    // Copyright (C) 2007  Davis E. King (davis@dlib.net)
    // License: Boost Software License   See LICENSE.txt for the full license.
    #ifndef DLIB_ASSIGN_IMAGe_
    #define DLIB_ASSIGN_IMAGe_

    #include "../pixel.h"
    #include "assign_image_abstract.h"
    #include "../statistics.h"

    namespace dlib
    {

    // ----------------------------------------------------------------------------------------

        template <
            typename dest_image_type,
            typename src_pixel_type
            >
        typename enable_if<is_matrix<dest_image_type> >::type impl_assign_single_pixel (
            dest_image_type& img,
            long r,
            long c,
            const src_pixel_type& pix
        )
        {
            assign_pixel(img(r,c), pix);
        }

        template <
            typename dest_image_type,
            typename src_pixel_type
            >
        typename disable_if<is_matrix<dest_image_type> >::type impl_assign_single_pixel (
            dest_image_type& img,
            long r,
            long c,
            const src_pixel_type& pix
        )
        {
            assign_pixel(img[r][c], pix);
        }

    // ----------------------------------------------------------------------------------------

        template <
            typename dest_image_type,
            typename src_image_type
            >
        void impl_assign_image (
            dest_image_type& dest,
            const src_image_type& src
        )
        {
            dest.set_size(src.nr(),src.nc());

            for (long r = 0; r < src.nr(); ++r)
            {
                for (long c = 0; c < src.nc(); ++c)
                {
                    impl_assign_single_pixel(dest,r,c, src(r,c));
                }
            }
        }

        template <
            typename dest_image_type,
            typename src_image_type
            >
        void assign_image (
            dest_image_type& dest,
            const src_image_type& src
        )
        {
            // check for the case where dest is the same object as src
            if (is_same_object(dest,src))
                return;

            impl_assign_image(dest, mat(src));
        }

    // ----------------------------------------------------------------------------------------

        template <
            typename dest_image_type,
            typename src_image_type
            >
        void impl_assign_image_scaled (
            dest_image_type& dest,
            const src_image_type& src,
            const double thresh = 4
        )
        {
            DLIB_ASSERT( thresh > 0,
                "\tvoid assign_image_scaled()"
                << "\n\t You have given an threshold value"
                << "\n\t thresh: " << thresh
                );

            // If the destination has a dynamic range big enough to contain the source image data then just do a
            // regular assign_image()
            if (pixel_traits<typename dest_image_type::type>::max() >= pixel_traits<typename src_image_type::type>::max() &&
                pixel_traits<typename dest_image_type::type>::min() <= pixel_traits<typename src_image_type::type>::min() )
            {
                assign_image(dest, src);
                return;
            }

            dest.set_size(src.nr(),src.nc());

            if (src.size() == 0)
                return;

            if (src.size() == 1)
            {
                impl_assign_single_pixel(dest,0,0, src(0,0));
                return;
            }

            // gather image statistics
            running_stats<double> rs;
            for (long r = 0; r < src.nr(); ++r)
            {
                for (long c = 0; c < src.nc(); ++c)
                {
                    rs.add(get_pixel_intensity(src(r,c)));
                }
            }
            typedef typename pixel_traits<typename src_image_type::type>::basic_pixel_type spix_type;

            if (std::numeric_limits<spix_type>::is_integer)
            {
                // If the destination has a dynamic range big enough to contain the source image data then just do a
                // regular assign_image()
                if (pixel_traits<typename dest_image_type::type>::max() >= rs.max() &&
                    pixel_traits<typename dest_image_type::type>::min() <= rs.min() )
                {
                    impl_assign_image(dest, src);
                    return;
                }
            }

            // Figure out the range of pixel values based on image statistics.  There might be some huge
            // outliers so don't just pick the min and max values.
            const double upper = std::min(rs.mean() + thresh*rs.stddev(), rs.max());
            const double lower = std::max(rs.mean() - thresh*rs.stddev(), rs.min());

            const double dest_min = pixel_traits<typename dest_image_type::type>::min();
            const double dest_max = pixel_traits<typename dest_image_type::type>::max();

            const double scale = (upper!=lower)? ((dest_max - dest_min) / (upper - lower)) : 0;

            for (long r = 0; r < src.nr(); ++r)
            {
                for (long c = 0; c < src.nc(); ++c)
                {
                    const double val = get_pixel_intensity(src(r,c)) - lower;

                    impl_assign_single_pixel(dest,r,c, scale*val + dest_min);
                }
            }
        }

        template <
            typename dest_image_type,
            typename src_image_type
            >
        void assign_image_scaled (
            dest_image_type& dest,
            const src_image_type& src,
            const double thresh = 4
        )
        {
            // check for the case where dest is the same object as src
            if (is_same_object(dest,src))
                return;

            impl_assign_image_scaled(dest, mat(src),thresh);
        }

    // ----------------------------------------------------------------------------------------

        template <
            typename dest_image_type,
            typename src_pixel_type
            >
        void assign_all_pixels (
            dest_image_type& dest_img,
            const src_pixel_type& src_pixel
        )
        {
            for (long r = 0; r < dest_img.nr(); ++r)
            {
                for (long c = 0; c < dest_img.nc(); ++c)
                {
                    assign_pixel(dest_img[r][c], src_pixel);
                }
            }
        }

    // ----------------------------------------------------------------------------------------

        template <
            typename image_type
            >
        void assign_border_pixels (
            image_type& img,
            long x_border_size,
            long y_border_size,
            const typename image_type::type& p
        )
        {
            DLIB_ASSERT( x_border_size >= 0 && y_border_size >= 0,
                "\tvoid assign_border_pixels(img, p, border_size)"
                << "\n\tYou have given an invalid border_size"
                << "\n\tx_border_size: " << x_border_size
                << "\n\ty_border_size: " << y_border_size
                );

            y_border_size = std::min(y_border_size, img.nr()/2+1);
            x_border_size = std::min(x_border_size, img.nc()/2+1);

            // assign the top border
            for (long r = 0; r < y_border_size; ++r)
            {
                for (long c = 0; c < img.nc(); ++c)
                {
                    img[r][c] = p;
                }
            }

            // assign the bottom border
            for (long r = img.nr()-y_border_size; r < img.nr(); ++r)
            {
                for (long c = 0; c < img.nc(); ++c)
                {
                    img[r][c] = p;
                }
            }

            // now assign the two sides
            for (long r = y_border_size; r < img.nr()-y_border_size; ++r)
            {
                // left border
                for (long c = 0; c < x_border_size; ++c)
                    img[r][c] = p;

                // right border
                for (long c = img.nc()-x_border_size; c < img.nc(); ++c)
                    img[r][c] = p;
            }
        }

    // ----------------------------------------------------------------------------------------

        template <
            typename image_type
            >
        void zero_border_pixels (
            image_type& img,
            long x_border_size,
            long y_border_size
        )
        {
            DLIB_ASSERT( x_border_size >= 0 && y_border_size >= 0,
                "\tvoid zero_border_pixels(img, p, border_size)"
                << "\n\tYou have given an invalid border_size"
                << "\n\tx_border_size: " << x_border_size
                << "\n\ty_border_size: " << y_border_size
                );

            typename image_type::type zero_pixel;
            assign_pixel_intensity(zero_pixel, 0);
            assign_border_pixels(img, x_border_size, y_border_size, zero_pixel);
        }

    // ----------------------------------------------------------------------------------------

        template <
            typename image_type
            >
        void zero_border_pixels (
            image_type& img,
            rectangle inside
        )
        {
            inside = inside.intersect(get_rect(img));
            if (inside.is_empty())
                return;

            for (long r = 0; r < inside.top(); ++r)
            {
                for (long c = 0; c < img.nc(); ++c)
                    assign_pixel(img[r][c], 0);
            }
            for (long r = inside.top(); r <= inside.bottom(); ++r)
            {
                for (long c = 0; c < inside.left(); ++c)
                    assign_pixel(img[r][c], 0);
                for (long c = inside.right()+1; c < img.nc(); ++c)
                    assign_pixel(img[r][c], 0);
            }
            for (long r = inside.bottom()+1; r < img.nr(); ++r)
            {
                for (long c = 0; c < img.nc(); ++c)
                    assign_pixel(img[r][c], 0);
            }
        }

    // ----------------------------------------------------------------------------------------

    }

    #endif // DLIB_ASSIGN_IMAGe_