vigra - voronoi.cxx

[ VIGRA Homepage | Function Index | Class Index | Namespaces | File List | Main Page ]

voronoi.cxx |

Generate a Voronoi diagram, using distanceTransform() and seededRegionGrowing()
Usage: `example_voronoi`, generates: `distances.gif` (Euclidean distance transform) and `voronoi.gif` (Voronoi diagram)

/************************************************************************/
/* */
/* Copyright 1998-2002 by Ullrich Koethe */
/* */
/* This file is part of the VIGRA computer vision library. */
/* The VIGRA Website is */
/* http://hci.iwr.uni-heidelberg.de/vigra/ */
/* Please direct questions, bug reports, and contributions to */
/* ullrich.koethe@iwr.uni-heidelberg.de or */
/* vigra@informatik.uni-hamburg.de */
/* */
/* Permission is hereby granted, free of charge, to any person */
/* obtaining a copy of this software and associated documentation */
/* files (the "Software"), to deal in the Software without */
/* restriction, including without limitation the rights to use, */
/* copy, modify, merge, publish, distribute, sublicense, and/or */
/* sell copies of the Software, and to permit persons to whom the */
/* Software is furnished to do so, subject to the following */
/* conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the */
/* Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES */
/* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND */
/* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT */
/* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, */
/* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING */
/* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR */
/* OTHER DEALINGS IN THE SOFTWARE. */
/* */
/************************************************************************/
#include <iostream>
#include <vigra/multi_array.hxx>
#include <vigra/random.hxx>
#include <vigra/distancetransform.hxx>
#include <vigra/labelimage.hxx>
#include <vigra/seededregiongrowing.hxx>
#include <vigra/impex.hxx>
using namespace vigra;
int main(int argc, char ** argv)
{
try
{
int number_of_points = 25;
int size = 512;
// create input image
MultiArray<2, float> in(size, size);
MersenneTwister random;
for(int i=1; i<=number_of_points; ++i)
{
// mark a number of points
int x = random. uniformInt(size);
int y = random.uniformInt(size);
// label each point with a unique number
in(x,y) = i;
}
// create output image and paint it white
MultiArray<2, int> out(size, size);
out = 255;
// in the output image, paint the points black which were
// marked in the input image
initImageIf(out, in, 0);
// create image to hold the distance transform
MultiArray<2, float> distances(size, size);
// calculate Euclidean distance transform
// all pixels with value 0 are considered background
distanceTransform(in, distances, 0, 2);
exportImage(distances, ImageExportInfo("distances.gif"));
std::cout << "Wrote distance transform (distances.gif)" << std::endl;
// initialize statistics functor for region growing
ArrayOfRegionStatistics<SeedRgDirectValueFunctor<float> > statistics(number_of_points);
// perform region growing, starting at the points marked in the input
// image; as the feature (first source) image contains the distances,
// the will calculate the voronoi regions of these points
seededRegionGrowing(distances, in, in, statistics);
// in the output image, mark the borders of the voronoi regions black
regionImageToEdgeImage(in, out, 0);
exportImage(out, ImageExportInfo("voronoi.gif"));
std::cout << "Wrote voronoi diagram (voronoi.gif)" << std::endl;
}
catch (std::exception & e)
{
std::cout << e.what() << std::endl;
return 1;
}
return 0;
}

© Ullrich Köthe (ullrich.koethe@iwr.uni-heidelberg.de) Heidelberg Collaboratory for Image Processing, University of Heidelberg, Germany | html generated using doxygen and Python vigra 1.11.0 (Thu Mar 17 2016)