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Related papers: Lempel-Ziv Decoding in External Memory

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Recent years has witnessed dramatic progress of neural machine translation (NMT), however, the method of manually guiding the translation procedure remains to be better explored. Previous works proposed to handle such problem through…

Computation and Language · Computer Science 2019-02-01 Ya Li , Xinyu Liu , Dan Liu , Xueqiang Zhang , Junhua Liu

Dynamic dictionary-based compression schemes are the most daily used data compression schemes since they appeared in the foundational papers of Ziv and Lempel in 1977, commonly referred to as LZ77. Their work is the base of Deflate, gZip,…

Data Structures and Algorithms · Computer Science 2012-11-26 Maxime Crochemore , Alessio Langiu , Filippo Mignosi

Data compression continues to evolve, with traditional information theory methods being widely used for compressing text, images, and videos. Recently, there has been growing interest in leveraging Generative AI for predictive compression…

Information Theory · Computer Science 2024-09-24 Swathi Shree Narashiman , Nitin Chandrachoodan

Compression refers to encoding data using bits, so that the representation uses as few bits as possible. Compression could be lossless: i.e. encoded data can be recovered exactly from its representation) or lossy where the data is…

Information Theory · Computer Science 2012-10-19 Narayana Santhanam , Dharmendra Modha

Tries are among the most versatile and widely used data structures on words. They are pertinent to the (internal) structure of (stored) words and several splitting procedures used in diverse contexts ranging from document taxonomy to IP…

Probability · Mathematics 2012-09-20 Kevin Leckey , Ralph Neininger , Wojciech Szpankowski

We consider the problem of decompressing the Lempel--Ziv 77 representation of a string $S$ of length $n$ using a working space as close as possible to the size $z$ of the input. The folklore solution for the problem runs in $O(n)$ time but…

Data Structures and Algorithms · Computer Science 2019-11-05 Philip Bille , Mikko Berggren Ettienne , Travis Gagie , Inge Li Gørtz , Nicola Prezza

Lempel-Ziv is an easy-to-compute member of a wide family of so-called macro schemes; it restricts pointers to go in one direction only. Optimal bidirectional macro schemes are NP-complete to find, but they may provide much better…

Data Structures and Algorithms · Computer Science 2020-03-06 Luís M. S. Russo , Ana D. Correia , Gonzalo Navarro , Alexandre P. Francisco

The compression-complexity trade-off of lossy compression algorithms that are based on a random codebook or a random database is examined. Motivated, in part, by recent results of Gupta-Verd\'{u}-Weissman (GVW) and their underlying…

Information Theory · Computer Science 2009-04-23 Chris Gioran , Ioannis Kontoyiannis

We present an algorithm which computes the Lempel-Ziv factorization of a word $W$ of length $n$ on an alphabet $\Sigma$ of size $\sigma$ online in the following sense: it reads $W$ starting from the left, and, after reading each $r =…

Data Structures and Algorithms · Computer Science 2012-12-03 Tatiana Starikovskaya

The aim of this note is to provide some reference facts for LZW---mostly from Thomas and Cover \cite{Cover:2006aa} and provide a reference for some metrics that can be derived from it. LZW is an algorithm to compute a Kolmogorov Complexity…

Information Theory · Computer Science 2017-08-01 Giulio Ruffini

Tokenization efficiency plays a critical role in the performance and cost of large language models (LLMs), yet most models rely on static tokenizers optimized on general-purpose corpora. These tokenizers' fixed vocabularies often fail to…

Computation and Language · Computer Science 2025-10-27 Saibo Geng , Nathan Ranchin , Yunzhen yao , Maxime Peyrard , Chris Wendler , Michael Gastpar , Robert West

Web archives, query and proxy logs, and so on, can all be very large and highly repetitive; and are accessed only sporadically and partially, rather than continually and holistically. This type of data is ideal for compression-based…

Information Theory · Computer Science 2016-03-01 Matthias Petri , Alistair Moffat , P. C. Nagesh , Anthony Wirth

Sequence processing has long been a central area of machine learning research. Recurrent neural nets have been successful in processing sequences for a number of tasks; however, they are known to be both ineffective and computationally…

Machine Learning · Computer Science 2022-11-28 Rebecca Saul , Mohammad Mahmudul Alam , John Hurwitz , Edward Raff , Tim Oates , James Holt

The majority of online content is written in languages other than English, and is most commonly encoded in UTF-8, the world's dominant Unicode character encoding. Traditional compression algorithms typically operate on individual bytes.…

Information Theory · Computer Science 2017-01-17 Adam Gleave , Christian Steinruecken

Relative Lempel-Ziv (RLZ) parsing is a dictionary compression method in which a string $S$ is compressed relative to a second string $R$ (called the reference) by parsing $S$ into a sequence of substrings that occur in $R$. RLZ is…

Data Structures and Algorithms · Computer Science 2022-08-25 Philip Bille , Inge Li Gørtz , Simon J. Puglisi , Simon R. Tarnow

We consider the problem of {\em restructuring} compressed texts without explicit decompression. We present algorithms which allow conversions from compressed representations of a string $T$ produced by any grammar-based compression…

Data Structures and Algorithms · Computer Science 2011-07-15 Keisuke Goto , Shirou Maruyama , Shunsuke Inenaga , Hideo Bannai , Hiroshi Sakamoto , Masayuki Takeda

The paper proposes an improved error-resilient Lempel-Ziv'77 (LZ'77) algorithm employing an adaptive amount of parity bits for error protection. It is a modified version of error resilient algorithm LZRS'77, proposed recently, which uses a…

Information Theory · Computer Science 2008-04-21 Tomaz Korosec , Saso Tomazic

We raise the question of approximating the compressibility of a string with respect to a fixed compression scheme, in sublinear time. We study this question in detail for two popular lossless compression schemes: run-length encoding (RLE)…

Data Structures and Algorithms · Computer Science 2007-06-11 Sofya Raskhodnikova , Dana Ron , Ronitt Rubinfeld , Adam Smith

We initiate the study of differentially private data-compression schemes motivated by the insecurity of the popular "Compress-Then-Encrypt" framework. Data compression is a useful tool which exploits redundancy in data to reduce…

Computational Complexity · Computer Science 2025-09-25 Jeremiah Blocki , Seunghoon Lee , Brayan Sebastián Yepes Garcia

Advances in DNA sequencing technology will soon result in databases of thousands of genomes. Within a species, individuals' genomes are almost exact copies of each other; e.g., any two human genomes are 99.9% the same. Relative Lempel-Ziv…

Data Structures and Algorithms · Computer Science 2011-11-08 Travis Gagie , Juha Kärkkäinen , Yakov Nekrich , Simon J. Puglisi