### 抄録

Ziv-Lempel (ZL) codes and Bayes codes are typical universal codes. An improved algorithm of the ZL code is widely used in compression software. On the other hand, practical use of Bayes codes is difficult due to the large amount of computation needed. However, a realizable algorithm in terms of computation effort has been constructed for the FSMX model group [9]. In this paper, an information source generating a sequence by word units is assumed as a model that can represent the probabilistic structure of actual data such as text data. The asymptotic compression performance of both codes is analyzed and evaluated for the information source class (information source for the block unit) with a constant (fixed) word length. As a result, it is found that Bayes code cannot directly be universal as a coding algorithm for symbol units. On the other hand, the ZL78 code can be directly universal. Also, a configuration method for the Bayes coding method is given for an information source with a block unit.

元の言語 | English |
---|---|

ページ（範囲） | 58-69 |

ページ数 | 12 |

ジャーナル | Electronics and Communications in Japan, Part III: Fundamental Electronic Science (English translation of Denshi Tsushin Gakkai Ronbunshi) |

巻 | 86 |

発行部数 | 1 |

DOI | |

出版物ステータス | Published - 2003 |

### ASJC Scopus subject areas

- Electrical and Electronic Engineering

### これを引用

*Electronics and Communications in Japan, Part III: Fundamental Electronic Science (English translation of Denshi Tsushin Gakkai Ronbunshi)*,

*86*(1), 58-69. https://doi.org/10.1002/ecjc.10017

**On universality of both Bayes codes and Ziv-Lempel codes for sources which emit data sequence by block unit.** / Ishida, Takashi; Goto, Masayuki; Hirasawa, Shigeichi.

研究成果: Article

*Electronics and Communications in Japan, Part III: Fundamental Electronic Science (English translation of Denshi Tsushin Gakkai Ronbunshi)*, 巻. 86, 番号 1, pp. 58-69. https://doi.org/10.1002/ecjc.10017

}

TY - JOUR

T1 - On universality of both Bayes codes and Ziv-Lempel codes for sources which emit data sequence by block unit

AU - Ishida, Takashi

AU - Goto, Masayuki

AU - Hirasawa, Shigeichi

PY - 2003

Y1 - 2003

N2 - Ziv-Lempel (ZL) codes and Bayes codes are typical universal codes. An improved algorithm of the ZL code is widely used in compression software. On the other hand, practical use of Bayes codes is difficult due to the large amount of computation needed. However, a realizable algorithm in terms of computation effort has been constructed for the FSMX model group [9]. In this paper, an information source generating a sequence by word units is assumed as a model that can represent the probabilistic structure of actual data such as text data. The asymptotic compression performance of both codes is analyzed and evaluated for the information source class (information source for the block unit) with a constant (fixed) word length. As a result, it is found that Bayes code cannot directly be universal as a coding algorithm for symbol units. On the other hand, the ZL78 code can be directly universal. Also, a configuration method for the Bayes coding method is given for an information source with a block unit.

AB - Ziv-Lempel (ZL) codes and Bayes codes are typical universal codes. An improved algorithm of the ZL code is widely used in compression software. On the other hand, practical use of Bayes codes is difficult due to the large amount of computation needed. However, a realizable algorithm in terms of computation effort has been constructed for the FSMX model group [9]. In this paper, an information source generating a sequence by word units is assumed as a model that can represent the probabilistic structure of actual data such as text data. The asymptotic compression performance of both codes is analyzed and evaluated for the information source class (information source for the block unit) with a constant (fixed) word length. As a result, it is found that Bayes code cannot directly be universal as a coding algorithm for symbol units. On the other hand, the ZL78 code can be directly universal. Also, a configuration method for the Bayes coding method is given for an information source with a block unit.

KW - Bayes code

KW - Information source with a word unit

KW - Universal code

KW - Ziv-Lempel code

UR - http://www.scopus.com/inward/record.url?scp=0037210036&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0037210036&partnerID=8YFLogxK

U2 - 10.1002/ecjc.10017

DO - 10.1002/ecjc.10017

M3 - Article

AN - SCOPUS:0037210036

VL - 86

SP - 58

EP - 69

JO - Electronics and Communications in Japan, Part III: Fundamental Electronic Science (English translation of Denshi Tsushin Gakkai Ronbunshi)

JF - Electronics and Communications in Japan, Part III: Fundamental Electronic Science (English translation of Denshi Tsushin Gakkai Ronbunshi)

SN - 1042-0967

IS - 1

ER -