class_2dim_unsupclass_2dim_unsupClass2dimUnsupClass2dimUnsupclass_2dim_unsup (Operator)

Name

class_2dim_unsupclass_2dim_unsupClass2dimUnsupClass2dimUnsupclass_2dim_unsup — Segment two images by clustering.

Signature

class_2dim_unsup(Image1, Image2 : Classes : Threshold, NumClasses : )

Description

class_2dim_unsupclass_2dim_unsupClass2dimUnsupClass2dimUnsupclass_2dim_unsup performs a classification with two single-channel images. First, a two-dimensional histogram of the two images is computed (histo_2dimhisto_2dimHisto2dimHisto2dimhisto_2dim). In this histogram, the first maximum is extracted; it serves as the first cluster center. The histogram is computed with the intersection of the domains of both images (see reduce_domainreduce_domainReduceDomainReduceDomainreduce_domain). After this, all pixels in the images that are at most ThresholdThresholdThresholdthresholdthreshold pixels from the cluster center in the maximum norm, are determined. These pixels form one output region. Next, the pixels thus classified are deleted from the histogram so that they are not taken into account for the next class. In this modified histogram, again the maximum is extracted; it again serves as a cluster center. The above steps are repeated NumClassesNumClassesNumClassesnumClassesnum_classes times; thus, NumClassesNumClassesNumClassesnumClassesnum_classes output regions result. Only pixels defined in both images are returned.

Attention

Both input images must have the same size.

Execution Information

Multithreading type: reentrant (runs in parallel with non-exclusive operators).
Multithreading scope: global (may be called from any thread).
Processed without parallelization.

Parameters

Image1Image1Image1image1image_1 (input_object) singlechannelimage → object (byte)

First input image.

Image2Image2Image2image2image_2 (input_object) singlechannelimage → object (byte)

Second input image.

ClassesClassesClassesclassesclasses (output_object) region-array → object

Classification result.

ThresholdThresholdThresholdthresholdthreshold (input_control) integer → (integer)

Threshold (maximum distance to the cluster's center).

Default: 15

Suggested values: 0, 2, 5, 8, 12, 17, 20, 30, 50, 70

NumClassesNumClassesNumClassesnumClassesnum_classes (input_control) integer → (integer)

Number of classes (cluster centers).

Default: 5

Suggested values: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, 30, 40, 50

Example (C++)

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

int main (int argc, char *argv[])
{
  if (argc != 2)
  {
    cout << "Usage : " << argv[0] << " 'image' " << endl;
    return (-1);
  }

  HImage   colimg (argv[1]),
           green, blue;

  HWindow  w;
  Hlong     nc;

  if ((nc = colimg.CountChannels ()) != 3)
  {
    cout << argv[1] << " is not a rgb-image " << endl;
    return (-2);
  }

  colimg.Display (w);

  HImage        red = colimg.Decompose3 (&green, &blue);
  HRegionArray  seg = red.Class2dimUnsup (green, 15, 5);

  w.SetDraw ("margin");
  w.SetColored (12);
  seg.Display (w);
  w.Click ();

  return (0);
}

Example (C)

read_image(&ColorImage,"patras");
decompose3(ColorImage,&Red,&Green,&Blue);
class_2dim_unsup(Red,Green,&Seg,15,5);
set_colored(WindowHandle,12);
disp_region(Seg,WindowHandle);

Example (C++)

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

int main (int argc, char *argv[])
{
  if (argc != 2)
  {
    cout << "Usage : " << argv[0] << " 'image' " << endl;
    return (-1);
  }

  HImage   colimg (argv[1]),
           green, blue;

  HWindow  w;
  Hlong     nc;

  if ((nc = colimg.CountChannels ()) != 3)
  {
    cout << argv[1] << " is not a rgb-image " << endl;
    return (-2);
  }

  colimg.Display (w);

  HImage        red = colimg.Decompose3 (&green, &blue);
  HRegionArray  seg = red.Class2dimUnsup (green, 15, 5);

  w.SetDraw ("margin");
  w.SetColored (12);
  seg.Display (w);
  w.Click ();

  return (0);
}

Example (C++)

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

int main (int argc, char *argv[])
{
  if (argc != 2)
  {
    cout << "Usage : " << argv[0] << " 'image' " << endl;
    return (-1);
  }

  HImage   colimg (argv[1]),
           green, blue;

  HWindow  w;
  Hlong     nc;

  if ((nc = colimg.CountChannels ()) != 3)
  {
    cout << argv[1] << " is not a rgb-image " << endl;
    return (-2);
  }

  colimg.Display (w);

  HImage        red = colimg.Decompose3 (&green, &blue);
  HRegionArray  seg = red.Class2dimUnsup (green, 15, 5);

  w.SetDraw ("margin");
  w.SetColored (12);
  seg.Display (w);
  w.Click ();

  return (0);
}

Result

class_2dim_unsupclass_2dim_unsupClass2dimUnsupClass2dimUnsupclass_2dim_unsup returns 2 ( H_MSG_TRUE) if all parameters are correct. The behavior with respect to the input images and output regions can be determined by setting the values of the flags 'no_object_result'"no_object_result""no_object_result""no_object_result""no_object_result", 'empty_region_result'"empty_region_result""empty_region_result""empty_region_result""empty_region_result", and 'store_empty_region'"store_empty_region""store_empty_region""store_empty_region""store_empty_region" with set_systemset_systemSetSystemSetSystemset_system. If necessary, an exception is raised.

Possible Predecessors

decompose2decompose2Decompose2Decompose2decompose2, decompose3decompose3Decompose3Decompose3decompose3, median_imagemedian_imageMedianImageMedianImagemedian_image, anisotropic_diffusionanisotropic_diffusionAnisotropicDiffusionAnisotropicDiffusionanisotropic_diffusion, reduce_domainreduce_domainReduceDomainReduceDomainreduce_domain

Possible Successors

select_shapeselect_shapeSelectShapeSelectShapeselect_shape, select_grayselect_graySelectGraySelectGrayselect_gray, connectionconnectionConnectionConnectionconnection

Alternatives

thresholdthresholdThresholdThresholdthreshold, histo_2dimhisto_2dimHisto2dimHisto2dimhisto_2dim, class_2dim_supclass_2dim_supClass2dimSupClass2dimSupclass_2dim_sup, class_ndim_normclass_ndim_normClassNdimNormClassNdimNormclass_ndim_norm

Module

Foundation

Operators