DICTIONARY GENERATING DEVICE FOR TEXT COMPRESSION AND TEXT COMPRESSING DEVICE

摘要

PROBLEM TO BE SOLVED: To improve the compressibility of a large-capacity fixed text by providing a frequency guideline calculating means which calculates a guideline for frequency of which appearance is requested in the text and a long character string segmenting means. SOLUTION: A frequency guideline calculating means 111 calculates at what frequency each symbol of a static dictionary for compression to be outputted needs to be segmented for every character string length to meet give compression specifications. The long character string segmenting means 112 segments a symbol of character string length 2 or longer of the static dictionary for compression to be outputted out of a source text at the specified frequency in character string length decreasing order together with its actual frequency and generates a set of uncut texts that do not meet the specific frequency at the same time. The frequency table generated by the long character string segmenting means 112 and the frequency table extracted by a character symbol extracting means 113 are combined to obtain the static dictionary for compression.