I can’t claim to have known his name, but like you I know his work: Petro Vlahos pioneered blue- and green-screen techniques & founded Ultimatte before passing away this past week at the age of 96. The BBC writes,

Mr Vlahos’s breakthrough was to create a complicated laboratory process which involved separating the blue, green and red parts of each frame before combining them back together in a certain order.

He racked up more than 35 movie-related patents and numerous Academy commendations.
By coincidence, I came across the following peek behind the scenes of The Hobbit. It bears out what Robin Shenfield from compositing firm The Mill says of Mr. Vlahos’s work: “It’s the absolute building block of all the visual effects that you see in television and movies.”

[Via]