

Real Time Edge Detection in Haskell - johngunderman
http://disciple-devel.blogspot.com/2011/03/real-time-edge-detection-in-haskell.html

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liuliu
It should be noted that the OpenCV implementation the article mentioned (I
believe it refers to cvCanny) is highly optimized to integer operation - word8
(there are several approximation used to avoid computing arctan).

