METHOD AND DEVICE FOR COMPRESSING DATA AND METHOD AND DEVICE FOR RESTORING DATA

摘要

PURPOSE:To improve the compressibility of the Ziv-Lempel codes of a slide dictionary type. CONSTITUTION:In this data compression method of a slide dictionary type for retrieving a coincident character string which coincides with the character string of an encoding object for a maximum length from encoded character strings stored inside a dictionary 101 and switching a raw data mode for sending out the character string of the encoding object itself as codes for every one character as unit and a duplication mode for sending out information relating to the position of the coincident character string in the dictionary 101 and the information relating to the coincident length as the codes corresponding to the coincident length, a series of numbers are supplied to mutually different encoded results obtained in the raw data mode and the mutually different encoded results obtained in the duplication mode, the numbers corresponding to the encoded results respectively obtained in the raw data mode and the duplication mode are encoded by using a code chart, the code chart is rearranged and a code length corresponding to the pertinent number is subtracted.