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

From: Sylvain Galineau <sylvaing@microsoft.com>
Date: Thu, 15 Jul 2010 21:14:00 +0000
To: Aryeh Gregor <Simetrical+w3c@gmail.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>
Message-ID: <045A765940533D4CA4933A4A7E32597E215200EE@TK5EX14MBXC111.redmond.corp.microsoft.com>
OK so you mean that it works as you expect because you get the same result for equivalent inputs across SVG, canvas and CSS.
That's what I thought but I wanted to check because I strongly support this criteria. Any solution that would require authors
to monkey with input values when jumping from one feature to the other would be a fail imo.

-----Original Message-----
From: simetrical@gmail.com [mailto:simetrical@gmail.com] On Behalf Of Aryeh Gregor
Sent: Thursday, July 15, 2010 2:10 PM
To: Sylvain Galineau
Cc: Tab Atkins Jr.; L. David Baron; Brad Kemper; Simon Fraser; Brendan Kenny; www-style list
Subject: Re: [css3-background] Where we are with Blur value discussion

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 spec.

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:
<http://test.w3.org/html/tests/submission/PhilipTaylor/canvas/index.2d.shadow.blur.html>
 Opera passes (again, superimposing the expected/actual and flipping back and forth).  This is pretty definitive.

Received on Thursday, 15 July 2010 22:57:32 GMT

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