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ABSTRACT: A new video coding paradigm (PRISM) built on distributed coding principles has recently been proposed in R. Puri and K. Ramchandran, (2002, 2003). The PRISM framework rests heavily on channel coding concepts. The basic idea is to do intra-frame coding but to approach the coding efficiency of motion-compensated inter-frame coding by using channel codes to derive a coding rate rebate by "exploiting" the correlated side-information present in the form of previous temporal frames at the decoder. The coding strategy described in R. Puri and K. Ramchandran, (2002, 2003) was limited to rate-1/2 trellis coset codes, which limit the granularity at which the correlated side-information can be exploited. In this work, we generalize the coset coding framework to multi-level codes which allow more flexible encoding rates and the capability to exploit correlations with much finer granularity. Simulation results validate the better compression performance (of the order of 1 dB for typical tests) of the multilevel framework.
Signals, Systems and Computers, 2003. Conference Record of the Thirty-Seventh Asilomar Conference on; 12/2003
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ABSTRACT: We explore the information-theoretic duality between source coding with side information at the decoder and channel coding with side information at the encoder. We begin with a mathematical characterization of the functional duality between classical source and channel coding, formulating the precise conditions under which the optimal encoder for one problem is functionally identical to the optimal decoder for the other problem. We then extend this functional duality to the case of coding with side information. By invoking this duality, we are able to generalize the result of Wyner and Ziv (1976) relating to no rate loss for source coding with side information from Gaussian to more arbitrary distributions. We consider several examples corresponding to both discrete- and continuous-valued cases to illustrate our formulation. For the Gaussian cases of coding with side information, we invoke geometric arguments to provide further insights into their duality. Our geometric treatment inspires the construction and dual use of practical coset codes for a large class of emerging applications for coding with side information, such as distributed sensor networks, watermarking, and information-hiding communication systems.
IEEE Transactions on Information Theory 06/2003; · 3.01 Impact Factor
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ABSTRACT: There has been a lot of interest recently in applying channel coding with side information (CCSI) concepts to data hiding. Part of the interest stems from the fact that information theoretic bounds can be derived for such systems. In this paper, we model the audio data embedding problem as a parallel CCSI problem. This is done by dividing the audio spectrum into frequency bins and then treating each bin as a separate CCSI channel. A perceptual mask is derived from the audio signal to determine the amount of power to use in each channel. It acts as a "water-filling" formula by determining the amount of distortion that can be introduced into each frequency bin without introducing audible distortion. As a result, our data embedding scheme will be imperceptible to the human ear. An exciting application for our audio data embedding solution is to embed data within the audio signal that will enable surround sound at the receiver. The resulting surround sound system will be better than existing surround sound systems that are based on manipulating two stereo channels to derive the other surround channels.
Acoustics, Speech, and Signal Processing, 2003. Proceedings. (ICASSP '03). 2003 IEEE International Conference on; 05/2003 · 4.63 Impact Factor
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ABSTRACT: The problem of rate-distortion efficient constructions is studied for the problem of source coding with side information (SCSI), which has assumed heightened interest. While the Wyner-Ziv theorem from information theory has prescribed rate-distortion performance bounds for the SCSI problem, the gap between theory and practice has remained large. To reduce this gap, two different frameworks are proposed based on a trellis construction and a turbo-based construction respectively. Simulation results on the Gaussian SCSI problem reveal the promise of the proposed approaches: at 1 bit per sample, 0.5 bits/sample, 0.25 bits/sample and 0.125 bits/sample, these constructions attain performance within 1.3 dB, 1.1 dB, 0.85 dB and 0.5 dB respectively of the theoretical Wyner-Ziv rate-distortion bound.
