// // 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 // #ifndef BOOST_GIL_EXTENSION_NUMERIC_RESAMPLE_HPP #define BOOST_GIL_EXTENSION_NUMERIC_RESAMPLE_HPP #include <boost/gil/extension/numeric/affine.hpp> #include <boost/gil/extension/dynamic_image/dynamic_image_all.hpp> #include <algorithm> #include <functional> namespace boost { namespace gil { // Support for generic image resampling // NOTE: The code is for example use only. It is not optimized for performance /////////////////////////////////////////////////////////////////////////// //// //// resample_pixels: set each pixel in the destination view as the result of a sampling function over the transformed coordinates of the source view //// /////////////////////////////////////////////////////////////////////////// template <typename MapFn> struct mapping_traits {}; /// \brief Set each pixel in the destination view as the result of a sampling function over the transformed coordinates of the source view /// \ingroup ImageAlgorithms /// /// The provided implementation works for 2D image views only template <typename Sampler, // Models SamplerConcept typename SrcView, // Models RandomAccess2DImageViewConcept typename DstView, // Models MutableRandomAccess2DImageViewConcept typename MapFn> // Models MappingFunctionConcept void resample_pixels(const SrcView& src_view, const DstView& dst_view, const MapFn& dst_to_src, Sampler sampler=Sampler()) { typename DstView::point_t dst_dims=dst_view.dimensions(); typename DstView::point_t dst_p; for (dst_p.y=0; dst_p.y<dst_dims.y; ++dst_p.y) { typename DstView::x_iterator xit = dst_view.row_begin(dst_p.y); for (dst_p.x=0; dst_p.x<dst_dims.x; ++dst_p.x) { sample(sampler, src_view, transform(dst_to_src, dst_p), xit[dst_p.x]); } } } /////////////////////////////////////////////////////////////////////////// //// //// resample_pixels when one or both image views are run-time instantiated. //// /////////////////////////////////////////////////////////////////////////// namespace detail { template <typename Sampler, typename MapFn> struct resample_pixels_fn : public binary_operation_obj<resample_pixels_fn<Sampler,MapFn> > { MapFn _dst_to_src; Sampler _sampler; resample_pixels_fn(const MapFn& dst_to_src, const Sampler& sampler) : _dst_to_src(dst_to_src), _sampler(sampler) {} template <typename SrcView, typename DstView> BOOST_FORCEINLINE void apply_compatible(const SrcView& src, const DstView& dst) const { resample_pixels(src, dst, _dst_to_src, _sampler); } }; } /// \brief resample_pixels when the source is run-time specified /// If invoked on incompatible views, throws std::bad_cast() /// \ingroup ImageAlgorithms template <typename Sampler, typename ...Types1, typename V2, typename MapFn> void resample_pixels(const any_image_view<Types1...>& src, const V2& dst, const MapFn& dst_to_src, Sampler sampler=Sampler()) { apply_operation(src, std::bind( detail::resample_pixels_fn<Sampler, MapFn>(dst_to_src, sampler), std::placeholders::_1, dst)); } /// \brief resample_pixels when the destination is run-time specified /// If invoked on incompatible views, throws std::bad_cast() /// \ingroup ImageAlgorithms template <typename Sampler, typename V1, typename ...Types2, typename MapFn> void resample_pixels(const V1& src, const any_image_view<Types2...>& dst, const MapFn& dst_to_src, Sampler sampler=Sampler()) { using namespace std::placeholders; apply_operation(dst, std::bind( detail::resample_pixels_fn<Sampler, MapFn>(dst_to_src, sampler), src, std::placeholders::_1)); } /// \brief resample_pixels when both the source and the destination are run-time specified /// If invoked on incompatible views, throws std::bad_cast() /// \ingroup ImageAlgorithms template <typename Sampler, typename ...SrcTypes, typename ...DstTypes, typename MapFn> void resample_pixels(const any_image_view<SrcTypes...>& src, const any_image_view<DstTypes...>& dst, const MapFn& dst_to_src, Sampler sampler=Sampler()) { apply_operation(src,dst,detail::resample_pixels_fn<Sampler,MapFn>(dst_to_src,sampler)); } /////////////////////////////////////////////////////////////////////////// //// //// resample_subimage: copy into the destination a rotated rectangular region from the source, rescaling it to fit into the destination //// /////////////////////////////////////////////////////////////////////////// // Extract into dst the rotated bounds [src_min..src_max] rotated at 'angle' from the source view 'src' // The source coordinates are in the coordinate space of the source image // Note that the views could also be variants (i.e. any_image_view) template <typename Sampler, typename SrcMetaView, typename DstMetaView> void resample_subimage(const SrcMetaView& src, const DstMetaView& dst, double src_min_x, double src_min_y, double src_max_x, double src_max_y, double angle, const Sampler& sampler=Sampler()) { double src_width = std::max<double>(src_max_x - src_min_x - 1,1); double src_height = std::max<double>(src_max_y - src_min_y - 1,1); double dst_width = std::max<double>((double)(dst.width()-1),1); double dst_height = std::max<double>((double)(dst.height()-1),1); matrix3x2<double> mat = matrix3x2<double>::get_translate(-dst_width/2.0, -dst_height/2.0) * matrix3x2<double>::get_scale(src_width / dst_width, src_height / dst_height)* matrix3x2<double>::get_rotate(-angle)* matrix3x2<double>::get_translate(src_min_x + src_width/2.0, src_min_y + src_height/2.0); resample_pixels(src,dst,mat,sampler); } /////////////////////////////////////////////////////////////////////////// //// //// resize_view: Copy the source view into the destination, scaling to fit //// /////////////////////////////////////////////////////////////////////////// template <typename Sampler, typename SrcMetaView, typename DstMetaView> void resize_view(const SrcMetaView& src, const DstMetaView& dst, const Sampler& sampler=Sampler()) { resample_subimage(src,dst,0.0,0.0,(double)src.width(),(double)src.height(),0.0,sampler); } } } // namespace boost::gil #endif // BOOST_GIL_EXTENSION_NUMERIC_RESAMPLE_HPP