Probability adaptation for arithmetic coders
US5099440A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 5, 1990 |
| Grant date | Mar 24, 1992 |
| Priority date | — |
| Expiry date | Jan 5, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M7/4006
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The present invention relates to computer apparatus and methodology for adapting the value of a probability of the occurrence of a first of two binary symbols which includes (a) maintaining a count of the number k of occurrences of the first symbol; (b) maintaining a total count of the number n of occurrences of all symbols; (c) selecting confidence limits for the probability; and (d) when the probability is outside the confidence limits, effectuating a revision in the value of the probability directed toward restoring confidence in the probability value. The number of allowed probabilities is, optionally, less than the total number of possible probabilities given the probability precision. Moreover, an approximation is employed which limits the number of probabilities to which a current probability can be changed, thereby enabling the probability adaptation to be implemented as a deterministic finite state machine.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.