We present a rate-distortion optimal joint source/channel coding framework for efficient and robust low bit rate video communications in packet networks. The proposed algorithm combines layered coding with transport p...
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ISBN:
(纸本)0780362977
We present a rate-distortion optimal joint source/channel coding framework for efficient and robust low bit rate video communications in packet networks. The proposed algorithm combines layered coding with transport prioritization in a novel operational rate-distortion optimization framework that trades off source coding performance for channel coding protection. The system is demonstrated to achieve significant improvement in reconstructed video quality for a range of packet loss rates.
We present a method for modeling the distortion-rate characteristics of compressed video sequences. It is assumed that the source coders rely on motion-compensated prediction, and thus error propagation will contribut...
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ISBN:
(纸本)0780362977
We present a method for modeling the distortion-rate characteristics of compressed video sequences. It is assumed that the source coders rely on motion-compensated prediction, and thus error propagation will contribute significantly to the degradation of the reconstructed video. It is shown that through the use of the modeled characteristics source and channel coding rate can be allocated across frames in a video sequence in order to minimize the effects of error propagation.
This paper discusses encoding of vehicular position information using predictive algorithms in inter-vehicle communications (IVC) from the viewpoints of source coding and noisy channels. Two vehicular driving models a...
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This paper discusses encoding of vehicular position information using predictive algorithms in inter-vehicle communications (IVC) from the viewpoints of source coding and noisy channels. Two vehicular driving models are assumed;one is the 15-mode as a suburban rapid transit driving pattern, the other is called calming mode as a street-driving pattern. Three types of schemes are compared;a pulse code modulation (PCM) scheme, a predictive coding (PC) scheme, and the variable interval prediction (VIP) scheme that is proposed here. This paper assumes that precise position information is got from a positioning system, and that all the transmitters and receivers have common predictors. Performance comparisons of the three types of schemes are carried out both of noiseless and noisy channels. Results show that the VIP scheme is superior to any other scheme.
Memory quantization is studied in detail. We propose a framework, power series vector quantization (PSVQ), for analysis and development of memory quantizers. Furthermore, we present an optimization algorithm for the f...
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Memory quantization is studied in detail. We propose a framework, power series vector quantization (PSVQ), for analysis and development of memory quantizers. Furthermore, we present an optimization algorithm for the framework, and new memory quantization methods are derived from the framework. The new methods are applied to spectrum quantization, and are shown to outperform previous methods.
Consider a memoryless, loss-tolerant and delay-sensitive source, the output of which is transmitted through a packet-switched communication network. Network parameters such as congestion, route quality, link capacity ...
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Consider a memoryless, loss-tolerant and delay-sensitive source, the output of which is transmitted through a packet-switched communication network. Network parameters such as congestion, route quality, link capacity etc., have a great impact on the achievable distortion at the receiver. In our previous publication (see IEEE Trans. on Inform. Theory, vol.47, no.3, p.891-903, March 2000)., we investigated the significance of using multiple description coding (MDC) in reducing the average end-to-end distortion. Also we demonstrated the value of intelligent routing in reducing distortion for single description coding. In this paper, we show that the relative improvement that is achieved by using intelligent routing is much more noticeable in systems employing MDC.
Scalar quantizers with uniform encoders and channel optimized decoders are studied for uniform sources and binary symmetric channels. It is shown that the natural binary code and folded binary code induce point densit...
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ISBN:
(纸本)0769514774
Scalar quantizers with uniform encoders and channel optimized decoders are studied for uniform sources and binary symmetric channels. It is shown that the natural binary code and folded binary code induce point density functions that are uniform on proper subintervals of the source support, whereas the Gray code does not induce a point density function. The mean squared errors for the natural binary code, folded binary code, Gray code, and for randomly chosen index assignments are calculated and the natural binary code is shown to be mean squared optimal among all possible index assignments. In contrast, it is shown that almost all index assignments perform poorly and have degenerate codebooks.
BCJR based source coding of image residuals is explored. From a trellis representation of the residual, a joint source-channel coding system is formed. The use of the BCJR algorithm is possible due to a procedure whic...
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BCJR based source coding of image residuals is explored. From a trellis representation of the residual, a joint source-channel coding system is formed. The use of the BCJR algorithm is possible due to a procedure which transforms the residuals to a representation with independent identically distributed components having unit variance.
Error control and power allocation for transmitting wireless video over CDMA networks are considered in conjunction with multiuser detection. We map a layered video bitstream to several CDMA fading channels and inject...
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ISBN:
(纸本)0780374002
Error control and power allocation for transmitting wireless video over CDMA networks are considered in conjunction with multiuser detection. We map a layered video bitstream to several CDMA fading channels and inject multiple source/parity layers into each of these channels at the transmitter. At the receiver, we employ a linear minimum mean-square error (MMSE) multiuser detector in the uplink and two types of blind linear MMSE detectors in the downlink, for demodulating the received data. For given constraints on the available bandwidth and transmit power, the transmitter determines the optimal power allocation among different CDMA fading channels and the optimal number of source and parity packets to send that offer the best video quality. Simulation results show a performance gain of up to 1.5 dB with joint optimization over that with rate optimization only.
The Csisza forward /spl beta/-cutoff rate (/spl beta/<0) for hypothesis testing is defined as the largest rate R/sub 0//spl ges/0 such that for all rates 0
The Csisza forward /spl beta/-cutoff rate (/spl beta/<0) for hypothesis testing is defined as the largest rate R/sub 0//spl ges/0 such that for all rates 0
With the increasing usage of multimedia technologies, image compression requires higher performance as well as new features. To address these needs in the specific area of continuous tone still image encoding, a new s...
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With the increasing usage of multimedia technologies, image compression requires higher performance as well as new features. To address these needs in the specific area of continuous tone still image encoding, a new standard is currently being developed, JPEG2000. We first present an overview of this standard. We are interested in evaluation of its performance by means of Kakadu software.
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