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Contrast Limited Adaptive Histogram Equalization (CLAHE)

20 Nov 2008

No BSD License

Best to read the reference in "Graphics Gems IV", Academic Press, 1994 pages 474-485

File Information
Description	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
Required Products	Image Processing Toolbox
MATLAB release	MATLAB 7.4 (R2007a)
Zip File Content
Other Files	clipHistogram.m, interpolate.m, makeHistogram.m, makeLUT.m, mapHistogram.m, runCLAHE.m

Tags for This File
Everyone's Tags	adaptive histogram equalization, clahe, histogram equalization, image processing
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Comments and Ratings (3)
20 Nov 2008	Steve Eddins	You might want to take a look at adapthisteq, which is in the Image Processing Toolbox. This function also implements CLAHE. See: http://www.mathworks.com/access/helpdesk/help/toolbox/images/adapthisteq.html
20 Nov 2008	Leslie Smith	Thanks for the reference. I had looked for and did not find the Matlab CLAHE and was surprised when I thought it did not exist. Leslie
15 Apr 2009	Idillus

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Tag Activity for this File
Tag	Applied By	Date/Time
histogram equalization	Leslie Smith	20 Nov 2008 13:44:55
adaptive histogram equalization	Leslie Smith	20 Nov 2008 13:44:55
clahe	Leslie Smith	20 Nov 2008 13:44:55
image processing	Leslie Smith	20 Nov 2008 13:44:55

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