%0 Journal Article
%J Circuits and Systems for Video Technology, IEEE Transactions on
%D 2005
%T Efficient bandwidth resource allocation for low-delay multiuser video streaming
%A Su,Guan-Ming
%A M. Wu
%K algorithm;
%K allocation
%K allocation;
%K approaches;
%K average
%K Bandwidth
%K channel
%K channels;
%K coding;
%K complexity;
%K computational
%K control;
%K distortion;
%K dynamic
%K efficient
%K fine
%K fluctuation;
%K granularity
%K look-ahead
%K low-delay
%K MPEG-4
%K multiple
%K multiuser
%K QUALITY
%K quality;
%K rate-control
%K resource
%K scalability
%K scenario;
%K single-user
%K sliding-window
%K streaming;
%K Telecommunication
%K utilization;
%K video
%K visual
%X This paper studies efficient bandwidth resource allocation for streaming multiple MPEG-4 fine granularity scalability (FGS) video programs to multiple users. We begin with a simple single-user scenario and propose a rate-control algorithm that has low delay and achieves an excellent tradeoff between the average visual distortion and the quality fluctuation. The proposed algorithm employs two weight factors for adjusting the tradeoff, and the optimal choice of these factors is derived. We then extend to the multiuser case and propose a dynamic resource allocation algorithm with low delay and low computational complexity. By exploring the variations in the scene complexity of video programs as well as dynamically and jointly distributing the available system resources among users, our proposed algorithm provides low fluctuation of quality for each user, and can support consistent or differentiated quality among all users to meet applications' needs. Experimental results show that compared to traditional look-ahead sliding-window approaches, our algorithm can achieve comparable visual quality and channel utilization at a much lower cost of delay, computation, and storage.
%B Circuits and Systems for Video Technology, IEEE Transactions on
%V 15
%P 1124 - 1137
%8 2005/09//
%@ 1051-8215
%G eng
%N 9
%R 10.1109/TCSVT.2005.852626
%0 Conference Paper
%B Computer Vision and Pattern Recognition, 2005. CVPR 2005. IEEE Computer Society Conference on
%D 2005
%T Flattening curved documents in images
%A Liang,Jian
%A DeMenthon,D.
%A David Doermann
%K calibration;
%K camera
%K character
%K content;
%K curved
%K distortion;
%K document
%K document;
%K image
%K images;
%K OCR
%K optical
%K page
%K pictures;
%K printed
%K processing;
%K recognition;
%K restoration;
%K scanned
%K techniques;
%K textual
%K warping;
%X Compared to scanned images, document pictures captured by camera can suffer from distortions due to perspective and page warping. It is necessary to restore a frontal planar view of the page before other OCR techniques can be applied. In this paper we describe a novel approach for flattening a curved document in a single picture captured by an uncalibrated camera. To our knowledge this is the first reported method able to process general curved documents in images without camera calibration. We propose to model the page surface by a developable surface, and exploit the properties (parallelism and equal line spacing) of the printed textual content on the page to recover the surface shape. Experiments show that the output images are much more OCR friendly than the original ones. While our method is designed to work with any general developable surfaces, it can be adapted for typical special cases including planar pages, scans of thick books, and opened books.
%B Computer Vision and Pattern Recognition, 2005. CVPR 2005. IEEE Computer Society Conference on
%V 2
%P 338 - 345 vol. 2 - 338 - 345 vol. 2
%8 2005/06//
%G eng
%R 10.1109/CVPR.2005.163
%0 Conference Paper
%B Acoustics, Speech, and Signal Processing, 2005. Proceedings. (ICASSP '05). IEEE International Conference on
%D 2005
%T Joint uplink and downlink optimization for video conferencing over wireless LAN
%A Su,Guan-Ming
%A Han,Zhu
%A M. Wu
%A Liu,K. J.R
%K 802.11
%K conferencing
%K conferencing;
%K distortion;
%K end-to-end
%K expected
%K IEEE
%K joint
%K LAN;
%K maximal
%K minimisation;
%K modes;
%K multiple
%K networks;
%K optimization;
%K pairs;
%K PHY
%K PSNR;
%K real-time
%K teleconferencing;
%K time;
%K transmission
%K uplink-downlink
%K video
%K wireless
%X A real-time video conferencing framework is proposed for multiple conferencing pairs by jointly considering the uplink and downlink conditions within IEEE 802.11 networks. We formulate this system so as to minimize the maximal end-to-end expected distortion received by all users by selecting the PHY modes and transmission time. Compared with the strategy of individually optimizing uplink and downlink, the proposed framework outperforms by 3.67-8.65 dB for the average received PSNR among all users.
%B Acoustics, Speech, and Signal Processing, 2005. Proceedings. (ICASSP '05). IEEE International Conference on
%V 2
%P ii/1101 - ii/1104 Vol. 2 - ii/1101 - ii/1104 Vol. 2
%8 2005/03//
%G eng
%R 10.1109/ICASSP.2005.1415601
%0 Conference Paper
%B Multimedia Signal Processing, 2004 IEEE 6th Workshop on
%D 2004
%T Image hashing resilient to geometric and filtering operations
%A Swaminathan,A.
