opening_segopening_segOpeningSegOpeningSeg (Operator)

Name

opening_segopening_segOpeningSegOpeningSeg — Separate overlapping regions.

Warning

opening_segopening_segOpeningSegOpeningSegOpeningSeg is obsolete and is only provided for reasons of backward compatibility.

Signature

opening_seg(Region, StructElement : RegionOpening : : )

Description

The opening_segopening_segOpeningSegOpeningSegOpeningSeg operation is defined as a sequence of the following operators: erosion1erosion1Erosion1Erosion1Erosion1, connectionconnectionConnectionConnectionConnection and dilation1dilation1Dilation1Dilation1Dilation1 (see example). Only one iteration is done in erosion1erosion1Erosion1Erosion1Erosion1 and dilation1dilation1Dilation1Dilation1Dilation1.

opening_segopening_segOpeningSegOpeningSegOpeningSeg serves to separate overlapping regions whose area of overlap is smaller than StructElementStructElementStructElementStructElementstructElement. It should be noted that the resulting regions can overlap without actually merging (see expand_regionexpand_regionExpandRegionExpandRegionExpandRegion). opening_segopening_segOpeningSegOpeningSegOpeningSeg uses the center of gravity as the reference point of the structuring element.

Structuring elements (StructElementStructElementStructElementStructElementstructElement) can be generated with operators such as gen_circlegen_circleGenCircleGenCircleGenCircle, gen_rectangle1gen_rectangle1GenRectangle1GenRectangle1GenRectangle1, gen_rectangle2gen_rectangle2GenRectangle2GenRectangle2GenRectangle2, gen_ellipsegen_ellipseGenEllipseGenEllipseGenEllipse, draw_regiondraw_regionDrawRegionDrawRegionDrawRegion, gen_region_polygongen_region_polygonGenRegionPolygonGenRegionPolygonGenRegionPolygon, gen_region_pointsgen_region_pointsGenRegionPointsGenRegionPointsGenRegionPoints, etc.

Execution Information

Multithreading type: reentrant (runs in parallel with non-exclusive operators).
Multithreading scope: global (may be called from any thread).
Automatically parallelized on tuple level.

Parameters

RegionRegionRegionRegionregion (input_object) region(-array) → object

Regions to be opened.

StructElementStructElementStructElementStructElementstructElement (input_object) region → object

Structuring element (position-invariant).

RegionOpeningRegionOpeningRegionOpeningRegionOpeningregionOpening (output_object) region-array → object

Opened regions.

Example (HDevelop)

* Simulation of opening_seg
* opening_seg(Region,StructElement,RegionOpening):
    erosion1(Region,StructElement,H1,1)
    connection(H1,H2)
    dilation1(H2,StructElement,RegionOpening,1)

Example (C)

/* Simulation of opening_seg */
my_opening_seg(Hobject Region, Hobject StructElement, Hobject *Opening)
{
  Hobject  H1,H2;
  erosion1(Region,StructElement,&H1,1);
  connection(H1,&H2);
  dilation1(H2,StructElement,Opening,1);
  clear_obj(H1); clear_obj(H2);
}

/* separation of circular objects */
gen_random_regions(&Regions,"circle",8.5,10.5,0.0,0.0,0.0,0.0,400,512,512);
union1(Regions,&UnionReg);
gen_circle(&Mask,100,100,8.5);
opening_seg(UnionReg,Mask,&RegionsNew);

Example (HDevelop)

* Simulation of opening_seg
* opening_seg(Region,StructElement,RegionOpening):
    erosion1(Region,StructElement,H1,1)
    connection(H1,H2)
    dilation1(H2,StructElement,RegionOpening,1)

Example (HDevelop)

* Simulation of opening_seg
* opening_seg(Region,StructElement,RegionOpening):
    erosion1(Region,StructElement,H1,1)
    connection(H1,H2)
    dilation1(H2,StructElement,RegionOpening,1)

Example (HDevelop)

* Simulation of opening_seg
* opening_seg(Region,StructElement,RegionOpening):
    erosion1(Region,StructElement,H1,1)
    connection(H1,H2)
    dilation1(H2,StructElement,RegionOpening,1)

Complexity

Let F1 be the area of the input region, and F2 be the area of the structuring element. Then the runtime complexity for one region is:

Result

opening_segopening_segOpeningSegOpeningSegOpeningSeg returns 2 (H_MSG_TRUE) if all parameters are correct. The behavior in case of empty or no input region can be set via:

no region: set_system('no_object_result',<RegionResult>)

empty region: set_system('empty_region_result',<RegionResult>)

Otherwise, an exception is raised.

Possible Predecessors

thresholdthresholdThresholdThresholdThreshold, regiongrowingregiongrowingRegiongrowingRegiongrowingRegiongrowing, connectionconnectionConnectionConnectionConnection, union1union1Union1Union1Union1, watershedswatershedsWatershedsWatershedsWatersheds, class_ndim_normclass_ndim_normClassNdimNormClassNdimNormClassNdimNorm, gen_circlegen_circleGenCircleGenCircleGenCircle, gen_ellipsegen_ellipseGenEllipseGenEllipseGenEllipse, gen_rectangle1gen_rectangle1GenRectangle1GenRectangle1GenRectangle1, gen_rectangle2gen_rectangle2GenRectangle2GenRectangle2GenRectangle2, draw_regiondraw_regionDrawRegionDrawRegionDrawRegion, gen_region_pointsgen_region_pointsGenRegionPointsGenRegionPointsGenRegionPoints, gen_region_polygon_filledgen_region_polygon_filledGenRegionPolygonFilledGenRegionPolygonFilledGenRegionPolygonFilled

Possible Successors

expand_regionexpand_regionExpandRegionExpandRegionExpandRegion, reduce_domainreduce_domainReduceDomainReduceDomainReduceDomain, select_shapeselect_shapeSelectShapeSelectShapeSelectShape, area_centerarea_centerAreaCenterAreaCenterAreaCenter, connectionconnectionConnectionConnectionConnection

Alternatives

erosion1erosion1Erosion1Erosion1Erosion1, connectionconnectionConnectionConnectionConnection, dilation1dilation1Dilation1Dilation1Dilation1

Module

Foundation

Operators