Embedded image metadata in WordPress
James Duncan Davidson has written a few times (April, 2008 and January, 2009) on the problem of Flickr’s approach to embedded image metadata such as Exif (technical metadata) and IPTC and XMP (content metadata)—it’s stripped from all versions save the original uploaded image. This is not only the default behaviour—there’s no option to control this, it’s one of the conditions of using Flickr. (My guess is that this is a pragmatic decision about what users want—i.e. most don’t care—versus Yahoo!’s bandwidth costs, rather than the price of storing this information.)
It turns out that the same behaviour applies to current versions of the WordPress image resizer. This means that if you use WordPress’s native media support to display images for which copyright metadata is important, be aware that you might be serving up “orphaned” content, whose author cannot be determined when the asset is separated from your page, if you’re using the dynamically created thumbnails on your site. It looks like this might be changed in an upcoming release, but the details are hazy… The workaround is to size images yourself, output them with intact metadata, and insert them as “full size” into your posts or galleries.