Convexity, Roughness  
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Menu:   Measure > Parameters  
Script:   SelectParam ("Convexity","Roughness")  

Select these parameters to compute the shape factors based on the convex hulls of objects. A convex hall is defined as an imaginary elastic string, stretched around the object.

The parameters are returned in calibrated units.

The Convexity describes how convex the outline of the object is. It is equal to the ratio of the outline area divided by the convex area:
convexity

Convex objects like rectangles or ellipses have this value equal to 1. If the object contains cavities, the value is less than 1.


The Roughness describes how winding the outline of the object is. It is equal to the ratio of the outline perimeter to the convex perimeter:
roughness

Smooth convex objects have this value close to 1. For objects with meandering oulines this value is less than 1.

Internal holes do not affect Convexity and Roughness.

Also see AreaConv
and PerimConv.