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Re: [css3-background] Where we are with Blur value discussion

From: Aryeh Gregor <Simetrical+w3c@gmail.com>
Date: Thu, 15 Jul 2010 17:10:19 -0400
Message-ID: <AANLkTimSOBPeIsfsGZT7qzol_11c-xWf7l4WOTN2vFS4@mail.gmail.com>
To: Sylvain Galineau <sylvaing@microsoft.com>
Cc: "Tab Atkins Jr." <jackalmage@gmail.com>, "L. David Baron" <dbaron@dbaron.org>, Brad Kemper <brad.kemper@gmail.com>, Simon Fraser <smfr@me.com>, Brendan Kenny <bckenny@gmail.com>, www-style list <www-style@w3.org>
On Wed, Jul 14, 2010 at 6:01 PM, Sylvain Galineau
<sylvaing@microsoft.com> wrote:
>> From: www-style-request@w3.org [mailto:www-style-request@w3.org] On
>> Opera displays it correctly, pixel-for-pixel.
> OK, I'll ask the dumb question: how did you determine that was the case ?

Okay, I didn't mean it was *exactly* correct -- I didn't check the RGB
values of the pixels against a real Gaussian blur.  I meant that it
looks indistinguishable to me from a correct result when I superimpose
the images and flip between them.  I concluded this because:

1) Opera 10.60's canvas rendering of this case looks identical to
IE9PP3 and Safari 5/Windows.  Chrome and Firefox both display
differently from the other three and each other.  Either Opera and IE
both reverse-engineered Safari, or they're all just following the

2) Opera 10.60's canvas rendering looks identical to its SVG
rendering, as it's supposed to.  This SVG rendering, in turn, looks
identical to Chrome's and Firefox's SVG renderings.  Either everyone
is reverse-engineering everyone else here too, and they happened to
get the same result in this case as well, or they're all just
following the spec.

3) Philip Taylor wrote a test using an actual Gaussian blur:
 Opera passes (again, superimposing the expected/actual and flipping
back and forth).  This is pretty definitive.
Received on Thursday, 15 July 2010 21:10:56 UTC

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