Compression method, compression device, and computer-readable recording medium

Patent metadata

Field	Value
Publication number	US-9397696-B2
Application number	US-201514799773-A
Country	US
Kind code	B2
Filing date	Jul 15, 2015
Priority date	Jul 22, 2014
Publication date	Jul 19, 2016
Grant date	Jul 19, 2016

Abstract

A non-transitory computer-readable recording medium stores a compression program that causes a computer to execute a process. The process includes: detecting a matched data that matches a processing target data with a longest length among pieces of data, the pieces of data being extracted from a data sequence that is a compression target; acquiring an appearance frequency of a code corresponding to character data contained in the matched data when a data length of the matched data is smaller than a predetermined length; acquiring an appearance frequency of a code corresponding to the matched data when the data length of the match data is equal to or larger than the predetermined length; and compressing the data sequence using a compression code generated based on the acquired appearance frequency of the code.

First claim

What is claimed is:

1. A non-transitory computer-readable recording medium storing a compression program that causes a computer to execute a process comprising:
detecting a matched data that matches a processing target data with a longest length among pieces of data, the pieces of data being extracted from a data sequence that is a compression target;
acquiring an appearance frequency of a code corresponding to character data contained in the matched data when a data length of the matched data is smaller than a predetermined length;
acquiring an appearance frequency of a code corresponding to the matched data when the data length of the matched data is equal to or larger than the predetermined length; and
compressing the data sequence using a compression code generated based on the acquired appearance frequency of the code.

2. The non-transitory computer-readable recording medium according to claim 1 , wherein the compressing includes generating a tree based on a frequency calculated by adding up an appearance frequency of character data and an appearance frequency of length data that correspond to a same code.

3. The non-transitory computer-readable recording medium according to claim 1 , wherein the compressing includes compressing the data sequence as the compression target using a tree in which a code corresponding to character data and length data is assigned to each leaf of a tree.

4. A compression method comprising:
detecting a matched data that matches a processing target data with a longest length among pieces of data, the pieces of data being extracted from a data sequence that is a compression target;
acquiring an appearance frequency of a code corresponding to character data contained in the matched data when a data length of the matched data is smaller than a predetermined length;
acquiring an appearance frequency of a code corresponding to the matched data when the data length of the matched data is equal to or larger than the predetermined length; and
compressing the data sequence using a compression code generated based on the acquired appearance frequency of the code.

5. A compression device comprising:
a processor configured to:
detect a matched data that matches a processing target data with a longest length among pieces of data, the pieces of data being extracted from a data sequence that is a compression target;
acquire an appearance frequency of a code corresponding to character data contained in the matched data when a data length of the matched data is smaller than a predetermined length;
acquire an appearance frequency of a code corresponding to the matched data when the data length of the matched data is equal to or larger than the predetermined length; and
compress the data sequence using a compression code generated based on the acquired appearance frequency of the code.

Assignees

• Fujitsu Ltd

Inventors

• Kataoka Masahiro

Classifications

• H03K5/04 Primary

  by increasing duration; by decreasing duration · CPC title

• H03K5/00006

  Changing the frequency (modulating pulses H03K7/00; frequency dividers H03K21/00 - H03K29/00; additive or subtractive mixing of two pulse rates into one G06F7/605; pulse rate dividers G06F7/68) · CPC title

• H03M7/4031 Primary

  Fixed length to variable length coding · CPC title

• H03M7/3084

  using adaptive string matching, e.g. the Lempel-Ziv method · CPC title

• H03M7/30

  Compression (speech analysis-synthesis for redundancy reduction G10L19/00; for image communication H04N); Expansion; Suppression of unnecessary data, e.g. redundancy reduction · CPC title