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erosion_circleerosion_circleErosionCircleErosionCircleerosion_circle (Operator)

Name

erosion_circleerosion_circleErosionCircleErosionCircleerosion_circle — Erode a region with a circular structuring element.

Signature

erosion_circle(Region : RegionErosion : Radius : )

Herror erosion_circle(const Hobject Region, Hobject* RegionErosion, double Radius)

Herror T_erosion_circle(const Hobject Region, Hobject* RegionErosion, const Htuple Radius)

void ErosionCircle(const HObject& Region, HObject* RegionErosion, const HTuple& Radius)

HRegion HRegion::ErosionCircle(const HTuple& Radius) const

HRegion HRegion::ErosionCircle(double Radius) const

static void HOperatorSet.ErosionCircle(HObject region, out HObject regionErosion, HTuple radius)

HRegion HRegion.ErosionCircle(HTuple radius)

HRegion HRegion.ErosionCircle(double radius)

def erosion_circle(region: HObject, radius: Union[float, int]) -> HObject

Description

erosion_circleerosion_circleErosionCircleErosionCircleErosionCircleerosion_circle applies a Minkowski subtraction with a circular structuring element to the input regions RegionRegionRegionRegionregionregion. Because the circular mask is symmetrical, this is identical to an erosion. The size of the circle used as structuring element is determined by RadiusRadiusRadiusRadiusradiusradius.

The operator results in reduced regions, smoothed region boundaries, and the regions smaller than the circular mask are eliminated. It is useful to select only values like 3.5, 5.5, etc. for RadiusRadiusRadiusRadiusradiusradius in order to avoid a translation of a region, because integer radii result in a circle having a non-integer center of gravity which is rounded to the next integer.

Execution Information

Parameters

RegionRegionRegionRegionregionregion (input_object)  region(-array) → objectHRegionHObjectHRegionHobject

Regions to be eroded.

RegionErosionRegionErosionRegionErosionRegionErosionregionErosionregion_erosion (output_object)  region(-array) → objectHRegionHObjectHRegionHobject *

Eroded regions.

RadiusRadiusRadiusRadiusradiusradius (input_control)  real → HTupleUnion[float, int]HTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

Radius of the circular structuring element.

Default value: 3.5

Suggested values: 1.5, 2.5, 3.5, 4.5, 5.5, 7.5, 9.5, 12.5, 15.5, 19.5, 25.5, 33.5, 45.5, 60.5, 110.5

Typical range of values: 0.5 ≤ Radius Radius Radius Radius radius radius ≤ 511.5 (lin)

Minimum increment: 1.0

Recommended increment: 1.0

Example (C++)

#include "HIOStream.h"
#if !defined(USE_IOSTREAM_H)
using namespace std;
#endif
#include "HalconCpp.h"

main()
{
  cout << "Simulation of 'erosion_circle ()'" << endl;
  cout << "First = original image " << endl;
  cout << "Red   = after segmentation " << endl;
  cout << "Blue  = after erosion " << endl;

  HByteImage img("monkey");
  HWindow    w;

  HRegion      circ   = HRegion::GenCircle (10, 10, 1.5);
  HRegionArray regs   = (img >= 128).Connection();
  HRegionArray minsub = regs.MinkowskiSub1 (circ, 1);

                         img.Display (w);      w.Click ();
  w.SetColor ("red");   regs.Display (w);     w.Click ();
  w.SetColor ("blue");  minsub.Display (w);   w.Click ();

  return(0);
}

Example (C)

my_erosion_circle(Hobject In, double Radius, Hobject *Out)
{
  Hobject Circle;
  gen_circle(&Circle,100.0,100.0,Radius);
  minkowski_sub1(In,Circle,Out,1);
}

Example (C++)

#include "HIOStream.h"
#if !defined(USE_IOSTREAM_H)
using namespace std;
#endif
#include "HalconCpp.h"

main()
{
  cout << "Simulation of 'erosion_circle ()'" << endl;
  cout << "First = original image " << endl;
  cout << "Red   = after segmentation " << endl;
  cout << "Blue  = after erosion " << endl;

