| 摘要 |
PURPOSE:To improve a data compressibility by detecting the increase of the data compressibility and a dictionary capacity, and erasing an old registered content causing the deterioration of the compressibility, as for a dictionary registering system in a data compression and a data restoration. CONSTITUTION:A data compressor 1 which encodes original data 2 to compressed data 3 while preparing a dictionary 4, is equipped with a compressibility detecting means 5 which detects the compressibility, dictionary capacity detecting means 12 which detects the capacity of the dictionary, and registration erasing means 6 which erases one part of the registered content of the dictionary 4 based on the detected result of the above mentioned compressibility detecting means 5, or the above mentioned compressibility detecting means 5 and the above mentioned dictionary capacity detecting means 12. And also, a data restoring device 7 which decodes the compressed data 3 to restored data 9 while preparing a dictionary 8 which is the same with the dictionary 4 of the data compressor 1, is constituted of a compressibility detecting means 10 which detects the compressibility, dictionary capacity detecting means 13, and registration erasing means 11 which erases the registered content of the dictionary based on the detected result of the above mentioned compressibility detecting means 10, or the compressibility detecting means 10 and the dictionary capacity detecting means 13. |
