NAME¶

png - Portable Network Graphics (PNG) format

DESCRIPTION¶

PNG (Portable Network Graphics) is an extensible file format for the lossless, portable, well-compressed storage of raster images. PNG provides a patent-free replacement for GIF, and can also replace many common 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 display 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 heterogeneous platforms.

SEE ALSO¶

libpng(3), zlib(3), deflate(5), and zlib(5)

PNG Specification (Third Edition), June 2025:

https://www.w3.org/TR/2025/REC-png-3-20250624/

PNG Specification (Second Edition), November 2003:

https://www.w3.org/TR/2003/REC-PNG-20031110/

PNG 1.2 Specification, August 1999:

https://www.libpng.org/pub/png/spec/1.2/

PNG 1.1 Specification, December 1998:

https://www.libpng.org/pub/png/spec/1.1/

PNG 1.0 Specification, October 1996:

RFC 2083
https://www.ietf.org/rfc/rfc2083.txt

or W3C Recommendation
https://www.w3.org/TR/REC-png-961001

AUTHORS¶

This man page: Glenn Randers-Pehrson, Cosmin Truta

Portable Network Graphics (PNG) Specification (Third Edition). W3C Recommendation 24 June 2025: Chris Blume et al.

Portable Network Graphics (PNG) Specification (Second Edition) Information technology - Computer graphics and image processing - Portable Network Graphics (PNG): Functional specification. ISO/IEC 15948:2003 (E), W3C Recommendation 10 November 2003: David Duce et al.

Portable Network Graphics (PNG) Specification Version 1.2 (11 August 1999): Glenn Randers-Pehrson et al.

Portable Network Graphics (PNG) Specification Version 1.1 (31 December 1998): Glenn Randers-Pehrson et al.

Portable Network Graphics (PNG) Specification Version 1.0. IETF RFC 2083, W3C Recommendation 1 October 1996: Thomas Boutell et al.