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Re: [css3-color] ICC implementation

From: Bert Bos <bert@w3.org>
Date: Thu, 10 Jul 2008 14:50:54 +0200
To: www-style@w3.org
Message-Id: <200807101450.55432.bert@w3.org>

On Wednesday 09 July 2008 05:26, Chris Murphy wrote:
> Hi list,
>
> I've just learned of some changes basically pulling planned ICC
> profile and rendering intent support for CSS3. Considering the recent
> work and achievement with Firefox and Safari web browsers in this
> regard, I find this a disappointing.
>
> Considering that:
>
> 1. display technologies are diverging from sRGB, in the high-end
> photo use where gamuts are substantially exceeding that of sRGB, and
> in the laptop arena which has exploded in numbers where gamuts are
> not only smaller than sRGB but have variably shaped gamuts; and
>
> 2. that CSS3 has been in the works for almost a decade and will
> likely be around for a very long time as CSS2 has been and will
> continue to be around for a long time;
>
> I think the w3c needs to join the 21st century in recognizing the
> inherent issues with respect to content creation and display on
> myriad devices and display technologies, instead of looking backwards
> (i.e. section 3.1.1 on gamma correction).

You're preaching to the choir. Device-independence was already a goal of 
W3C (and of CSS) when most people still thought that "Web" was another 
word for "Mosaic." But W3C also has another goal: making standards that 
work in practice.

There were demands for reliable color rendering already back in 1996 
(from online shops, e.g.) and the authors of CSS tried to convince 
implementers to support color profiles even then. But the implementers 
(which basically meant Netscape, in those days) decided it was too 
difficult and wouldn't bring them any money. We made them promise, as a 
compromise, to at least compensate the gamma on different platforms, 
but in the end they didn't keep their promise. (IE on Mac may have done 
it, but I think that was the only one.)

We did manage to reach consensus on sRGB (basically because it required 
no implementation effort on most platforms). At the time, we had to 
work off early drafts of sRGB that people gave us, and we had trouble 
finding anything to put in the bibliography section of CSS, but it 
turned out the right thing to do.

We have made some progress since then, however. SVG includes color 
profiles with rendering intent and although we again failed to put 
color profiles in CSS, they are at least mentioned now. (And you can 
include SVG from within CSS.)

Note that sRGB is not a gamut for CSS. CSS only uses it as a "coordinate 
system" for colors. CSS can specify every color; it is the device that 
CSS is rendered on that has a gamut. However, because of the way sRGB 
is defined, some colors may require unintuitive notations, such as 
negative numbers: rgb(0, 0, -0.1), or numbers greater than 1: rgb(0, 0, 
1.1).

The reason color profiles are not in CSS is not that they are a bad 
idea, the reason is that there too many other good ideas competing for 
limited resources. It makes no sense (and the W3C process even forbids) 
to standardize a feature that has not been implemented. To get color 
profiles into CSS requires either making an implementation yourself, or 
convincing others who make implementations that this has higher 
priority than, say, columns, page numbers, vertical text, drop shadows, 
downloadable fonts, hyphenation, leaders, transition effects, resizing 
backgrounds, attribute selectors, Greek list counters, grid layout or 
vh/vw units...



Bert
-- 
  Bert Bos                                ( W 3 C ) http://www.w3.org/
  http://www.w3.org/people/bos                               W3C/ERCIM
  bert@w3.org                             2004 Rt des Lucioles / BP 93
  +33 (0)4 92 38 76 92            06902 Sophia Antipolis Cedex, France
Received on Thursday, 10 July 2008 12:56:02 GMT

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