W3C home > Mailing lists > Public > www-style@w3.org > December 1997

Re: Cascading Style Sheets

From: Chris Lilley <Chris.Lilley@sophia.inria.fr>
Date: Mon, 1 Dec 1997 22:09:30 +0100 (MET)
Message-Id: <9712012209.ZM13465@grommit.inria.fr>
To: Space Cowboy <spacecow@mis.net>, Chris Lilley <Chris.Lilley@sophia.inria.fr>
Cc: www-style@w3.org
On Dec 1,  4:01pm, Space Cowboy wrote:

> Chris Lilley wrote:
> > whose screen? Do you have the same make of monitor I do?
>
> Both of our monitors are constrained by the limitations of CRTs (of course,
Neil
> was right, I didn't think of plasma or LCD screens that can display more
> colors). At the least, you can display from 0-255 red [...]

Those aren't colors. You can't measure them, in the absence of a particular
monitor. And my monitor, given a particular set of drive voltages, will
display a different color from yours with the same input.

> and I'm not going to try to fix your gamma and color curve for you. That's
> something we are always going to have to deal with.

CSS1 already deals with it.

> > Certainly CSS is good for screen layout, and certainly CSS2 adds some
> > features that are needed for printing. Go look at the CSS2 spec, the ack
>
> That's a conversion. It's not a straight line either way.

Pardon?

> > Not at all. Adding colors that some screens can display while others
> > can't is fine, particularly if your monitor has a wider gamut than the
> > next guys. And, it isn't a screen standard. If a company logo happens
> > to contain colors that can't be represented on a particular screen, it
> > still makes sense to be able to say what the color should be - and you
> > may get a closer match when you print.
>
> I stand corrected. I guess we should go all out and do the L*A*B if where
trying
> to get the color match, eh?

No, sRGB as currently specified will do just as well and can be unambiguously
converted to LAB if required.

> > You do *not* want to have CMYK specifications in stylesheets, unless your
> > stylesheet is targetted at a particular make and model of printer with a
> > particular ink set printing on a particular weight and finish of paper.
>
> That's still a chance you have to take. I could have a dusty, ten-year-old
> monitor with a C:\> burnt into the top-left corner, and a 3-shade gamut.

Yes you could.

>  It's the same parable.

No, not at all. Conversion from one RGB space to another is fairly simple,
to a reasonable degree of accuracy. Conversion of one CMYK separation to
another is real hard and printers vary a whole heap more than monitors do.

> Of course, printers are notorious about that, but I think that
> most drivers try to compesate now

Uh ... no. Not really. Conversion to CMYK from an additive color space
is still non trivial (check how long any real-world color separation
program takes to do a single image). Conversion from CMYK to CMYK is
definitely not something that a driver is going to do.


-- 
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, 1 December 1997 16:09:51 GMT

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