How can I 'subtract' the brighter parts of an image without making it too unnatural?

Good day!

I want to lessen or subtract the brighter part of an image without it being too unnatural. I find thresholding [I(I>250) = 0] a bit awkward. I was hoping for the neighboring pixels to adjust, too. How can you do that?

I am pretty new with image processing and I am using imgradient for edge detection of crystals but I want to omit information for brighter parts of the image (maxima).

Here is an image of what I currently am working out.

Thank you very much.

[c4mm11]

Hi! Someone suggested using log, but it didn't do what I needed it to do since it just changes the brigtness of the whole image and not do it 'locally' to ''remove' the bright parts.

http://i.imgur.com/OrJS3Vt.png

Anyone?

Answer 1

[Image Analyst]

You might want to use the "shadows and highlights" algorithm that Photoshop uses. I'm sure it's probably on the web somewhere. https://www.google.com/#q=photoshop+shadows+highlights+algorithm

[c4mm11]

Thank you for the answer! I will check this out in a while. Just a quick question tho. I found out that what I want to do is similar with imhmax(I,h), but instead lower than h, I want to suppress higher than h. Is this possible?

[Image Analyst]

If it does what you want, then fine, but I have my doubts. See this link