topology/homotopicThinning3D.cpp

An homotopic thinning is an iterative removal of simple points from a given digital object.

See also:

Simple points

Resulting 3d thinning with the 6_26 object

#include <iostream>
#include <queue>
#include <QImageReader>
#include <QtGui/qapplication.h>
#include "DGtal/io/viewers/Viewer3D.h"
#include "DGtal/io/DrawWithDisplay3DModifier.h"
#include "DGtal/io/Color.h"
#include "DGtal/shapes/Shapes.h"
#include "DGtal/helpers/StdDefs.h"


using namespace std;
using namespace DGtal;
using namespace Z3i;




int main( int argc, char** argv )
{

  trace.beginBlock ( "Example simple example of 3DViewer" );
  
  QApplication application(argc,argv);
  Viewer3D viewer;
  viewer.setWindowTitle("simpleExample3DViewer");
  viewer.show();  
  
  // Domain cretation from two bounding points.
  Point c( 0, 0, 0 );
  Point p1( -50, -50, -50 );
  Point p2( 50, 50, 50 );
  Domain domain( p1, p2 );
  
  trace.warning() << "Constructing a ring DigitalSet  ... ";
  DigitalSet shape_set( domain );
  for ( Domain::ConstIterator it = domain.begin(); it != domain.end(); ++it )
    {
      if ( ((*it - c ).norm() <= 25) && ((*it - c ).norm() >= 18)
     && ( (((*it)[0] <= 3)&& ((*it)[0] >= -3))|| (((*it)[1] <= 3)&& ((*it)[1] >= -3)))){
  shape_set.insertNew( *it );
      }
    }
  trace.warning() << "  [Done]";
  

  Object6_26 shape( dt6_26, shape_set );
  int nb_simple=0; 
  int layer = 0;
  do 
    {
      DigitalSet & S = shape.pointSet();
      std::queue<DigitalSet::Iterator> Q;
      for ( DigitalSet::Iterator it = S.begin(); it != S.end(); ++it )
  if ( shape.isSimple( *it ) )
    Q.push( it );
      nb_simple = 0;
      while ( ! Q.empty() )
  {
    DigitalSet::Iterator it = Q.front();
    Q.pop();
    if ( shape.isSimple( *it ) )
      {
        cerr << "point simple " << (*it) << endl; 
        S.erase( *it );
        ++nb_simple;
      }
  }
      ++layer;
    }
  while ( nb_simple != 0 );

  DigitalSet & S = shape.pointSet();

  // Display by using two different list to manage OpenGL transparency.

  viewer << SetMode3D( shape_set.className(), "Paving" );
  viewer << CustomColors3D(Color(25,25,255, 255), Color(25,25,255, 255));
  viewer << S ; 

  viewer << SetMode3D( shape_set.className(), "PavingTransp" );
  viewer << CustomColors3D(Color(250, 0,0, 25), Color(250, 0,0, 5));
  viewer << shape_set;

  viewer<< Viewer3D::updateDisplay;
   
  
  trace.endBlock();
  return application.exec();

}
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