Name
watershedswatershedsWatershedswatershedsWatershedsWatersheds — Extract watersheds and basins from an image.
watershedswatershedsWatershedswatershedsWatershedsWatersheds segments an image based on the topology of
the gray values. The image is interpreted as a “mountain range.”
Higher gray values correspond to “mountains,” while lower gray
values correspond to “valleys.” In the resulting mountain range
watersheds are extracted. These correspond to the bright ridges
between dark basins. On output, the parameter BasinsBasinsBasinsBasinsBasinsbasins
contains these basins, while WatershedsWatershedsWatershedsWatershedsWatershedswatersheds contains the
watersheds, which are at most one pixel wide.
WatershedsWatershedsWatershedsWatershedsWatershedswatersheds always is a single
region per input image, while BasinsBasinsBasinsBasinsBasinsbasins contains a separate
region for each basin.
It is advisable to apply a smoothing operator (e.g.,
binomial_filterbinomial_filterBinomialFilterbinomial_filterBinomialFilterBinomialFilter or gauss_filtergauss_filterGaussFiltergauss_filterGaussFilterGaussFilter) to the input image
before calling watershedswatershedsWatershedswatershedsWatershedsWatersheds in order to reduce the number of
output regions. A more sophisticated way to reduce the number of
output regions is to merge neighboring basins based on a threshold
criterion by using watersheds_thresholdwatersheds_thresholdWatershedsThresholdwatersheds_thresholdWatershedsThresholdWatershedsThreshold instead (for more
details please refer to the documentation of
watersheds_thresholdwatersheds_thresholdWatershedsThresholdwatersheds_thresholdWatershedsThresholdWatershedsThreshold).
If the image contains many fine structures or is noisy, many output
regions result, and thus the runtime increases considerably.
- Multithreading type: reentrant (runs in parallel with non-exclusive operators).
- Multithreading scope: global (may be called from any thread).
- Automatically parallelized on tuple level.
Watersheds between the basins.
#include "HIOStream.h"
#if !defined(USE_IOSTREAM_H)
using namespace std;
#endif
#include "HalconCpp.h"
using namespace Halcon;
int main (int argc, char *argv[])
{
HImage image (argv[1]), gauss;
HWindow win;
cout << "Gauss of original " << endl;
gauss = image.GaussImage (9);
image.Display (win);
HRegion watersheds;
HRegionArray basins = gauss.Watersheds (&watersheds);
win.SetColored (12);
basins.Display (win);
win.Click ();
return (0);
}
read_image(&Cells,"meningg5");
gauss_filter(Cells,&CellsGauss,9);
invert_image(CellsGauss,&CellsInvert);
watersheds(CellsInvert,&Bassins,&Watersheds);
set_colored(WindowHandle,12);
disp_region(Bassins,WindowHandle);
#include "HIOStream.h"
#if !defined(USE_IOSTREAM_H)
using namespace std;
#endif
#include "HalconCpp.h"
using namespace Halcon;
int main (int argc, char *argv[])
{
HImage image (argv[1]), gauss;
HWindow win;
cout << "Gauss of original " << endl;
gauss = image.GaussImage (9);
image.Display (win);
HRegion watersheds;
HRegionArray basins = gauss.Watersheds (&watersheds);
win.SetColored (12);
basins.Display (win);
win.Click ();
return (0);
}
#include "HIOStream.h"
#if !defined(USE_IOSTREAM_H)
using namespace std;
#endif
#include "HalconCpp.h"
using namespace Halcon;
int main (int argc, char *argv[])
{
HImage image (argv[1]), gauss;
HWindow win;
cout << "Gauss of original " << endl;
gauss = image.GaussImage (9);
image.Display (win);
HRegion watersheds;
HRegionArray basins = gauss.Watersheds (&watersheds);
win.SetColored (12);
basins.Display (win);
win.Click ();
return (0);
}
#include "HIOStream.h"
#if !defined(USE_IOSTREAM_H)
using namespace std;
#endif
#include "HalconCpp.h"
using namespace Halcon;
int main (int argc, char *argv[])
{
HImage image (argv[1]), gauss;
HWindow win;
cout << "Gauss of original " << endl;
gauss = image.GaussImage (9);
image.Display (win);
HRegion watersheds;
HRegionArray basins = gauss.Watersheds (&watersheds);
win.SetColored (12);
basins.Display (win);
win.Click ();
return (0);
}
#include "HIOStream.h"
#if !defined(USE_IOSTREAM_H)
using namespace std;
#endif
#include "HalconCpp.h"
using namespace Halcon;
int main (int argc, char *argv[])
{
HImage image (argv[1]), gauss;
HWindow win;
cout << "Gauss of original " << endl;
gauss = image.GaussImage (9);
image.Display (win);
HRegion watersheds;
HRegionArray basins = gauss.Watersheds (&watersheds);
win.SetColored (12);
basins.Display (win);
win.Click ();
return (0);
}
watershedswatershedsWatershedswatershedsWatershedsWatersheds always returns 2 (H_MSG_TRUE). 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""no_object_result",
'empty_region_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""store_empty_region"
with set_systemset_systemSetSystemset_systemSetSystemSetSystem. If necessary, an exception is raised.
binomial_filterbinomial_filterBinomialFilterbinomial_filterBinomialFilterBinomialFilter,
gauss_filtergauss_filterGaussFiltergauss_filterGaussFilterGaussFilter,
smooth_imagesmooth_imageSmoothImagesmooth_imageSmoothImageSmoothImage,
invert_imageinvert_imageInvertImageinvert_imageInvertImageInvertImage
expand_regionexpand_regionExpandRegionexpand_regionExpandRegionExpandRegion,
select_shapeselect_shapeSelectShapeselect_shapeSelectShapeSelectShape,
reduce_domainreduce_domainReduceDomainreduce_domainReduceDomainReduceDomain,
openingopeningOpeningopeningOpeningOpening
watersheds_thresholdwatersheds_thresholdWatershedsThresholdwatersheds_thresholdWatershedsThresholdWatershedsThreshold,
pouringpouringPouringpouringPouringPouring
L. Vincent, P. Soille: “Watersheds in Digital Space: An Efficient
Algorithm Based on Immersion Simulations”; IEEE Transactions on Pattern
Analysis and Machine Intelligence; vol. 13, no. 6; pp. 583-598; 1991.
Foundation