local_minLocalMinLocalMinlocal_minlocal_min🔗

Short description🔗

local_minLocalMinLocalMinlocal_minlocal_min — Detect all local minima in an image.

Signature🔗

local_min( image Image, out region LocalMinima )

HRegion HImage::LocalMin( ) const

HRegion HImage.LocalMin( )

Description🔗

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

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🔗

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

Image to be processed.

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

Extracted local minima as regions.

Number of elements: LocalMinima == Image

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)\;

(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)\;
}

Combinations with other operators🔗

Combinations

Possible predecessors

binomial_filterBinomialFilter, gauss_filterGaussFilter, smooth_imageSmoothImage

Possible successors

get_region_pointsGetRegionPoints, connectionConnection

Alternatives

gray_skeletonGraySkeleton, lowlandsLowlands, lowlands_centerLowlandsCenter

Module🔗

Foundation