PNG(5)PNG(5)NAMEpng - Portable Network Graphics (PNG) format
PNG (Portable Network Graphics) is an extensible file format for the
lossless, portable, well-compressed storage of raster images. PNG pro‐
vides a patent-free replacement for GIF and can also replace many com‐
mon uses of TIFF. Indexed-color, grayscale, and truecolor images are
supported, plus an optional alpha channel. Sample depths range from 1
to 16 bits.
PNG is designed to work well in online viewing applications, such as
the World Wide Web, so it is fully streamable with a progressive dis‐
play option. PNG is robust, providing both full file integrity checking
and fast, simple detection of common transmission errors. Also, PNG can
store gamma and chromaticity data for improved color matching on het‐
SEE ALSOlibpng(3), libpngpf(3), zlib(3), deflate(5), and zlib(5)
PNG specification (second edition), November 2003:
<http://www.w3.org/TR/2003/REC-PNG-20031110/ PNG 1.2 specifi‐
cation, July 1999:
PNG 1.0 specification, October 1996:
or (as a W3C Recommendation) at
This man page: Glenn Randers-Pehrson
Portable Network Graphics (PNG) Specification (Second Edition) Informa‐
tion technology - Computer graphics and image processing - Portable
Network Graphics (PNG): Functional specification. ISO/IEC 15948:2003
(E) (November 10, 2003): David Duce and others.
Portable Network Graphics (PNG) Specification Version 1.2 (July 8,
1999): Glenn Randers-Pehrson and others (png-list).
Portable Network Graphics (PNG) Specification Version 1.0 (October 1,
1996): Thomas Boutell and others (png-list).
This man page is Copyright (c) 1998-2006 Glenn Randers-Pehrson. See
png.h for conditions of use and distribution.
The PNG Specification (Second Edition) is Copyright (c) 2003 W3C. (MIT,
ERCIM, Keio), All Rights Reserved.
The PNG-1.2 specification is copyright (c) 1999 Glenn Randers-Pehrson.
See the specification for conditions of use and distribution.
The PNG-1.0 specification is copyright (c) 1996 Massachusetts Institute
of Technology. See the specification for conditions of use and distri‐
December 9, 2010 PNG(5)