geometry/volumes/distance/exampleFMM2D.cpp

Example of use the FMM (fast marching method) class in 2D.

See also

nD Fast Marching Methods

This program outputs this image:

#include <iostream>
#include <iomanip>
#include <functional>
#include <iostream>

#include "DGtal/base/Common.h"

//space, domain and image
#include "DGtal/kernel/SpaceND.h"
#include "DGtal/kernel/domains/HyperRectDomain.h"
#include "DGtal/kernel/sets/DigitalSetFromMap.h"
#include "DGtal/images/ImageContainerBySTLMap.h"
#include "DGtal/topology/SCellsFunctors.h"

//shape and tracking
#include "DGtal/shapes/ShapeFactory.h"
#include "DGtal/shapes/Shapes.h"
#include "DGtal/helpers/StdDefs.h"
#include "DGtal/topology/helpers/Surfaces.h"
#include "DGtal/shapes/GaussDigitizer.h"


//FMM
#include "DGtal/geometry/volumes/distance/FMM.h"

//Display
#include "DGtal/io/colormaps/HueShadeColorMap.h"
#include "DGtal/io/boards/Board2D.h"


using namespace std;
using namespace DGtal;



template< typename TImage >
void draw( const TImage aImg, const double& aMaxValue, std::string aBasename) 
{
  typedef typename TImage::Domain::ConstIterator ConstIteratorOnPoints; 
  typedef typename TImage::Domain::Point Point; 
  HueShadeColorMap<double, 2> colorMap(0,aMaxValue);

  Board2D b; 
  b.setUnit ( LibBoard::Board::UCentimeter );
 
  for (ConstIteratorOnPoints it = aImg.domain().begin(), itEnd = aImg.domain().end();
       it != itEnd; ++it)
    {
      Point p = *it; 
      b << CustomStyle( p.className(), new CustomFillColor( colorMap( aImg(p) ) ) );
      b << p;
    }

  {
    std::stringstream s; 
    s << aBasename << ".eps"; 
    b.saveEPS(s.str().c_str());
  }
  #ifdef WITH_CAIRO
  {
    std::stringstream s; 
    s << aBasename << ".png"; 
    b.saveCairo(s.str().c_str(), Board2D::CairoPNG);
  }
  #endif
} 


void example()
{

  trace.beginBlock ( "DT by FMM from one point" );

  //Typedefs
  typedef ImageContainerBySTLMap<Z2i::Domain,double> DistanceImage; 
  typedef DigitalSetFromMap<DistanceImage> AcceptedPointSet; 
  typedef Z2i::Domain::Predicate DomainPredicate;
  typedef FMM<DistanceImage, AcceptedPointSet, DomainPredicate> FMM;

  //Constructions
  int size = 25; 
  Z2i::Domain domain(Z2i::Point::diagonal(-size), 
                     Z2i::Point::diagonal(size) ); 
  DistanceImage distanceImage( domain ); 
  AcceptedPointSet set( distanceImage );

  Z2i::Point origin = Z2i::Point::diagonal(0); 
  set.insert( origin ); 
  distanceImage.setValue( origin, 0.0 ); 

  FMM fmm( distanceImage, set, domain.predicate() ); 

  trace.info() << "Init: " << fmm << std::endl;

  fmm.compute(); 

  trace.info() << "End: " << fmm << std::endl;

  //display - you should see concentric circles
  //around the center point. 
  std::stringstream s; 
  s << "DTbyFMM-" << size; 
  draw(distanceImage, fmm.max(), s.str());

  trace.endBlock();
}






// Standard services - public :

int main ( int argc, char** argv )
{
  trace.beginBlock ( "Example 2d FMM" );
  trace.info() << "Args:";
  for ( int i = 0; i < argc; ++i )
    trace.info() << " " << argv[ i ];
  trace.info() << endl;

  //computation
  example(); 

  trace.endBlock();
  return 1;
}
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