Overlay card
From Wikipedia, the free encyclopedia
Overlay card is controller that digitizes NTSC signals from a video source for display in the computer.[1]
Overlay cards are connected between normal VGA card monitor output and computer monitor. Typically a a PCI-bus expansion card, they can also be a USB device.
Generally video conferencing software requires overlay card. If it does not require an overlay card, ordinary software would not satisfy the users in terms of image and sound quality. Overlay cards use a chroma key color, so that video shows through the chroma-key-colored object on the screen.
