update boost

linx64/include/boost/gil/image_processing/hessian.hpp

@@ -0,0 +1,80 @@
+//
+// Copyright 2019 Olzhas Zhumabek <anonymous.from.applecity@gmail.com>
+// Copyright 2021 Scramjet911 <36035352+Scramjet911@users.noreply.github.com>
+// Use, modification and distribution are subject to 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)
+
+#ifndef BOOST_GIL_IMAGE_PROCESSING_HESSIAN_HPP
+#define BOOST_GIL_IMAGE_PROCESSING_HESSIAN_HPP
+
+#include <boost/gil/image_view.hpp>
+#include <boost/gil/typedefs.hpp>
+#include <boost/gil/image_processing/kernel.hpp>
+#include <stdexcept>
+
+namespace boost { namespace gil {
+
+/// \brief Computes Hessian response
+///
+/// Computes Hessian response based on computed entries of Hessian matrix, e.g. second order
+/// derivates in x and y, and derivatives in both x, y.
+/// d stands for derivative, and x or y stand for derivative direction. For example,
+/// ddxx means taking two derivatives (gradients) in horizontal direction.
+/// Weights change perception of surroinding pixels.
+/// Additional filtering is strongly advised.
+template <typename GradientView, typename T, typename Allocator, typename OutputView>
+inline void compute_hessian_responses(
+    GradientView ddxx,
+    GradientView dxdy,
+    GradientView ddyy,
+    const detail::kernel_2d<T, Allocator>& weights,
+    OutputView dst)
+{
+    if (ddxx.dimensions() != ddyy.dimensions()
+        || ddyy.dimensions() != dxdy.dimensions()
+        || dxdy.dimensions() != dst.dimensions()
+        || weights.center_x() != weights.center_y())
+    {
+        throw std::invalid_argument("dimensions of views are not the same"
+            " or weights don't have equal width and height"
+            " or weights' dimensions are not odd");
+    }
+    // Use pixel type of output, as values will be written to output
+    using pixel_t = typename std::remove_reference<decltype(std::declval<OutputView>()(0, 0))>::type;
+
+    using channel_t = typename std::remove_reference
+        <
+            decltype(std::declval<pixel_t>().at(std::integral_constant<int, 0>{}))
+        >::type;
+
+
+    auto center = weights.center_y();
+    for (auto y = center; y < dst.height() - center; ++y)
+    {
+        for (auto x = center; x < dst.width() - center; ++x)
+        {
+            auto ddxx_i = channel_t();
+            auto ddyy_i = channel_t();
+            auto dxdy_i = channel_t();
+            for (typename OutputView::coord_t w_y = 0; w_y < static_cast<std::ptrdiff_t>(weights.size()); ++w_y)
+            {
+                for (typename OutputView::coord_t w_x = 0; w_x < static_cast<std::ptrdiff_t>(weights.size()); ++w_x)
+                {
+                    ddxx_i += ddxx(x + w_x - center, y + w_y - center)
+                        .at(std::integral_constant<int, 0>{}) * weights.at(w_x, w_y);
+                    ddyy_i += ddyy(x + w_x - center, y + w_y - center)
+                        .at(std::integral_constant<int, 0>{}) * weights.at(w_x, w_y);
+                    dxdy_i += dxdy(x + w_x - center, y + w_y - center)
+                        .at(std::integral_constant<int, 0>{}) * weights.at(w_x, w_y);
+                }
+            }
+            auto determinant = ddxx_i * ddyy_i - dxdy_i * dxdy_i;
+            dst(x, y).at(std::integral_constant<int, 0>{}) = determinant;
+        }
+    }
+}
+
+}} // namespace boost::gil
+
+#endif