Technique for decoding variable length data codes
US6385341B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 17, 1997 |
| Grant date | May 7, 2002 |
| Priority date | — |
| Expiry date | Apr 17, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T9/005
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system for the efficient decoding of data encoded with variable length codes uses an N-bit buffer as an index to a data look-up table or other suitable data structure. The encoded data is stored in an encoded data storage area and extracted N bits at a time. The N bits are used as an index or indicator to a location within the data look-up table. The contents of the data look-up table in the indicated location correspond to one or more decoded tokens and also provide an indication of the number of data bits from the N-bit buffer that were used to represent the decoded tokens. A pointer is incremented by the number and indicates a location within the encoded data storage area where the next N bits will be extracted and stored in the buffer. If the N-bit buffer is greater than or equal to the maximal length for the variable codes, at least one valid token is guaranteed as a result of a single data look-up operation. However, a data look-up operation typically results in a plurality of decoded tokens. In one embodiment, the decoding system is used for facsimile operation and may include additional data in the data look-up table to permit rapid decoding of two dimensional facsimile c…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.