2 // Copyright 2005-2007 Adobe Systems Incorporated
3 // Copyright 2019 Pranam Lashkari <plashkari628@gmail.com>
5 // Distributed under the Boost Software License, Version 1.0
6 // See accompanying file LICENSE_1_0.txt or copy at
7 // http://www.boost.org/LICENSE_1_0.txt
9 #ifndef BOOST_GIL_EXTENSION_NUMERIC_ALGORITHM_HPP
10 #define BOOST_GIL_EXTENSION_NUMERIC_ALGORITHM_HPP
12 #include <boost/gil/extension/numeric/pixel_numeric_operations.hpp>
14 #include <boost/gil/metafunctions.hpp>
15 #include <boost/gil/pixel_iterator.hpp>
16 #include <boost/gil/image.hpp>
18 #include <boost/assert.hpp>
23 #include <type_traits>
25 namespace boost { namespace gil {
27 /// \brief Reference proxy associated with a type that has a \p "reference" member type alias.
29 /// The reference proxy is the reference type, but with stripped-out C++ reference.
30 /// Models PixelConcept.
32 struct pixel_proxy : std::remove_reference<typename T::reference> {};
34 /// \brief std::for_each for a pair of iterators
35 template <typename Iterator1, typename Iterator2, typename BinaryFunction>
36 BinaryFunction for_each(Iterator1 first1, Iterator1 last1, Iterator2 first2, BinaryFunction f)
38 while (first1 != last1)
39 f(*first1++, *first2++);
43 template <typename SrcIterator, typename DstIterator>
45 auto assign_pixels(SrcIterator src, SrcIterator src_end, DstIterator dst) -> DstIterator
47 for_each(src, src_end, dst,
50 typename pixel_proxy<typename std::iterator_traits<SrcIterator>::value_type>::type,
51 typename pixel_proxy<typename std::iterator_traits<DstIterator>::value_type>::type
53 return dst + (src_end - src);
58 template <std::size_t Size>
59 struct inner_product_k_t
66 class BinaryOperation1,
67 class BinaryOperation2
70 InputIterator1 first1,
71 InputIterator2 first2, T init,
72 BinaryOperation1 binary_op1,
73 BinaryOperation2 binary_op2)
75 init = binary_op1(init, binary_op2(*first1, *first2));
76 return inner_product_k_t<Size - 1>::template apply(
77 first1 + 1, first2 + 1, init, binary_op1, binary_op2);
82 struct inner_product_k_t<0>
89 class BinaryOperation1,
90 class BinaryOperation2
93 InputIterator1 first1,
94 InputIterator2 first2,
96 BinaryOperation1 binary_op1,
97 BinaryOperation2 binary_op2)
103 } // namespace detail
105 /// static version of std::inner_product
109 class InputIterator1,
110 class InputIterator2,
112 class BinaryOperation1,
113 class BinaryOperation2
117 InputIterator1 first1,
118 InputIterator2 first2,
120 BinaryOperation1 binary_op1,
121 BinaryOperation2 binary_op2)
123 return detail::inner_product_k_t<Size>::template apply(
124 first1, first2, init, binary_op1, binary_op2);
127 /// \brief 1D un-guarded cross-correlation with a variable-size kernel
131 typename SrcIterator,
132 typename KernelIterator,
137 auto correlate_pixels_n(
138 SrcIterator src_begin,
140 KernelIterator kernel_begin,
142 DstIterator dst_begin)
145 using src_pixel_ref_t = typename pixel_proxy
147 typename std::iterator_traits<SrcIterator>::value_type
149 using dst_pixel_ref_t = typename pixel_proxy
151 typename std::iterator_traits<DstIterator>::value_type
153 using kernel_value_t = typename std::iterator_traits<KernelIterator>::value_type;
155 PixelAccum accum_zero;
156 pixel_zeros_t<PixelAccum>()(accum_zero);
157 while (src_begin != src_end)
159 pixel_assigns_t<PixelAccum, dst_pixel_ref_t>()(
162 src_begin + kernel_size,
165 pixel_plus_t<PixelAccum, PixelAccum, PixelAccum>(),
166 pixel_multiplies_scalar_t<src_pixel_ref_t, kernel_value_t, PixelAccum>()),
175 /// \brief 1D un-guarded cross-correlation with a fixed-size kernel
180 typename SrcIterator,
181 typename KernelIterator,
185 auto correlate_pixels_k(
186 SrcIterator src_begin,
188 KernelIterator kernel_begin,
189 DstIterator dst_begin)
192 using src_pixel_ref_t = typename pixel_proxy
194 typename std::iterator_traits<SrcIterator>::value_type
