exampleFrechetShortcut.cpp

#include <iostream>
#include "DGtal/base/Common.h"
#include "DGtal/helpers/StdDefs.h"

#include "ConfigExamples.h"
#include "DGtal/io/boards/Board2D.h"
#include "DGtal/geometry/curves/FrechetShortcut.h"
#include "DGtal/geometry/curves/GreedySegmentation.h"

using namespace std;
using namespace DGtal;
using namespace Z2i;





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

  std::string filename = examplesPath + "samples/plant-frechet.dat";
  ifstream instream; // input stream
  instream.open (filename.c_str(), ifstream::in);

  
  double error = atof(argv[1]);
  trace.info() << error << endl;
  
  Curve c; //grid curve
  c.initFromVectorStream(instream);
  
  Board2D board;
  
  // Display the pixels as arrows range to show the way the curve is scanned
  board << c.getArrowsRange();
  
  trace.beginBlock("Simple example");

  Curve::PointsRange r = c.getPointsRange(); 
  
  typedef FrechetShortcut<Curve::PointsRange::ConstIterator,int> Shortcut;
  
  // Computation of one shortcut
  Shortcut s(error);
  
  s.init( r.begin() );
  while ( ( s.end() != r.end() )
          &&( s.extendForward() ) ) {}
  


  // Computation of a greedy segmentation
  
  typedef GreedySegmentation<Shortcut> Segmentation;
  
  Segmentation theSegmentation( r.begin(), r.end(), Shortcut(error) );
  
  // the segmentation is computed here
  Segmentation::SegmentComputerIterator it = theSegmentation.begin();
  Segmentation::SegmentComputerIterator itEnd = theSegmentation.end();

  for ( ; it != itEnd; ++it) {
    s=Shortcut(*it);
    trace.info() << s << std::endl;
    board << s; 
  }
  
  board.saveEPS("FrechetShortcutExample.eps", Board2D::BoundingBox, 5000 ); 



  trace.endBlock();
  return 0;
}
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