Thanks -- and it may turn out to be just a misunderstanding on my part of what "image borders" mean in the import man page (-frame is probably what I should have been using all along, but now I'm curious about -border).
Thanks -- and it may turn out to be just a misunderstanding on my part of what "image borders" mean in the import man page (-frame is probably what I should have been using all along, but now I'm curious about -border).