Method of and apparatus for compressing and restoring data
US6061398A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 14, 1996 |
| Grant date | May 9, 2000 |
| Priority date | — |
| Expiry date | Nov 14, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T9/005
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A data compression apparatus is capable of compressing data at a high compression rate and at a high speed. A data decompression apparatus is used in combination with this data compression apparatus to decode the compressed data. The data compression apparatus includes a RAM which stores Huffman code trees each of which corresponds to a character string, i.e. "context." A CPU encodes each character which is to be encoded by use of a Huffman code tree corresponding to the context at that time. Each time a character is encoded, the Huffman code tree used is reconstructed so as to account for the encoded character. The data decompression apparatus stores Huffman code trees corresponding to contexts respectively, decodes the code to be decoded by use of a Huffman code tree corresponding to the context (a character string previously decoded). Each time one character is decoded, the Huffman code tree used for decoding is reconstructed so as to account for the decoded character.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.