DGtal  1.4.beta

This example a simple alpha-thick segment recognition given from a freeman chain contour.

See also
Alpha-thick Segment Recognition
Simple example of some alpha-thick segments recognition with alpha = 2, 5 and 15.
#include <iostream>
#include "ConfigExamples.h"
#include "DGtal/helpers/StdDefs.h"
#include "DGtal/base/Common.h"
#include "DGtal/geometry/curves/AlphaThickSegmentComputer.h"
#include "DGtal/io/boards/Board2D.h"
#include "DGtal/io/readers/PointListReader.h"
using namespace std;
using namespace DGtal;
int main( )
trace.beginBlock ( "Example exampleAlphaThickSegment" );
typedef AlphaThickSegmentComputer< Z2i::Point, FCConstIterator > AlphaThickSegmentComputer2D;
Board2D aBoard;
// Reading input contour
std::string freemanChainFilename = examplesPath + "samples/contourS.fc";
fstream fst;
fst.open (freemanChainFilename.c_str(), ios::in);
FreemanChain<Z2i::Space::Integer> fc(fst);
aBoard << fc;
//construction of an AlphaThickSegmentComputer2D from the freemanchain iterator
AlphaThickSegmentComputer2D anAlphaSegment(15), anAlphaSegment2(5), anAlphaSegment3(2);
while (anAlphaSegment.end() != fc.end() &&
anAlphaSegment.extendFront()) {
aBoard << anAlphaSegment;
// Example of thickness definition change: usin the euclidean thickness definition.
AlphaThickSegmentComputer2D anAlphaSegment2Eucl(5, functions::Hull2D::EuclideanThickness);
while (anAlphaSegment2Eucl.end() != fc.end() &&
anAlphaSegment2Eucl.extendFront()) {
aBoard << CustomStyle( anAlphaSegment2Eucl.className(),
new CustomColors( DGtal::Color(20, 250, 255), DGtal::Color::None ) );
aBoard << anAlphaSegment2Eucl;
while (anAlphaSegment2.end() != fc.end() && anAlphaSegment2.extendFront()) {
aBoard << CustomStyle( anAlphaSegment2.className(), new CustomColors( DGtal::Color::Blue, DGtal::Color::None ) );
aBoard << anAlphaSegment2;
FCConstIterator fcIt = fc.begin();
while (anAlphaSegment3.extendFront(*fcIt)) {
aBoard << CustomStyle( anAlphaSegment3.className(), new CustomColors( DGtal::Color::Green, DGtal::Color::None ) );
aBoard << anAlphaSegment3;
return 0;
// //
Structure representing an RGB triple with alpha component.
Definition: Color.h:68
static const Color None
Definition: Color.h:412
static const Color Green
Definition: Color.h:417
static const Color Blue
Definition: Color.h:419
void beginBlock(const std::string &keyword="")
double endBlock()
MyDigitalSurface::ConstIterator ConstIterator
DGtal is the top-level namespace which contains all DGtal functions and types.
Trace trace
Definition: Common.h:153
int main(int argc, char **argv)