You could always get an anti-vandal bot set up, which may be able to spot vandalism faster than any human could. Obviously it wouldn't catch everything, but it's worth a try.
-- Alex (User:Majorly)
I don't think a bot could get this kind of vandalism. Using a page blanking bot could be nice but most work has to be done by humans.
I am happy to notice when I am patrolling new edits I get a often a edit conflict with somebody else that is also reverting the vandalism. But I am afraid not everything can be found while paroling.
Does Flagged Revisions also works on images?
Best regards, Huib