Fujitsu Corporation

Noriko Itani

Yasuhiko Nakano

Ryuji Kan

Takumi Maruyama

Shigeki Itou

Takahiro Nomiyama

A data compression apparatus includes a memory and a processor. The processor extracts a second character string as a matching string from a character string after a first character string in a character string of data before compression that is stored in the memory, the second character string being identical with the first character string, and identifies a length of the matching string, and a relative position indicating how many addresses the first character string precedes the second character string by. The processor extracts a third character string having a length that is less than the relative position from the extracted second character string. The processor encodes a length of the third character string. The processor encodes the relative position.

Data compression apparatus and method

In a first data compression process, a compressed code of an input symbol is generated in accordance with a compression dictionary selected on the basis of P symbols immediately preceding the input symbol, and a (P+1)K+1-th compressed code is encrypted to generate a compressed and encrypted code. Then, compressed and encrypted data comprising compressed and encrypted codes and other compressed codes is output. In a second data compression process, a bit string is added to the head of compression target data, and a compressed code of an input symbol is generated in accordance with a compression dictionary selected on the basis of a bit string or a symbol immediately preceding the input symbol. Then, a plurality of compressed codes are alternately output to different output destinations.

Data compression apparatus and data decompression apparatus

Repetitive portions are sequentially detected in compression target data, and it is determined whether the approximately corresponding position of each repetitive portion is under a word-repetition condition, which is a position corresponding to a multiple of a length of an instruction word, or whether the position is under a byte-repetition condition. When it is under a word-repetition condition, a word-repetition code including at least a value obtained by dividing an approximately corresponding position by an instruction word length and a value specifying a length of a corresponding portion is generated and output as compressed data. When it is a byte-repetition condition, a byte-repetition code including at least a value specifying an approximately corresponding position and a value specifying a length of a corresponding portion is generated and output as compressed data.

Data compression/decompression method and computer readable storage medium storing compression/decompression program

A bit string having a predetermined length is added to a head of a data string. The data string to which the bit string is added is compressed to produce a compressed data string. A head part is taken off from the compressed data string. The head part includes from a head position of the compressed data string to a predetermined position of the bit string compressed at the compressing. The head part and a latter part of the compressed data are output separately.

Method and apparatus for compressing and decompressing data, and computer product

Structured documents can be compressed without impairing visual recognizability of data structure or flexibility/expandability of structured documents. This invention provides a tag list generating unit for generating a single tag list in which tags in a structured document are listed in the order of appearance, a structured document compressing unit for generating a compressed document in which tags in each of the structured documents are replaced with predetermined delimiter codes, and an outputting unit for outputting the single tag list generated by the tag list generating unit along with a plurality of compressed documents generated from a plurality of structured documents by the structured document compressing unit, in correspondence with one another. This invention is applied to XML and SGML structured documents, and is effective, for example, when a number of slips having the same format are compressed/decompressed.

Structured document compressing apparatus and method, record medium in which a structured document compressing program is stored, structured document decompressing apparatus and method, record medium in which a structured document decompressing program is stored, and structured document processing system

Providing a data compression method, program, and apparatus that allows coding by detecting a repetition of a matching character string even without successiveness of the same numbers in a recent match position list. Using a recent match position list for narrowing down candidates for a matching character string that have previously appeared and to perform detection and coding of a matching character string by performing comparison with each character string in the input buffer as a candidate.

Data compression method, program, and apparatus to allow coding by detecting a repetition of a matching character string

This invention provides a structured document processing system comprising: a structured document storage unit for storing a structured document; a partial tree control unit which conceives the structured document stored in the structured document storage unit as a tree structure and controls the tree structure with divided partial trees; an expanding unit which acquires part of the structured document corresponding to a partial tree notified from the partial tree control unit from the structured document storage unit, analyzes part of the acquired structured document from viewpoints of its structure and expands as a hierarchical object in tree structure; and a processing unit for processing the object expanded by the expanding unit following an instruction from a user application.

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Kawasaki, Japan

Noriko Itani