%A Mao,Yinian
%A M. Wu
%K compact
%K cryptographic
%K cryptography;
%K discrete
%K distortion;
%K Filtering
%K Fourier
%K function;
%K geometric
%K hash
%K image
%K key
%K key;
%K operation;
%K polar
%K PROCESSING
%K public
%K representation;
%K theory;
%K transform;
%K transforms;
%X Image hash functions provide compact representations of images, which is useful for search and authentication applications. In this work, we have identified a general three step framework and proposed a new image hashing scheme that achieves a better overall performance than the existing approaches under various kinds of image processing distortions. By exploiting the properties of discrete polar Fourier transform and incorporating cryptographic keys, the proposed image hash is resilient to geometric and filtering operations, and is secure against guessing and forgery attacks.
%B Multimedia Signal Processing, 2004 IEEE 6th Workshop on
%P 355 - 358
%8 2004/10/01/sept
%G eng
%R 10.1109/MMSP.2004.1436566
%0 Journal Article
%J Circuits and Systems for Video Technology, IEEE Transactions on
%D 2003
%T Joint security and robustness enhancement for quantization based data embedding
%A Wu,M.
%K (signal);
%K authentication;
%K binary
%K compensation;
%K data
%K data;
%K DETECTION
%K digital
%K distortion
%K distortion;
%K embedding;
%K encapsulation;
%K enhancement;
%K error
%K features;
%K hiding;
%K lookup
%K lookup;
%K LUT;
%K message
%K multimedia
%K nontrivial
%K probability;
%K quantisation
%K quantization
%K quantized
%K Robustness
%K run
%K Security
%K statistics;
%K systems;
%K table
%K table;
%K watermarking;
%X The paper studies joint security and robustness enhancement of quantization-based data embedding for multimedia authentication applications. We present an analysis showing that through a nontrivial run lookup table (LUT) that maps quantized multimedia features randomly to binary data, the probability of detection error can be considerably smaller than the traditional quantization embedding. We quantify the security strength of LUT embedding and enhance its robustness through distortion compensation. Introducing a joint security and capacity measure, we show that the proposed distortion-compensated LUT embedding provides joint enhancement of security and robustness over the traditional quantization embedding.
%B Circuits and Systems for Video Technology, IEEE Transactions on
%V 13
%P 831 - 841
%8 2003/08//
%@ 1051-8215
%G eng
%N 8
%R 10.1109/TCSVT.2003.815951
%0 Journal Article
%J Pattern Analysis and Machine Intelligence, IEEE Transactions on
%D 2003
%T Properties of embedding methods for similarity searching in metric spaces
%A Hjaltason,G. R
%A Samet, Hanan
%K complex
%K contractiveness;
%K data
%K databases;
%K decomposition;
%K dimension
%K distance
%K distortion;
%K DNA
%K documents;
%K EMBEDDING
%K embeddings;
%K Euclidean
%K evaluations;
%K FastMap;
%K images;
%K Lipschitz
%K methods;
%K metric
%K MetricMap;
%K multimedia
%K processing;
%K query
%K reduction
%K search;
%K searching;
%K sequences;
%K similarity
%K singular
%K spaces;
%K SparseMap;
%K types;
%K value
%X Complex data types-such as images, documents, DNA sequences, etc.-are becoming increasingly important in modern database applications. A typical query in many of these applications seeks to find objects that are similar to some target object, where (dis)similarity is defined by some distance function. Often, the cost of evaluating the distance between two objects is very high. Thus, the number of distance evaluations should be kept at a minimum, while (ideally) maintaining the quality of the result. One way to approach this goal is to embed the data objects in a vector space so that the distances of the embedded objects approximates the actual distances. Thus, queries can be performed (for the most part) on the embedded objects. We are especially interested in examining the issue of whether or not the embedding methods will ensure that no relevant objects are left out. Particular attention is paid to the SparseMap, FastMap, and MetricMap embedding methods. SparseMap is a variant of Lipschitz embeddings, while FastMap and MetricMap are inspired by dimension reduction methods for Euclidean spaces. We show that, in general, none of these embedding methods guarantee that queries on the embedded objects have no false dismissals, while also demonstrating the limited cases in which the guarantee does hold. Moreover, we describe a variant of SparseMap that allows queries with no false dismissals. In addition, we show that with FastMap and MetricMap, the distances of the embedded objects can be much greater than the actual distances. This makes it impossible (or at least impractical) to modify FastMap and MetricMap to guarantee no false dismissals.
%B Pattern Analysis and Machine Intelligence, IEEE Transactions on
%V 25
%P 530 - 549
%8 2003/05//
%@ 0162-8828
%G eng
%N 5
%R 10.1109/TPAMI.2003.1195989