Reason for Histogram Equalisation for having "stacked" effects?

2 views (last 30 days)
I read in an image, run histeq on the it and store it as Img2. Then I run histeq again on Img2 and store it as Img3.
It turns out that when I compare the histograms of Img2 and Img3, the histogram of Img3 looks more equalised and uniform. Both Img2 and Img3, however, look almost identical with naked eyes.
This is a screenshot of their histograms. The one on the left is the histogram for Img2, while the right one is for Img3:
So it looks like the histogram equalisation can be "stacked" and by running many times can make the image even more uniform? Is there a reason for this?

Accepted Answer

Image Analyst
Image Analyst on 11 Feb 2013
What was your second input argument to histeq()?
  4 Comments
Charles
Charles on 12 Feb 2013
oh wait a minute, I just realise that I put 255 as my second argument. Would this matter?
Image Analyst
Image Analyst on 12 Feb 2013
Let's take a step back and figure out why you want to do histogram equalization anyway. Almost always it's unnecessary to the subsequent processing and analysis, and produces a lousy, unnatural looking image.

Sign in to comment.

More Answers (0)

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!