Data Compression Conference, 2003. Proceedings. DCC 2003; 04/2003
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ABSTRACT: In this paper, we propose a novel method for reducing energy consumption in a sensor network. It is important in a sensor network to minimize the energy usage of each sensor, because the nodes typically have finite battery life and if a node dies, this can lead to a loss of data or a network partition. As a result, several researchers have proposed various methods of routing and communication between nodes to reduce energy consumption. We propose an orthogonal approach to previous methods. In particular, we propose to exploit the inherent correlations that exist between sensor nodes by devising a novel algorithm that enables sensor nodes to compress their readings without knowing the exact measurements of the other nodes. Our simulations show that our algorithm used is promising as it leads to significant energy saving for various types of sensor nodes.
Signals, Systems and Computers, 2002. Conference Record of the Thirty-Sixth Asilomar Conference on; 12/2002
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ABSTRACT: Channel coding with side information (CCSI) provides a powerful framework for constructing data embedding codes. As a result, there has been a considerable amount of work done in trying to apply these CCSI codes to the field of image and video watermarking. The CCSI codes that exist in the literature (see Chou, J. et al., 1999; Kesal, M. et al., 2000; Eggers, J. et al., 2001), however, are relatively far from theoretical bounds. Furthermore, these codes, by themselves, are not well-suited for dealing with geometrical distortions which often appear in watermarking attacks. We propose a CCSI code that is closer to the theoretical bounds (within 2.0 dB) than the codes that exist in the literature. In addition, we show how this code construction can be combined with a synchronization code to deal with geometrical distortions.
Multimedia and Expo, 2002. ICME '02. Proceedings. 2002 IEEE International Conference on; 02/2002
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ABSTRACT: Source coding under a rate-distortion (R-D) constraint and channel coding under a channel cost constraint have long been considered as duals of each other starting from Shannon (1959). We address this duality with the objective of providing a mathematical characterization of it in a functional sense. To be specific, given an optimal source (channel) coding scheme, we detail the conditions under which such a scheme is a functional dual to a channel (respectively source) coding scheme. We show that this functional duality is enabled through appropriate choices of metrics and constraints for the dual source (or channel) coding problem. We then extend this duality formulation to source and channel coding with side information.
Information Theory, 2002. Proceedings. 2002 IEEE International Symposium on; 02/2002
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ABSTRACT: We combine theoretical and algorithmic advances in the area of information-hiding with the current mature knowledge-base in the human audio perception system to propose a novel audio data hiding technique that significantly pushes the state-of-the-art in the field. Our work is based on a combination of advances in two disjoint fields: information hiding and human auditory masking. The field of information hiding has seen a resurgence due to advances in the understanding of fundamental bounds from information theory. By integrating this with the human perceptual system knowledge that has been successfully exploited for several years in the audio compression community, we derive a new and improved audio data hiding technique that finds application in a number of exciting scenarios like music enhancement and digital communications over analog data channels. Our preliminary results show that we can embed data at an order of magnitude higher rate than existing audio data hiding systems, while being robust to channel noise
Information Technology: Coding and Computing, 2001. Proceedings. International Conference on; 05/2001
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ABSTRACT: We combine recent theoretical and algorithmic advances in the area
of information-hiding with the current mature knowledge-base in the
human audio perception system to propose a novel audio data-hiding
technique that significantly pushes the state-of-the-art in the field.
Our work is based on a combination of advances in two disjoint fields:
information-hiding and human auditory masking. The field of
information-hiding has recently seen a resurgence due to advances in the
understanding of fundamental bounds from information theory. By
integrating this with the human perceptual system knowledge that has
been successfully exploited for several years in the audio compression
community, we derive a new and improved audio data-hiding technique that
finds application in a number of exciting scenarios like music
enhancement and digital communications over analog data channels. Our
preliminary results show that we can embed data at a rate an order of
magnitude higher than existing audio data hiding systems, while being
robust to channel noise
Acoustics, Speech, and Signal Processing, 2001. Proceedings. (ICASSP '01). 2001 IEEE International Conference on; 02/2001 · 4.63 Impact Factor
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ABSTRACT: A host of emerging applications in multimedia and communications are connected to the problem of channel coding with side information (CCSI). In CCSI, side information about the transmission channel is present at the sender but not at the receiver. The goal of this paper is to bridge the gap between practical code constructions and the theoretical capacity bounds. Specifically, we present a new turbo-coded trellis-based code construction that appears to be very promising: for the Gaussian CCSI problem at a transmission rate of 1 bit/channel use, our proposed approach comes within 2.72 dB of the information-theoretic capacity established by M. Costa (see IEEE Trans. on Information Theory, vol.29, p.439-41, 1983).
Signals, Systems and Computers, 2001. Conference Record of the Thirty-Fifth Asilomar Conference on; 02/2001
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ABSTRACT: Block cyclic redundancy check (CRC) codes are typically used to
perform error detection in automatic repeat request (ARQ) protocols for
data communications. Although efficient, CRCs can detect errors only
after an entire block of data has been received and processed. We
propose a new “continuous” error detection scheme using
arithmetic coding that provides a novel tradeoff between the amount of
added redundancy and the amount of time needed to detect an error once
it occurs. This method of error detection, first introduced by Bell,
Witten, and Cleary (1990), is achieved through the use of an arithmetic
codec, and has the attractive feature that it can be combined physically
with arithmetic source coding, which is widely used in state of-the-art
image coders. We analytically optimize the tradeoff between added
redundancy and error-detection time, achieving significant gains in bit
rate throughput over conventional ARQ schemes for binary symmetric
channel models for all probabilities of error
IEEE Journal on Selected Areas in Communications 07/2000; · 3.41 Impact Factor
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ABSTRACT: Inspired by a previously proposed constructive framework for the distributed source coding problem, we propose a powerful constructive approach to the watermarking problem, emphasizing the dual roles of "source codes" and "channel codes". In our framework, we explore various source and channel codes to achieve watermarks that are robust to attackers in terms of maximizing the distortion between the corrupted coded-source signal and the original signal while holding the distortion between the coded-source signal and the original signal constant. Simulations show that performance gains are accredited to a careful choice of source and channel codes.
Signals, Systems, and Computers, 1999. Conference Record of the Thirty-Third Asilomar Conference on; 02/1999
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ABSTRACT: Block cyclic redundancy check (CRC) codes represent a popular and
powerful class of error detection techniques in modern data
communication systems. Though efficient, CRCs can detect errors only
after an entire block of data has been received and processed. We
propose a new “continuous” error detection scheme using
arithmetic coding that provides a novel tradeoff between the amount of
added redundancy and the amount of time needed to detect an error once
it occurs. We demonstrate how the new error detection framework improves
the overall performance of transmission systems, and show how sizeable
performance gains can be attained. We focus on two popular scenarios:
(i) automatic repeat request (ARQ) based transmission; and (ii) forward
error correction frameworks based on (serially) concatenated coding
systems involving an inner error-correction code and an outer
error-detection code
Data Compression Conference, 1998. DCC '98. Proceedings; 01/1998
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ABSTRACT: We propose a novel approach to reducing energy consumption in sensor networks using a distributed adaptive signal processing framework and efficient algorithm. While the topic of energy-aware routing to alleviate energy consumption in sensor networks has received attention recently (C. Toh, 2001; R. Shah et al., 2002), in this paper, we propose an orthogonal approach to previous methods. Specifically, we propose a distributed way of continuously exploiting existing correlations in sensor data based on adaptive signal processing and distributed source coding principles. Our approach enables sensor nodes to blindly compress their readings with respect to one another without the need for explicit and energy-expensive intersensor communication to effect this compression. Furthermore, the distributed algorithm used by each sensor node is extremely low in complexity and easy to implement (i.e., one modulo operation), while an adaptive filtering framework is used at the data gathering unit to continuously learn the relevant correlation structures in the sensor data. Our simulations show the power of our proposed algorithms, revealing their potential to effect significant energy savings (from 10%-65%) for typical sensor data corresponding to a multitude of sensor modalities.
INFOCOM 2003. Twenty-Second Annual Joint Conference of the IEEE Computer and Communications. IEEE Societies;
