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ShapeCircularity

Header:	AVL.h
Namespace:	avl

Computes the area of a shape divided by the area of a circle having the same feature.

Syntax

void avl::ShapeCircularity
(
	const avl::Path& inShape,
	const avl::CircularityMeasure::Type inCircularityMeasure,
	float& outCircularity
)

Parameters

Name	Type	Default
inShape	const Path&
inCircularityMeasure	const CircularityMeasure::Type	RadiusPreserving
outCircularity	float&

Description

Circularity is a measure of similarity of a shape to the perfect circle. Circular shapes have circularity close to 1.0, while the more elongated the shape is (or contains more holes), the closer to 0.0 is its circularity.

Mathematically, the circularity is calculated as follows: Where c denotes a circular shape having the same feature as input shape s. The feature being considered depends on the inCircularityMeasure chosen and it is:

the minimal bounding circle in case of BoundingCirclePreserving
the perimeter in case of PerimeterPreserving
the radius (maximal distance from mass center to any of the shape points) in case of RadiusPreserving

Note that if the input path is not a valid shape (i.e. it has at least one self-intersection), the computation may lead to results that are not intuitive.

Examples

Circularity with RadiusPreserving of the sample shape equals to 0.340.

Circularity with PerimeterPreserving of the sample shape equals to 0.998.

Errors

List of possible exceptions: