← Back
Editing: pixel.hpp
// // Copyright 2005-2007 Adobe Systems Incorporated // Copyright 2019 Mateusz Loskot <mateusz at loskot dot net> // // 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 // #ifndef BOOST_GIL_PIXEL_HPP #define BOOST_GIL_PIXEL_HPP #include <boost/gil/channel.hpp> #include <boost/gil/color_base.hpp> #include <boost/gil/color_base_algorithm.hpp> #include <boost/gil/concepts.hpp> #include <boost/gil/metafunctions.hpp> #include <boost/gil/utilities.hpp> #include <boost/gil/detail/mp11.hpp> #include <functional> #include <type_traits> namespace boost { namespace gil { // Forward-declare gray_t struct gray_color_t; using gray_t = mp11::mp_list<gray_color_t>; template <typename PixelBased> struct color_space_type; template <typename PixelBased> struct channel_mapping_type; template <typename PixelBased> struct channel_type; template <typename PixelBased> struct is_planar; template <typename PixelBased> struct color_space_type<PixelBased const> : color_space_type<PixelBased> {}; template <typename PixelBased> struct channel_mapping_type<PixelBased const> : channel_mapping_type<PixelBased> {}; template <typename PixelBased> struct channel_type<PixelBased const> : channel_type<PixelBased> {}; template <typename PixelBased> struct is_planar : std::false_type {}; template <typename PixelBased> struct is_planar<PixelBased const> : is_planar<PixelBased> {}; template <typename T> struct is_pixel : std::false_type {}; template <typename T> struct is_pixel<T const> : is_pixel<T> {}; /// \ingroup PixelBasedAlgorithm /// \brief Returns the number of channels of a pixel-based GIL construct template <typename PixelBased> struct num_channels : mp11::mp_size<typename color_space_type<PixelBased>::type>::type {}; /** \addtogroup PixelBasedAlgorithm Example: \code static_assert(num_channels<rgb8_view_t>::value == 3, ""); static_assert(num_channels<cmyk16_planar_ptr_t>::value == 4, ""); static_assert(is_planar<rgb16_planar_image_t>::value)); static_assert(std::is_same<color_space_type<rgb8_planar_ref_t>::type, rgb_t>::value, ""); static_assert(std::is_same<channel_mapping_type<cmyk8_pixel_t>::type, channel_mapping_type<rgba8_pixel_t>::type>::value, ""); static_assert(std::is_same<channel_type<bgr8_pixel_t>::type, uint8_t>::value, ""); \endcode */ /// \defgroup ColorBaseModelPixel pixel /// \ingroup ColorBaseModel /// \brief A homogeneous color base whose element is a channel value. Models HomogeneousColorBaseValueConcept /// \defgroup PixelModelPixel pixel /// \ingroup PixelModel /// \brief A homogeneous pixel value. Models HomogeneousPixelValueConcept /// \ingroup PixelModelPixel ColorBaseModelPixel PixelBasedModel /// \brief Represents a pixel value (a container of channels). Models: HomogeneousColorBaseValueConcept, PixelValueConcept, HomogeneousPixelBasedConcept /// /// A pixel is a set of channels defining the color at a given point in an image. Conceptually, a pixel is little more than a color base whose elements /// model \p ChannelConcept. The class \p pixel defines a simple, homogeneous pixel value. It is used to store /// the value of a color. The built-in C++ references to \p pixel, \p pixel& and \p const \p pixel& are used to represent a reference to a pixel /// inside an interleaved image view (a view in which all channels are together in memory). Similarly, built-in pointer types \p pixel* and \p const \p pixel* /// are used as the standard iterator over a row of interleaved homogeneous pixels. /// /// Since \p pixel inherits the properties of color base, assigning, equality comparison and copy-construcion are allowed between compatible pixels. /// This means that an 8-bit RGB pixel may be assigned to an 8-bit BGR pixel, or to an 8-bit planar reference. The channels are properly paired semantically. /// /// The single-channel (grayscale) instantiation of the class pixel, (i.e. \p pixel<T,gray_layout_t>) is also convertible to/from a channel value. /// This allows grayscale pixels to be used in simpler expressions like *gray_pix1 = *gray_pix2 instead of more complicated at_c<0>(gray_pix1) = at_c<0>(gray_pix2) /// or get_color<gray_color_t>(gray_pix1) = get_color<gray_color_t>(gray_pix2) /// /// \tparam ChannelValue TODO /// \tparam Layout mp11::make_integer_sequence<int, ColorSpace::size> template <typename ChannelValue, typename Layout> struct pixel : detail::homogeneous_color_base < ChannelValue, Layout, mp11::mp_size<typename Layout::color_space_t>::value > { private: using channel_t = ChannelValue; using parent_t = detail::homogeneous_color_base < ChannelValue, Layout, mp11::mp_size<typename Layout::color_space_t>::value >; public: using value_type = pixel<ChannelValue, Layout>; using reference = value_type&; using const_reference = value_type const&; static constexpr bool is_mutable = channel_traits<channel_t>::is_mutable; pixel() = default; explicit pixel(channel_t v) : parent_t(v) {} // sets all channels to v pixel(channel_t v0, channel_t v1) : parent_t(v0, v1) {} pixel(channel_t v0, channel_t v1, channel_t v2) : parent_t(v0, v1, v2) {} pixel(channel_t v0, channel_t v1, channel_t v2, channel_t v3) : parent_t(v0, v1, v2, v3) {} pixel(channel_t v0, channel_t v1, channel_t v2, channel_t v3, channel_t v4) : parent_t(v0, v1, v2, v3, v4) {} pixel(channel_t v0, channel_t v1, channel_t v2, channel_t v3, channel_t v4, channel_t v5) : parent_t(v0, v1, v2, v3, v4, v5) {} pixel(const pixel& p) : parent_t(p) {} pixel& operator=(pixel const& p) { static_copy(p,*this); return *this; } // Construct from another compatible pixel type template <typename Pixel> pixel(Pixel const& p, typename std::enable_if<is_pixel<Pixel>::value>::type* /*dummy*/ = nullptr) : parent_t(p) { check_compatible<Pixel>(); } template <typename Pixel> pixel& operator=(Pixel const& p) { assign(p, is_pixel<Pixel>()); return *this; } template <typename Pixel> bool operator==(Pixel const& p) const { return equal(p, is_pixel<Pixel>()); } template <typename Pixel> bool operator!=(Pixel const& p) const { return !(*this == p); } // homogeneous pixels have operator[] auto operator[](std::size_t index) -> typename channel_traits<channel_t>::reference { return dynamic_at_c(*this, index); } auto operator[](std::size_t index) const -> typename channel_traits<channel_t>::const_reference { return dynamic_at_c(*this, index); } private: template <typename Pixel> void assign(Pixel const& p, std::true_type) { check_compatible<Pixel>(); static_copy(p, *this); } template <typename Pixel> bool equal(Pixel const& p, std::true_type) const { check_compatible<Pixel>(); return static_equal(*this, p); } template <typename Pixel> void check_compatible() const { gil_function_requires<PixelsCompatibleConcept<Pixel, pixel>>(); } // Support for assignment/equality comparison of a channel with a grayscale pixel private: static void check_gray() { static_assert(std::is_same<typename Layout::color_space_t, gray_t>::value, ""); } template <typename Channel> void assign(Channel const& channel, std::false_type) { check_gray(); gil::at_c<0>(*this) = channel; } template <typename Channel> bool equal (Channel const& channel, std::false_type) const { check_gray(); return gil::at_c<0>(*this) == channel; } public: pixel& operator= (channel_t channel) { check_gray(); gil::at_c<0>(*this) = channel; return *this; } bool operator==(channel_t channel) const { check_gray(); return gil::at_c<0>(*this) == channel; } }; ///////////////////////////// // ColorBasedConcept ///////////////////////////// template <typename ChannelValue, typename Layout, int K> struct kth_element_type<pixel<ChannelValue,Layout>, K> { using type = ChannelValue; }; template <typename ChannelValue, typename Layout, int K> struct kth_element_reference_type<pixel<ChannelValue,Layout>, K> { using type = typename channel_traits<ChannelValue>::reference; }; template <typename ChannelValue, typename Layout, int K> struct kth_element_reference_type<const pixel<ChannelValue,Layout>, K> { using type = typename channel_traits<ChannelValue>::const_reference; }; template <typename ChannelValue, typename Layout, int K> struct kth_element_const_reference_type<pixel<ChannelValue,Layout>, K> { using type = typename channel_traits<ChannelValue>::const_reference; }; ///////////////////////////// // PixelConcept ///////////////////////////// template <typename ChannelValue, typename Layout> struct is_pixel<pixel<ChannelValue,Layout>> : std::true_type {}; ///////////////////////////// // HomogeneousPixelBasedConcept ///////////////////////////// template <typename ChannelValue, typename Layout> struct color_space_type<pixel<ChannelValue, Layout>> { using type = typename Layout::color_space_t; }; template <typename ChannelValue, typename Layout> struct channel_mapping_type<pixel<ChannelValue, Layout>> { using type = typename Layout::channel_mapping_t; }; template <typename ChannelValue, typename Layout> struct is_planar<pixel<ChannelValue, Layout>> : std::false_type {}; template <typename ChannelValue, typename Layout> struct channel_type<pixel<ChannelValue, Layout>> { using type = ChannelValue; }; }} // namespace boost::gil #endif
Save File
Cancel