JPEG-LS

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|subcat=Graphics
 
|subcat=Graphics
 
|extensions={{ext|jls}}
 
|extensions={{ext|jls}}
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|mimetypes={{mimetype|image/jls}}
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|locfdd={{LoCFDD|fdd000151}}
 
|pronom={{PRONOM|fmt/150}}
 
|pronom={{PRONOM|fmt/150}}
 
|released=1998
 
|released=1998
 
}}
 
}}
== Overview ==
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'''JPEG-LS''' is an image file format and compressed data format. It supports both lossy and lossless compression. The lossy compression is often called "near-lossless", because the encoder can set a limit on the maximum error. Its compression algorithm is [[LOCO-I]], developed by HP Labs.
'''JPEG-LS''' is an image compression scheme and file format. It supports both lossy and lossless compression. The lossy compression is often called "near-lossless", because the encoder can set a limit on the maximum error. Its compression algorithm is [[LOCO-I]], developed by HP Labs.
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== Disambiguation ==
 
== Disambiguation ==
The file format is similar in structure to [[JPEG]] interchange format, and it was developed by the same organization that developed JPEG. Beyond that, JPEG-LS is not closely related to JPEG.
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JPEG-LS files are very similar in structure to [[JPEG]], to the extent that JPEG-LS could be considered to be a kind of JPEG, or an extension of JPEG. However, given that they use different filename extensions, and that few applications that support JPEG support JPEG-LS, JPEG and JPEG-LS should probably be thought of as different and incompatible formats.
  
The term '''lossless JPEG''' is best reserved for the [[JPEG#Lossless JPEG|lossless compression mode]] defined the JPEG standard, but it is sometimes (accidentally?) used to mean JPEG-LS, or lossless JPEG-LS, or perhaps even ''all lossless formats whose names contain "JPEG"''.
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The terms "JPEG-LS" and "Lossless JPEG" do not have the same meaning(s). See [[Lossless JPEG]] for more information.
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== Identification ==
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Like [[JPEG]], JPEG-LS files begin with bytes <code>FF D8 FF</code>.
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A JPEG-LS file will contain an 0xF7 ("SOF55" or "JPG7") segment somewhere in it. Often, the 4th byte in the file is 0xF7.
  
 
== Related formats ==
 
== Related formats ==
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== Specifications ==
 
== Specifications ==
* [http://www.itu.int/rec/T-REC-T.87/en ITU-T Recommendation T.87]
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* [http://www.itu.int/rec/T-REC-T.87/en ITU-T Rec. T.87]
  
 
== Software ==
 
== Software ==
* [http://charls.codeplex.com/ CharLS] - A C++ JPEG-LS library. Includes sample files.
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* [http://charls.codeplex.com/ CharLS]: A C++ JPEG-LS library. Includes sample files.
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* [https://github.com/thorfdbg/libjpeg Thomas Richter's libjpeg]
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* [[Konvertor]]
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* [http://www.stat.columbia.edu/~jakulin/jpeg-ls/mirror.htm UBC JPEG-LS Codec]
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* [http://www.dclunie.com/jpegls.html JPEG-LS Software] (David A. Clunie)
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* [[XnView]]
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* [http://info.elf.stuba.sk/packages/pub/pc/pack/jlsref.zip HP JPEG-LS Reference Encoder v1.00] (Windows binaries)
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* [https://codeberg.org/kaleido/wuimg wuimg]
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== Sample files ==
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* {{DexvertSamples|image/jpegLS}}
  
 
== External links ==
 
== External links ==
* [http://www.hpl.hp.com/loco/ HP Labs LOCO-I/JPEG-LS Home Page]
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* [http://www.hpl.hp.com/research/info_theory/loco/ HP Labs LOCO-I/JPEG-LS Home Page]
* [http://en.wikipedia.org/wiki/Lossless_JPEG#JPEG-LS Wikipedia article]
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* [http://en.wikipedia.org/wiki/Lossless_JPEG#JPEG-LS Wikipedia: Lossless JPEG: JPEG-LS]
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[[Category:Compression]]
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[[Category:JPEG]]
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[[Category:JPEG (organization)]]

Latest revision as of 19:31, 15 September 2024

File Format
Name JPEG-LS
Ontology
Extension(s) .jls
MIME Type(s) image/jls
LoCFDD fdd000151
PRONOM fmt/150
Released 1998

JPEG-LS is an image file format and compressed data format. It supports both lossy and lossless compression. The lossy compression is often called "near-lossless", because the encoder can set a limit on the maximum error. Its compression algorithm is LOCO-I, developed by HP Labs.

Contents

[edit] Disambiguation

JPEG-LS files are very similar in structure to JPEG, to the extent that JPEG-LS could be considered to be a kind of JPEG, or an extension of JPEG. However, given that they use different filename extensions, and that few applications that support JPEG support JPEG-LS, JPEG and JPEG-LS should probably be thought of as different and incompatible formats.

The terms "JPEG-LS" and "Lossless JPEG" do not have the same meaning(s). See Lossless JPEG for more information.

[edit] Identification

Like JPEG, JPEG-LS files begin with bytes FF D8 FF.

A JPEG-LS file will contain an 0xF7 ("SOF55" or "JPG7") segment somewhere in it. Often, the 4th byte in the file is 0xF7.

[edit] Related formats

JPEG-LS compression can be used in some other file formats, such as JPX, JPM, SPIFF, and DICOM.

[edit] Specifications

[edit] Software

[edit] Sample files

[edit] External links

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