How to use imhist() for a part of an image

How do I define a part of an image to display the histogram?

I don't want to use imcrop() on my image because in my application I have to crop it twice, and the coordinates will be reset back to 0 and I have to declare the bounding box again, which I don't want as I have to automate this over several photos.

imhist(I) only allows me to display the histogram of an image I, but I only want to display a certain portion of it, not the whole image.

Answer 1

[Adam]

e.g.

imhist( I(200:300, 320:420) )

[Ga Ree]

May I ask what does the (200:300, 320:420) mean?

Is it (x start coordinate:x end coordinate, y start coordinate:y end coordinate)?

I can't seem to get the right portion of the original image.

[Adam]

It is actually indexed as rows and columns which, confusingly, maps to y first and then x for an image you are looking at a plot of.

[Ga Ree]

Alright! Thanks a lot Adam! It worked!