Keyed, true-transparency image information combine
US5214512A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 11, 1991 |
| Grant date | May 25, 1993 |
| Priority date | — |
| Expiry date | Feb 11, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/275
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A keyed, true-transparency combine and keyer receive prioritized image information signals and their corresponding input key signals. On the one hand, others have changed the order of the channels carrying the image signals as the priority of the image signals changes. On the other hand, here we interchange the order of a plurality of substantially identical keyer units within a keyer as the priority of the image signals changes. In interchanging the keyer units, true transparency processed key signals are also generated. In so doing that, the i-th keyer unit modifies the value of its input key signal Bk.sub.i using values of input key signals from higher priority channels. Thereby a true transparency processed key signal Pk.sub.i is generated for the i-th priority channel. In one embodiment, a key-taken signal is generated by multiplying a key-requested signal and a key-available signal while a key-now-available signal is generated by subtracting the key-taken signal from the key-available signal. In another embodiment, a key-taken signal is generated by subtracting a key-now-available signal from a key-available signal while a key-now-available signal is generated by multiplying …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.