topology/ctopo-2-3d.cpp

A simple example illustrating the extraction of the sequence of surfels boudary. This program outputs this image.

See also

Tracking a 3D boundary to build a surface.

#include <iostream>
#include "DGtal/base/Common.h"
 
#include "DGtal/helpers/StdDefs.h"
#include "DGtal/topology/KhalimskySpaceND.h"
#include "DGtal/topology/helpers/Surfaces.h"
 
#include "DGtal/io/viewers/PolyscopeViewer.h"
#include "DGtal/io/readers/VolReader.h"
#include "DGtal/images/ImageSelector.h"
#include "DGtal/images/imagesSetsUtils/SetFromImage.h"
#include "DGtal/io/Color.h"
#include "DGtal/io/colormaps/GradientColorMap.h"
 
#include "ConfigExamples.h"

using namespace std;
using namespace DGtal;
 
int main( int argc, char** argv )
{
  trace.beginBlock ( "Example ctopo-2-3d" );
  // for 3D display with PolyscopeViewer
 
  typedef ImageSelector < Z3i::Domain, int>::Type Image;
  std::string inputFilename = examplesPath + "samples/cat10.vol";
  Image image = VolReader<Image>::importVol(inputFilename);
  Z3i::DigitalSet set3d (image.domain());
  SetFromImage<Z3i::DigitalSet>::append<Image>(set3d, image, 0,255);
 
  // Construct the Khalimsky space from the image domain
  Z3i::KSpace ks;
  bool space_ok = ks.init( image.domain().lowerBound(), image.domain().upperBound(), true );
 
  if (!space_ok)
    {
      trace.error() << "Error in the Khamisky space construction."<<std::endl;
      return 2;
    }
 
  std::vector<Z3i::SCell> vectBdrySCell;
  std::vector<Z3i::SCell> vectBdrySCell2;
  std::set<Z3i::SCell> vectBdrySCellALL;
  SurfelAdjacency<3> SAdj( true );
 
 
  //Extract an initial boundary cell
  Z3i::SCell aCell = Surfaces<Z3i::KSpace>::findABel(ks, set3d);
  trace.info() << "Tracking Boundary.."<<std::endl;
  // Extracting all boundary surfels which are connected to the initial boundary Cell.
  Surfaces<Z3i::KSpace>::trackBoundary( vectBdrySCellALL,
          ks,SAdj, set3d, aCell );
 
  // Extract the bondary contour associated to the initial surfel in its first direction
  Surfaces<Z3i::KSpace>::track2DSliceBoundary( vectBdrySCell,
                 ks, *(ks.sDirs( aCell )), SAdj,
                 set3d, aCell );
 
  // Extract the bondary contour associated to the initial surfel in its second direction
  Surfaces<Z3i::KSpace>::track2DSliceBoundary( vectBdrySCell2,
                 ks, *(++(ks.sDirs( aCell ))), SAdj,
                 set3d, aCell );
 
 
  // Displaying all the surfels in transparent mode
  typedef PolyscopeViewer <Z3i::Space,Z3i::KSpace> MyViewer;
  MyViewer viewer(ks);
 
  trace.info() << "Displaying the surfels.."<<std::endl;
  for( std::set<Z3i::SCell>::iterator it=vectBdrySCellALL.begin();
       it!= vectBdrySCellALL.end(); it++){
    viewer<< *it;
  }
  trace.info()<<"done"<<std::endl;
  // Displaying First surfels cut with gradient colors.;
  GradientColorMap<int> cmap_grad(0, (const int)vectBdrySCell2.size());
  cmap_grad.addColor( Color( 50, 50, 255 ) );
  cmap_grad.addColor( Color( 255, 0, 0 ) );
  cmap_grad.addColor( Color( 255, 255, 10 ) );
 
  // Need to avoid surfel superposition (the surfel size in increased)
  viewer.drawColor(Color(180, 200, 25, 255));
 
  int d=0;
  for( std::vector<Z3i::SCell>::iterator it=vectBdrySCell2.begin();
       it!= vectBdrySCell2.end(); it++){
    Color col= cmap_grad(d);
    viewer.drawColor(Color(col.red(),col.green() ,col.blue(), 255));
    viewer<< *it;
    d++;
  }
 
  GradientColorMap<int> cmap_grad2(0, (const int)vectBdrySCell.size());
  cmap_grad2.addColor( Color( 50, 50, 255 ) );
  cmap_grad2.addColor( Color( 255, 0, 0 ) );
  cmap_grad2.addColor( Color( 255, 255, 10 ) );
 
  d=0;
  for( std::vector<Z3i::SCell>::iterator it=vectBdrySCell.begin();
       it!= vectBdrySCell.end(); it++){
     Color col= cmap_grad2(d);
     viewer.drawColor(Color(col.red(),col.green() ,col.blue(), 255));
     viewer<< *it;
    d++;
  }
 
  // On need once again to avoid superposition.
  viewer.drawColor(Color(18, 200, 25, 255));
  viewer << aCell ;
 
  viewer.show();
  return 0;
}
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