Kate:
To address this, I've written a very basic Perl script a while ago that makes a dump of a wiki's images that are only in the Commons. It's in /home/erik/extractdb.pl. I'm sure it could be done a lot faster, though.
in fact, it should rather be slower than faster. this is the idea of trickle. otherwise it's too much load on albert.
Indeed. I should have said "efficiently." The script above is a hack.
can we just include the image description pages in the image dumps?
Yes, including cur_namespace 6 and 10 should be sufficient (10 because most copyright information makes use of templates).
Erik