simple genlock query??
2 messages in this thread
Here is an elementary video question: what is required to mix a video
source (a foreground scene with a single color flat background) and
computer generated graphics? The idea is to replace the flat background
with the graphics. I assume this can be done with a SuperGen and some
software, or with the Toaster. Is it simple? Does one method have great
advantages over the other? TIA,
David
David,
What you are describing is "keying". It gets confusing because what we all
call genlocks are really keyers that also genlock TO THE AMIGA. Got that?
🙂 Keying is replacing one color with another source and genlocking is
matching timing.
The toaster does a creditable job of luminance keying. That means it can
work with a black or a white solid background. Lumi Keying is more
dificult to work with because it is based solely on the level of light or
brightness. What it means in practical terms is that it is hard to
separate the shadows/hotspots on your subject from the color of the
background that is being replaced.
Chroma keying works with the color part of the signal and is therefore more
predictable. Lighting is still very important, but it is possible to pick
a background color that is not normally present in your subject. Typically
a garish blue or sometimes green screen is used.
The toaster does luminace keying and not chroma keying.
There are a few chroma keys available – check the mags for reviews.
Generally you get what you pay for.
Good Luck
patrick