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- From: fitzhugh@hplred.HP.COM (Andrew Fitzhugh)
- Date: Wed, 29 Jul 1992 23:01:56 GMT
- Subject: Re: Convert 4:1:1 YUV data to RGB
- Message-ID: <116780001@hplred.HP.COM>
- Organization: Hewlett Packard Labs, Palo Alto CA
- Path: sparky!uunet!usc!sdd.hp.com!hpscdc!hplextra!hplred!fitzhugh
- Newsgroups: comp.multimedia
- References: <1992Jul23.211649.28491@cs.cornell.edu>
- Lines: 40
-
- / hplred:comp.multimedia / pej@hpfcso.FC.HP.COM (Phil Jensen) / 6:04 am Jul 27, 1992 /
- > In comp.multimedia, soam@freyja.cs.cornell.edu (Soam Acharya) writes:
- > > Can anyone point me towards a reference that explains how to convert
- > > 4:1:1 subsampled YUV data to RGB?
- > >
- >
- > Call your local Signetics Rep and ask for the Phillips Video Data Handbook.
- > This contains specs on the parts that are on your board. Look at the SAA7192
- > Digital Colour Space Converter. This is a YUV to RGB converter. Included are
- > equations for the YUV to RGB conversion.
-
- Actually, the Signetics book gives the equations for YCbCr (normalized
- YUV, so they're essentially the same). I just happened to be typing
- in these numbers so I can save you some time:
-
- |R| | 1.000 0.000 1.000 | |Y|
- |G| = | 1.000 -0.186 -0.508 | |U|
- |B| | 1.000 1.000 0.000 | |V|
-
- |Y| | 0.299 0.587 0.114 | |R|
- |U| = |-0.299 -0.587 0.866 | |G|
- |V| | 0.701 -0.587 -0.114 | |B|
-
- And if you want to use YCbCr,
-
- |Y | | Y |
- |Cb| = | 0.564 * U |
- |Cr| | 0.713 * V |
-
- Benson's "Television Engineering Handbook" (ISBN 0-07-004779-0),
- though poorly organized and containing plenty of typos, contains all
- kinds of stuff like this. It's a better general reference than the
- Sig. data book, but it's far from free (~$100, I think).
-
- Andrew Fitzhugh
- Computational Color Reproduction
- HP Laboratories
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