boost/gil/extension/numeric/resample.hpp
/*
Copyright 2005-2007 Adobe Systems Incorporated
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_EXTENSION_NUMERIC_RESAMPLE_HPP
#define BOOST_GIL_EXTENSION_NUMERIC_RESAMPLE_HPP
#include <boost/lambda/lambda.hpp>
#include <boost/lambda/bind.hpp>
#include <boost/gil/extension/dynamic_image/dynamic_image_all.hpp>
#include <boost/gil/extension/numeric/affine.hpp>
////////////////////////////////////////////////////////////////////////////////////////
/// \file
/// \brief support for generic image resampling
/// NOTE: The code is for example use only. It is not optimized for performance
/// \author Lubomir Bourdev and Hailin Jin \n
/// Adobe Systems Incorporated
/// \date 2005-2007 \n
///
////////////////////////////////////////////////////////////////////////////////////////
namespace boost { namespace gil {
///////////////////////////////////////////////////////////////////////////
////
//// 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;
typename mapping_traits<MapFn>::result_type src_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,bind(detail::resample_pixels_fn<Sampler,MapFn>(dst_to_src,sampler), _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()) {
apply_operation(dst,bind(detail::resample_pixels_fn<Sampler,MapFn>(dst_to_src,sampler), src, _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
