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0b24f4cdbf
* Added all missing examples, dodgy Jamfile still * Fixed attributions and Jamfile indent * One readme per example: synopsis, build and exec reqs * Cleaned up example/convolve2d.cpp * Added example target to root Jamfile Closes #436
52 lines
1.3 KiB
C++
52 lines
1.3 KiB
C++
//
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// Copyright 2005-2007 Adobe Systems Incorporated
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//
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// Distributed under the Boost Software License, Version 1.0
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// See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt
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//
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#include <boost/gil.hpp>
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#include <boost/gil/extension/io/jpeg.hpp>
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#include <algorithm>
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#include <fstream>
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// Demonstrates a way to compute a histogram
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// This example relies on a colour-converting view to work with a greyscale view
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using namespace boost::gil;
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template <typename GrayView, typename R>
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void gray_image_hist(GrayView const& img_view, R& hist)
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{
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for (auto it = img_view.begin(); it != img_view.end(); ++it)
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++hist[*it];
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// Alternatively, prefer the algorithm with lambda
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// for_each_pixel(img_view, [&hist](gray8_pixel_t const& pixel) {
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// ++hist[pixel];
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// });
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}
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template <typename V, typename R>
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void get_hist(const V& img_view, R& hist) {
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gray_image_hist(color_converted_view<gray8_pixel_t>(img_view), hist);
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}
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int main() {
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rgb8_image_t img;
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read_image("test.jpg", img, jpeg_tag());
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int histogram[256];
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std::fill(histogram,histogram + 256, 0);
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get_hist(const_view(img), histogram);
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std::fstream histo_file("out-histogram.txt", std::ios::out);
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for(std::size_t ii = 0; ii < 256; ++ii)
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histo_file << histogram[ii] << std::endl;
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histo_file.close();
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return 0;
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}
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