| 摘要 |
PROBLEM TO BE SOLVED: To realize high speed and high compression for data having especially the large structure of binary picture and the like with respect to the data companding system of Ziv-Lempel. SOLUTION: The data compression system is constituted of the dictionary of tree structure for searching a longest matched character string, a longest matched character string search means 101 searching the longest matched character string, an encoding means 102 encoding and outputting a searched result, and a dictionary update means 103 registering a new entry in the dictionary. In this case, the character strings of finite length are especially stored in the respective entries of the search tree. Thus, restriction on the finiteness of matched length in searching the longest matched character string can be removed. Furthermore, a data expansion system is constituted of a decoding means, a data copying means and a conversion table update means for easily restoring a compression code into original data. |
