pmeanselection

Selects regions from mean grayscale value.

Synopsis

pmeansselection relation threshold [-m mask] [rg_in|-] [im_in|-][rg_out|-]

Description

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

The mean value mi of the region i is calculated as follows:

mi= SUM(im_in[p] / p in Ri) / N

where N is the number of pixels in the region.

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 an integer defined in grayscale unit.

Inputs

rg_in: a region map.
im_in: a grayscale image.

Outputs

rg_out: a region map.

Result

Returns the number of selected regions.

Examples

Selects regions with a mean value > 50:

   pmeanselection 1 50 rin.pan a.pan rout.pan

C++ prototype

Errc PMeanSelection( const Reg2d &rg_in, const Img2duc &im_in, Reg2d &rg_out, int relation, Uchar threshold );

Version française

Sélection de régions sur leur valeur de moyenne intérieure.

Author: Régis Clouard