mapnik/include/mapnik/image_util.hpp

425 lines
13 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2006 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
*
*****************************************************************************/
//$Id: image_util.hpp 39 2005-04-10 20:39:53Z pavlenko $
#ifndef IMAGE_UTIL_HPP
#define IMAGE_UTIL_HPP
// mapnik
#include <mapnik/config.hpp>
#include <mapnik/map.hpp>
#include <mapnik/graphics.hpp>
// boost
#include <boost/algorithm/string.hpp>
#include <boost/lexical_cast.hpp>
#include <boost/optional.hpp>
// stl
#include <string>
namespace mapnik {
class ImageWriterException : public std::exception
{
private:
std::string message_;
public:
ImageWriterException(const std::string& message)
: message_(message) {}
~ImageWriterException() throw() {}
virtual const char* what() const throw()
{
return message_.c_str();
}
};
MAPNIK_DECL void save_to_cairo_file(mapnik::Map const& map,
std::string const& filename,
std::string const& type);
template <typename T>
MAPNIK_DECL void save_to_file(T const& image,
std::string const& filename,
std::string const& type);
// guess type from file extension
template <typename T>
MAPNIK_DECL void save_to_file(T const& image,
std::string const& filename);
template <typename T>
MAPNIK_DECL std::string save_to_string(T const& image,
std::string const& type);
template <typename T>
void save_as_png(T const& image,
std::string const& filename);
#if defined(HAVE_JPEG)
template <typename T>
void save_as_jpeg(std::string const& filename,
int quality,
T const& image);
#endif
inline bool is_png (std::string const& filename)
{
return boost::algorithm::iends_with(filename,std::string(".png"));
}
inline bool is_jpeg (std::string const& filename)
{
return boost::algorithm::iends_with(filename,std::string(".jpg")) ||
boost::algorithm::iends_with(filename,std::string(".jpeg"));
}
inline bool is_tiff (std::string const& filename)
{
return boost::algorithm::iends_with(filename,std::string(".tif")) ||
boost::algorithm::iends_with(filename,std::string(".tiff"));
}
inline bool is_pdf (std::string const& filename)
{
return boost::algorithm::iends_with(filename,std::string(".pdf"));
}
inline bool is_svg (std::string const& filename)
{
return boost::algorithm::iends_with(filename,std::string(".svg"));
}
inline bool is_ps (std::string const& filename)
{
return boost::algorithm::iends_with(filename,std::string(".ps"));
}
inline boost::optional<std::string> type_from_filename(std::string const& filename)
{
typedef boost::optional<std::string> result_type;
if (is_png(filename)) return result_type("png");
if (is_jpeg(filename)) return result_type("jpeg");
if (is_tiff(filename)) return result_type("tiff");
if (is_pdf(filename)) return result_type("pdf");
if (is_svg(filename)) return result_type("svg");
if (is_ps(filename)) return result_type("ps");
return result_type();
}
inline std::string guess_type( const std::string & filename )
{
std::string::size_type idx = filename.find_last_of(".");
if ( idx != std::string::npos ) {
return filename.substr( idx + 1 );
}
return "<unknown>";
}
template <typename T>
double distance(T x0,T y0,T x1,T y1)
{
double dx = x1-x0;
double dy = y1-y0;
return std::sqrt(dx * dx + dy * dy);
}
// add 1-px border around image - useful for debugging alignment issues
template <typename T>
void add_border(T & image)
{
for (unsigned x = 0; x < image.width();++x)
{
image(x,0) = 0xff0000ff; // red
image(x,image.height()-1) = 0xff00ff00; //green
}
for (unsigned y = 0; y < image.height();++y)
{
image(0,y) = 0xff00ffff; //yellow
image(image.width()-1,y) = 0xffff0000; // blue
}
}
template <typename Image>
inline void scale_image (Image& target,const Image& source)
{
int source_width=source.width();
int source_height=source.height();
int target_width=target.width();
int target_height=target.height();
if (source_width<1 || source_height<1 ||
target_width<1 || target_height<1) return;
int int_part_y=source_height/target_height;
int fract_part_y=source_height%target_height;
int err_y=0;
int int_part_x=source_width/target_width;
int fract_part_x=source_width%target_width;
int err_x=0;
int x=0,y=0,xs=0,ys=0;
int prev_y=-1;
for (y=0;y<target_height;++y)
{
if (ys==prev_y)
{
target.setRow(y,target.getRow(y-1),target_width);
}
else
{
xs=0;
for (x=0;x<target_width;++x)
{
target(x,y)=source(xs,ys);
xs+=int_part_x;
err_x+=fract_part_x;
if (err_x>=target_width)
{
err_x-=target_width;
++xs;
}
}
prev_y=ys;
}
ys+=int_part_y;
err_y+=fract_part_y;
if (err_y>=target_height)
{
err_y-=target_height;
++ys;
}
}
#ifdef MAPNIK_DEBUG
add_border(target);
#endif
}
template <typename Image>
inline void scale_image_bilinear (Image& target,const Image& source, double x_off_f=0, double y_off_f=0)
{
