eccentricity

eccentricity ( Regions : : : Anisometry, Bulkiness, StructureFactor )

Shape features derived from the ellipse parameters.

The operator eccentricity calculates three shape features derived from the geometric moments.

Definition: If the ellipse radii Ra, Rb and the area A of the
            region are given (see elliptic_axis),
            the following applies:
	      
   Anisometry = Ra / Rb
   
   Bulkiness = pi Ra Rb / A
   
   StructureFactor = Anisometry * Bulkiness - 1

Parameters

`Regions` (input_object)	region(-array) `->` object
Region(s) to be examined.

`Anisometry` (output_control)	real(-array) `->` real
Shape feature (in case of a circle = 1.0).
Assertion: `Anisometry >= 1.0`

`Bulkiness` (output_control)	real(-array) `->` real
Calculated shape feature.

`StructureFactor` (output_control)	real(-array) `->` real
Calculated shape feature.

Complexity

If F is the area of the region the mean runtime complexity is O(sqrt(F)).

Result

The operator eccentricity returns the value 2 (H_MSG_TRUE) if the input is not empty. The behavior in case of empty input (no input regions available) is set via the operator set_system('no_object_result',<Result>). The behavior in case of empty region (the region is the empty set) is set via set_system('empty_region_result',<Result>). If necessary an exception handling is raised.

Parallelization Information

eccentricity is reentrant and automatically parallelized (on tuple level).

Possible Predecessors

threshold, regiongrowing, connection

Module

Region processing