Remember that scene where the protagonists are running with the dino swarm around them? The paths of the dinosaurs were laid out in the real world with tennis balls, and back then we wondered "wow they must have great image processing code to remove all those tracking markers". Turns out it wasn't algorithms but humans who removed them frame by frame, pixel by pixel (it didn't occur to us computer nerds that brute force makes the most sense if you're on a tight schedule).