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pyramid.cxx | ![]() |
Reduce image size by mean of a Gaussian pyramid
Usage: pyramid 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 <stdio.h> #include "vigra/stdimage.hxx" #include "vigra/convolution.hxx" #include "vigra/resizeimage.hxx" #include "vigra/impex.hxx" using namespace vigra; // 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 (ullrich.koethe@iwr.uni-heidelberg.de) |
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