| 摘要 |
PURPOSE: To reduce a transmission time of data by selecting an optimum compression algorithm or data table among plural compression algorithms or data tables so as to improve the data compression efficiency thereby increasing the capacity of a file device substantially. CONSTITUTION: A compression control means 3 discriminates information specific to a file being an object of compression and specifies a data structure when the file is designated (A), a storage means 2 retrieves (B) and selects (C) an optimum compression algorithm or data table corresponding to the data structure. Then the means 3 reads a data string of the table from the file device 1 and converts the input data string D into a variable length coding data string E based on the selected compression algorithm or data table. As a result, the data compression efficiency is always maintained in a best state. |
