Choose all regions containing a given pixel.

The operator ::select_region_point selects alle regions from Regions containing the test pixel (Row,Column), i.e.:

            |Region[n] intersection {(Row,Column)}| = 1

If the regions overlap more than one region might contain the pixel. In this case all these regions are returned. If no region contains the indicated pixel the empty tuple (= no region) is returned.

#include  <iostream.h>
#include  "HalconCpp.h"

int main ()
{
  HImage        img ("fabrik");
  HWindow       w;
  HRegionArray  ireg, reg;
  DPoint2D      rc;
  int           Button;

  img.Display (w);
  reg = img.Regiongrowing (3, 3, 5, 100);
  reg.Display (w);
  w.SetColor ("red");
  w.SetDraw  ("margin");

  cout << "Select any region with left mouse button (right button ends)"
       << endl;
  do
  {
    rc = w.GetMbutton (&Button);
    cout << "[x, y] = " << (long) rc.X() << ", " << (long) rc.Y() << endl;
    ireg = reg.SelectRegionPoint ((long) rc.Y(), (long) rc.X());
    ireg.Display (w);
  } while (Button != 4);
  return(0);
}

If F is the area of the region and N is the number of regions, the mean runtime complexity is O(ln(F) * N).

The operator ::select_region_point returns the value H_MSG_TRUE if the parameters are correct. The behavior in case of empty input (no input regions available) is set via the operator ::set_system('no_object_result',<Result>). If necessary an exception handling is raised.

::threshold, ::regiongrowing, ::connection

::test_region_point

::get_mbutton, ::get_mposition

Region processing