Merhav Neri
The Viterbi Faculty of Electrical and Computer Engineering, Technion-Israel Institute of Technology, Technion City, Haifa 3200003, Israel.
Entropy (Basel). 2025 Mar 31;27(4):370. doi: 10.3390/e27040370.
We consider the problem of successive-refinement coding for lossy compression of individual sequences, namely, compression in two stages, where in the first stage, a coarse description at a relatively low rate is sent from the encoder to the decoder, and in the second stage, an additional coding rate is allocated in order to refine the description and thereby improve the reproduction. Our main result is in establishing outer bounds (converse theorems) for the rate region where we limit the encoders to be finite-state machines in the spirit of Ziv and Lempel's 1978 model. The matching achievability scheme is conceptually straightforward. We also consider the more general multiple description coding problem on a similar footing and propose achievability schemes that are analogous to the well-known El Gamal-Cover and the Zhang-Berger achievability schemes of memoryless sources and additive distortion measures.
我们考虑用于单个序列有损压缩的逐次细化编码问题，即分两个阶段进行压缩，在第一阶段，以相对较低的速率从编码器向解码器发送一个粗略描述，在第二阶段，分配额外的编码速率以细化描述从而改善再现效果。我们的主要成果是为速率区域建立外界限（逆定理），在此我们将编码器限制为符合齐夫和莱姆佩尔1978年模型精神的有限状态机。匹配的可达性方案在概念上很简单。我们还在类似基础上考虑更一般的多描述编码问题，并提出类似于无记忆源和加性失真度量的著名的埃尔加马尔 - 科弗以及张 - 伯杰可达性方案的可达性方案。
