The objective of multipledescriptioncoding (MDC) is to encode a single information source into multiple bitstreams, in a manner that the reconstructed source can be produced at different qualities according to the a...
详细信息
ISBN:
(纸本)9781538671207
The objective of multipledescriptioncoding (MDC) is to encode a single information source into multiple bitstreams, in a manner that the reconstructed source can be produced at different qualities according to the amount of bitstreams received at the decoder. In this paper, we propose to employ an optimal filtering strategy as a post processing method for a multiple description transform coding (MDTC) approach which utilizes discrete wavelet transform (DWT). Experimental results show that the proposed approach provides better results compared to existing approaches in the literature.
We consider image transmission using multiple description transform coding (MDTC) over orthogonal frequency division multiplexed (OFDM) wireless broadcast channels, where the system may not have any feedback on channe...
详细信息
We consider image transmission using multiple description transform coding (MDTC) over orthogonal frequency division multiplexed (OFDM) wireless broadcast channels, where the system may not have any feedback on channel gains. We investigate the redundancy allocation in MDTC-OFDM system, physical layer frequency diversity, and decoding strategies to maximize the quality of reconstruction. Via mathematical analysis, supported by MATLAB simulations, we show that, error resilience of the descriptions can be increased by suitable assignment of coding redundancy in the transform modules at the source, which can be further optimized if the channel characteristics are known at the transmitter. Additionally, the relative performance of the MDTC-OFDM system is studied with respect to a competitive approach, called forward error correction based multipledescriptioncoding (MDC) over OFDM, where we show that, for the same redundancy assignment, the MDTC based system performs better under harsh channel conditions. (C) 2014 Elsevier B.V. All rights reserved.
multipledescriptioncoding has been shown to provide improved error resiliency for video streaming over error-prone channels. In a typical multipledescription codec, the decoder simply reproduces the signal using th...
详细信息
multipledescriptioncoding has been shown to provide improved error resiliency for video streaming over error-prone channels. In a typical multipledescription codec, the decoder simply reproduces the signal using the received description(s). The optimal reconstruction is obtained from the available description in the sense that the mean squared error is minimized. However, this reconstruction operation does not consider the unique spatial and temporal properties underlying a video signal. In this paper, we propose a joint multiple description transform coding and statistical error concealment algorithm that adopts a maximum a posteriori estimation approach to compensate for the loss of descriptions. Our method considers not only the correlation between descriptions but also the spatial/temporal redundancy in video signals. Simulation results with several video sequences show that the proposed algorithm results in significant visual improvements over a conventional multipledescriptiontransform decoder. (C) 2003 Published by Elsevier B.V.
暂无评论