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Message from discussion IE7 .png transparency bug on fadeIn and fadeOut

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Subject: Re: IE7 .png transparency bug on fadeIn and fadeOut
From: kuralj <opt...@gmail.com>
To: jQuery Development <jquery-dev@googlegroups.com>
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Hi,

I can't offer you a solution (unfortunately), but I can at least
clarify the problem for you a bit further:

This issue is not a jQuery issue as such, it is an IE7 filter issue
and is a known and documented problem with the way IE address things
like clear type (anti-aliased) text rendering and PNG opacity when
IE's in built filters are applied.

So, the good news (or is that bad news?) is that this isn't a jQuery
'bug', and the bad news (or is that just - more bad news?), is that
I'm not aware of any workaround for this.

More details from the IE developer team is available on the IE blog:
http://blogs.msdn.com/ie/archive/2005/04/26/412263.aspx

Specifically the excerpt below from that article:

"Certain filters may not behave as expected due to how filters are
implemented.  Filters work by rendering the content of their attached
element to their work surface and then modifying that surface before
compositing it to the output surface.  Because of this, alpha blending
of a transparent PNG with non-binary transparency may lead to
unexpected results.  For example, applying a BasicImage filter with an
opacity attribute to an IMG element with a transparent PNG will fill
the work surface with the transparent PNG alpha alpha blended with a
solid gray background.  The work surface will then be alpha blended at
the specified opacity level with whatever is under the filter."

Hope that helps a bit, and if you come up with a solid solution,
please share :)

Ian

On Aug 5, 5:31=A0am, Chuck <asdi...@gmail.com> wrote:
> Hey all,
>
> I've run across a bug and am wondering if others have found a
> workaround or solution. I have an absolutely positioned div with a
> background image that has .png alpha transparency. =A0Debugging has
> isolated the issue to jQuery's fadein effect. It also errs with
> animate({opacity}). It works fine before calling the animation.
>
> A screenshot demonstrating it in Safari (left) and IE (right) post-
> animation.
>
> http://i36.tinypic.com/28krlh4.jpg
>
> Has anyone run across this bug before? Are there any fixes or
> workarounds?
>