How does the imhist function work for RGB image?

Hello everyone.

I looked up the use of imhist function. It plots the histogram for a grayscale image. But if the input is an RGB image, it still produces a histogram? Is it converting the RGB to grayscale and then showing the histogram?

And would it be technically correct to show the histogram for a RGB image this way? Thanks in advance!

Answer 1

[Image Analyst]

Did you try to look at the source code

>> edit imhist.m

Also, see attached demo. You might like it.

[John Doe]

Thanks for the prompt answer, Image analyst.

So, should I go for color histograms in case of RGB image or should I use the default imhist function? imhist shows a colorbar in graytone for RGB image. I just want to be technically correct here.

[John Doe]

I checked the source code. I think it's performing operation determining the class (uint8/logical) etc.