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smooth_convolve.cxx |

Convolve an image in different ways (gray scale or color)
Usage: `smooth_convolve infile outfile`

#include <vigra/multi_array.hxx>
#include <vigra/impex.hxx>
#include <vigra/convolution.hxx>
#include <iostream>
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: " << impexListFormats() << ")" << std::endl;
return 1;
}
try
{
// read image given as first argument
ImageImportInfo info(argv[1]);
// choose convolving mode
std::cout << "Which mode of convolution?\n";
std::cout << "1 - disk average\n";
std::cout << "2 - corners of a 3x3-box\n";
std::cout << "3 - Gaussian filter\n";
std::cout << "4 - separable Gaussian filter (x- and x-dimension separately)\n";
int mode;
std::cin >> mode;
// instantiate convolution kernels
Kernel2D<double> kernel2dim;
Kernel1D<double> kernel1dim;
// initialize kernel
switch(mode)
{
case 1:
// homogenous averaging within a disk of radius 2
kernel2dim.initDisk(2);
break;
case 2:
// strange custom-made filter: averaging the corners of a 3x3-box
kernel2dim.initExplicitly(Diff2D(-1,-1), Diff2D(1,1)) =
0.25, 0.0, 0.25,
0.0, 0.0, 0.0,
0.25, 0.0, 0.25;
break;
case 3:
// gaussian convolution
kernel2dim.initGaussian(1.5);
break;
case 4:
// separable gaussian convolution
kernel1dim.initGaussian(1.5);
break;
default:
vigra_precondition(false, "mode must be between 1 and 4.");
}
// process grayscale image
if (info.isGrayscale())
{
// instantiate arrays for image data and for smoothed image of appropriate size
MultiArray<2, float> imageArray(info.shape()),
exportArray(info.shape());
// copy image data into array
importImage(info, imageArray);
// convolve image
if (mode == 4)
{
convolveImage(imageArray, exportArray, kernel1dim, kernel1dim);
}
else
{
convolveImage(imageArray, exportArray, kernel2dim);
}
// write image data to the file given as second argument
exportImage(exportArray, ImageExportInfo(argv[2]));
}
// process color image
else
{
// instantiate arrays for image data and for smoothed image of appropriate size
MultiArray<2, RGBValue<float> > imageArray(info.shape());
MultiArray<2, RGBValue<float> > exportArray(info.shape());
// copy image data into array
importImage(info, imageArray);
// convolve image
if (mode == 4)
{
convolveImage(imageArray, exportArray, kernel1dim, kernel1dim);
}
else
{
convolveImage(imageArray, exportArray, kernel2dim);
}
// write image data to the file given as second argument
exportImage(exportArray, ImageExportInfo(argv[2]));
}
}
catch (std::exception & e)
{
// catch any errors that might have occurred and print their reason
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)