Stream Data Compression by Online Grammar Compression and VF Coding Algorithm

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K00002
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Theory of informatics
• Research Institution: Hokkaido University
• Principal Investigator: Kida Takuya 北海道大学, 情報科学研究科, 准教授 (70343316)
• Co-Investigator(Renkei-kenkyūsha): SAKAMOTO HIROSHI 九州工業大学, 大学院情報工学研究院, 教授 (50315123)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: データ圧縮 / VF符号化 / 圧縮照合 / 文法圧縮

Outline of Final Research Achievements

In this study, the applicant addressed the problem of improving the Re-Pair-VF algorithm which is a combination of VF code and grammar compression. Re-Pair-VF has better compression performance than the existing VF code, but it is difficult to apply it to large-scale data because it is based on Re-Pair which is offline type grammar transformation. Therefore, the applicant modified Re-Pair and developed online grammar transformation algorithm. Moreover, the applicant proposed an ALT (Adaptive LT-Repair) method that compresses while adaptively expanding the block length using the algorithm.

Free Research Field

情報学基礎