196 using dst_pixel_ref_t = typename pixel_proxy
198 typename std::iterator_traits<DstIterator>::value_type
200 using kernel_type = typename std::iterator_traits<KernelIterator>::value_type;
202 PixelAccum accum_zero;
203 pixel_zeros_t<PixelAccum>()(accum_zero);
204 while (src_begin != src_end)
206 pixel_assigns_t<PixelAccum, dst_pixel_ref_t>()(
207 inner_product_k<Size>(
211 pixel_plus_t<PixelAccum, PixelAccum, PixelAccum>(),
212 pixel_multiplies_scalar_t<src_pixel_ref_t, kernel_type, PixelAccum>()),
221 /// \brief destination is set to be product of the source and a scalar
222 /// \tparam PixelAccum - TODO
223 /// \tparam SrcView Models ImageViewConcept
224 /// \tparam DstView Models MutableImageViewConcept
225 template <typename PixelAccum, typename SrcView, typename Scalar, typename DstView>
227 void view_multiplies_scalar(SrcView const& src_view, Scalar const& scalar, DstView const& dst_view)
229 static_assert(std::is_scalar<Scalar>::value, "Scalar is not scalar");
230 BOOST_ASSERT(src_view.dimensions() == dst_view.dimensions());
231 using src_pixel_ref_t = typename pixel_proxy<typename SrcView::value_type>::type;
232 using dst_pixel_ref_t = typename pixel_proxy<typename DstView::value_type>::type;
233 using y_coord_t = typename SrcView::y_coord_t;
235 y_coord_t const height = src_view.height();
236 for (y_coord_t y = 0; y < height; ++y)
238 typename SrcView::x_iterator it_src = src_view.row_begin(y);
239 typename DstView::x_iterator it_dst = dst_view.row_begin(y);
240 typename SrcView::x_iterator it_src_end = src_view.row_end(y);
241 while (it_src != it_src_end)
243 pixel_assigns_t<PixelAccum, dst_pixel_ref_t>()(
244 pixel_multiplies_scalar_t<src_pixel_ref_t, Scalar, PixelAccum>()(*it_src, scalar),
254 /// \ingroup ImageAlgorithms
255 /// \brief Boundary options for image boundary extension
256 enum class boundary_option
258 output_ignore, /// do nothing to the output
259 output_zero, /// set the output to zero
260 extend_padded, /// assume the source boundaries to be padded already
261 extend_zero, /// assume the source boundaries to be zero
262 extend_constant /// assume the source boundaries to be the boundary value
268 template <typename SrcView, typename RltView>
269 void extend_row_impl(
270 SrcView const& src_view,
272 std::size_t extend_count,
273 boundary_option option)
275 std::ptrdiff_t extend_count_ = static_cast<std::ptrdiff_t>(extend_count);
277 if (option == boundary_option::extend_constant)
279 for (std::ptrdiff_t i = 0; i < result_view.height(); i++)
281 if(i >= extend_count_ && i < extend_count_ + src_view.height())
284 src_view.row_begin(i - extend_count_),
285 src_view.row_end(i - extend_count_),
286 result_view.row_begin(i)
289 else if(i < extend_count_)
291 assign_pixels(src_view.row_begin(0), src_view.row_end(0), result_view.row_begin(i));
296 src_view.row_begin(src_view.height() - 1),
297 src_view.row_end(src_view.height() - 1),
298 result_view.row_begin(i)
304 else if (option == boundary_option::extend_zero)
306 typename SrcView::value_type acc_zero;
307 pixel_zeros_t<typename SrcView::value_type>()(acc_zero);
309 for (std::ptrdiff_t i = 0; i < result_view.height(); i++)
311 if (i >= extend_count_ && i < extend_count_ + src_view.height())
314 src_view.row_begin(i - extend_count_),
315 src_view.row_end(i - extend_count_),
316 result_view.row_begin(i)
321 std::fill_n(result_view.row_begin(i), result_view.width(), acc_zero);
325 else if (option == boundary_option::extend_padded)
327 auto original_view = subimage_view(
332 src_view.height() + (2 * extend_count)
334 for (std::ptrdiff_t i = 0; i < result_view.height(); i++)
337 original_view.row_begin(i),
338 original_view.row_end(i),
339 result_view.row_begin(i)
345 BOOST_ASSERT_MSG(false, "Invalid boundary option");
352 /// \brief adds new row at top and bottom.
