Boost C++ Libraries of the most highly regarded and expertly designed C++ library projects in the world. Herb Sutter and Andrei Alexandrescu, C++ Coding Standards


// 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

#include <boost/gil.hpp>
#include <boost/gil/extension/io/jpeg.hpp>
#include <boost/gil/extension/numeric/sampler.hpp>
#include <boost/gil/extension/numeric/resample.hpp>

// Performs an arbitrary affine transformation on the image.

// This example relies on the matrices and functions available in GIL to define the operation,
// in include/boost/gil/extension/numeric/affine.hpp
// and calls resample_pixels(), avaiable in the numeric extension, to apply it

int main()
    namespace gil = boost::gil;

    gil::rgb8_image_t img;
    gil::read_image("test.jpg", img, gil::jpeg_tag());

    // test resample_pixels
    // Transform the image by an arbitrary affine transformation using nearest-neighbor resampling
    gil::rgb8_image_t transf(gil::rgb8_image_t::point_t(gil::view(img).dimensions() * 2));
    gil::fill_pixels(gil::view(transf), gil::rgb8_pixel_t(255, 0, 0)); // the background is red

    gil::matrix3x2<double> mat =
        gil::matrix3x2<double>::get_translate(-gil::point<double>(200,250)) *
    gil::resample_pixels(const_view(img), gil::view(transf), mat, gil::nearest_neighbor_sampler());
    gil::write_view("out-affine.jpg", gil::view(transf), gil::jpeg_tag());

    return 0;