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Re: [css3-images] Gradients feedback

From: L. David Baron <dbaron@dbaron.org>
Date: Mon, 6 Sep 2010 08:29:21 -0700
To: Alan Gresley <alan@css-class.com>
Cc: Boris Zbarsky <bzbarsky@MIT.EDU>, www-style list <www-style@w3.org>
Message-ID: <20100906152921.GA11852@pickering.dbaron.org>
On Monday 2010-09-06 22:37 +1000, Alan Gresley wrote:
> I highly object to this. Gradient interpolation must be performed in
> non-premultiplied space. Some major reason are:
> 
> 1. Gradients are not another vector in sRGB space (not sure how
> matrix works).
> 
> 2. This affects all colors in sRGB space that become have a gradient
> to transparent. There is precise maths.

I don't understand either of these reasons.  Could you explain them
more clearly?

Computing gradients in premultiplied space makes gradients to
transparent work much better.  In non-premultiplied space they all
look black-ish in the middle.

> If premultiplied space gradients are allowed, this must be by an
> added keyword. This is because a bell shape arc must be trace along
> a vector.

I don't know what you're talking about.  Could you explain?

-David

-- 
L. David Baron                                 http://dbaron.org/
Mozilla Corporation                       http://www.mozilla.com/
Received on Monday, 6 September 2010 15:29:52 GMT

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