libjpeg
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| Developer(s) | Independent JPEG Group |
|---|---|
| Stable release | 8d / January 15, 2012 |
| Written in | C |
| Type | library |
| License | Free, can be used in commercial applications without royalty, with acknowledgement. |
| Website | ijg.org |
libjpeg is a library written entirely in C which contains a widely-used implementation of a JPEG decoder, JPEG encoder and other JPEG utilities. This library is maintained by the Independent JPEG Group.
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[edit] Utilities
The following utility programs are available with libjpeg:
- cjpeg and djpeg, for performing conversions between JPEG and some other popular image file formats.
- rdjpgcom and wrjpgcom, for inserting and extracting textual comments in JFIF files.
- jpegtran – a utility for lossless transcoding between different JPEG formats.
The jpegtran command-line program is useful to:
- optimize the Huffman coding layer of a JPEG file to increase compression,
- convert between progressive and non-progressive JPEG formats,
- eliminate non-standard application-specific data inserted by some image programs, or
- to perform certain transformations on a file, such as:
...all done "losslessly" (i.e. without decompressing and recompressing the data, and so causing a reduction of image quality due to generation loss).
There is an associated Windows application, Jpegcrop, which provides a user interface to jpegtran.
[edit] libjpeg-turbo
libjpeg-turbo is a fork of libjpeg that uses SIMD instructions to accelerate JPEG encoding and decoding. Fedora 14 switched to libjpeg-turbo in 2010. Mozilla switched to libjpeg-turbo in Firefox 5.0.[1]Chrome 11 also has switched to this version.[2]
[edit] See also
[edit] References
- ^ Software Which Uses libjpeg-turbo. June 21, 2011.
- ^ [1].April 14, 2011.
[edit] External links
- Independent JPEG Group Website
- Binary package of libjpeg for Microsoft Windows (at GnuWin32 in SourceForge)
- Binary packages of libjpeg for Microsoft Windows (MingW and Microsoft Visual C++ versions 7 and 8), and for Mac OS X (Universal, GCC 4.0; PowerPC, GCC 4.0; PowerPC, GCC 3.3) (at ClanLib)
- libjpeg-turbo, an ABI-/API-compatible extension of libjpeg which uses x86 SIMD instructions to achieve a substantial speedup over the reference implementation.
- Jpeg Faqs
- Additional features for libjpeg
