xu, S. Dumitrescu, „Fast R-D Optimal Packetization of Embedded Bitstreams into Independent Source Packets”, IEEE Data Compression Conf., Mar. 2011, Snowbird, UT, pp. 283—292.

J. Chen, S. Dumitrescu, Y. Zhang, and J. Wang,“Robust Multiresolution Coding with Hamming Distortion Measure”, IEEE Intern. Symposium on Inform. Theory, June 2010, Austin, TX.

Y. Zhang, S. Dumitrescu, J. Chen, and Z. Sun, “Multiple Description Coding Based on LDGM Codes”, Proc. IEEE Information Theory Workshop, Taormina, Italy, Oct. 2009, pp. 85-89.

M. Shao, S. Dumitrescu, and X. Wu, “Rate-distortion Optimized Network Communication Using General MDC”, Proc. of IEEE Information Theory Workshop on Networking and Information Theory, June 2009, Volos, Greece, pp.176-180.

S. Dumitrescu, M. Shao, X. Wu, „Layered Multicast with Inter-layer Network Coding”, Proc. of IEEE INFOCOM 2009, April 2009, Rio de Janeiro, Brazil, pp.442-449.

G. Rivers, S. Dumitrescu, S. Shirani, “Novel R-D Optimized Uneven Erasure-Protection Strategy for Scalable Data Formed of Multiple Code Streams”, Proc. of IEEE Int. Workshop on Multimedia Signal Processing, Oct. 2008, Queensland, Australia, pp. 418-423.

M. Shao, S. Dumitrescu, X. Wu, “Toward the Optimal Multirate Multicast for Lossy Packet Network”, ACM Multimedia Conf., Oct. 2008, Vancouver, Canada.

S. Dumitrescu, “Speed-up of Encoder Optimization Step in Multiple Description Scalar Quantizer Design”, Proc. of IEEE Data Compression Conference, pp. 382—391, March 2008, Snowbird, UT.

S. Dumitrescu and T. Zheng, “Improved Multiple Description Framework Based on Successively Refinable Quantization and Uneven Erasure Protection”, Proc. of IEEE Data Compression Conference, pp. 514—514, March 2008, Snowbird, UT.

S. Dumitrescu, „Fast Joint Source-Channel Decoding of Convolutional Coded Markov Sequences with Monge Property”, Proc. of IEEE Information Theory Workshop, Sept. 2007, Lake Tahoe.

X. Wang, X. Wu and S. Dumitrescu, „On Optimal Index Assignment for MAP Decoding of Markov Sequences”, Proc. of the 2006 IEEE Int. Symposium on Information Theory, July 2006.

S. Dumitrescu, X. Wu and Z. Wang, „Efficient Algorithm for Globally optimal Uneven Erasure-protected Packetization of Scalable Code Streams”, Proc. of the 2006 IEEE Int. Conf. on Multimedia and Expo, July 2006.

M. Roeder, X. Wu and S. Dumitrescu, „Error Resilient Multiple Description Compression of Vector Graphics”, Proc. of the 2006 IEEE Int. Conf. on Multimedia and Expo, July 2006.

S. Dumitrescu, „Faster Algorithm for Designing Optimal Prefix-Free Codes with Unequal Letter Costs”, Proc. of the 2006 IEEE Data Compression Conference, pp. 444, March 2006.

S. Dumitrescu, X. Wu, „On the Complexity of Joint Source-Channel Decoding of Markov Sequences over Memoryless Channels”, Proc. of Int. Symp. on Information Theory 2005, pp. 1666—1670, Sept. 2005.

S. Dumitrescu, X. Wu, „LSB Steganalysis Based on High-order Statistics”, Proc. of ACM Multimedia Security Workshop 2005, pp. 25—32, August 2005.

S. Dumitrescu, X. Wu, „Globally Optimal Uneven Erasure-Protected Multi-Group Packetization of Scalable Codes”, Proc. of Int. Conf. on Multimedia and Expo2005, pp. 900—903, July 2005.

S. Dumitrescu, X. Wu, „On Multiple Description Scalar Quantizers with Convex Codecells”, Proc. of Canadian Workshop on Information Theory 2005, pp. 215- 218, June 2005.

S. Dumitrescu and X. Wu, „On Global Optimality of Gradient Descent Algorithms for Fixed-Rate Scalar Multiple Description Quantizer Design”, Proc IEEE Data Compression Conference, pp. 388-397, March 2005.

X. Wu, P. Biyani, S. Dumitrescu, and Q. Wu, „Globally Optimal Classification and Pairing of Human Chromosomes”, Proc. 26th Annual Int. Conf. of IEEE Engineering in Medicine and Biology Society, Sept. 2004.

S. Dumitrescu and X. Wu, "Lagrangian Global Optimization of Two-description Scalar Quantizers", Proc. IEEE Int. Symposium on Information Theory, pp. 300, June 2004.

S. Dumitrescu, X. Wu, and G. Bahl, ’’ Fast algorithms for optimal two-description scalar quantizer design’’, Proc. IEEE Data Compression Conf., pp. 42-51, March 2004.

Z. Wang, X. Wu, S. Dumitrescu, ’’Fast length-constrained MAP decoding of variable length coded Markov sequences over noisy channels’’, Proc. IEEE Int. Conf. on Communications, June 2004.

