Lossless JPEG (original)
From Just Solve the File Format Problem
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* [ftp://ftp.graphicsmagick.org/pub/GraphicsMagick/delegates/ljpeg-6b.tar.gz ljpeg-6b.tar.gz]: Lossless JPEG patch for [http://www.ijg.org/files/jpegsrc.v6b.tar.gz IJG libjpeg 6b] (presumably by Ken Murchison) | * [ftp://ftp.graphicsmagick.org/pub/GraphicsMagick/delegates/ljpeg-6b.tar.gz ljpeg-6b.tar.gz]: Lossless JPEG patch for [http://www.ijg.org/files/jpegsrc.v6b.tar.gz IJG libjpeg 6b] (presumably by Ken Murchison) | ||
* [ftp://ftp.cs.cornell.edu/pub/multimed/ljpg.tar.Z Lossless JPEG Codec (Cornell University)]: pnmtoljpg, ljpgtopnm | * [ftp://ftp.cs.cornell.edu/pub/multimed/ljpg.tar.Z Lossless JPEG Codec (Cornell University)]: pnmtoljpg, ljpgtopnm | ||
| + | * [http://www.dclunie.com/jpegge.html Stanford PVRG JPEG] | ||
| + | ** [http://www.cs.unibo.it/~roffilli/pub/JPEGv1.2.1_LINUXport.tgz Linux port] by [http://www.cs.unibo.it/~roffilli/sw.html Matteo Roffilli] | ||
== Sample files == | == Sample files == | ||
Revision as of 00:45, 20 November 2013
- See Lossless JPEG for other uses of the term.
The original lossless JPEG (sometimes called lossless JPEG-1) refers to the original JPEG format when used with lossless compression, instead of the usual lossy compression. It is a standard type of JPEG file, defined in the original JPEG standard (ITU-T Rec. T.81). Few applications support it, though it has found some use in the medical industry, such as in DICOM files. Note that this format is distinct from JPEG-LS.
A lossless JPEG image may have any bit depth from 2 to 16 bits per sample.
Contents |
Identification
A lossless JPEG file is identified by the presence of an SOF3, SOF7, SOF11, or SOF15 segment. Refer to JPEG for a discussion of JPEG segments.
Specifications
- ITU-T Rec. T.81: The JPEG standard
Software
- Thomas Richter's libjpeg
- ljpeg-6b.tar.gz: Lossless JPEG patch for IJG libjpeg 6b (presumably by Ken Murchison)
- Lossless JPEG Codec (Cornell University): pnmtoljpg, ljpgtopnm
- Stanford PVRG JPEG
Sample files
- ljpeg-6b.tar.gz → testimgl.jpg
- ljpg.tar.Z → F-18.ljpg
