Coding method of image information
US5059976A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 1990 |
| Grant date | Oct 22, 1991 |
| Priority date | — |
| Expiry date | Jan 25, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M7/4006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A coding method of a binary Markov information source comprises the steps of providing a range on a number line from 0 to 1 which corresponds to an output symbol sequence from the information source, and performing data compression by binary expressing the position information on the number line corresponding to the output symbol sequence. The present method further includes the steps of providing a normalization number line to keep a desired calculation accuracy by expanding a range of the number line which includes a mapping range, by means of a multiple of a power of 2, when the mapping range becomes below 0.5 of the range of the number line; allocating a predetermined mapping range on the normalization number line for less probable symbols LPS proportional to its normal occurrence probability; allocating the remaining mapping range on the normalization number line for more probable symbols MPS; and reassigning the predetermined mapping range to the remaining mapping range the half of a portion where the allocated remaining range is less than 0.5, when the allocated remaining range becomes below 0.5.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.