A free book about the PNG image format.

This book was published by O'Reilly and it has three parts:

- Part I, Using PNG, consists of six chapters and covers the main categories of PNG-supporting applications: image editors, viewers, converters, web browsers and servers, and 3D apps. - Part II, The Design of PNG, also consists of six chapters and looks in more detail at PNG as a file format. It covers not only PNG's fundamental chunk structure and compression technology but also its history, its animated cousin MNG, and some of the intricacies of cross-platform gamma and color correction. - Part III, Programming with PNG, steps the reader through the design of three functional demo programs based on the free libpng C library: rpng, a very simple PNG viewer; rpng2, a progressive PNG viewer such as might be found in a web browser; and wpng, a basic program to convert RGB image data from binary PBMPLUS / NetPBM format into PNG format. The final chapter in this section lists a number of other PNG-supporting programming toolkits for various languages, including C, C++, Java, Perl, Python, tcl/tk, and Visual Basic.