The threshold for originality in copyright is the bare minimum, so it's not a good standard for "invention". Patents have a much higher bar to overcome, and it is hard to put into a simple explanatory phrase.
I think what you are describing in copyright isn't the issue of originality, but determining what is encompassed in a copyrighted work. The court will analyze what the work consists of, and what of it was your expression, as opposed to someone else's. So, it's not novelty exactly but it's close.