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Re: Re: CIE color definitions in CSS3 color module

From: <alexis.shaw@gmail.com>
Date: Wed, 29 Sep 2010 21:10:30 +0000
Message-ID: <0016364175e12eb80204916c64c7@google.com>
To: Chris Lilley <chris@w3.org>, Alexis Shaw <alexis.shaw@gmail.com>
Cc: www-style@w3.org
That was I think the general consensus for the bulk of this discussion,
This requires a lot of work to get out the nuts and bolts, and I think that
it may require a De-coupling of the actual color and the requested color,
and that if possible that color blending be able to be done in Lab.
That or the ability to specify the bounding volume of the gamut that
is being displayed upon. or both. Neither of these can come in the short  
needed for CSS3 color.
So yes, Not in CSS3 color, but working for inclusion in CSS4 color.


Alexis Shaw.

On , Chris Lilley <chris@w3.org> wrote:
> Hi Alexis.

> I'm one of the editors of the CSS3 Color module, and am just back today  
> from two weeks vacation. I see that you made a comment while I was away -  
> it is being tracked as last call comment 31.

> On Friday, September 10, 2010, 4:29:21 PM, Alexis wrote:

> AS> I wish to propose the following types of color definitions.

> In general I am sympathetic with (and understand) the desire to be able  
> to specify colour in a CIE colour space.

> However, the current state of CSS3 color is that is stable, has been  
> around for years, finally has a test suite and passing implementations,  
> and is therefore ready to become a Proposed Recommendation very soon.  
> Indeed ,there was functionality about ICC profiles for images, which was  
> dropped for lack of implementations (in browsers, using that syntax).

> We don't, therefore, want to be adding new and unimplemented (in  
> browsers, using a CSS syntax) features at this stage.

> Your comments are certainly worthy of consideration and further  
> discussion, but would more appropriately fit with the proposed CSS4 color  
> module.

> In particular, being able to specify values in CIE Lab (together with the  
> appropriate white point) would be very handy.

> I see that in further discussion, Tab pointed out that this would also  
> require control over the interpolation colourspace as well.

> So we would like to reject your comment, as being too late for CSS3, and  
> instead consider it for a future specification. Would that be acceptable  
> for you?

> AS> A CIE XYZ color definition.

> AS> xyz(x, y, z) where x, y and z are the floating point values of the  
> CIE 1931 XYZ color space

> AS>

> AS> along with the corresponding

> AS> xyza(x, y, z, a)

> AS> A CIE xyY color definition.

> AS>

> AS> xyy(x, y, Y) where x, y, and Y are the floating point values of the  
> CIE 1931 xyY color space.

> AS>

> AS> along with a corresponding

> AS> xyya(x, y, Y, a)

> AS>

> AS> a CIELUV color definition

> AS>

> AS> luv(L*, u*, v*, white_point) where L, u, v are the floating point

> AS> values in the CIELUV colorspace. the white point term will be defined  
> below.

> AS>

> AS> along with the

> AS> luva(L*, u*, v*, white_point, a)

> AS>

> AS> A CIELAB color definition

> AS> lab(L*, a* , b*, white_point) where L*, a*, b* are the floating

> AS> point values in the CIELAB colorspace, white point defined below.

> AS>

> AS> The LAB and LUV colorspaces take a white point as a parameter

> AS> this may be one of the following values.

> AS> One of the CIE standard illuminates

> AS> A, B, C, D50, D55, D65, D75, F1-12,

> AS>

> AS> the following common illuminants

> AS> UL_3000, TL80, A_T8

> AS> the following black body format.

> AS> xxxxxK

> AS> or a custom white point defined by an @whitepoint rule.

> AS>

> AS>

> --

> Chris Lilley Technical Director, Interaction Domain

> W3C Graphics Activity Lead, Fonts Activity Lead

> Co-Chair, W3C Hypertext CG

> Member, CSS, WebFonts, SVG Working Groups
Received on Wednesday, 29 September 2010 21:18:51 UTC

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