Monday, December 2, 2002 |
15:50 - Image Issues
http://www.panic.com/~stevenf/mt/archives/000125.php#000125
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Reader Neil McKeown alerted me to this weird, weird problem that seems to have affected a number of images on or linked to from this blog page. From various comments at the site where this is being discussed:
Secondly, and even worse, Windows versions of Internet Explorer, mostly 5.5 and 6.0 get thoroughly confused by a file that identifies itself as .jpg but contains XML. When you try to load one of these inflated images with Win IE 5 or 6, it spins endlessly, trying to figure out what to do. From that point on, you have completely lost your ability to view images in that browser session. Even if you go to another site. All graphics loading will spin endlessly from that point on. Only completely quitting and relaunching Win IE fixes the problem.
Don't believe me? Try it yourself. I've seen it reproduced on at least five different Windows machines. I've even reproduced it myself on Virtual PC.
It doesn't seem to affect Mozilla-based browsers, or any Mac browser. But you must appreciate the danger and/or irony here -- designer on Mac OS X generating lethal .jpgs, hapless Windows browser locking up when they visit the site.
It's hard to say where the blame lays here.. Adobe or Microsoft? Either way, if anyone knows anyone in a position of influence at either company please bring this to their attention, as it makes the web a suckier place to be for everybody.
Update: The problem may be specific to certain combinations of tainted images and HTML. The following URL reproduces the problem consistently for me on Windows XP with IE 6 (under Virtual PC): http://www.snapclub.com/wintest.php
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Obviously, at some level the blame lays with Microsoft. There shouldn't be anything I can put on my webpage to destroy your entire ability to view images.
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The "XML" you see is actually an XMP packet. XMP is the Adobe-defined open metadata format for metadata. It uses RDF as its data representation hence the comment it "looks like XML".
Microsoft and Adobe worked together to identify the problems Windows Explorer had with JPEG files that contained application-specified data. This problem appeared not only for JPEG but TIFF files as well. The latest XP service pack fixes the known issues related to Windows Explorer and these files, include some bugs that can corrupt such files and make then unreadable at all if you use Windows Explorer to edit the metadata in the file.
Note this appears to be a different issue than the one you are reporting about Internet Explorer being unable to display such files.
Marc Pawliger Photoshop Team, Adobe Systems
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However, there are some people who _don't_ realize what's going on and need to be made aware. My web site, Snap Club, for example, allows users to upload images from their hard drives. Every so often, someone uploads a JPEG that contains this extra data, and from that point on all the Windows IE users who visit my site lose the ability to view images.
They think my web site has a virus or something. They never come back.
Neil reported that some images on my site that were causing trouble were the larger versions of screenshots which I linked in with thumbnails, which always did work, as in this post. But these images work for me on my IE 6.0, so it seems to depend heavily on individual platform combinations.
One poster did comment that a mogrify command can strip out the offending IPTC header, so I'll add that to my posting script and run it against all my existing images, so it shouldn't cause any more problems... please keep an eye out, though, and if you're using Windows and you see this happening, please spread the word. Mac-using bloggers and website owners in particular, take note. (Does this happen at lileks.com?)
Pretty fugly problem, if you ask me.
UPDATE: Oh, and it should be noted that it is not "malformed" JPEG files that are causing this to happen. It's simply JPEG files that-- quite legally-- use an RDF text block in their headers (which Adobe's Mac software does as a matter of course), which is something that IE chokes on, thinking it's XML that it has to parse and execute.
This is an IE problem, pure and simple, and the onus is on Microsoft to fix it, not on website designers and bloggers who happen to use Photoshop or other software that writes RDF or XML headers. But we'll "fix" up our files anyway, just to be good citizens and clean up after Microsoft's mess yet again.
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