Journal ArticleDOI
Compression of individual sequences via variable-rate coding
Jacob Ziv,A. Lempel +1 more
TLDR
The proposed concept of compressibility is shown to play a role analogous to that of entropy in classical information theory where one deals with probabilistic ensembles of sequences rather than with individual sequences.Abstract:
Compressibility of individual sequences by the class of generalized finite-state information-lossless encoders is investigated. These encoders can operate in a variable-rate mode as well as a fixed-rate one, and they allow for any finite-state scheme of variable-length-to-variable-length coding. For every individual infinite sequence x a quantity \rho(x) is defined, called the compressibility of x , which is shown to be the asymptotically attainable lower bound on the compression ratio that can be achieved for x by any finite-state encoder. This is demonstrated by means of a constructive coding theorem and its converse that, apart from their asymptotic significance, also provide useful performance criteria for finite and practical data-compression tasks. The proposed concept of compressibility is also shown to play a role analogous to that of entropy in classical information theory where one deals with probabilistic ensembles of sequences rather than with individual sequences. While the definition of \rho(x) allows a different machine for each different sequence to be compressed, the constructive coding theorem leads to a universal algorithm that is asymptotically optimal for all sequences.read more
Citations
More filters
Proceedings ArticleDOI
Design and Implementation of FPGA-based Systolic Array for LZ Data Compression
TL;DR: The main objective of this paper is to enhance the efficiency of systolic-array approach for implementation of Lempel-Ziv algorithm by increasing the compression rate and reducing the design area.
Proceedings ArticleDOI
Guessing Based On Length Functions
TL;DR: The results show that hiding the parameters of the key-stream generating source in a private key crypto-system may not enhance the privacy of the system, the privacy level being measured by the difficulty in brute-force guessing of theKey stream.
Proceedings ArticleDOI
Compression of low entropy strings with Lempel-Ziv algorithms
S.R. Kosaraju,Giovanni Manzini +1 more
TL;DR: It is shown that the compression ratio of the Lempel-Ziv algorithms can be much higher than the zeroth order entropy H/sub 0/ of the input string, and it is proved that for any string s the compression ratios achieved by LZ77 is bounded by 8H/ sub 0/(s).
Proceedings ArticleDOI
Logzip: extracting hidden structures via iterative clustering for log compression
TL;DR: This paper proposes a novel and effective log compression method, namely logzip, capable of extracting hidden structures from raw logs via fast iterative clustering and further generating coherent intermediate representations that allow for more effective compression.
Journal ArticleDOI
Examining the Limits of Predictability of Human Mobility
TL;DR: It is shown that extensions of recurrent-neural network architectures achieve significantly higher prediction accuracy, surpassing this upper bound on maximum mobility predictability, and the systematic bias that culminates into an inaccurate upper bound is exposed.
References
More filters
Book
Information Theory and Reliable Communication
TL;DR: This chapter discusses Coding for Discrete Sources, Techniques for Coding and Decoding, and Source Coding with a Fidelity Criterion.
Journal ArticleDOI
A universal algorithm for sequential data compression
Jacob Ziv,A. Lempel +1 more
TL;DR: The compression ratio achieved by the proposed universal code uniformly approaches the lower bounds on the compression ratios attainable by block-to-variable codes and variable- to-block codes designed to match a completely specified source.
Journal ArticleDOI
On the Complexity of Finite Sequences
A. Lempel,Jacob Ziv +1 more
TL;DR: A new approach to the problem of evaluating the complexity ("randomness") of finite sequences is presented, related to the number of steps in a self-delimiting production process by which a given sequence is presumed to be generated.
Journal ArticleDOI
Coding theorems for individual sequences
TL;DR: The finite-state complexity of a sequence plays a role similar to that of entropy in classical information theory (which deals with probabilistic ensembles of sequences rather than an individual sequence).
Journal ArticleDOI
On Information Lossless Automata of Finite Order
TL;DR: The application of the tests to finite deterministic automata is discussed and a method of constructing a decoder for a given finite automaton that is information lossless of finite order, is described.