Contrast Limited Adaptive Histogram Equalization (CLAHE)

This is an image contrast enhancement algorithm that overcomes limitations in standard histogram equalization (HE). The two primary features is adaptive HE (AHE), which divides the images into regions and performs local HE, and the contrast limited AHE (CLAHE), which reduces noise by partially reducing the local HE. Bilinear interpolation is used to avoid visibility of region boundaries.
"Contrast Limited Adaptive Histogram Equalization"
by Karel Zuiderveld, karel@cv.ruu.nl
in "Graphics Gems IV", Academic Press, 1994

Ported by Leslie Smith