Image analysis of alginate particles

I have prepared some capsules of alginate which are around 2mm in diameter. In core part is oil and shell part alginate. I have to analyse hundred of these images.

I have taken images of capsules with my mobile. Most of the images are without the scale.

My analysis goal is to determine circularity/sphericity of whole capsules as well as core, diameter of capsule and core, area of shell and core, volume of core and shell.