Do you know any histogram modification methods?

I'm looking for any histogram modification methods besides Equalization and Stretching the histogram. Code for them would be very helpful too.

Answer 1

[Image Analyst]

In the Image Processing Toolbox there are

1. histeq, which gives lousy images,
2. adapthisteq which gives good images.
3. imadjust which expands the dynamic range. Usually not needed but can be if you want to save a contrastier image with imwrite
4. Morphological functions like imclose and friends
5. Denoising functions like medfilt2

There are many, many others. Almost anything you do to an image will change the image, even something as simple as adding a number to it or multiplying it by an intensity scaling factor, or even denoising. Your question can't be answered comprehensively because there are just a bazillion answers.

[Jakub Mis]

Thank you very much, but I'm looking for methods that operate more on the histogram then on image itself. Something like histeq or imadjust. Do you know any?

[Image Analyst]

The histogram is an array of counts. Just a normal array of numbers. Again, you can do virtually anything with a generic array of numbers. Like you could use cumsum to compute a cdf. Or you could use findpeaks or max() or islocalmin() or anyone of hundreds of functions that operate on vectors.

Rather than ask the unanswerable "What can I do?", why don't you explain what you want to do and ask "How can I do that?"

[Jakub Mis]

Besides functions before I need to implement some of the modifications below. Honestly even one could be helpful. Then I'll be able to implement rest of them.

[Image Analyst]

You can get the probability with the 'Normalization' option in histogram. Then you can plug that P into your equations to get a new gray level for the graylevel at P(z). You can transform the whole image in one equation like they show.

[Jakub Mis]

I meanged to get the propablity using P=histogram(X,'Normalization','probability');

,at least I think I did, but can't extract any data from that what shoud I do next?