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Named colors in SVG

From: Jeremias Maerki <dev@jeremias-maerki.ch>
Date: Tue, 08 Jun 2010 14:31:39 +0200
To: www-svg@w3.org
Message-Id: <20100608135940.FC9B.60BA733C@jeremias-maerki.ch>
Hi folks,

I'm looking into adding support for named colors to Apache Batik and
I've got a few observations/comments concerning the current working
draft of SVG Color 1.2 (http://www.w3.org/TR/2009/WD-SVGColor12-20091001/).

--- ICC named color profiles in general

I've just spent about 3 hours looking around on the internet, trying to
find example ICC named color profiles or some freely available tool to
create such color profiles. I haven't found anything. Does anyone have
something in this direction for me? I'm almost at the point where I have
to think about writing such a tool myself.

My main goal is to produce PDF. But like PostScript, PDF doesn't support
ICC named color profiles. You have to resort to the "Separation" color
space which requires a PostScript function which transforms the tint
value to an alternative color space (be that CMYK, RGB or CIElab).

So I'm trying to figure out the best way to implement this. In the
absence of an easy way to create and consume ICC named color profiles,
it seems easiest to define abstract URIs used on the svg:color-profile
element to define a set of named colors (defined by some means other
than an ICC profile which could be considered a hack).

In my particular case I need to support, there's no color profile. The
print service provider has defined the named color directly on the RIP
using a mixture of the 6 inks available in the printer. So I just need a
way to get the color name and an sRGB value (for the tint transform
function) into the PDF using the "Separation" color space.

--- tint support

The PDF and PostScript specifications allow for a "tint" value for
Separation colors. I was wondering if it made sense to add an optional
tint value to the icc-named-color function. The spec would then be:

<fallback> icc-named-color(<name>, <namedColor>[, tint])

Valid values for the parameter "tint" are in the range 0.0 to 1.0. The
value 0.0 represents the minimum amount of colorant that can be applied;
1.0 represents the maximum. In the absence of the tint parameter, the
initial value is 1.0.

<circle fill="#8080FF" icc-named-color(MyColors, SpecialBlue, 0.5)"/>

--- typos

BTW, there's a little typo in the existing example: the closing
paranthesis is missing.

Jeremias Maerki (not yet a color specialist)
Received on Tuesday, 8 June 2010 12:32:56 UTC

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