png++

This is the home of png++, a C++ wrapper for libpng library.

What is it?

PNG++ aims to provide simple yet powerful C++ interface to libpng, the PNG reference implementation library.

PNG++ is free software distributed under a modified variant of the BSD license.

Why is it?

Using raw libpng in C++ may impose serious challenge since lots of precautions must be taken to handle initialization/deinitialization of control structures as well as handling errors correctly. With png++ you can read or write PNG images just in a single line of C++ code:

png::image< png::rgb_pixel > image("input.png");
image.write("output.png");

The code reads an image from the file named "input.png", then writes the image to a file named "output.png". In this example png++ does all the transformations needed to create adequate in-memory RGB representation of the image (well, in most cases it simply instructs libpng to do so).

The image in "input.png" can be RGB image, or it might be grayscale or even indexed image with a palette -- png++ will just convert any input to RGB format. However, for technical reasons such automatic transformation is supported for RGB and Grayscale color types only. Optionally there may be an alpha channel in the target color space (RGBA and Gray+Alpha respectively).

Download

You can grab the latest version here.

Or point your Subversion client here: svn://svn.sv.nongnu.org/pngpp/trunk/ to get the current development version (not necessarily usable, tough). The SVN repository is also accessible through HTTP protocol: http://svn.sv.nongnu.org/svn/pngpp/trunk/.

Documentation

Online documentation is available here: docs.

Bugs

Lacks support for output transformations.

Lacks support for optional/unknown chunks in PNG data stream.

Documentation sucks.

To report bugs, please use Savannah bug tracker. Do not forget to check if the bug was already filed. :-)

You can help!

Interested? Then help by improving code, documentation or whatever could be improved about it. :-)

For more information on how to participate visit png++ development site at Savannah.

There is a mailing list for developers. You can also contact me by dropping a mail to alex.shulgin@gmail.com.