what does regionprops.inertia_tensor_eigvals return? I test on 2d image, it give the major and minor axis, But when I use it on 3d image, it return 3-element tuple, but not as expected. (for I just put two zeros array upon and behind the 2d one, the result should be the 2d result, with a 0 added)

so, what does the inertia_tensor_eigvals mean? How can I get the expected result.

I want np.eig(np.cov(np.where(label==xxx)))