Lossless JPEG (original)
From Just Solve the File Format Problem
(Difference between revisions)
(Created page with "{{FormatInfo |formattype=electronic |subcat=Graphics |extensions={{ext|jpg}}, {{ext|ljpg}}, {{ext|ljpeg}} |locfdd={{LoCFDD|fdd000334}} |released=1992 }} :''See [[Lossless JPEG...") |
|||
| Line 26: | Line 26: | ||
* [ftp://ftp.graphicsmagick.org/pub/GraphicsMagick/delegates/ljpeg-6b.tar.gz ljpeg-6b.tar.gz] → testimgl.jpg | * [ftp://ftp.graphicsmagick.org/pub/GraphicsMagick/delegates/ljpeg-6b.tar.gz ljpeg-6b.tar.gz] → testimgl.jpg | ||
* [ftp://ftp.cs.cornell.edu/pub/multimed/ljpg.tar.Z ljpg.tar.Z] → F-18.ljpg | * [ftp://ftp.cs.cornell.edu/pub/multimed/ljpg.tar.Z ljpg.tar.Z] → F-18.ljpg | ||
| + | |||
| + | [[Category:JPEG]] | ||
Revision as of 23:35, 19 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
Sample files
- ljpeg-6b.tar.gz → testimgl.jpg
- ljpg.tar.Z → F-18.ljpg
