Video coder for color signals
US4129882A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 6, 1977 |
| Grant date | Dec 12, 1978 |
| Priority date | — |
| Expiry date | May 6, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N11/046
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The luminance and two chrominance signals generated in a color video system are all translated into pulse code modulation signals by a plurality of analog-to-digital encoders. The luminance signal is then differentially encoded into variable length digital words and applied to a buffer. The encoded differences of the luminance signal are between the values of successive picture elements along horizontal scan lines. At least one of the chrominance signals is encoded using differences between corresponding picture element values in alternate horizontal scan lines. When the differences are large, the value of the corresponding picture element of the intermediate horizontal scan line is classified. If half the difference between the large transition of alternate picture element values does not correspond to the value of the intermediate picture element, another code word indicative of both intermediate picture element and alternate picture element is used. This improves the coding accuracy of large transitions in the chrominance signal which is also applied to the buffer. The output of the buffer is then transmitted over a channel to receiver. The receiver decodes each signal component…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.