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| profile.cxx |
--- | --- | ---

Find the gray value profile along the image diagonal by means of a vigra::LineIterator
Usage: `profile infile`, generates `profile.gif`

    /************************************************************************/
    /*                                                                      */
    /*               Copyright 1998-2002 by Ullrich Koethe                  */
    /*       Cognitive Systems Group, University of Hamburg, Germany        */
    /*                                                                      */
    /*    This file is part of the VIGRA computer vision library.           */
    /*    ( Version 1.3.2, Jan 27 2005 )                                    */
    /*    You may use, modify, and distribute this software according       */
    /*    to the terms stated in the LICENSE file included in               */
    /*    the VIGRA distribution.                                           */
    /*                                                                      */
    /*    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                              */
    /*                                                                      */
    /*  THIS SOFTWARE IS PROVIDED AS IS AND WITHOUT ANY EXPRESS OR          */
    /*  IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED      */
    /*  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. */
    /*                                                                      */
    /************************************************************************/

    #include <iostream>
    #include "vigra/stdimage.hxx"
    #include "vigra/imageiteratoradapter.hxx"
    #include "vigra/impex.hxx"

    using namespace vigra;

    int main(int argc, char ** argv)
    {
        if(argc != 2)
        {
            std::cout << "Usage: " << argv[0] << " infile" << std::endl;
            std::cout << "(supported formats: " << vigra::impexListFormats() << ")" << std::endl;

            return 1;
        }

        try
        {
            vigra::ImageImportInfo info(argv[1]);

            vigra_precondition(info.isGrayscale(), "Sorry, cannot operate on color images");

            int w = info.width();
            int h = info.height();

            vigra::BImage in(w, h);
            importImage(info, destImage(in));

            int length = (w < h) ? h : w;

            // create output image of appropriate size
            vigra::BImage out(length, 256);

            // paint output image white
            out = 255;

            // create line iterator that iterates along the image diagonal
            vigra::LineIterator<vigra::BImage::Iterator> line(in.upperLeft(), in.lowerRight());

            // create line iterator that marks the end of iteration
            vigra::LineIterator<vigra::BImage::Iterator> end(in.lowerRight(), in.lowerRight());

            // create image iterator that points to the first pixel of the last
            // row of the destination image
            vigra::BImage::Iterator column = out.upperLeft() + vigra::Diff2D(0, 255);

            // iterate along the line and across the destination image
            for(; line != end; ++line, ++column.x)
            {
                vigra::BImage::Iterator row(column);
                // paint all pixels black whose coordinates are smaller than the
                // current gray value along the diagonal
                for(int y=0; y <= *line; ++y, --row.y)  *row = 0;
            }

            std::cout << "Writing profile.gif" << std::endl;
            exportImage(srcImageRange(out), vigra::ImageExportInfo("profile.gif"));
        }
        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 1.3.2 (27 Jan 2005)