opening_segopening_segOpeningSegOpeningSegopening_seg (Operator)

Name

opening_segopening_segOpeningSegOpeningSegopening_seg — Separate overlapping regions.

Warning

opening_segopening_segOpeningSegOpeningSegOpeningSegopening_seg is obsolete and is only provided for reasons of backward compatibility.

Signature

opening_seg(Region, StructElement : RegionOpening : : )

Description

The opening_segopening_segOpeningSegOpeningSegOpeningSegopening_seg operation is defined as a sequence of the following operators: erosion1erosion1Erosion1Erosion1Erosion1erosion1, connectionconnectionConnectionConnectionConnectionconnection and dilation1dilation1Dilation1Dilation1Dilation1dilation1 (see example). Only one iteration is done in erosion1erosion1Erosion1Erosion1Erosion1erosion1 and dilation1dilation1Dilation1Dilation1Dilation1dilation1.

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

Structuring elements (StructElementStructElementStructElementStructElementstructElementstruct_element) can be generated with operators such as gen_circlegen_circleGenCircleGenCircleGenCirclegen_circle, gen_rectangle1gen_rectangle1GenRectangle1GenRectangle1GenRectangle1gen_rectangle1, gen_rectangle2gen_rectangle2GenRectangle2GenRectangle2GenRectangle2gen_rectangle2, gen_ellipsegen_ellipseGenEllipseGenEllipseGenEllipsegen_ellipse, draw_regiondraw_regionDrawRegionDrawRegionDrawRegiondraw_region, gen_region_polygongen_region_polygonGenRegionPolygonGenRegionPolygonGenRegionPolygongen_region_polygon, gen_region_pointsgen_region_pointsGenRegionPointsGenRegionPointsGenRegionPointsgen_region_points, 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

RegionRegionRegionRegionregionregion (input_object) region(-array) → object

Regions to be opened.

StructElementStructElementStructElementStructElementstructElementstruct_element (input_object) region → object

Structuring element (position-invariant).

RegionOpeningRegionOpeningRegionOpeningRegionOpeningregionOpeningregion_opening (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);
}

/* 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_segOpeningSegOpeningSegOpeningSegopening_seg returns 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

thresholdthresholdThresholdThresholdThresholdthreshold, regiongrowingregiongrowingRegiongrowingRegiongrowingRegiongrowingregiongrowing, connectionconnectionConnectionConnectionConnectionconnection, union1union1Union1Union1Union1union1, watershedswatershedsWatershedsWatershedsWatershedswatersheds, class_ndim_normclass_ndim_normClassNdimNormClassNdimNormClassNdimNormclass_ndim_norm, gen_circlegen_circleGenCircleGenCircleGenCirclegen_circle, gen_ellipsegen_ellipseGenEllipseGenEllipseGenEllipsegen_ellipse, gen_rectangle1gen_rectangle1GenRectangle1GenRectangle1GenRectangle1gen_rectangle1, gen_rectangle2gen_rectangle2GenRectangle2GenRectangle2GenRectangle2gen_rectangle2, draw_regiondraw_regionDrawRegionDrawRegionDrawRegiondraw_region, gen_region_pointsgen_region_pointsGenRegionPointsGenRegionPointsGenRegionPointsgen_region_points, gen_region_polygon_filledgen_region_polygon_filledGenRegionPolygonFilledGenRegionPolygonFilledGenRegionPolygonFilledgen_region_polygon_filled

Possible Successors

expand_regionexpand_regionExpandRegionExpandRegionExpandRegionexpand_region, reduce_domainreduce_domainReduceDomainReduceDomainReduceDomainreduce_domain, select_shapeselect_shapeSelectShapeSelectShapeSelectShapeselect_shape, area_centerarea_centerAreaCenterAreaCenterAreaCenterarea_center, connectionconnectionConnectionConnectionConnectionconnection

Alternatives

erosion1erosion1Erosion1Erosion1Erosion1erosion1, connectionconnectionConnectionConnectionConnectionconnection, dilation1dilation1Dilation1Dilation1Dilation1dilation1

Module

Foundation

Operators