dilation_circleDilationCircleDilationCircledilation_circledilation_circle🔗

Short description🔗

dilation_circleDilationCircleDilationCircledilation_circledilation_circle — Dilate a region with a circular structuring element.

Signature🔗

dilation_circle( region Region, out region RegionDilation, real Radius )

Description🔗

dilation_circleDilationCircle applies a Minkowski addition with a circular structuring element to the input regions Regionregionregion. Because the circular mask is symmetrical, this is identical to a dilation. The size of the circle used as structuring element is determined by Radiusradiusradius.

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

Attention🔗

dilation_circleDilationCircle is applied to each input region separately. If gaps between different regions are to be closed, union1Union1 or union2Union2 has to be called first.

Execution information🔗

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🔗

Regionregionregion (input_object) region(-array) → objectHObjectHRegionHObjectHobject

Regions to be dilated.

RegionDilationregionDilationregion_dilation (output_object) region(-array) → objectHObjectHRegionHObjectHobject *

Dilated regions.

Radiusradiusradius (input_control) real → (real / integer)HTuple (double / Hlong)HTuple (double / int / long)Union[float, int]Htuple (double / Hlong)

Radius of the circular structuring element.

Default: 3.53.5
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
Value range: 0.5 ≤ Radius ≤ 511.5 (lin)
Minimum increment: 1.0
Recommended increment: 1.0

Example🔗

(C)

my_dilation_circle(Hobject In, double Radius, Hobject *Out)
{
  Hobject Circle\;
  gen_circle(&Circle,100.0,100.0,Radius)\;
  minkowski_add1(In,Circle,Out,1)\;
}

(C++)

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

main()
{
  cout << "Reproduction of 'dilation_circle ()'" << endl\;
  cout << "First = original image " << endl\;
  cout << "Blue  = after dilation " << endl\;
  cout << "Red   = before dilation " << endl\;
 HByteImage img("monkey")\;
  HWindow    w\;
 HRegion      circ   = HRegion::GenCircle (10, 10, 1.5)\;
  HRegionArray regs   = (img >= 128).Connection()\;
  HRegionArray minadd = regs.MinkowskiAdd1 (circ, 1)\;
                       img.Display (w)\;      w.Click ()\;
  w.SetColor ("blue")\;  minadd.Display (w)\;   w.Click ()\;
  w.SetColor ("red")\;   regs.Display (w)\;     w.Click ()\;
 return(0)\;
}

Complexity🔗

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

\[\begin{eqnarray*} O(2 \cdot \textrm{Radius} \cdot \sqrt{F1}) \enspace . \end{eqnarray*}\]

Result🔗

dilation_circleDilationCircle 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.

Combinations with other operators🔗

Combinations

Possible predecessors

thresholdThreshold, regiongrowingRegiongrowing, connectionConnection, union1Union1, watershedsWatersheds, class_ndim_normClassNdimNorm

Possible successors

reduce_domainReduceDomain, select_shapeSelectShape, area_centerAreaCenter, connectionConnection

Alternatives

minkowski_add1MinkowskiAdd1, minkowski_add2MinkowskiAdd2, expand_regionExpandRegion, dilation1Dilation1, dilation2Dilation2, dilation_rectangle1DilationRectangle1

Module🔗

Foundation