int source_width=source.width();
int source_height=source.height();
int target_width=target.width();
int target_height=target.height();
if (source_width<1 || source_height<1 ||
target_width<1 || target_height<1) return;
int x=0,y=0,xs=0,ys=0;
int tw2 = target_width/2;
int th2 = target_height/2;
int offs_x = rint((source_width-target_width-x_off_f*2*source_width)/2);
int offs_y = rint((source_height-target_height-y_off_f*2*source_height)/2);
unsigned yprt, yprt1, xprt, xprt1;
//no scaling or subpixel offset
if (target_height == source_height && target_width == source_width && offs_x == 0 && offs_y == 0){
for (y=0;y<target_height;++y)
target.setRow(y,source.getRow(y),target_width);
return;
}
for (y=0;y<target_height;++y)
{
ys = (y*source_height+offs_y)/target_height;
int ys1 = ys+1;
if (ys1>=source_height)
ys1--;
if (ys<0)
ys=ys1=0;
if (source_height/2<target_height)
yprt = (y*source_height+offs_y)%target_height;
else
yprt = th2;
yprt1 = target_height-yprt;
for (x=0;x<target_width;++x)
{
xs = (x*source_width+offs_x)/target_width;
if (source_width/2<target_width)
xprt = (x*source_width+offs_x)%target_width;
else
xprt = tw2;
xprt1 = target_width-xprt;
int xs1 = xs+1;
if (xs1>=source_width)
xs1--;
if (xs<0)
xs=xs1=0;
unsigned a = source(xs,ys);
unsigned b = source(xs1,ys);
unsigned c = source(xs,ys1);
unsigned d = source(xs1,ys1);
unsigned out=0;
unsigned t = 0;
for(int i=0; i<4; i++){
unsigned p,r,s;
// X axis
p = a&0xff;
r = b&0xff;
if (p!=r)
r = (r*xprt+p*xprt1+tw2)/target_width;
p = c&0xff;
s = d&0xff;
if (p!=s)
s = (s*xprt+p*xprt1+tw2)/target_width;
// Y axis
if (r!=s)
r = (s*yprt+r*yprt1+th2)/target_height;
// channel up
out |= r << t;
t += 8;
a >>= 8;
b >>= 8;
c >>= 8;
d >>= 8;
}
target(x,y)=out;
}
}
}
template <typename Image>
inline void scale_image_bilinear8 (Image& target,const Image& source, double x_off_f=0, double y_off_f=0)
{
int source_width=source.width();
int source_height=source.height();
int target_width=target.width();
int target_height=target.height();
if (source_width<1 || source_height<1 ||
target_width<1 || target_height<1) return;
int x=0,y=0,xs=0,ys=0;
int tw2 = target_width/2;
int th2 = target_height/2;
int offs_x = rint((source_width-target_width-x_off_f*2*source_width)/2);
int offs_y = rint((source_height-target_height-y_off_f*2*source_height)/2);
unsigned yprt, yprt1, xprt, xprt1;
//no scaling or subpixel offset
if (target_height == source_height && target_width == source_width && offs_x == 0 && offs_y == 0){
for (y=0;y<target_height;++y)
target.setRow(y,source.getRow(y),target_width);
return;
}
for (y=0;y<target_height;++y)
{
ys = (y*source_height+offs_y)/target_height;
int ys1 = ys+1;
if (ys1>=source_height)
ys1--;
if (ys<0)
ys=ys1=0;
if (source_height/2<target_height)
yprt = (y*source_height+offs_y)%target_height;
else
yprt = th2;
yprt1 = target_height-yprt;
for (x=0;x<target_width;++x)
{
xs = (x*source_width+offs_x)/target_width;
if (source_width/2<target_width)
xprt = (x*source_width+offs_x)%target_width;
else
xprt = tw2;
xprt1 = target_width-xprt;
int xs1 = xs+1;
if (xs1>=source_width)
xs1--;
if (xs<0)
xs=xs1=0;
unsigned a = source(xs,ys);
unsigned b = source(xs1,ys);
unsigned c = source(xs,ys1);
unsigned d = source(xs1,ys1);
unsigned p,r,s;
// X axis
p = a&0xff;
r = b&0xff;
if (p!=r)
r = (r*xprt+p*xprt1+tw2)/target_width;
p = c&0xff;
s = d&0xff;
if (p!=s)
s = (s*xprt+p*xprt1+tw2)/target_width;
// Y axis
if (r!=s)
r = (s*yprt+r*yprt1+th2)/target_height;
target(x,y)=(0xff<<24) | (r<<16) | (r<<8) | r;
}
}
}
inline MAPNIK_DECL void save_to_file (image_32 const& image,
std::string const& file,
std::string const& type)
{
save_to_file<image_data_32>(image.data(),file,type);
}
inline MAPNIK_DECL void save_to_file(image_32 const& image,
std::string const& file)
{
save_to_file<image_data_32>(image.data(),file);
}
inline MAPNIK_DECL std::string save_to_string(image_32 const& image,
std::string const& type)
{
return save_to_string<image_data_32>(image.data(),type);
}
#ifdef _MSC_VER
template MAPNIK_DECL void save_to_file<image_data_32>(image_data_32 const&,
std::string const&,
std::string const&);
template MAPNIK_DECL void save_to_file<image_data_32>(image_data_32 const&,
std::string const&);
template MAPNIK_DECL std::string save_to_string<image_data_32>(image_data_32 const&,
std::string const&);
template MAPNIK_DECL void save_to_file<image_view<image_data_32> > (image_view<image_data_32> const&,
std::string const&,
std::string const&);
template MAPNIK_DECL void save_to_file<image_view<image_data_32> > (image_view<image_data_32> const&,
std::string const&);
template MAPNIK_DECL std::string save_to_string<image_view<image_data_32> > (image_view<image_data_32> const&,
std::string const&);
#endif
}
#endif //IMAGE_UTIL_HPP