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//
// Copyright 2005-2007 Adobe Systems Incorporated
//
// Distributed under the Boost Software License, Version 1.0
// See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt
//
#include <boost/gil.hpp>
#include <boost/gil/extension/io/jpeg.hpp>
#include <algorithm>
#include <fstream>
// Example file to demonstrate a way to compute histogram
using namespace boost::gil;
template <typename GrayView, typename R>
void gray_image_hist(GrayView const& img_view, R& hist)
{
for (auto it = img_view.begin(); it != img_view.end(); ++it)
++hist[*it];
// Alternatively, prefer the algorithm with lambda
// for_each_pixel(img_view, [&hist](gray8_pixel_t const& pixel) {
// ++hist[pixel];
// });
}
template <typename V, typename R>
void get_hist(const V& img_view, R& hist) {
gray_image_hist(color_converted_view<gray8_pixel_t>(img_view), hist);
}
int main() {
rgb8_image_t img;
read_image("test.jpg", img, jpeg_tag());
int histogram[256];
std::fill(histogram,histogram + 256, 0);
get_hist(const_view(img), histogram);
std::fstream histo_file("out-histogram.txt", std::ios::out);
for(std::size_t ii = 0; ii < 256; ++ii)
histo_file << histogram[ii] << std::endl;
histo_file.close();
return 0;
}
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