How to Calculate Mean and StDev of Bimodal Grayscale?

Hello everyone. I’m new to the forum and I’ve searched through the history here but am unable to find an answer.

I need to calculate the mean and standard deviation of bimodal grayscale images.

My image data files always have a dark area and a light area and I want a simple way to return the mean and Stdev of each area.

The histogram feature of ImageJ returns a unimodal result.
Is there a simple way to get a bimodal analysis of the image?

Hello @Jebbo1234,

If you set a different ROI for each area and click on Analyze > Measure, you should get different measurements per area.


Ignacio, thank you for your reply and suggestion.

Unfortunately, the nature of the images that have to be analyzed need to have a set spacial dimension for the ROI to properly capture the effect that I’m trying to measure. In essence, I have to calculate the distribution of both peaks at the same time.

I have many thousands of these files to process and I’d like to find a simple way to do this or modify the code to automate it so I can hand it off to an intern or lab tech.

I’m a bit out of my element with modifying the java code, thought I’m willing to learn if necessary. My background is Chemical Engineering…years of Fortran experience which doesn’t seem very relevant here.

If possible, later this week I will try to post an example of one of these images and maybe that will make it clearer what I’m trying to accomplish.

Thanks again and best regards, James

Hello again, James,

Yes, an image example would really help the community to better understand the problem.