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arXiv cs/0701197cs.ITmath.IT
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相关信源的延迟序列编码

On Delayed Sequential Coding of Correlated Sources

Nan Ma, Ye Wang, Prakash Ishwar

摘要:

受视频编码应用的启发,研究了具有编码和/或解码帧延迟的相关信源的顺序编码问题。个体帧速率、个体帧失真和编码/解码帧延迟之间的基本权衡是根据一般帧间源相关性的速率失真区域的单字母信息理论表征和某些类型的潜在帧特定和耦合的单字母保真度标准来导出的。和率失真区域的特点是广义有向信息措施,突出其在延迟顺序信源编码问题中的作用。对于视频源,这是空间上固定的无记忆和时间高斯马尔可夫,MSE帧失真,和一个总和速率约束,我们的研究结果暴露了最优的理想化的差分预测编码之间的所有因果顺序编码器,当编码器使用一个积极的速率来描述每一帧。令人惊讶的是,因果顺序编码与一帧延迟的非因果顺序解码可以完全匹配的总和速率MSE性能的联合编码的所有非平凡的MSE元组满足一定的半正定条件。因此,即使是单个帧延迟也有可能产生显著的性能改进。高阶马尔可夫源的推广也提出和讨论。因果顺序编码与延迟非因果顺序解码之间的率失真性能等价,以及延迟非因果顺序编码与因果顺序解码,也被建立。

英文摘要:

Motivated by video coding applications, the problem of sequential coding of correlated sources with encoding and/or decoding frame-delays is studied. The fundamental tradeoffs between individual frame rates, individual frame distortions, and encoding/decoding frame-delays are derived in terms of a single-letter information-theoretic characterization of the rate-distortion region for general inter-frame source correlations and certain types of potentially frame specific and coupled single-letter fidelity criteria. The sum-rate-distortion region is characterized in terms of generalized directed information measures highlighting their role in delayed sequential source coding problems. For video sources which are spatially stationary memoryless and temporally Gauss-Markov, MSE frame distortions, and a sum-rate constraint, our results expose the optimality of idealized differential predictive coding among all causal sequential coders, when the encoder uses a positive rate to describe each frame. Somewhat surprisingly, causal sequential encoding with one-frame-delayed noncausal sequential decoding can exactly match the sum-rate-MSE performance of joint coding for all nontrivial MSE-tuples satisfying certain positive semi-definiteness conditions. Thus, even a single frame-delay holds potential for yielding significant performance improvements. Generalizations to higher order Markov sources are also presented and discussed. A rate-distortion performance equivalence between, causal sequential encoding with delayed noncausal sequential decoding, and, delayed noncausal sequential encoding with causal sequential decoding, is also established.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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