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invert_explicitly.cxx |

Invert an image file (create a negative) by coding the loop explicitly
Usage: `invert_explicitly infile outfile`

    /************************************************************************/
    /*                                                                      */
    /*               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       */
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    /*    WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING      */
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    /************************************************************************/

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

    using namespace vigra;

    int main(int argc, char ** argv)
    {
        if(argc != 3)
        {
            std::cout << "Usage: " << argv[0] << " infile outfile" << std::endl;
            std::cout << "(supported formats: " << vigra::impexListFormats() << ")" << std::endl;

            return 1;
        }

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

            if(info.isGrayscale())
            {
                vigra::BImage in(info.width(), info.height());
                vigra::BImage out(info.width(), info.height());

                importImage(info, destImage(in));

                // create image iterator that points to upper left corner
                // of source image
                vigra::BImage::Iterator sy = in.upperLeft();

                // create image iterator that points past the lower right corner of
                // source image (similarly to the past-the-end iterator in the STL)
                vigra::BImage::Iterator send = in.lowerRight();

                // create image iterator that points to upper left corner
                // of destination image
                vigra::BImage::Iterator dy = out.upperLeft();

                // iterate down the first column of the images
                for(; sy.y != send.y; ++sy.y, ++dy.y)
                {
                    // create image iterator that points to the first
                    // pixel of the current row of the source image
                    vigra::BImage::Iterator sx = sy;

                    // create image iterator that points to the first
                    // pixel of the current row of the destination image
                    vigra::BImage::Iterator dx = dy;

                    // iterate across current row
                    for(; sx.x != send.x; ++sx.x, ++dx.x)
                    {
                        // calculate negative gray value
                        *dx = 255 - *sx;
                    }
                }

                exportImage(srcImageRange(out), vigra::ImageExportInfo(argv[2]));
            }
            else
            {
                vigra::BRGBImage in(info.width(), info.height());
                vigra::BRGBImage out(info.width(), info.height());

                importImage(info, destImage(in));

                vigra::RGBValue<int> offset(255, 255, 255);

                // create image iterator that points to upper left corner
                // of source image
                vigra::BRGBImage::Iterator sy = in.upperLeft();

                // create image iterator that points past the lower right corner of
                // source image (similarly to the past-the-end iterator in the STL)
                vigra::BRGBImage::Iterator send = in.lowerRight();

                // create image iterator that points to upper left corner
                // of destination image
                vigra::BRGBImage::Iterator dy = out.upperLeft();

                // iterate down the first column of the images
                for(; sy.y != send.y; ++sy.y, ++dy.y)
                {
                    // create image iterator that points to the first
                    // pixel of the current row of the source image
                    vigra::BRGBImage::Iterator sx = sy;

                    // create image iterator that points to the first
                    // pixel of the current row of the destination image
                    vigra::BRGBImage::Iterator dx = dy;

                    // iterate across current row
                    for(; sx.x != send.x; ++sx.x, ++dx.x)
                    {
                        // calculate negative color
                        *dx = offset - *sx;
                    }
                }

                exportImage(srcImageRange(out), vigra::ImageExportInfo(argv[2]));
            }
        }
        catch (vigra::StdException & 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 1.7.1 (3 Dec 2010)