Video Difference key generator
US4800432A · kind A · utility
87Cited by
5References
5Claims
0Family size
Assignee
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Key dates
| Filing date | Oct 24, 1986 |
| Grant date | Jan 24, 1989 |
| Priority date | — |
| Expiry date | Oct 24, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/75
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A video difference key generator has a stored reference video image. An input video image is compared with the reference video image by an absolute difference circuit which substracts corresponding pixels of the two video images, the smaller from the larger, to produce a difference video image. The difference video image may be filtered, and then is input to a transfer function circuit to produce an output which may be used as a key signal for compositing video images.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.