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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/extension/io/jpeg.hpp>
- // Example to demonstrate a way to compute gradients along x-axis
- using namespace boost::gil;
- template <typename Out>
- struct halfdiff_cast_channels {
- template <typename T> Out operator()(const T& in1, const T& in2) const {
- return Out((in2-in1)/2);
- }
- };
- template <typename SrcView, typename DstView>
- void x_gradient(SrcView const& src, DstView const& dst)
- {
- using dst_channel_t = typename channel_type<DstView>::type;
- for (int y = 0; y < src.height(); ++y)
- {
- typename SrcView::x_iterator src_it = src.row_begin(y);
- typename DstView::x_iterator dst_it = dst.row_begin(y);
- for (int x = 1; x < src.width() - 1; ++x)
- {
- static_transform(src_it[x - 1], src_it[x + 1], dst_it[x],
- halfdiff_cast_channels<dst_channel_t>());
- }
- }
- }
- template <typename SrcView, typename DstView>
- void x_luminosity_gradient(SrcView const& src, DstView const& dst)
- {
- using gray_pixel_t = pixel<typename channel_type<SrcView>::type, gray_layout_t>;
- x_gradient(color_converted_view<gray_pixel_t>(src), dst);
- }
- int main()
- {
- rgb8_image_t img;
- read_image("test.jpg",img, jpeg_tag{});
- gray8s_image_t img_out(img.dimensions());
- fill_pixels(view(img_out),int8_t(0));
- x_luminosity_gradient(const_view(img), view(img_out));
- write_view("out-x_gradient.jpg",color_converted_view<gray8_pixel_t>(const_view(img_out)), jpeg_tag{});
- return 0;
- }
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