353 /// Image padding introduces new pixels around the edges of an image.
354 /// The border provides space for annotations or acts as a boundary when using advanced filtering techniques.
355 /// \tparam SrcView Models ImageViewConcept
356 /// \tparam extend_count number of rows to be added each side
357 /// \tparam option - TODO
358 template <typename SrcView>
360 SrcView const& src_view,
361 std::size_t extend_count,
362 boundary_option option
363 ) -> typename gil::image<typename SrcView::value_type>
365 typename gil::image<typename SrcView::value_type>
366 result_img(src_view.width(), src_view.height() + (2 * extend_count));
368 auto result_view = view(result_img);
369 detail::extend_row_impl(src_view, result_view, extend_count, option);
374 /// \brief adds new column at left and right.
375 /// Image padding introduces new pixels around the edges of an image.
376 /// The border provides space for annotations or acts as a boundary when using advanced filtering techniques.
377 /// \tparam SrcView Models ImageViewConcept
378 /// \tparam extend_count number of columns to be added each side
379 /// \tparam option - TODO
380 template <typename SrcView>
382 SrcView const& src_view,
383 std::size_t extend_count,
384 boundary_option option
385 ) -> typename gil::image<typename SrcView::value_type>
387 auto src_view_rotate = rotated90cw_view(src_view);
389 typename gil::image<typename SrcView::value_type>
390 result_img(src_view.width() + (2 * extend_count), src_view.height());
392 auto result_view = rotated90cw_view(view(result_img));
393 detail::extend_row_impl(src_view_rotate, result_view, extend_count, option);
397 /// \brief adds new row and column at all sides.
398 /// Image padding introduces new pixels around the edges of an image.
399 /// The border provides space for annotations or acts as a boundary when using advanced filtering techniques.
400 /// \tparam SrcView Models ImageViewConcept
401 /// \tparam extend_count number of rows/column to be added each side
402 /// \tparam option - TODO
403 template <typename SrcView>
404 auto extend_boundary(
405 SrcView const& src_view,
406 std::size_t extend_count,
407 boundary_option option
408 ) -> typename gil::image<typename SrcView::value_type>
410 if (option == boundary_option::extend_padded)
412 typename gil::image<typename SrcView::value_type>
413 result_img(src_view.width()+(2 * extend_count), src_view.height()+(2 * extend_count));
414 typename gil::image<typename SrcView::value_type>::view_t result_view = view(result_img);
416 auto original_view = subimage_view(
420 src_view.width() + (2 * extend_count),
421 src_view.height() + (2 * extend_count)
424 for (std::ptrdiff_t i = 0; i < result_view.height(); i++)
427 original_view.row_begin(i),
428 original_view.row_end(i),
429 result_view.row_begin(i)
436 auto auxilary_img = extend_col(src_view, extend_count, option);
437 return extend_row(view(auxilary_img), extend_count, option);
440 }} // namespace boost::gil