geometry/curves/exampleAlphaThickSegmentNoisy.cpp

This example shows a simple alpha-thick segment recognition given from a noisy input contour with floating point coordinates.

See also

Alpha-thick Segment Recognition

Simple example of some alpha-thick segments recognition with alpha = 2, 9 and 15.

 
#include <iostream>
#include "ConfigExamples.h"
#include "DGtal/base/Common.h"
#include "DGtal/geometry/curves/AlphaThickSegmentComputer.h"
#include "DGtal/helpers/StdDefs.h"
#include "DGtal/io/readers/PointListReader.h"
#include "DGtal/io/boards/Board2D.h"
 
using namespace std;
using namespace DGtal;
 
 
int main(  )
{
  trace.beginBlock ( "Example exampleAlphaThickSegment" );
 
  typedef  AlphaThickSegmentComputer< Z2i::RealPoint > AlphaThickSegmentComputer2D;
  
  Board2D aBoard;
  std::string file = examplesPath + "samples/contourSnoisy.sdp";
  std::vector<Z2i::RealPoint> aContour = PointListReader<Z2i::RealPoint>::getPointsFromFile(file);
 
  // displaying contour
  aBoard << SetMode(aContour[0].className(), "Grid"); 
  for (unsigned int i = 0; i< aContour.size(); i++){
      aBoard << aContour[i];
      aBoard.drawLine(aContour[i][0], aContour[i][1], 
                  aContour[(i+1)%aContour.size()][0], aContour[(i+1)%aContour.size()][1]);
  }
 
  
  //initialisation of an AlphaThickSegmentComputer2D of thickness 10 and forward recognition.
  AlphaThickSegmentComputer2D anAlphaSegment(15);
  std::vector<Z2i::RealPoint>::const_iterator it =  aContour.begin();  
  while (anAlphaSegment.extendFront(*it)) {
    it++;
  }
 
  aBoard << anAlphaSegment;  
  AlphaThickSegmentComputer2D anAlphaSegment2(9);
  anAlphaSegment2.init(aContour.begin());
  while (anAlphaSegment2.end() != aContour.end() && 
         anAlphaSegment2.extendFront()) {
  }
 
  aBoard << CustomStyle( anAlphaSegment2.className(), new CustomColors( DGtal::Color::Blue, DGtal::Color::None ) );  
  aBoard << anAlphaSegment2;  
 
  AlphaThickSegmentComputer2D  anAlphaSegment3(2);
  anAlphaSegment3.init(aContour.begin());
  while (anAlphaSegment3.end() != aContour.end() && 
         anAlphaSegment3.extendFront()) {
  }
  aBoard  << CustomStyle( anAlphaSegment3.className(), new CustomColors( DGtal::Color::Green, DGtal::Color::None ) );  
  aBoard << anAlphaSegment3;
  
 
  aBoard.saveEPS("exampleAlphaThickSegmentNoisy.eps");
 
  trace.endBlock();
  return 0;
}
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