The answer is: process :resize_and_pad => [1200, 1200, 'white'] { |img| do_everything_else.call img }
No idea why I can't just use process :resize_and_pad => [1200, 1200, 'white'] do_everything_else
EDIT: Cancel that, nothing happens! The block isn't even run...I put a direct block in there and also put in a "raise 'WTF'.inspect" and no error popped up. I don't know if there's any way to do this...it seems the yield(img) in minimagick's methods are useless as there's no way to pass a block to the method at all by using 'process'.