Z. Wang, X. Wu, S. Dumitrescu , ”Length-Constrained MAP Decoding Revisited”, Proc. IEEE Int. Conf. on Multimedia and Expo, June 2004.

S. Dumitrescu, X. Wu, "On Optimality of JPEG 2000 Code Stream", Proc. IEEE Int. Conf. on Image Processing, vol. 3, pp. III_773 – III_776, Sept. 2003.

S. Dumitrescu, X.Wu, „Optimal variable rate multiplexing of scalable code streams”, Proc. IEEE Data Compression Conf., pp. 424 – 424, March 2003.

S. Dumitrescu, X. Wu, "Optimal multiresolution quantization for scalable multimedia coding", Proc. IEEE Information Theory Workshop, pp. 139 – 142, Oct. 2002.

S. Dumitrescu, X. Wu, Z. Wang , "Detection of LSB Steganography via Sample Pair Analysis", Proc. 5-th Int. Workshop on Information Hiding, pp. 355 – 372, Oct. 2002.

S. Dumitrescu, X. Wu, N. Memon, "On steganalysis of random LSB embedding in continuous-tone images", Proc. IEEE Int. Conf.on Image Processing, vol. 3, pp. 641 – 644, Sept. 2002.

S. Dumitrescu, X. Wu, "Steganalysis of LSB embedding in multimedia signals", Proc. IEEE Int. Con. on Multimedia and Expo, vol. 1, pp. 581 – 584, August 2002.

S. Dumitrescu, X. Wu, "On embedded scalable code stream of minimum expected distortion for variable rate channels", Proc. IEEE Int. Symposium on Information Theory, pp. 347 – 347, July 2002.

X. Wu, S. Dumitrescu, "On optimal multi-resolution scalar quantization", Proc. IEEE Data Compression Conf., pp. 322 – 331, April 2002.

S. Dumitrescu, X. Wu, Z. Wang , "Globally optimal uneven error-protected packetization of scalable code streams", Proc. IEEE Data Compression Conf., pp. 73 – 82, April 2002.

Publications in Formal Languages and Automata Theory

Refereed Journal Papers

S. Dumitrescu, Gh. Păun, A. Salomaa, “Pattern languages versus parallel communicating grammar systems”, Int. J. of Foundations of Computer Science, 8,1 (1997), 67--80.

S. Dumitrescu, Gh. Păun, “On the power of parallel communicating grammar systems with right-linear components”, RAIRO Informatique Théoretique et Applications, 31, 4 (1997), 331--354.

S. Dumitrescu, Gh. Păun, A. Salomaa, “Languages associated to finite and infinite sets of patterns”, Revue Roumaine de Mathématiques Pure et Appliquées, 9-10 (1997) 331--354.

S. Dumitrescu, “Non-returning parallel communicating grammar systems can be simulated by returning systems”, Theoretical Computer Science, 165(1996), 463 –474.

J. Dassow, Gh. Păun, S. Vicolov, “On the generative capacity of certain classes of cooperating grammar systems”, Fundamenta Informaticae, 22, 5 (1995), 217--226.

J. Dassow, Gh. Păun, S. Vicolov, “On the power of CDGS with regular components”, Foundations of Computing and Decisions Sciences, 18, 2 (1993), 83--108.

S. Vicolov, “Cooperating distributed grammar systems with registers : the regular case”, Computers and Artificial Intelligence, 1, 12 (1993), 89--98.

S. Vicolov, “Infinite hierachies of valence languages”, Bulletin of the European Association for Theoretical Computer Science, 49 (1993), 192--194.

Gh. Păun, A. Salomaa, S. Vicolov, “On the generative capacity of parallel communicating grammar systems”, Int. J. of Computer Mathematics, 46 (1992), 137--147.

Gh. Paun, M. Szijarto, S. Vicolov, “Further remarks on reduced languages”, Fundamenta Informaticae, 16 (1992), 337--347.

S. Vicolov, “Non-centralized parallel grammar systems”, Studii si Cercetari Matematice (in Romanian), 44 (1992), 455--462.

Gh. Păun, S. Vicolov, “Language representation starting from fully initial languages”, Acta Cybernetica, 10, 1-2 (1991), 65--70.

S. Vicolov, “A note on fully initial grammars”, Acta Cybernetica, 10, 1-2 (1991), 113--118.

S. Vicolov, “Two theorems about Marcus contextual languages”, Bull. Math. Soc. Sci. Math. Roumanie, 35 (83), 1-2 (1991), 167--170.

Articles in books

S. Dumitrescu, “Characterization of recursively enumerable languages using CD grammar systems with two registers and right-linear rules”, in vol. New Trends in Formal Languages, (Gh. Păun, A. Salomaa, eds.), Lecture Notes of Computer Science 1218, Springer-Verlag, Berlin, 1997, 167--177.

S Vicolov-Dumitrescu, “On total parallelism in contextual grammars”, in vol. Mathematical Linguistics and Related Topics, (Gh. Păun, ed.), Editura Academică, Bucharest, 1995, 350--360.

S. Vicolov-Dumitrescu, “Grammars, grammar systems and gsm mappings with valences”, in vol. Mathematical Aspects of Natural and Formal Languages, (Gh. Păun, ed.) World Sci. Publ., Singapore, 1994, 473--491.