What was the first feature film to use digital image processing?

Westworld is a 1973 science fiction western-thriller film written and directed by novelist Michael Crichton and produced by Paul Lazarus III about amusement park robots that become crazy after a power surge and start to kill people. It stars Yul Brynner as an android in a futuristic Western-themed amusement park, and Richard Benjamin and James Brolin as guests of the park.

Westworld was the first theatrical feature directed by Michael Crichton. It was also the first feature film to use digital image processing, to pixellate photography to simulate an android point of view.The film was nominated for Hugo, Nebula and Golden Scroll (a.k.a. Saturn) awards, and was followed by a sequel film, Futureworld, and a short-lived television series, Beyond Westworld. In August 2013, HBO announced plans for a television series based on the original film.