distancetransform2D.cpp File Reference

#include <iostream>
#include <iomanip>
#include "DGtal/base/Common.h"
#include "DGtal/helpers/StdDefs.h"
#include "DGtal/io/colormaps/GrayscaleColorMap.h"
#include "DGtal/io/colormaps/HueShadeColorMap.h"
#include "DGtal/io/colormaps/TickedColorMap.h"
#include "DGtal/io/colormaps/GradientColorMap.h"
#include "DGtal/io/boards/Board2D.h"
#include "DGtal/images/ImageSelector.h"
#include "DGtal/images/SimpleThresholdForegroundPredicate.h"
#include "DGtal/geometry/volumes/distance/DistanceTransformation.h"

Go to the source code of this file.

Functions
template<typename Image >
void	randomSeeds (Image &image, const unsigned int nb, const int value)
int	main ()

Detailed Description

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

Author

David Coeurjolly (david.nosp@m..coe.nosp@m.urjol.nosp@m.ly@l.nosp@m.iris..nosp@m.cnrs.nosp@m..fr ) Laboratoire d'InfoRmatique en Image et Systèmes d'information - LIRIS (CNRS, UMR 5205), CNRS, France

Date

2010/11/28

An example file named distancetransform2D. The aim of this example is to demonstrate the distance transformation package of the DGtal library. Using a simple random seed example, we compute the distance transformation (linear in time algorithm) using the L1, Linfinity and L2 metrics.

This file is part of the DGtal library.

Definition in file distancetransform2D.cpp.

Function Documentation

main()

int main

(

void

)

[DTDef]

[DTDef]

[DTPredicate]

[DTPredicate]

[DTCompute]

[DTCompute]

[DTColormaps]

[DTColormaps]

Definition at line 88 of file distancetransform2D.cpp.

{
  trace.beginBlock ( "Example distancetransform2D" );
 
  Z2i::Point a ( 0, 0 );
  Z2i::Point b ( 127, 127);
  
  //Input image with unsigned char values
  typedef ImageSelector<Z2i::Domain, unsigned int>::Type Image;
  Image image ( Z2i::Domain(a, b ));
 
  //We fill the image with the 128 value
  for ( Image::Iterator it = image.begin(), itend = image.end();it != itend; ++it)
    (*it)=128;
  //We generate 16 seeds with 0 values.
  randomSeeds(image,16,0);
 
  //Input shape output
  typedef GrayscaleColorMap<Image::Value> Gray;
  Board2D board;
  board.setUnit ( LibBoard::Board::UCentimeter );
  Display2DFactory::drawImage<Gray>(board, image, (unsigned int)0, (unsigned int)129);
  board.saveSVG("inputShape.svg");
 
  //Point Predicate from random seed image
  typedef functors::SimpleThresholdForegroundPredicate<Image> PointPredicate;
  PointPredicate predicate(image,0);
 
  typedef  DistanceTransformation<Z2i::Space, PointPredicate, Z2i::L2Metric> DTL2;
  typedef  DistanceTransformation<Z2i::Space, PointPredicate, Z2i::L1Metric> DTL1;
 
 
  DTL2 dtL2(image.domain(), predicate, Z2i::l2Metric);
  DTL1 dtL1(image.domain(), predicate, Z2i::l1Metric);
 
 
  DTL2::Value maxv2=0;
  //We compute the maximum DT value on the L2 map
  for ( DTL2::ConstRange::ConstIterator it = dtL2.constRange().begin(), itend = dtL2.constRange().end();it != itend; ++it)
    if ( (*it) > maxv2)  maxv2 = (*it);
 
  DTL1::Value maxv1=0;
  //We compute the maximum DT value on the L1 map
  for ( DTL1::ConstRange::ConstIterator it = dtL1.constRange().begin(), itend = dtL1.constRange().end();it != itend; ++it)
    if ( (*it) > maxv1)  maxv1 = (*it);
  
  //Colormap used for the SVG output
  typedef HueShadeColorMap<DTL2::Value, 2> HueTwice;
 
 
  
  
  trace.warning() << dtL2 << " maxValue= "<<maxv2<< endl;
  board.clear();
  Display2DFactory::drawImage<HueTwice>(board, dtL2, 0.0, maxv2 + 1);
  board.saveSVG ( "example-DT-L2.svg" );
 
  trace.warning() << dtL1 << " maxValue= "<<maxv1<< endl;
  board.clear();
  Display2DFactory::drawImage<HueTwice>(board, dtL1, 0.0, maxv1 + 1);
  board.saveSVG ( "example-DT-L1.svg" );
 
  //Explicit export with ticked colormap
  //We compute the maximum DT value on the L2 map
  board.clear();
  TickedColorMap<double, GradientColorMap<double> > ticked(0.0,maxv2, Color::White);
  ticked.addRegularTicks(5, 0.5);
  ticked.finalize();
  ticked.colormap()->addColor( Color::Red );
  ticked.colormap()->addColor( Color::Black );
  for ( DTL2::Domain::ConstIterator it = dtL2.domain().begin(), itend = dtL2.domain().end();it != itend; ++it)
  {
    board<< CustomStyle((*it).className(),new CustomColors(ticked(dtL2(*it)),ticked(dtL2(*it))));
    board << *it;
  }
  board.saveSVG("example-DT-L2-ticked.svg");
  
  trace.endBlock();
  return 0;
}

References DGtal::TickedColorMap< TValue, TColorMap >::addRegularTicks(), DGtal::Trace::beginBlock(), DGtal::Color::Black, LibBoard::Board::clear(), DGtal::TickedColorMap< TValue, TColorMap >::colormap(), DGtal::Trace::endBlock(), DGtal::TickedColorMap< TValue, TColorMap >::finalize(), DGtal::Z2i::l1Metric, DGtal::Z2i::l2Metric, randomSeeds(), DGtal::Color::Red, LibBoard::Board::saveSVG(), LibBoard::Board::setUnit(), DGtal::trace, LibBoard::Board::UCentimeter, DGtal::Trace::warning(), and DGtal::Color::White.

randomSeeds()

template<typename Image >

void randomSeeds	(	Image &	image,
		const unsigned int	nb,
		const int	value
	)

Set to a given value a random set of nb points.

Parameters

image	the image
nb	the number of random points to insert
value	the value to add at each random point

Definition at line 72 of file distancetransform2D.cpp.

{
  typename Image::Point p, low = image.domain().lowerBound();
  typename Image::Vector ext;
 
  ext = image.extent();
 
  for (unsigned int k = 0 ; k < nb; k++)
  {
    for (unsigned int dim = 0; dim < Image::dimension; dim++)
      p[dim] = rand() % (ext[dim]) +  low[dim];
    
    image.setValue(p, value);
  }
}

References dim.

Referenced by main().