mapnik/src/image_util_jpeg.cpp
2024-07-22 10:20:47 +01:00

145 lines
5.3 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2024 Artem Pavlenko
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*****************************************************************************/
// mapnik
#if defined(HAVE_JPEG)
#include <mapnik/jpeg_io.hpp>
#endif
#include <mapnik/image_util.hpp>
#include <mapnik/image_util_jpeg.hpp>
#include <mapnik/image.hpp>
#include <mapnik/image_view.hpp>
#include <mapnik/image_options.hpp>
#include <mapnik/util/conversions.hpp>
// stl
#include <string>
namespace mapnik {
jpeg_saver::jpeg_saver(std::ostream& stream, std::string const& t)
: stream_(stream)
, t_(t)
{}
namespace detail {
int parse_jpeg_quality(std::string const& params)
{
int quality = 85;
if (params != "jpeg")
{
for (auto const& kv : parse_image_options(params))
{
auto const& key = kv.first;
auto const& val = kv.second;
if (key == "jpeg")
continue;
else if (key.size() > 4 && key.substr(0, 4) == "jpeg")
{
if (!mapnik::util::string2int(key.substr(4), quality))
{
throw image_writer_exception("invalid jpeg quality: '" + key.substr(4) + "'");
}
}
else if (key == "quality")
{
if (val && !(*val).empty())
{
if (!mapnik::util::string2int(*val, quality) || quality < 0 || quality > 100)
{
throw image_writer_exception("invalid jpeg quality: '" + *val + "'");
}
}
}
}
}
return quality;
}
} // namespace detail
template<typename T>
void process_rgba8_jpeg(T const& image, std::string const& type, std::ostream& stream)
{
#if defined(HAVE_JPEG)
int quality = detail::parse_jpeg_quality(type);
save_as_jpeg(stream, quality, image);
#else
throw image_writer_exception("jpeg output is not enabled in your build of Mapnik");
#endif
}
template<>
void jpeg_saver::operator()<image_rgba8>(image_rgba8 const& image) const
{
process_rgba8_jpeg(image, t_, stream_);
}
template<>
void jpeg_saver::operator()<image_view_rgba8>(image_view_rgba8 const& image) const
{
process_rgba8_jpeg(image, t_, stream_);
}
template<>
void jpeg_saver::operator()<image_null>(image_null const& image) const
{
throw image_writer_exception("Can not save a null image to jpeg");
}
template<>
void jpeg_saver::operator()<image_view_null>(image_view_null const& image) const
{
throw image_writer_exception("Can not save a null image to jpeg");
}
template<typename T>
void jpeg_saver::operator()(T const& image) const
{
throw image_writer_exception("Mapnik does not support jpeg grayscale images");
}
template void jpeg_saver::operator()<image_gray8>(image_gray8 const& image) const;
template void jpeg_saver::operator()<image_gray8s>(image_gray8s const& image) const;
template void jpeg_saver::operator()<image_gray16>(image_gray16 const& image) const;
template void jpeg_saver::operator()<image_gray16s>(image_gray16s const& image) const;
template void jpeg_saver::operator()<image_gray32>(image_gray32 const& image) const;
template void jpeg_saver::operator()<image_gray32s>(image_gray32s const& image) const;
template void jpeg_saver::operator()<image_gray32f>(image_gray32f const& image) const;
template void jpeg_saver::operator()<image_gray64>(image_gray64 const& image) const;
template void jpeg_saver::operator()<image_gray64s>(image_gray64s const& image) const;
template void jpeg_saver::operator()<image_gray64f>(image_gray64f const& image) const;
template void jpeg_saver::operator()<image_view_gray8>(image_view_gray8 const& image) const;
template void jpeg_saver::operator()<image_view_gray8s>(image_view_gray8s const& image) const;
template void jpeg_saver::operator()<image_view_gray16>(image_view_gray16 const& image) const;
template void jpeg_saver::operator()<image_view_gray16s>(image_view_gray16s const& image) const;
template void jpeg_saver::operator()<image_view_gray32>(image_view_gray32 const& image) const;
template void jpeg_saver::operator()<image_view_gray32s>(image_view_gray32s const& image) const;
template void jpeg_saver::operator()<image_view_gray32f>(image_view_gray32f const& image) const;
template void jpeg_saver::operator()<image_view_gray64>(image_view_gray64 const& image) const;
template void jpeg_saver::operator()<image_view_gray64s>(image_view_gray64s const& image) const;
template void jpeg_saver::operator()<image_view_gray64f>(image_view_gray64f const& image) const;
} // namespace mapnik