DGtal 1.3.0
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This example shows the tangential cover of an noisy contour from the alpha-thick segment primitive with alpha = 4.

See also
Alpha-thick Segment Recognition
Tangential cover with alpha-thick segments with alpha = 4
#include <iostream>
#include "ConfigExamples.h"
#include "DGtal/helpers/StdDefs.h"
#include "DGtal/base/Common.h"
#include "DGtal/geometry/curves/AlphaThickSegmentComputer.h"
#include "DGtal/geometry/curves/SaturatedSegmentation.h"
#include "DGtal/base/Circulator.h"
#include "DGtal/geometry/curves/SegmentComputerUtils.h"
#include "DGtal/io/boards/Board2D.h"
using namespace std;
using namespace DGtal;
int main()
trace.beginBlock ( "Example of AlphaThickSegment tangential cover obtained from SaturatedSegmentation" );
typedef std::vector<Z2i::RealPoint>::const_iterator RAConstIterator;
typedef Circulator<RAConstIterator> ConstCirculator;
Board2D aBoard, aBoard2;
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");
aBoard2 << SetMode(aContour[0].className(), "Grid");
std::vector<LibBoard::Point> poly;
for (unsigned int i = 0; i< aContour.size(); i++) poly.push_back(LibBoard::Point(aContour[i][0], aContour[i][1]));
aBoard.setPenColor(DGtal::Color(200, 200, 200));
aBoard2.setPenColor(DGtal::Color(200, 200, 200));
Circulator<RAConstIterator> circulator (aContour.begin(), aContour.begin(), aContour.end());
AlphaThickSegmentComputer2D computer(4, functions::Hull2D::EuclideanThickness);
AlphaSegmentation segmentator(circulator, circulator, computer);
AlphaSegmentation::SegmentComputerIterator i = segmentator.begin();
AlphaSegmentation::SegmentComputerIterator end = segmentator.end();
for ( ; i != end; ++i) {
AlphaThickSegmentComputer2D current(*i);
aBoard << SetMode(current.className(), "BoundingBox");
aBoard << current;
trace.beginBlock ( "Example of AlphaThickSegment tangential cover obtained for a single point" );
// Displaying Tangential cover associated to a single point:
unsigned int index = 80;
firstMaximalSegment(computer, circulator+index, circulator, circulator);
AlphaThickSegmentComputer2D first (computer);
lastMaximalSegment(computer, circulator+index, circulator, circulator);
AlphaThickSegmentComputer2D last (computer);
aBoard2.fillCircle((*(circulator+index))[0], (*(circulator+index))[1], 1.0);
while(first.end() != last.end()){
aBoard2 << SetMode(first.className(), "BoundingBox");
aBoard2 << first;
nextMaximalSegment(first, circulator);
aBoard2 << last;
stringstream name;
name << "exampleAlphaThickSegmentTgtCoverPoint" << index<< ".eps";
return 0;
// //
Aim: This class is devoted to the recognition of alpha thick segments as described in ....
Aim: This class specializes a 'Board' class so as to display DGtal objects more naturally (with <<)....
Definition: Board2D.h:71
Aim: Provides an adapter for classical iterators that can iterate through the underlying data structu...
Definition: Circulator.h:86
Structure representing an RGB triple with alpha component.
Definition: Color.h:68
static const Color Blue
Definition: Color.h:419
Aim: Computes the saturated segmentation, that is the whole set of maximal segments within a range gi...
void beginBlock(const std::string &keyword="")
double endBlock()
Board & setPenColor(const DGtal::Color &color)
Definition: Board.cpp:298
void fillCircle(double x, double y, double radius, int depthValue=-1)
Definition: Board.cpp:471
void fillPolyline(const std::vector< Point > &points, int depthValue=-1)
Definition: Board.cpp:551
void saveEPS(const char *filename, PageSize size=Board::BoundingBox, double margin=10.0) const
Definition: Board.cpp:805
DGtal is the top-level namespace which contains all DGtal functions and types.
STL namespace.
Aim: Implements method to read a set of points represented in each line of a file.
Modifier class in a Board2D stream. Useful to choose your own mode for a given class....
Definition: Board2D.h:247
Struct representing a 2D point.
Definition: Point.h:27
int main()
Definition: testBits.cpp:56