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invert_explicitly.cxx |

Invert an image file (create a negative) by coding the loop explicitly
Usage: `example_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 */
/* 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/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 1.11.1 (Fri May 19 2017)