  HByteImage img("monkey");
  HWindow    w;

  HRegion      circ   = HRegion::GenCircle (10, 10, 1.5);
  HRegionArray regs   = (img >= 128).Connection();
  HRegionArray minsub = regs.MinkowskiSub1 (circ, 1);

                         img.Display (w);      w.Click ();
  w.SetColor ("red");   regs.Display (w);     w.Click ();
  w.SetColor ("blue");  minsub.Display (w);   w.Click ();

  return(0);
}

Example (C++)

#include "HIOStream.h"
#if !defined(USE_IOSTREAM_H)
using namespace std;
#endif
#include "HalconCpp.h"

main()
{
  cout << "Simulation of 'erosion_circle ()'" << endl;
  cout << "First = original image " << endl;
  cout << "Red   = after segmentation " << endl;
  cout << "Blue  = after erosion " << endl;

  HByteImage img("monkey");
  HWindow    w;

  HRegion      circ   = HRegion::GenCircle (10, 10, 1.5);
  HRegionArray regs   = (img >= 128).Connection();
  HRegionArray minsub = regs.MinkowskiSub1 (circ, 1);

                         img.Display (w);      w.Click ();
  w.SetColor ("red");   regs.Display (w);     w.Click ();
  w.SetColor ("blue");  minsub.Display (w);   w.Click ();

  return(0);
}

Example (C++)

#include "HIOStream.h"
#if !defined(USE_IOSTREAM_H)
using namespace std;
#endif
#include "HalconCpp.h"

main()
{
  cout << "Simulation of 'erosion_circle ()'" << endl;
  cout << "First = original image " << endl;
  cout << "Red   = after segmentation " << endl;
  cout << "Blue  = after erosion " << endl;

  HByteImage img("monkey");
  HWindow    w;

  HRegion      circ   = HRegion::GenCircle (10, 10, 1.5);
  HRegionArray regs   = (img >= 128).Connection();
  HRegionArray minsub = regs.MinkowskiSub1 (circ, 1);

                         img.Display (w);      w.Click ();
  w.SetColor ("red");   regs.Display (w);     w.Click ();
  w.SetColor ("blue");  minsub.Display (w);   w.Click ();

  return(0);
}

Complexity

Let F1 be the area of an input region. Then the runtime complexity for one region is:

Result

erosion_circleerosion_circleErosionCircleErosionCircleErosionCircleerosion_circle returns TRUE if all parameters are correct. The behavior in case of empty or no input region can be set via:

Otherwise, an exception is raised.

Possible Predecessors

thresholdthresholdThresholdThresholdThresholdthreshold, regiongrowingregiongrowingRegiongrowingRegiongrowingRegiongrowingregiongrowing, watershedswatershedsWatershedsWatershedsWatershedswatersheds, class_ndim_normclass_ndim_normClassNdimNormClassNdimNormClassNdimNormclass_ndim_norm

Possible Successors

connectionconnectionConnectionConnectionConnectionconnection, reduce_domainreduce_domainReduceDomainReduceDomainReduceDomainreduce_domain, select_shapeselect_shapeSelectShapeSelectShapeSelectShapeselect_shape, area_centerarea_centerAreaCenterAreaCenterAreaCenterarea_center

Alternatives

minkowski_sub1minkowski_sub1MinkowskiSub1MinkowskiSub1MinkowskiSub1minkowski_sub1

See also

gen_circlegen_circleGenCircleGenCircleGenCirclegen_circle, dilation_circledilation_circleDilationCircleDilationCircleDilationCircledilation_circle, closing_circleclosing_circleClosingCircleClosingCircleClosingCircleclosing_circle, opening_circleopening_circleOpeningCircleOpeningCircleOpeningCircleopening_circle

Module

Foundation

ClassesClasses | | Operators
HALCON Operator Reference 20.11.4.0 Copyright © 1996-2023 MVTec Software GmbH