geometry/curves/greedy-dss-decomposition.cpp

This example outputs a greedy segmentation of a closed and 4-connected digital curve into DSSs.

* $ ./examples/geometry/curves/greedy-dss-decomposition
* 

Greedy segmentation into DSSs

See also

Digital straight lines and segments
and Analysis of one-dimensional discrete structures

geometry/curves/greedy-dss-decomposition.cpp

 
#include <cmath>
#include <iostream>
#include <sstream>
#include "DGtal/base/Common.h"
#include "DGtal/io/boards/Board2D.h"
#include "DGtal/io/Color.h"
#include "DGtal/io/colormaps/GradientColorMap.h"
#include "DGtal/shapes/Shapes.h"
#include "DGtal/helpers/StdDefs.h"
#include "DGtal/geometry/curves/ArithmeticalDSSComputer.h"
#include "DGtal/geometry/curves/FreemanChain.h"
#include "DGtal/geometry/curves/GreedySegmentation.h"
 
using namespace std;
using namespace DGtal;
using namespace Z2i;
 
 
int main( )
{
  trace.beginBlock ( "Example dgtalboard-5-greedy-dss" );
 
  typedef FreemanChain<int> Contour4; 
  typedef ArithmeticalDSSComputer<Contour4::ConstIterator,int,4> DSS4;
  typedef GreedySegmentation<DSS4> Decomposition4;
 
  // A Freeman chain code is a string composed by the coordinates of the first pixel, and the list of elementary displacements. 
  std::stringstream ss(stringstream::in | stringstream::out);
  ss << "31 16 11121212121212212121212212122122222322323233323333333323333323303330330030300000100010010010001000101010101111" << endl;
  
  // Construct the Freeman chain
  Contour4 theContour( ss );
 
  // Segmentation
  Decomposition4 theDecomposition( theContour.begin(),theContour.end(),DSS4() );
 
  // Draw the domain and the contour
  Point p1( 0, 0 );
  Point p2( 31, 31 );
  Domain domain( p1, p2 );
  Board2D aBoard;
  aBoard << SetMode( domain.className(), "Grid" )
         << domain
         << SetMode( "PointVector", "Grid" ); 
 
  // Draw each segment
  string styleName = "";
  for ( Decomposition4::SegmentComputerIterator 
          it = theDecomposition.begin(),
          itEnd = theDecomposition.end();
        it != itEnd; ++it ) 
    {
      aBoard << SetMode( "ArithmeticalDSS", "Points" )
             << it->primitive(); 
      aBoard << SetMode( "ArithmeticalDSS", "BoundingBox" )
             << CustomStyle( "ArithmeticalDSS/BoundingBox", 
                             new CustomPenColor( Color::Blue ) )
             << it->primitive();
    } 
 
  
  aBoard.saveSVG("greedy-dss-decomposition.svg");
  aBoard.saveEPS("greedy-dss-decomposition.eps");
  #ifdef WITH_CAIRO
    aBoard.saveCairo("greedy-dss-decomposition.png"); 
  #endif
 
  trace.endBlock();
 
  return 0;
}
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