Encoded signal color image compositing
US4409611A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 24, 1981 |
| Grant date | Oct 11, 1983 |
| Priority date | — |
| Expiry date | Sep 24, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/75
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A linear color television compositing system of the "blue backing" type, in which the foreground signal channel is always open. The foreground and background channels are not switched by the edges of the pictorial subject matter. The hue of the colored (typically blue) background is removed by vector subtraction and the luminance thereof by arithmetic subtraction. Flare illumination of the foreground subject(s) from the backing is removed, improving color fidelity. The background pictorial scene that takes the place of the removed colored backing area is linearly turned up or down, allowing shadows of foreground subjects to appear in the background.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.