Circuit for selecting frames indicative of still pictures
US4009330A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 5, 1976 |
| Grant date | Feb 22, 1977 |
| Priority date | — |
| Expiry date | Apr 5, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/507
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Apparatus is disclosed for selecting video frames indicative of still pictures from successive video frames, a portion of which are indicative of moving objects and the remaining frames are indicative of still objects. The input and output video signal paths of a frame memory are completed through switches. A speed measurement circuit utilizes the signals at the input and output of the frame memory as the video signal is applied thereto to identify frames indicative of still objects. A logic circuit that operates the switches responds to the output of the speed measurement circuit by changing the position of the switches to retain the content of the frame memory and apply same to the output signal path. Timing circuits are also advantageously utilized to slow down the selection rate of frames indicative of still objects and force the selection of a more recent video frame when the speed of movement fails to fall below a predetermined value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.