VIGRA - Example Documentation

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

| voronoi.cxx |
--- | --- | ---

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

    /************************************************************************/
    /*                                                                      */
    /*               Copyright 1998-2002 by Ullrich Koethe                  */
    /*       Cognitive Systems Group, University of Hamburg, Germany        */
    /*                                                                      */
    /*    This file is part of the VIGRA computer vision library.           */
    /*    ( Version 1.5.0, Dec 07 2006 )                                    */
    /*    The VIGRA Website is                                              */
    /*        http://kogs-www.informatik.uni-hamburg.de/~koethe/vigra/      */
    /*    Please direct questions, bug reports, and contributions to        */
    /*        koethe@informatik.uni-hamburg.de          or                  */
    /*        vigra@kogs1.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/stdimage.hxx"
    #include "vigra/stdimagefunctions.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
            vigra::FImage in(size, size);

            // paint it black
            in = 0;

            for(int i=1; i<=number_of_points; ++i)
            {
                // mark a number of points
                int x = (int)((float)rand() / RAND_MAX * size);
                int y = (int)((float)rand() / RAND_MAX * size);

                // label each point with a unique number
                in(x,y) = i;
            }

            // create output image and paint it white
            vigra::IImage out(size, size);
            out = 255;

            // in the output image, paint the points black which were
            // marked in the input image
            initImageIf(destImageRange(out), maskImage(in), 0);

            // create image to hold the distance transform
            vigra::FImage distances(size, size);

            // calculate Euclidean distance transform
            distanceTransform(srcImageRange(in), destImage(distances), 0, 2);

            exportImage(srcImageRange(distances), vigra::ImageExportInfo("distances.gif"));
            std::cout << "Wrote distance transform (distances.gif)" << std::endl;

            // initialize statistics functor for region growing
            vigra::ArrayOfRegionStatistics<vigra::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(srcImageRange(distances), srcImage(in),
                                destImage(in), statistics);

            // in the output image, mark the borders of the voronoi regions black
            regionImageToEdgeImage(srcImageRange(in), destImage(out), 0);

            exportImage(srcImageRange(out), vigra::ImageExportInfo("voronoi.gif"));
            std::cout << "Wrote voronoi diagram (voronoi.gif)" << std::endl;
        }
        catch (vigra::StdException & e)
        {
            std::cout << e.what() << std::endl;
            return 1;
        }

        return 0;
    }

© Ullrich Köthe (koethe@informatik.uni-hamburg.de) Cognitive Systems Group, University of Hamburg, Germany | html generated using doxygen and Python VIGRA 1.5.0 (7 Dec 2006)