| 摘要 |
PURPOSE:To improve the rate of compression between character strings by preparing a dictionary to register a partial character string to be followed for each final character string of the preceding partial character string or for each group formed by the final character and applying the registration number of the character string to be registered to the dictionary for each dictionary. CONSTITUTION:In belonging relation with the preceding final character, the codes of current partial character strings ab and abc are applied. A tree 11 is composed of the head character and the developed character for respective final characters (a)-(c) of the preceding character string, and the numbers (indexes) of the respective character strings ab and abc are applied for each tree 11. Therefore, when the respective characters (a)-(c) appear with the equal probability, the length of the index (of the registration numbers of the respective partial character strings ab and abc in the tree 11 of each dictionary 2) is made short. Thus, the length of the code to identify the partial character strings ab and abc is made short and the rate of compression is improved. |
