Locate an Image with the higher pixel alteration

Hi there.

I'm new to Matlab, and i would like some help from experts!

The problem.

I have a series of MRI Images that shows a specific region of the body as a function of time. What i want to do is to locate (automatically) the frame with the maximum variation in luminosity in a specific region of the Image. The problem is that i have some regions with strong artefact which they have greater luminosity values than the Region of Interest.

Below you can see 2 of the images. The first one is the base object, and the second is the one with the higher pixel variation.

Thank you in advance. Andrew

Answer 1

[Image Analyst]

I'd look at the the coefficient of variation (CV), also known as relative standard deviation (RSD) That way, the variation in "luminosity" is normalized to the brightness in the region.