HALCON Reference Manual 10.0.2

Name

bottom_hatbottom_hatbottom_hatBottomHatBottomHat — Compute the bottom hat of regions.

Signature

bottom_hat(Region, StructElement : RegionBottomHat : : )

bottom_hatbottom_hatbottom_hatBottomHatBottomHat computes the closingclosingclosingClosingClosing of RegionRegionRegionRegionregion with StructElementStructElementStructElementStructElementstructElement. The difference between the result of the closing and the original region is called the bottom hat. In contrast to closingclosingclosingClosingClosing, which merges regions under certain circumstances, bottom_hatbottom_hatbottom_hatBottomHatBottomHat computes the regions generated by such a merge.

The position of StructElementStructElementStructElementStructElementstructElement is meaningless, since a closing operation is invariant with respect to the choice of the reference point.

Structuring elements (StructElementStructElementStructElementStructElementstructElement) can be generated with operators such as gen_circlegen_circlegen_circleGenCircleGenCircle, gen_rectangle1gen_rectangle1gen_rectangle1GenRectangle1GenRectangle1, gen_rectangle2gen_rectangle2gen_rectangle2GenRectangle2GenRectangle2, gen_ellipsegen_ellipsegen_ellipseGenEllipseGenEllipse, draw_regiondraw_regiondraw_regionDrawRegionDrawRegion, gen_region_polygongen_region_polygongen_region_polygonGenRegionPolygonGenRegionPolygon, gen_region_pointsgen_region_pointsgen_region_pointsGenRegionPointsGenRegionPoints, etc.

Parallelization

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

RegionRegionRegionRegionregion (input_object) region(-array) → object

Regions to be processed.

StructElementStructElementStructElementStructElementstructElement (input_object) region → object

Structuring element (position independent).

RegionBottomHatRegionBottomHatRegionBottomHatRegionBottomHatregionBottomHat (output_object) region(-array) → object

Result of the bottom hat operator.

Example (HDevelop)

read_image (Image,'/images/name.ext')
threshold (Image,Regions,128,255)
gen_circle (Circle,0,0,16)
bottom_hat (Regions,Circle,RegionBottomHat)

Example (C)

threshold(Image,&Regions,128.0,255.0);
gen_circle(&Circle,128.0,128.0,16.0);
bottom_hat(Regions,Circle,&RegionBottomHat);
set_color(WindowHandle,"red");
disp_region(Regions,WindowHandle);
set_color(WindowHandle,"green");
disp_region(RegionBottomHat,WindowHandle);

Example (C++)

#include "HalconCpp.h"

main()
{
  HByteImage    Monkey("monkey");
  HWindow       w;

  HRegion regs = (Monkey >= 128);
  HRegion circ = HRegion::GenCircle (128, 128, 3);

  HRegion rbht = regs.BottomHat (circ);

  Monkey.Display (w);  w.Click ();
  w.SetColor ("red");     regs.Display (w);  w.Click ();
  w.SetColor ("green");   rbht.Display (w);  w.Click ();

  return(0);
}

Example (HDevelop)

read_image (Image,'/images/name.ext')
threshold (Image,Regions,128,255)
gen_circle (Circle,0,0,16)
bottom_hat (Regions,Circle,RegionBottomHat)

Example (HDevelop)

read_image (Image,'/images/name.ext')
threshold (Image,Regions,128,255)
gen_circle (Circle,0,0,16)
bottom_hat (Regions,Circle,RegionBottomHat)

Result

bottom_hatbottom_hatbottom_hatBottomHatBottomHat returns 2 (H_MSG_TRUE) if all parameters are correct. The behavior in case of empty or no input region can be set via: