PNG
| 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 code |
|
| Uniform Type Identifier (UTI) | public.png |
| UTI conformation | public.image |
| Magic number | 89 50 4e 47 0d 0a 1a 0a (8 bytes Hexadecimal) |
| Developed by | PNG Development Group (donated to W3C) |
| Initial release | 1 October 1996 |
| Latest release | 3.0 24 June 2025 |
| Type of format | Lossless bitmap image format |
| Extended to | APNG, JNG, and MNG |
| Standard | ISO/IEC 15948,[1] IETF RFC 2083 |
| Open format? | Yes Zlib/libpng license[2] |
| Website |
|
Portable Network Graphics (PNG, officially pronounced /pɪŋ/ PING,[3][4] colloquially pronounced /ˌpiːɛnˈdʒiː/ PEE-en-JEE[5]) is a raster-graphics file format that supports lossless data compression.[6] PNG was developed as an improved, non-patented replacement for Graphics Interchange Format (GIF).
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]
- ^ 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.
- ^ "COPYRIGHT NOTICE, DISCLAIMER, and LICENSE - PNG Reference Library License version 2" (TXT). libpng.org. 1 July 2000.
- ^ Roelofs, Greg (29 May 2010). "History of PNG". libpng. Retrieved 20 October 2010.
- ^ W3C 2003, 1 Scope.
- ^ "Definition of PNG noun from the Oxford Advanced Learner's Dictionary". Oxford Learner's Dictionaries. Retrieved 21 January 2018.
- ^ "Portable Network Graphic .PNG File Description". surferhelp.goldensoftware.com. Retrieved 12 August 2022.
- ^ 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.
- ^ "Registration of new Media Type image/png". IANA. 27 July 1996.