pmeanmerging

Performs priority region merge based on mean criterion.

Synopsis

Description

pmeanmerging merges connected regions of the input image rg_in if the difference between the mean value of the region is lower than the specified threshold.

Two regions are connected if there exists a link between the related nodes in the input graph gr_in.

The principle of the algorithm is as follows:

For each region of the input region map rg_in:
If the difference between the criterion value of the two connected regions ≤ threshold
then merge them into one region.

The algorithm uses the priority merge that consists in merging regions with the lower difference.

The output region map reg_out defines the new regions and the output graph gr_out defines the new relationship between regions.

Parameters

iterations specifies the number of merges to perform. If number = -1 then all possible merges are done.
threshold specifies the maximum difference allowed between two regions to decide to merge them. Values are from the gray scale of the input image.

Inputs

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

Outputs

rg_out: a region map.
gr_out: a graph.

Result

Returns the number of merges.

Examples

Merges regions yielded by a quadtree splitting process:

   puniformityquadtree 0.9 tangram.pan a.pan
   prg2gr a.pan b.pan
   pmeanmerging -1 10 a.pan b.pan tangram.pan c.pan d.pan

C++ prototype

Errc PMeanMerging( const Reg2d &rg_in, const Graph2d &gr_in, const Img2duc &im_in, Reg2d &rg_out, Graph2d &gr_out, long iterations, float threshold );

Version française

Fusion prioritaire de régions selon la différence de moyennes intérieures.

Author: Laurent Quesnel