gil/example/x_gradient.cpp
Mateusz Loskot fb19a1205d
Apply clang-tidy modernize-use-using to all examples (#210)
Run clang-tidy 7.0 with -checks='-*,modernize-use-using' -fix
against TU-s of examples.

Manually refactor numerous typedef-s where missed by modernize-use-using
check, not uncommon in code snippets in comments.

Outcome is that searching for lower-case whole word typedef
in sources of all the tests should return only handful of matches
in boost/gil/extension/dynamic_image/apply_operation_base.hpp
2019-01-12 17:36:29 +01:00

60 lines
1.7 KiB
C++

//
// 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;
}