PNG

This article is about the file format. For the country, see Papua New Guinea. For other uses, see PNG (disambiguation).

Portable Network Graphics

A PNG image of four differently colored dice with an 8-bit transparency channel, overlaid onto a checkered background, typically used in graphics software to indicate transparency
Filename extension
.png
Internet media type
image/png
Type codePNGf
PNG (including a single trailing space)
Uniform Type Identifier (UTI)public.png
UTI conformationpublic.image
Magic number89 50 4e 47 0d 0a 1a 0a (8 bytes Hexadecimal)
Developed byPNG Development Group (donated to W3C)
Initial release1 October 1996; 28 years ago (1996-10-01)
Type of formatLossless bitmap image format
Extended toAPNG, JNG, and MNG
StandardISO/IEC 15948,[1] IETF RFC 2083
Open format?Yes
Website

Portable Network Graphics (PNG, officially pronounced /pɪŋ/[2][3] PING, colloquially pronounced /ˌpiːɛnˈdʒiː/[4] PEE-en-JEE) is a raster-graphics file format that supports lossless data compression.[5] PNG was developed as an improved, non-patented replacement for Graphics Interchange Format (GIF)—unofficially, the initials PNG stood for the recursive acronym "PNG's not GIF".[6]

PNG supports palette-based images (with palettes of 24-bit RGB or 32-bit RGBA colors), grayscale images (with or without an alpha channel for transparency), and full-color non-palette-based RGB or RGBA images. The PNG working group designed the format for transferring images on the Internet, not for professional-quality print graphics; therefore, non-RGB color spaces such as CMYK are not supported. A PNG file contains a single image in an extensible structure of chunks, encoding the basic pixels and other information such as textual comments and integrity checks documented in RFC 2083.[7]

PNG files have the ".png" file extension and the "image/png" MIME media type.[8] PNG was published as an informational RFC 2083 in March 1997 and as an ISO/IEC 15948 standard in 2004.[1]

  1. ^ a b "ISO/IEC 15948:2004 – Information technology – Computer graphics and image processing – Portable Network Graphics (PNG): Functional specification". International Organization for Standardization. 3 March 2004. Retrieved 19 February 2011.
  2. ^ Roelofs, Greg (29 May 2010). "History of PNG". libpng. Retrieved 20 October 2010.
  3. ^ W3C 2003, 1 Scope.
  4. ^ "Definition of PNG noun from the Oxford Advanced Learner's Dictionary". Oxford Learner's Dictionaries. Retrieved 21 January 2018.
  5. ^ "Portable Network Graphic .PNG File Description". surferhelp.goldensoftware.com. Retrieved 12 August 2022.
  6. ^ Roelofs, Greg. "Web Review: PNG's NOT GIF!". people.apache.org. Retrieved 24 November 2021.
  7. ^ T. Boutell; et al. (March 1997). PNG (Portable Network Graphics) Specification Version 1.0. Network Working Group. doi:10.17487/RFC2083. RFC 2083. Informational. sec. 3.
  8. ^ "Registration of new Media Type image/png". IANA. 27 July 1996.