EnigmA Amiga Run 1997 July/EnigmA AMIGA RUN 20 (1997)(G.R. Edizioni)(IT)[!][issue 1997-07 & 08][EAR-CD IV].iso/lightwave/lwmlist/95.lightwave-10/001383_owner-lightwav…mail.webcom.com_Tue Oct 24 21:06:26 1995.msg

Internet Message Format | 1995-11-07 | 3KB

Received: by mail.webcom.com
    (1.37.109.15/16.2) id AA013103985; Tue, 24 Oct 1995 21:06:26 -0700
Return-Path: <[e-mail]>
Received: from access4.digex.net by mail.webcom.com with ESMTP
    (1.37.109.15/16.2) id AA012953979; Tue, 24 Oct 1995 21:06:19 -0700
Received: (from erniew@localhost) by access4.digex.net (8.6.12/8.6.12) id XAA08326 ; for ; Tue, 24 Oct 1995 23:59:22 -0400
Date: Tue, 24 Oct 1995 23:59:21 -0400 (EDT)
From: Ernie Wright <[e-mail]>
To: [e-mail]
Subject: Re: Color Matching
In-Reply-To: <[e-mail]>
Message-Id: <[e-mail]>
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Sender: [e-mail]
Precedence: bulk

David Warner wrote:

> Your best bet is to just lower the RGB color values for your surfaces
> to something that will stay within the "legal" NTSC ranges...keeping
> the RGB sliders below 200 is a real good start, but you have to also
> be careful not to have more than 100% total surface values between
> Luminosity, Diffusity, Specularity, and Reflection.

It's never been clear to me how to tell what happens *in the encoder*
when RGB is converted to NTSC.  Some hardware is obviously doing its own
color gamut correction, because you can feed it fully saturated yellow
and cyan (which in theory should both translate to a luminance IRE level
around 131) and still get legal NTSC.  In fact, I've found that images
"NTSC-filtered" in software usually look much worse than the unfiltered
versions, and for this reason I've never worried about rendering images
that are too hot for NTSC.

Can somebody enlighten me a little more on this subject?  Has anyone
ever actually seen, for example, a bright lens flare that clips when
moved to video?  Is it possible to create an IFF that the Toaster can't
display?

And if color gamut correction is happening in your hardware, is it a
black box?  There's more than one way to do this, and if you don't know
how it's being done, is there any rational approach to even approximately
color matching RGB and NTSC displays?  And is this a problem?

- Ernie

--
Ernie Wright <[e-mail]> sent this message.
To Post a Message           : [e-mail]
Un/Subscription Requests To : [e-mail]
(DIGEST)                 or : [e-mail]
Administrative Items To     : [e-mail]