High speed CCITT decompressor
US5229863A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 24, 1990 |
| Grant date | Jul 20, 1993 |
| Priority date | — |
| Expiry date | Dec 24, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4175
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A new and improved decoder for decoding CCITT compressed image data. This decoder separates all the incoming codes into short codes and long codes. The short codes are sent to the short channel decoder and the long codes are sent to the long channel decoder. At each decoding cycle either the long channel decoder or the short channel decoder is active. The short channel decoder has a twin set decoder which decodes two short codes in parallel and guarantees two bits of decompressed data per decoding cycle. If the decoding of a first code generates a decompressed data of only one bit, then the decompressed data of a second code will be combined with the first decompressed data and the combination will be sent out. This process guarantees at least two bits of decompressed data per decoding cycle. The long channel decoder decodes the long intermediate codes which always generate at least four bits of decompressed data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.