How to find the centroid and the moment of inertia of a picture?

Hello, I'm not very good at using Matlab and my professor gave the class this problem. I'm hoping someone could help me out. Thank you.

Answer 1

[Walter Roberson]

You cannot calculate the centroid of that with the information given. Centroid is center of mass, but you do not know how the density varies. Considering it is x-rays you could probably infer some relationship between pixel brightness and density, but what relationship? Is it a linear relationship?

If you knew the mass corresponding to each pixel, you could calculate center of mass

[Neil Lallkissoon]

Thank you on this insight.