PNG
Portable Network Graphics (PNG, officially pronounced /pɪŋ/ PING, colloquially pronounced /ˌpiːɛnˈdʒiː/ PEE-en-JEE) is a raster-graphics file format that supports lossless data compression. 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".
A PNG image of four differently coloured 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 | PNGf PNG |
| 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 |
| Type of format | Lossless bitmap image format |
| Extended to | APNG, JNG and MNG |
| Standard | ISO/IEC 15948, IETF RFC 2083 |
| Open format? | Yes |
| Website | libpng |
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.
PNG files have the ".png" file extension and the "image/png" MIME media type. PNG was published as an informational RFC 2083 in March 1997 and as an ISO/IEC 15948 standard in 2004.