Method for transmitting pictures at a picture telephone transmission having limited bandwidth
US3976831A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 6, 1974 |
| Grant date | Aug 24, 1976 |
| Priority date | — |
| Expiry date | Dec 6, 1994 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/125
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention relates to a method for transmitting stationary pictures via a picture telephone transmission having limited bandwidth. Both fields of the picture are in the transmitter side divided into a number of line groups. In the first field, certain picture elements in one group are sampled and stored in a buffer memory in the transmitter and the rest of the line groups in the field are scanned without the sampling of further elements. After that, the second field is scanned in similar manner. The transmission of the stored values of the sampled elements are transmitted with a rate determined by the bandwidth of the transmission media and during the time when the rest of the line groups in the field are scanned.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.