Every time a reality TV star's mouth is pixelated to obscure a curse, the producers are using a technique pioneered for Yul Brynner's killer robot in Westworld. John Whitney Jr., who created the effect for director and writer Michael Crichton, wanted to simulate how an android might see the world. To do so, he divided the screen into tiny squares, calculating the average color of each one, and filling them with that color, creating a shifting low-resolution version of normal vision. It was a simpler, cheaper design than Crichton's desired "bizarre, computerized image of the world," but it also likely proved more timeless: it's since become an accepted convention for obscuring a video. The New Yorker has the full story, including more history for Westworld and special effects.