DGtal  0.9.4beta
topology/frontierAndBoundary.cpp

Frontiers and boundary of two intersecting balls. The first ball is labelled 1 (red), the second 2 (yellow), their intersection 3 (orange). The frontier between 1 and 0 is displayed in red, the frontier between 2 and 0 is displayed in yellow, the boundary of region 3 is displayed in orange.

See also
Boundary and frontiers examples of digital surface
digital-surface-intersecting-balls.png
#include <iostream>
#include "DGtal/helpers/StdDefs.h"
#include "DGtal/io/readers/VolReader.h"
#include "DGtal/io/DrawWithDisplay3DModifier.h"
#include "DGtal/io/viewers/Viewer3D.h"
#include "DGtal/io/Color.h"
#include "DGtal/io/colormaps/HueShadeColorMap.h"
#include "DGtal/images/ImageSelector.h"
#include "DGtal/images/imagesSetsUtils/SetFromImage.h"
#include "DGtal/shapes/implicit/ImplicitBall.h"
#include "DGtal/shapes/GaussDigitizer.h"
#include "DGtal/shapes/Shapes.h"
#include "DGtal/topology/DigitalSurface.h"
#include "DGtal/topology/ExplicitDigitalSurface.h"
#include "DGtal/topology/helpers/FrontierPredicate.h"
#include "DGtal/topology/helpers/BoundaryPredicate.h"
using namespace std;
using namespace DGtal;
using namespace Z3i;
int main( int argc, char** argv )
{
typedef ImplicitBall<Space> EuclideanShape;
Point c1( 2, 0, 0 );
int radius1 = 6;
EuclideanShape ball1( c1, radius1 ); // ball r=6
DigitalShape shape1;
shape1.attach( ball1 );
shape1.init( RealPoint( -10.0, -10.0, -10.0 ),
RealPoint( 10.0, 10.0, 10.0 ), 1.0 );
Point c2( -2, 0, 0 );
int radius2 = 5;
EuclideanShape ball2( c2, radius2 ); // ball r=6
DigitalShape shape2;
shape2.attach( ball2 );
shape2.init( RealPoint( -10.0, -10.0, -10.0 ),
RealPoint( 10.0, 10.0, 10.0 ), 1.0 );
Domain domain = shape1.getDomain();
Image image( domain ); // p1, p2 );
std::cerr << std::endl;
for ( Domain::ConstIterator it = domain.begin(), it_end = domain.end();
it != it_end; ++it )
{
DGtal::uint8_t label = shape1( *it ) ? 1 : 0;
label += shape2( *it ) ? 2 : 0;
image.setValue( *it, label );
std::cerr << (int) image( *it );
}
std::cerr << std::endl;
trace.beginBlock( "Construct the Khalimsky space from the image domain." );
KSpace K;
bool space_ok = K.init( domain.lowerBound(), domain.upperBound(), true );
if (!space_ok)
{
trace.error() << "Error in the Khamisky space construction."<<std::endl;
return 2;
}
trace.beginBlock( "Set up digital surface." );
typedef SurfelAdjacency<KSpace::dimension> MySurfelAdjacency;
MySurfelAdjacency surfAdj( true ); // interior in all directions.
// frontier between label 1 and 0 (connected part containing bel10)
SCell vox1 = K.sSpel( c1 + Point( radius1, 0, 0 ), K.POS );
SCell bel10 = K.sIncident( vox1, 0, true );
FSurfelPredicate surfPredicate10( K, image, 1, 0 );
Frontier frontier10 =
new FrontierContainer( K, surfPredicate10, surfAdj, bel10 );
// frontier between label 2 and 0 (connected part containing bel20)
SCell vox2 = K.sSpel( c2 - Point( radius2, 0, 0 ), K.POS );
SCell bel20 = K.sIncident( vox2, 0, false );
FSurfelPredicate surfPredicate20( K, image, 2, 0 );
Frontier frontier20 =
new FrontierContainer( K, surfPredicate20, surfAdj, bel20 );
// boundary of label 3 (connected part containing bel32)
SCell vox3 = K.sSpel( c1 - Point( radius1, 0, 0 ), K.POS );
SCell bel32 = K.sIncident( vox3, 0, false );
BSurfelPredicate surfPredicate3( K, image, 3 );
Boundary boundary3 =
new BoundaryContainer( K, surfPredicate3, surfAdj, bel32 );
trace.beginBlock( "Displaying surface in Viewer3D." );
QApplication application(argc,argv);
Viewer3D<> viewer;
viewer.show();
viewer << SetMode3D( domain.className(), "BoundingBox" )
<< domain;
Cell dummy;
// Display frontier between 1 and 0.
unsigned int nbSurfels10 = 0;
viewer << CustomColors3D( Color::Red, Color::Red );
for ( Frontier::ConstIterator
it = frontier10.begin(), it_end = frontier10.end();
it != it_end; ++it, ++nbSurfels10 )
viewer << *it;
// Display frontier between 2 and 0.
unsigned int nbSurfels20 = 0;
viewer << CustomColors3D( Color::Yellow, Color::Yellow );
for ( Frontier::ConstIterator
it = frontier20.begin(), it_end = frontier20.end();
it != it_end; ++it, ++nbSurfels20 )
viewer << *it;
// Display boundary of 3.
unsigned int nbSurfels3 = 0;
viewer << CustomColors3D( Color( 255, 130, 15 ), Color( 255, 130, 15 ) );
for ( Boundary::ConstIterator
it = boundary3.begin(), it_end = boundary3.end();
it != it_end; ++it, ++nbSurfels3 )
viewer << *it;
trace.info() << "nbSurfels10 = " << nbSurfels10
<< ", nbSurfels20 = " << nbSurfels20
<< ", nbSurfels3 = " << nbSurfels3 << std::endl;
viewer << Viewer3D<>::updateDisplay;
return application.exec();
}