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Re: [CSS21] Test Suite

From: ACJ <ego@acjs.net>
Date: Sun, 25 Jul 2004 02:22:20 +0200
Message-ID: <4102FD3C.5080800@acjs.net>
To: David Woolley <david@djwhome.demon.co.uk>
Cc: www-style@w3.org

David Woolley wrote:

>>With IE/Win having over 90% of the market share at the moment, it /must/
>>be "the dominant browser", yet it implements GIF transparency on which
>>many users depend; could you clarify exactly what you mean here, David ?
>GIF has a special case of transparency, a binary alpha channel.  PNG
>has a proper, analogue, alpha channel, but authors cannot use this when
>they want transparency because IE doesn't support alpha channels in PNG
>images.  That means that PNG will not, in real life, fill one of the
>main roles for GIF in web pages.
Actually, when you set a PNG to 'Indexed Color' mode (something which 
GIF always is), IE *does* support PNG transparancy, but binary (like GIF).
I've even seen examples[1] of PNG files that showed the analogue 
transparacy levels in browsers that support it, and only the binary 
(like GIF) one in IE (without offering different files!).
I haven't managed to accomplish this myself yet, but I think that's 
because of limitations of the software I use to make my PNG files 
(PhotoShop CS). LatinByrd seems to be able to do the trick.

The point is, transparancy is *not* an arguement that scores points for GIF.


[1] http://www.libpng.org/pub/png/pngs-img.html
Received on Saturday, 24 July 2004 20:21:48 UTC

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