Visibility Masking
Visibility threshold as predicted by w-model, around an edge. The video signal range corresponds to 0-255. The left dark side of the edge had the value 80, while right, bright side has the value (a) 130, (b) 180, and ( c) 230.
(Courtesy: Bernd Girod, SPIE Vil 1001, SPIE VCIP,88)