Thu Sep 18, 2003 9:14 pm ( http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=003j8d )
Browser Problems Caused by Photoshop 7 JPEG images
We would like to alert our users to a problem caused for Web browsers and other applications by certain JPEG files created with Photoshop 7.
With PS 7, Adobe decided by default to embed XML-encoded "preview" data into JPEG files, using a feature of the JPEG format that permits embedding of arbitrarily-named "profiles". In theory, these files are valid according to the JPEG specifications. However they break many applications, including Quark and, significantly, various versions of Internet Explorer on various platforms.
The symptom in Internet Explorer is that the browser becomes "stuck" in downloading an image file, and its memory utilization starts to increase at the rate of about 100K per minute. After this occurs, the browser can still navigate, but it will not display any images at all -- neither offending PS 7 JPEG images nor any other kind of images, on photo.net or any other site. People have noticed this behaviour and tend to blame it on photo.net, since they don't encounter it on other sites. This is only because other sites have more control over the images that are included on the site, whereas photo.net currently accepts all JPEG files.
Once the browser is blasted by one of these JPEG image bombs, one can recover on some platforms by closing all browser windows and restarting the browser. On some platforms, it is reported that it is necessary to reboot the entire system.
We have searched the Microsoft web site for Internet Explorer workarounds or patches for this problem, and we have not been able to find any. IE 5 and 6 on Windows 2K, and IE 6 on Windows XP are some of the version/platform combinations that are impacted, but there are likely others.
On Adobe's web site, various workarounds given include using the "Save for Web..." function to write the JPEG file, or to set Preferences to disable the saving of "preview" data in output files. Since these workarounds require action on the part of the Photoshop 7 user, photo.net is currently at the mercy of any PS 7 user who does not know about this problem or ignores it.
We are therefore working urgently on a way to filter out these JPEG images. In the meanwhile, we appeal to our users not to upload JPEG images created in PS7 unless they have been saved using the "Save for Web..." feature