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Re: Need to add <feColorRamp> to SVG [ISSUE-2380]

From: Doug Schepers <schepers@w3.org>
Date: Tue, 05 Oct 2010 20:37:37 -0400
Message-ID: <4CABC4D1.3000502@w3.org>
To: kitfox@golden.net
CC: www-svg@w3.org
Hi, Mark-

Thanks for the proposal; this is the right place for proposals like this.

We discussed this briefly during our SVG Working Group telcon, and will 
discuss it more in depth in the context of the filters module and SVG2. 
  I have raised this as issue-2380 in our issue tracker:
   http://www.w3.org/Graphics/SVG/WG/track/issues/2380

Right now, our plate is full, but we will probably pick this up more 
seriously in a couple of months. We'll want to talk with you further 
about it at that time, but in the meantime, we're interested in hearing 
feedback from you and others on this topic on this mailing list.

Regards-
-Doug Schepers
W3C Team Contact, SVG and WebApps WGs

kitfox@golden.net wrote (on 10/5/10 9:30 AM):
> I'd like to propose adding an<feColorRamp>  filter element to SVG.  This
> is  a simple filter that takes selects a channel from an input image and
> uses the intensity of a particular pixel to lookup a color value in a
> gradient.
>
> Reasons:
>
> At the moment, the SVG filtering system provides ways to perturb images in
> their domain (feDisplacementMap), but has only limited ability to remap
> their range (feColorMatrix is probably the best existing option).  To use
> fractal noise and turbulence to produce natural effects such as fire,
> clouds, marble or wood, the intensity of the noise needs to be mapped to a
> color ramp (gradient).  (See Ken Perlin's 'Making Noise'
> http://www.noisemachine.com/talk1/)
>
> Proposal:
>
> A new filter element should be added to svg called<feColorRamp>.  It
> would have the following attributes:
>
> in: "SourceGraphic | SourceAlpha | BackgroundImage | BackgroundAlpha  |
> FillPaint | StrokePaint |<filter-primitive-reference>"
> 	- Choose input image
>
> channelSelector: "R | G | B | A"
> 	- Determines channel of input image that is remapped
>
> ramp:<gradient>
> 	- The gradient that is used for remapping intensity values in the input
> channel
>
>
> Please let me know if you think this is a good idea, and where I should
> submit this proposal if this list is not the best place.
>
>
> Mark McKay
>
Received on Wednesday, 6 October 2010 00:37:40 GMT

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