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pyramid.cxx | ![]() |
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Reduce image size by mean of a Gaussian pyramid
Usage: pyramid 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 1.2.0, Aug 07 2003 ) */ /* 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 <stdio.h> #include "vigra/stdimage.hxx" #include "vigra/convolution.hxx" #include "vigra/resizeimage.hxx" #include "vigra/impex.hxx" using namespace vigra; // MSVC doesn't support Koenig lookup // Gaussian reduction to next pyramid level template <class Image> void reduceToNextLevel(Image & in, Image & out) { // image size at current level int width = in.width(); int height = in.height(); // image size at next smaller level int newwidth = (width + 1) / 2; int newheight = (height + 1) / 2; // resize result image to appropriate size out.resize(newwidth, newheight); // define a Gaussian kernel (size 5x1) vigra::Kernel1D<double> filter; filter.initExplicitly(-2, 2) = 0.05, 0.25, 0.4, 0.25, 0.05; vigra::BasicImage<typename Image::value_type> tmpimage1(width, height); vigra::BasicImage<typename Image::value_type> tmpimage2(width, height); // smooth (band limit) input image separableConvolveX(srcImageRange(in), destImage(tmpimage1), kernel1d(filter)); separableConvolveY(srcImageRange(tmpimage1), destImage(tmpimage2), kernel1d(filter)); // downsample smoothed image resizeImageNoInterpolation(srcImageRange(tmpimage2), destImageRange(out)); } 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 levels[4]; levels[0].resize(info.width(), info.height()); importImage(info, destImage(levels[0])); for(int i=1; i<4; ++i) { // reduce gray image 3 times reduceToNextLevel(levels[i-1], levels[i]); } exportImage(srcImageRange(levels[3]), vigra::ImageExportInfo(argv[2])); } else { vigra::BRGBImage levels[4]; levels[0].resize(info.width(), info.height()); importImage(info, destImage(levels[0])); for(int i=1; i<4; ++i) { // reduce color image 3 times reduceToNextLevel(levels[i-1], levels[i]); } exportImage(srcImageRange(levels[3]), 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) |
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