Method and a device for image coding
US5452103A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 21, 1992 |
| Grant date | Sep 19, 1995 |
| Priority date | — |
| Expiry date | Oct 21, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/146
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention relates to a method and a device for image coding having a particular, but not necessarily an exclusive, application in the transmission of video signals. The video signal is converted to a bit stream by coding and quantising and stored in a buffer store before it is transmitted on a transmission line at a constant bit rate. Problems experienced with the known technology have been the prevention of overflow in the buffer store and the buffer store being emptied prematurely. Both of these problems give rise to a deterioration in image quality. At the same time, the content of the buffer store should be as small as possible. According to the invention, not all the frames are coded and transmitted, but a certain number (k) of frames are skipped between each coded frame. The number k is based on the transmission rate R, the frame rate fo of the video signal and minimum value (bR/fo) set for the content of the buffer store. The number of skipped frames is selected so that the buffer store is not emptied below the set lower limit before the next frame is coded. The buffer store content is also regulated by skipping or setting to zero certain components in the bit stream fro…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.