Arithmetic coding data compression/de-compression by selectively employed, diverse arithmetic coding encoders and decoders
US4891643A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 15, 1986 |
| Grant date | Jan 2, 1990 |
| Priority date | — |
| Expiry date | Sep 15, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T9/005
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A data compression/de-compression system includes a first arithmetic coding encoder, characterized by a first set of encoding conventions, which encoder generates a code stream that points to an interval along a number line in response to decision event inputs. The code stream can be adjusted to point to the same interval as code streams generated by one or more other arithmetic coding encoders characterized by encoding conventions differing in some way from those in the first set. In a binary context, optimal hardware encoders increment or decrement the value of the code stream in response to each occurrence of a more probable decision event while optimal software so changes the code stream value for each occurrence of a less likely event. According to the invention, the code streams for optimal hardware encoders and optimal software encoders are made either identical or compatible to enable similar decoding for each. Identical or compatible code streams are obtained from encoders having different event sequence or symbol ordering along intervals on the number line. Moreover, various hardware and software decoders--with respective symbol ordering and other conventions--can be used…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.