That may be, but either way there has been a dramatic transformation of the original works. Copyright is not an infinitely extended ownership right over information. It is a special exception (to free speech and press) we offer conditionally encourage people to produce things by allowing them to exclusively profit from their production. Like patents. Copyright does not prohibit producing a "similar" work to a copyrighted work, or using similar techniques as a copyrighted work, or else every drawing of a soup can would owe royalties to Andy Warhol