DPCM system with interframe motion indicator signal
US4780760A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 5, 1987 |
| Grant date | Oct 25, 1988 |
| Priority date | — |
| Expiry date | Jun 5, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/50
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A digital television transmitter has a buffer that receives a low resolution low pass filtered signal. A high resolution high pass filtered signal is applied to the buffer only when the buffer can accept it without overflowing in accordance with a threshold signal. A controller provides a control signal that varies in accordance with an interframe difference motion indicator signal and the inverse of the occupancy of the buffer. A digital television receiver receives a digital television picture signal and preferably a transmitter buffer occupancy state signal. A low resolution low pass filtered signal is applied to an adder. A high resolution high pass filtered signal is applied to the adder in accordance with the buffer state and motion indication. The transmitter and receiver are useful in video teleconferencing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.