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Re: Undefined behaviour with filters?

From: Christian Brunschen <cb@df.lth.se>
Date: Wed, 2 Feb 2000 12:35:43 +0100 (CET)
To: www-svg@w3.org
Message-ID: <Pine.LNX.4.05-df.10002021232390.15653-100000@bartlet.df.lth.se>
On Wed, 2 Feb 2000, Christian Brunschen wrote:

> Now consider a second example. For this we will need an external image,
> 'hideAndSeek.png', a PNG image which has some pixels which are transparent
> and some which are opaque. However, as PNG stores RGBA in a
> non-premultiplied format, this permits that there be actual useful data
> stored in the RGB parts even of pixels whose A=0.
> 
> Now sau that we want to use the 'MakeLessTransparent' filter from the
> previous example on this PNG image, thus revealing some of what is
> 'hidden' in the image:

I just realized there is an error in the example; it does not invalidate
my point, but just for correctness' sake, replace

------
   <image xlink:href="hideAndSeek.png" 
          style="filter:url(#MakeLessTransparent)">
   </image>
------

with

------
   <svg style="filter:url(#MakeLessTransparent)">
      <image xlink:href="hideAndSeek.png"> 
      </image>
   </svg>
------

.. which should produce the same effect and thus trigger the same
undefined / undesirable behaviour (please do correct me if I am wrong).

Best regards

// Christian Brunschen
Received on Wednesday, 2 February 2000 06:35:46 GMT

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