A lot can change when you're in the reincarnation business, and with Tim Burton's upcoming "Frankenweenie," which opens Oct. 5, that means resurrecting a beloved live-action 1984 short film about a boy named Victor and his live-then-dead-then-live-again dog Sparky as a feature-length, stop-motion animated film. What's staying the same is the movie's evocative black-and-white look, a stylistic choice that the film's makers say became one of the more unintentionally hard-won artistic rewards on this 21/2-year-long production. "You'd think black-and-white would be forgiving because it's just shades of gray. But it isn't. It shows every little flaw," said Trey Thomas, "Frankenweenie's" animation director, speaking at his East London office about the movie's monochrome aesthetic.