[Clipart] The PNG problem in Windows Internet Explorer

[Glenn Randers-Pehrson]

At 10:08 AM 1/21/2005 -0500, Jonadab the Unsightly One wrote:
>Salvatore Davide Rapisarda <blackmicio at tiscali.it> writes:
>
>> The problem is that explorer ignore alpha transparency in a png
>> image,
>
>Didn't somebody here post a method for using a PNG-related
>command-line tool, pngcrunch or something like that, to fix an PNG
>image so that it would display more correctly on IE, without changing
>its appearance for standards-conformant browsers and image editors?
>
>Hang on, maybe I can dig it up...
>
>Message-Id: <3.0.6.32.20041113110721.0118ec78 at mail.comcast.net>
>
># See
>#                                                                                                                  
># http://www.graphicsmagick.org/libpng/ocal/openclipart.org.html
># which compares the original and the "sRGB" versions.  With Firefox
># they look the same, but with IE one is a lot darker than the other.
>#                                                                                                                  
># I used pngcrush to remove the gAMA chunk and add the sRGB chunk:
>#                                                                                                                  
>#   pngcrush -rem gama -srgb 1 -rem gama ocal-header.png ocal-header-sRGB.png
>#                                                                                                                  
># As a side benefit, the file is 3.5kbytes smaller.
>#                                                                                                                  
># Glenn

This fixes the IE bug with color-matching but not the IE bug with
transparency.

Glenn

>
>If we did this to the PNG thumbnails in the package,
> 1.  Would it improve the appearance of the site (especially the
>     browse portion) in MSIE?
> 2.  Would it have any downside, e.g., impact on other
>     browsers or remove wanted information from the images?
>
>It could be a little computation-intensive, but that is not a big
>problem if we do it just once to each batch of images as part of the
>release cycle.  I mean, generating the thumbnails in the first place
>is a bit CPU-intensive, but so what?
>
>-- 
>$;=sub{$/};@;=map{my($a,$b)=($_,$;);$;=sub{$a.$b->()}}
>split//,"ten.thgirb\@badanoj$/ --";$\=$ ;-> ();print$/
>
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