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From: karl@sugar.UUCP (Karl Lehenbauer)
Newsgroups: comp.graphics
Subject: Broadcast Digital Video Effects
Message-ID: <222@sugar.UUCP>
Date: Thu, 25-Jun-87 20:22:00 EDT
Article-I.D.: sugar.222
Posted: Thu Jun 25 20:22:00 1987
Date-Received: Sat, 4-Jul-87 22:27:51 EDT
Organization: Sugar Land UNIX - Houston, TX
Lines: 26
Keywords: chroma key  chromakey

(...had trouble posting this as a followup, sorry.)
In article <2026@cbmvax.cbmvax.cbm.UUCP>, hedley@cbmvax.cbm.UUCP (Hedley Davis) writes:
> In article <1171@osiris.UUCP> phil@osiris.UUCP (Philip Kos) writes:
> >Question for all you serious broadcast people out there: I imagine the
> >original chroma key hardware was analog.  Is it still done that way, or is
> >it done digitally now?  ...
> ...
> I've heard of full digital units which do digitize the incoming video.

All of the big video switchers have, since about 1979, digitized video as part
of their processing.  The ability to squeeze a full screen image into a smaller
area in a TV picture without cropping or camera tricks requires (I believe) such
a unit.  These units can do all sorts of mapping of TV images onto (apparent)
3D surfaces, "digital strobing" (a sort of video echoing), "pixilazation"
(averaging blocks of pixels to reduce the apparent number of pixels) and many
other things.

Specifically regarding how chroma keying is done now, analog is still the norm
for most places, but the ultimate chroma keyer is called UltiMatte (TM).  It's
digital and smart, so its keys don't leave those annoying edges around the
weatherman and glitches in his hair when he's in front of the blue screen.  The
Cars video "You Might Think" and the California Cooler commercials use extensive
digital video effects and are a good example of how "clean" the images generated
by these units are.
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