| 摘要 |
A data compression and decompression system based on the LZW data compressio n and decompression methodology that includes exclusion tables for storing strings that are infrequently encountered. If an extended string formed for updating the compressor and decompressor dictionaries is included in the exclusion tables, the extended string is not stored and the code counter for assigning codes to dictionary strings is not advanced. In this manner, dictionary codes are not usurped by infrequently encountered strings. The exclusion tables are dynamically modified in accordance with the input data by deleting strings from the exclusion tables that are frequently encountered therein and by adding infrequently encountered strings to the exclusion tabl es.
|
