Operator Reference

HALCON Operator Reference / Segmentation / Topography

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ClassesClasses | | Operators

local_minlocal_minLocalMinLocalMinlocal_min (Operator)

local_minlocal_minLocalMinLocalMinlocal_min — Detect all local minima in an image.

Signature

local_min(Image : LocalMinima : : )

Herror local_min(const Hobject Image, Hobject* LocalMinima)

Herror T_local_min(const Hobject Image, Hobject* LocalMinima)

void LocalMin(const HObject& Image, HObject* LocalMinima)

HRegion HImage::LocalMin() const

static void HOperatorSet.LocalMin(HObject image, out HObject localMinima)

HRegion HImage.LocalMin()

def local_min(image: HObject) -> HObject

Description

local_minlocal_minLocalMinLocalMinlocal_min extracts all points from ImageImageImageimageimage having a gray value smaller than the gray value of all its neighbors and returns them in LocalMinimaLocalMinimaLocalMinimalocalMinimalocal_minima. The neighborhood used can be set by set_system(::'neighborhood',<4/8>)set_system("neighborhood",<4/8>)SetSystem("neighborhood",<4/8>)SetSystem("neighborhood",<4/8>)set_system("neighborhood",<4/8>).

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

ImageImageImageimageimage (input_object)  singlechannelimage(-array) → objectHImageHObjectHObjectHobject (byte / direction / cyclic / int1 / int2 / uint2 / int4 / int8 / real)

Image to be processed.

LocalMinimaLocalMinimaLocalMinimalocalMinimalocal_minima (output_object)  region(-array) → objectHRegionHObjectHObjectHobject *

Extracted local minima as regions.

Number of elements: LocalMinima == Image

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] << " <name of image>" << endl;
    return (-1);
  }

  HImage   image (argv[1]);
  HWindow  win;

  image.Display (win);

  HImage       cres = image.CornerResponse (5, 0.04);
  HRegionArray mins = cres.LocalMin ();

  win.SetColored (12);
  mins.Display (win);
  win.Click ();

  return (0);
}

Example (C)

read_image(&Image,"fabrik");
corner_responce(Image,&CornerResp,5,0.04);
local_min(CornerResp,&Minima);
set_colored(WindowHandle,12);
disp_region(Minima,WindowHandle);
T_get_region_points(Minima,&Row,&Col);

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] << " <name of image>" << endl;
    return (-1);
  }

  HImage   image (argv[1]);
  HWindow  win;

  image.Display (win);

  HImage       cres = image.CornerResponse (5, 0.04);
  HRegionArray mins = cres.LocalMin ();

  win.SetColored (12);
  mins.Display (win);
  win.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] << " <name of image>" << endl;
    return (-1);
  }

  HImage   image (argv[1]);
  HWindow  win;

  image.Display (win);

  HImage       cres = image.CornerResponse (5, 0.04);
  HRegionArray mins = cres.LocalMin ();

  win.SetColored (12);
  mins.Display (win);
  win.Click ();

  return (0);
}

Possible Predecessors

binomial_filterbinomial_filterBinomialFilterBinomialFilterbinomial_filter, gauss_filtergauss_filterGaussFilterGaussFiltergauss_filter, smooth_imagesmooth_imageSmoothImageSmoothImagesmooth_image

Possible Successors

get_region_pointsget_region_pointsGetRegionPointsGetRegionPointsget_region_points, connectionconnectionConnectionConnectionconnection

Alternatives

gray_skeletongray_skeletonGraySkeletonGraySkeletongray_skeleton, lowlandslowlandsLowlandsLowlandslowlands, lowlands_centerlowlands_centerLowlandsCenterLowlandsCenterlowlands_center

See also

monotonymonotonyMonotonyMonotonymonotony, topographic_sketchtopographic_sketchTopographicSketchTopographicSketchtopographic_sketch, corner_responsecorner_responseCornerResponseCornerResponsecorner_response, texture_lawstexture_lawsTextureLawsTextureLawstexture_laws

Module

Foundation

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ClassesClasses | | Operators