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| invert.cxx |
--- | --- | ---

Invert an image file (create a negative) using the function Algorithms to Transform Images
Usage: `invert infile outfile`

    /************************************************************************/
    /*                                                                      */
    /*               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/stdimagefunctions.hxx"
    #include "vigra/impex.hxx"
    #include <string.h>

    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 a negative image by applying the expression
                //       newvalue = -1 * (oldvalue - 255)
                // to each pixel
                transformImage(srcImageRange(in), destImage(out),
                               vigra::linearIntensityTransform(-1, -255));

                if(strcmp(argv[2], "-") == 0)
                {
                    // write stdout
                    exportImage(srcImageRange(out),
                     vigra::ImageExportInfo(argv[2]).setFileType(info.getFileType()));
                }
                else
                {
                    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 a negative image by applying the expression
                //       newvalue = -1 * (oldvalue + RGBValue<int>(-255, -255, -255))
                // to each pixel
                transformImage(srcImageRange(in), destImage(out),
                               vigra::linearIntensityTransform(-1, offset));

                if(strcmp(argv[2], "-") == 0)
                {
                    // write stdout
                    exportImage(srcImageRange(out),
                     vigra::ImageExportInfo(argv[2]).setFileType(info.getFileType()));
                }
                else
                {
                    exportImage(srcImageRange(out), vigra::ImageExportInfo(argv[2]));
                }
            }
        }
        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)