HALCON Reference Manual 10.0.2
Table of Contents / Morphology / Region ClassesClassesClasses | | | Operators

erosion_circleerosion_circleerosion_circleErosionCircleErosionCircle (Operator)

Name

erosion_circleerosion_circleerosion_circleErosionCircleErosionCircle — 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)

Herror erosion_circle(Hobject Region, Hobject* RegionErosion, const HTuple& Radius)

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

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

void HOperatorSetX.ErosionCircle(
[in] IHUntypedObjectX* Region, [out] IHUntypedObjectX** RegionErosion, [in] VARIANT Radius)

IHRegionX* HRegionX.ErosionCircle([in] VARIANT Radius)

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

HRegion HRegion.ErosionCircle(HTuple radius)

HRegion HRegion.ErosionCircle(double radius)

Description

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

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 RadiusRadiusRadiusRadiusradius 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.

Parallelization

Parameters

RegionRegionRegionRegionregion (input_object)  region(-array) → objectHRegionHRegionHRegionXHobject

Regions to be eroded.

RegionErosionRegionErosionRegionErosionRegionErosionregionErosion (output_object)  region(-array) → objectHRegionHRegionHRegionXHobject *

Eroded regions.

RadiusRadiusRadiusRadiusradius (input_control)  real → HTupleHTupleVARIANTHtuple (real / integer) (double / int / long) (double / Hlong) (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 ≤ 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);
  clear_obj(Circle);
}

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: 

       O(2 * Radius * sqrt(F1)) .

Result

erosion_circleerosion_circleerosion_circleErosionCircleErosionCircle returns 2 (H_MSG_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

thresholdthresholdthresholdThresholdThreshold, regiongrowingregiongrowingregiongrowingRegiongrowingRegiongrowing, watershedswatershedswatershedsWatershedsWatersheds, class_ndim_normclass_ndim_normclass_ndim_normClassNdimNormClassNdimNorm

Possible Successors

connectionconnectionconnectionConnectionConnection, reduce_domainreduce_domainreduce_domainReduceDomainReduceDomain, select_shapeselect_shapeselect_shapeSelectShapeSelectShape, area_centerarea_centerarea_centerAreaCenterAreaCenter

Alternatives

minkowski_sub1minkowski_sub1minkowski_sub1MinkowskiSub1MinkowskiSub1

See also

gen_circlegen_circlegen_circleGenCircleGenCircle, dilation_circledilation_circledilation_circleDilationCircleDilationCircle, closing_circleclosing_circleclosing_circleClosingCircleClosingCircle, opening_circleopening_circleopening_circleOpeningCircleOpeningCircle

Module

Foundation

Table of Contents / Morphology / Region ClassesClassesClasses | | | Operators
HALCON Reference Manual 10.0.2 Copyright © 1996-2011 MVTec Software GmbH