Yes and no. You're right in that there wouldn't be a trademark problem, but if the character's first appearance (for example) still had a valid copyright, then your picture would be derivative of, and thus infringing on, it. The difference between the two is that the owner is allowed to ignore you in the latter and retain copyright, but must defend his own trademark to keep it.
Art always seems to confuse people, so let me try a text-based example where the rules are probably clearer: Star Trek has been out of the public eye for a while, now, if we ignore the recent movie for the purposes of an otherwise-valid example. It's been especially long since they've sold anything (excepting the movie) with the "final frontier" monologue, and so that as a franchise trademark might have otherwise elapsed.
However, if your company were to recite it/print it as the voyages of the USS Narfstar, that would be messing around with Paramount's copyright and their lawyers would find you very interesting.
A more technically correct example, if less evocative, would be something like the Casablanca "hill of beans" speech. Somebody owns it, even if the owner hasn't really used it to sell anything in a long while.