发明授权
- 专利标题: Multimedia overlay system for graphics and video
- 专利标题(中): 用于图形和视频的多媒体覆盖系统
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申请号: US354187申请日: 1994-12-12
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公开(公告)号: US5696527A公开(公告)日: 1997-12-09
- 发明人: Sherman T. King , Tommy C. Lee , Niantsu Wang , Yen-Fah Chu , Scott A. Kimura , Guorjuh T. Hwang
- 申请人: Sherman T. King , Tommy C. Lee , Niantsu Wang , Yen-Fah Chu , Scott A. Kimura , Guorjuh T. Hwang
- 申请人地址: CA Fremont
- 专利权人: AurVision Corporation
- 当前专利权人: AurVision Corporation
- 当前专利权人地址: CA Fremont
- 主分类号: G09G5/14
- IPC分类号: G09G5/14 ; G09G5/395 ; H04N9/75 ; G09G5/00
摘要:
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.