psphericityselection

Selects regions from sphericity degree.

Synopsis

psphericityselection relation threshold [-m mask] [rg_in|-] [rg_out|-]

Description

psphericityselection selects regions from their sphericity degree. The parameter relation specifies the order relation to the threshold value that is used to select or not a region.

Sphericity measures the degree to which an object approaches the shape of a sphere. It is calculated using:

sphericity = rayon_inscribing / rayon_circumscribing.

The maximum value is 1.0 for a circle.

Parameters

relation is an integer from [-3,3] which specifies the order relation to the threshold value:
- relation = 3: regions with the maximum value.
- relation = 2: regions >= threshold.
- relation = 1: regions > threshold.
- relation = 0: regions = threshold.
- relation = -1: regions < threshold.
- relation = -2: regions <= threshold.
- relation = -3: regions with the minimum value.
threshold is a real value from [0..1] which specifies a sphericity degree.

Inputs

rg_in: a 2D or 3D region map.

Outputs

rg_out: a 2D or 3D region map.

Result

Returns the number of selected regions.

Examples

Selects regions with the highest sphericity degree:

   psphericityselection 3 0 a.pan b.pan

C++ prototype

Errc PSphericitySelection( const Reg2d &rg_in, Reg2d &rg_out, int relation, float threshold );

Version française

Sélection de régions sur leur valeur de sphéricité.

Author: Régis Clouard