What exactly happens when you Posterize a grayscale image?

436 views1 repliesLast post: 6/18/2004
When you use the posterize command, are all the intensities rounded to the closest of the new values? What happens exactly? Thanks!

Charles
#1
Charles,

Divide 255 by N-1 (N is the number of posterization levels). Multiply the result including the fractional remainder by 0,1,2,3... and each time discard the fractional remainder. With 8 levels, for example, you then get 0/ 36/ 72/ 109/ 145/ 182/ 218/ 255 for the tonal levels produced.

George
#2