Roundness Shape Measurement Algorihtm

Goal: Measure the shape by how "round" it is.

Idea 1: Trace boundary of blob. Use only these pixels and fit the best fitting perfect circle to this data. Then measure the "error" and the summ of the distances each boundary pixel is from the closest point on the perfect best fitting circle. E = 0 then perflectly round, E= small then close to round, E= large not round.