Multimedia overlay system for graphics and video
US5696527A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 1994 |
| Grant date | Dec 9, 1997 |
| Priority date | — |
| Expiry date | Dec 12, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2340/12
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In the preferred embodiment, the RGB analog signals generated by a VGA card in a personal computer are applied to a first input of an analog multiplexer. The digital video data stored in a video memory buffer on a video card is converted to RGB analog signals using a D/A converter, and these analog signals are applied to a second input of the analog multiplexer. An analog comparator compares a preselected color key to the analog output of the VGA card. When there is a match, the analog comparator controls the multiplexer to pass the analog video data to the monitor for display. When the color key is not detected, the data from the VGA card is transmitted to the monitor for display. Other features for improving the video overlay precision and the quality of the displayed image are also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.