Tom Duff

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
Tom Duff in his office at Pixar

Thomas Douglas Selkirk Duff (born December 8, 1952) is a computer programmer.

Early life[edit]

Duff was born in Toronto, Ontario, Canada, and was named for his putative ancestor, the fifth Earl of Selkirk. He grew up in Toronto and Leaside. In 1974 he graduated from the University of Waterloo with a B.Math and, two years later, was awarded an M.Sc. from the University of Toronto.


Duff worked at the New York Institute of Technology Computer Graphics Lab and the Mark Williams Company in Chicago before moving to Lucasfilm's Computer Research and Development Division. He and Thomas Porter, another Lucasfilm employee, developed a new approach to compositing images; their 1984 paper, "Compositing Digital Images",[1] is "[t]he seminal work on an algebra for image compositing", according to Keith Packard.[2] and "Porter-Duff compositing" is now a key technique in computer graphics. (See, for example, XRender and Glitz.)

Duff later worked for 12 years at Bell Labs Computing Science Research Center, where he worked on computer graphics, wireless networking, and Plan 9;[3] in the course of his work there, he authored the well known "rc" shell for the Version 10 Unix operating system.

Duff has worked at Pixar Animation Studios since 1996.



  • "Shared libraries are the work of the devil, the one true sign that the apocalypse is at hand."[5]
  • "Nobody really knows what the Bourne shell's grammar is. Even examination of the source code is little help."[6]
  • "π seconds is a nanocentury."


  • Tom Duff makes a cameo appearance in the Niven/Pournelle science fiction novel Footfall as a co-discoverer of the invading spaceship: "Chap named Tom Duff, a computer type, spotted it."
  • Tom Duff appears briefly in the documentary film "Noisy People" (dir Tim Perkis, 2006) playing the banjo.[7]

See also[edit]


  1. ^ Porter, Thomas; Tom Duff (1984). "Compositing Digital Images". Computer Graphics. 18 (3): 253–259. doi:10.1145/800031.808606. ISBN 978-0-89791-138-2.
    (Available at
  2. ^ Keith Packard's webpage about Porter & Duff's 1984 paper
  3. ^
  4. ^ "Recipients of the J.W. Graham Medal in Computing & Innovation". University of Waterloo. Retrieved 2015-09-25.
  5. ^ "Archived copy". Archived from the original on September 29, 2007. Retrieved December 17, 2006.CS1 maint: archived copy as title (link)
  6. ^
  7. ^
  8. ^ N.J.A. Sloane, R.H. Hardin, T.S. Duff, J.H. Conway: "Minimal-Energy Clusters of Hard Spheres", Discrete & Computational Geometry 14, No. 3, 237–259, 1995.
  9. ^ J.H. Conway, H.T. Croft, P. Erdos, M.J.T. Guy: "On the Distribution of Values of Angles Determined by Coplanar Points", J. London Math. Soc., II., Ser. 19, 137–143, 1979.

External links[edit]