circularity equation

gingersnaps

Please confirm the equation for circularity.

 I don't think the formula is correct for circularity. Cir=(4*A)/Pi*MaxFeret2). What would make sense is 

Cir=A/(π × MaxFeret^2)

This would be 1 for circles (A=4×π×radius^2, MaxFeret=2×radius), 0 for lines (A=0, MaxFeret=undefined?), and in between for elliptical blobs with equal area but larger MaxFeret than the radius of the sphere.

Can someone please check this equation found in under range?

Thank you

 

YuriG

gingersnaps,

The formula for circularity is derived from the area of circle:

A = Pi * R^2 = Pi * D^2 / 4

and assuming that Circularity of a circle is 1, the formula is:

Cir=(4*A)/(Pi*MaxFeret^2)

which is shown in the tooltip.

You can validate it by measuring parameters of a circle.



Yuri