Method for encoding and decoding a digital image
US4888645A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 1987 |
| Grant date | Dec 19, 1989 |
| Priority date | — |
| Expiry date | Oct 21, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T9/005
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for encoding and decoding digital image data, includes the steps of: testing the data for a vertical relationship between adjacent lines of the image; generating directly a reference code word representative of the vertical relationship for each successful test; generating by table lookup a run code word for a stream of data bits of common value for each unsuccessful test whereby a data element representing a number of bits in a code word is stored at a predetermined offset from a table entry for the code word; merging the vertical reference code words and the run code words generated by the above steps to form an encoded data stream; testing the encoded data stream for a reference code; decoding directly the vertical relationship from the reference code for each successful test; decoding by table lookup a run of bits of common value by serial examination of said encoded data stream for each unsuccessful test; and storing data decoded by the above steps in a predetermined relationship. A fast algorithm for modifying an image in run representation form before encoding or after decoding is also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.