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Sphericity

Ratio that assesses how closely an object approaches the shape of a perfect sphere.

🔎 ROI options and parameters of sphericity accessor

Sphericity is a measure of the degree to which a particle approximates the shape of a sphere, and is independent of its size. The value is always between 0 and 1. The less spheric the ROI is the smaller is the number. It is calculated through this formula:

Sphericity=2∗Surface∗πPerimeter;Sphericity =\frac{ 2*\sqrt{Surface*\pi}}{Perimeter};

Sphericity has a similar role as roundness and can be used as a reference for shape comparison.

In ImageJS sphericity is a ROI class accessor that returns a sphericity index:

const sphericity = roi.sphericity;