PNG Files
Portable Network Graphics

PNG is a data directory which contains examples of files in the PNG or "Portable Network Graphics" file format.

PNG files can do a good job of showing both line graphics (what PostScript files do best), and bit-mapped graphics (which are commonly handled by JPEG or GIF files). Most web browsers support the PNG format, which makes it easy to include pictures directly in a web page.

A sequence of PNG files can be converted easily into an animation, using QuickTime Pro. Two important things to remember: the individual frames should all use the same scale, and the files should have names that are consecutive, as in picture001.png, picture002.png and so on.

PNG File Characteristics:


The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Related Data and Programs:

PNG_CRC, a C++ program which computes the CRC (cyclic redundancy checksum) for a PNG graphics file (or any other file, for that matter);


  1. The PNG Home Page at
  2. David Duce, editor,
    Portable Network Graphics (PNG) Specification, Second Edition.
    Technical Report REC-PNG-20031110,
    World Wide Web Consortium, 2003.
  3. Greg Roelofs,
    PNG: The Definitive Guide,
    O'Reilly, 1999,
    ISBN: 1-56592-542-4,
    LC: T385.R588.

Sample Files:

You can go up one level to the DATA page.

Last revised on 28 July 2011.