Video editing systems with allowable range for key signal set by detecting the range in a selected area
US4667221A · kind A · utility
33Cited by
8References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 5, 1985 |
| Grant date | May 19, 1987 |
| Priority date | — |
| Expiry date | Jul 5, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/75
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system for combining two or more video signal inputs using a chrome key like system. The keying is not done to one color, such as saturated blue, but to any color within a range. One of the video signal inputs (1) is frozen and appears as a still picture on a display (6). Graphic means (16) are used to define an area of the picture and the maximum and minimum values of the color components of the signals in that area are detected. Whenever a signal with components falling within the detected range is present in a switch (14) it operates to select a channel for output. This works to build up a composite picture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.