You may want to superimpose text or graphics from SundayPlus over a live camera feed or other video source that doesn't play from SundayPlus. If you are using live video now, no doubt you have a video switcher to switch from one camera to the next. The switcher would (usually) have a feature called a keyer. A keyer is used to cut a hole (like a key hole, get it?) in one signal and to insert into that hole another signal. There are two methods to do this overlay using different aspects of the picture to do so.

Luminance Keying
Luminance Keying uses the brightness (black and white) part of the picture to cut the hole. Say in SundayPlus you had white letters on a black background. The keyer could cut out all the black parts of the picture and insert a camera shot and (voila!) text on a live background!

Chrominance Keying
Chrominance (Chroma) Keying uses the color part of the picture to cut the hole where a certain color is. This is what they use in TV and Film to superimpose things by using blue or green. Sometimes it is even referred to as blue-screen or green-screen. The weather person uses this technique on your local news when they are standing in front of the weather map. In SundayPlus you could have your text over a blue or green background and the keyer could then cut out that color and insert the camera shot.

Scan Conversion
No matter which method you use, if you are going to use the signal from SundayPlus along-side a camera or two, the computer's output will need to be converted from Data (VGA) to Video. This requires a device known as a scan converter to make the change. Scan converters are available from your local Audio/Video dealer in a wide range of quality and price.