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Re: CIE color definitions in CSS3 color module

From: Alexis Shaw <alexis.shaw@gmail.com>
Date: Sat, 18 Sep 2010 08:21:46 +1000
Message-ID: <AANLkTikDtouKJxsS4oYodXPEXN+aVz-rJegWzXYNSb1s@mail.gmail.com>
To: "Tab Atkins Jr." <jackalmage@gmail.com>
Cc: www-style@w3.org
there are two use cases for these colors that I know of:
They render the need for a complete color profile embedding system
unnecessary,
L*a*b* and L*u*v* are often used in programmatic color selection so that if
you want a
color that is perceptional between two others these color space make it very
easy to do that.
As such they are often used in computer graphics. It means that any color
that the browser
can display can be displayed. In combination with custom color names, it
will allow one to
use exact pantone, munssel and other named color spaces accurately in the
browser.
The xyY color space is often used to show colorspaces, using these spaces
would allow
one to easily make such diagrams programatically in canvas. All in all it
would just allow
one to be more accurate about color in the browser. L*a*b** *would be very
useful in transitions
as a transition between colors in L*a*b* space appears to be linear (once
here should be used)

On 18 September 2010 03:19, Tab Atkins Jr. <jackalmage@gmail.com> wrote:

> On Fri, Sep 10, 2010 at 7:29 AM, Alexis Shaw <alexis.shaw@gmail.com>
> wrote:
> > I wish to propose the following types of color definitions.
> > A CIE XYZ color definition.
> > xyz(x, y, z) where x, y and z are the floating point values of the CIE
> 1931
> > XYZ color space
> > along with the corresponding
> > xyza(x, y, z, a)
> > A CIE xyY color definition.
> > xyy(x, y, Y) where x, y, and Y are the floating point values of the CIE
> 1931
> > xyY color space.
> > along with a corresponding
> > xyya(x, y, Y, a)
> > a CIELUV color definition
> > luv(L*, u*, v*, white_point) where L, u, v are the floating point values
> in
> > the CIELUV colorspace. the white point term will be defined below.
> > along with the
> > luva(L*, u*, v*, white_point, a)
> > A CIELAB color definition
> > lab(L*, a* , b*, white_point) where L*, a*, b* are the floating point
> values
> > in the CIELAB colorspace, white point defined below.
> > The LAB and LUV colorspaces take a white point as a parameter this may be
> > one of the following values.
> > One of the CIE standard illuminates
> > A, B, C, D50, D55, D65, D75, F1-12,
> > the following common illuminants
> > UL_3000, TL80, A_T8
> > the following black body format.
> > xxxxxK
> > or a custom white point defined by an @whitepoint rule.
>
> Returning to the core of the issue; what's the use-case for these new
> ways of defining a color?  I know that various other color definitions
> *exist*, but I don't understand what they're used for, or if they're
> useful for the web.  Could you elaborate on this?
>
> Note, as well, that CSS generally assumes that colors exist in the
> sRGB colorspace, and defines interpolation for things like transitions
> and gradients in terms of that space.
>
> ~TJ
>
Received on Friday, 17 September 2010 22:22:20 GMT

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