DATA COMPRESSOR, DATA RESTORING DEVICE AND DATA COMPRESSION/RESTORATION SYSTEM

摘要

PURPOSE: To provide a data compression/restoration system in which a memory capacity is saved and a code tree is updated so as to increase a compression rate of a symbol with a high incident frequency. CONSTITUTION: When a data entry means 102 inputs unit data in a data compressor 100, a coding means 103 references a compression table 101 to obtain a sequence corresponding to entered unit data and outputs a code corresponding to the sequence. Then a compression table update means 104 updates the sequence of unit data in the compression table 101 in a way of self-organization. On the other hand, when a code entry means 107 in a data restoring device 105 enters a code as the compression result, a data restoring means 108 references a restoration table 106 to obtain the sequence corresponding to the entered code and to output unit data. Then a restoration table update means 109 updates the sequence of unit data in the restoration table 106 in a way of self-organization based on only the sequence.