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pngxx

pngxx is a C++ library for reading and writing PNG images that wraps the libpng C library.

It allows you to read and write images to any source or sink, which may be described by standard C++ iterators or streams. By using the provided iterator adaptors, you can use your own image container objects.

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Code

Clone the repository using mercurial:

> hg clone http://bitbucket.org/edd/pngxx

Or get a zip file of the code.

Quick start

To load an image from a file:

#include <pngxx/read.hpp>

std::vector<unsigned char> raster;
imagexx::raster_details d = 
    pngxx::read_image("image.png", back_inserter(raster));

std::size_t width = d.width();
std::size_t height = d.height();
imagexx::pixel_format f = d.type();
double width_mm = d.width_mm(); // in millimeters
double height_mm = d.height_mm(); // in millimeters

To save an image to a file:

#include <pngxx/write.hpp>

imagexx::raster_details d(imagexx::rgba, width, height);
pngxx::write_image(d, "image.png", raster.begin(), raster.end());

These examples show reading and writing with a std::vector used for raster storage. You can use the provided iterator adaptors to have the library integrate with your own image container objects.

You can read and write to memory, or any location that can be exposed via a standard C++ a stream or via iterators.

Further reading

• The pngxx wiki
• Loading PNG images in to a custom image container object
• Saving PNG images from a custom image container object

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