- From: Chris Lilley <Chris.Lilley@sophia.inria.fr>
- Date: Mon, 25 Nov 1996 16:49:02 +0100 (MET)
- To: "David Perrell" <davidp@earthlink.net>, "Chris Lilley" <Chris.Lilley@sophia.inria.fr>, "www-style" <www-style@w3.org>
On Sep 10, 6:42am, David Perrell wrote: > Chris Lilley wrote: > > A guess - you don't use a Mac or an SGI or a NeXT to browse with. > > Right. > > > Another guess - the doument authors did. And it wasn't illegible to > > them. The difference being gamma correction, ignoring which causes > > errors of several hundred percent - especially for dark colors. > > May be. Or attempted subtlety by PC users with CRT brightness cranked > to maximum. Changing the brightness alters the slope of the transfer curve, it doesn't alter curvature. > > Note that the CSS1 specification defines what a color means, in > > terms of measurable objective color specifications, and also that > > the minimum that implementors must do to display these tightly > > specified colors is to implement reasonable gamma correction. > How does sRGB help without an opsys-level CMS or sRGB-compliant > display? Firstly, it helps by defining what the colors mean, precisely. So it then becomes a question of closeness of approach to an objective standard, rather than differeing and equally valid interpretations. Secondly, the defined gamma curve "happens" to be what a dumb PC uses anyway so no gamma correction is required for Wintel PCs. Ditto for the majority of Unix workstations and X terminals. It isn't what is used by default on a Mac and it isn't what is used by default on an SGI. But MacOS "happens" to have a CMS built in and an API to alter the lookup table; and Irix (>=6.2) also "happens" to have a CMS built in (and can display different windows with different gamma values, too). So for minimal implementation, the two platforms that need to do any processing are the two platforms that can readilly do that processing. This was not an accident. > Is there any progress in getting display hardware mfgr's to > buy into this? It seems so. Similarly for printer manufacturers. And W3C is tracking the issue of color rendering on the Web. -- Chris Lilley, W3C [ http://www.w3.org/ ] Graphics and Fonts Guy The World Wide Web Consortium http://www.w3.org/people/chris/ INRIA, Projet W3C chris@w3.org 2004 Rt des Lucioles / BP 93 +33 (0)4 93 65 79 87 06902 Sophia Antipolis Cedex, France
Received on Monday, 25 November 1996 10:49:16 UTC