JPEG 2000

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Most JPEG 2000-related files (but not the codestream format) begin with bytes <code>00 00 00 0c 6a 50 20 20 0d 0a 87 0a</code>.
 
Most JPEG 2000-related files (but not the codestream format) begin with bytes <code>00 00 00 0c 6a 50 20 20 0d 0a 87 0a</code>.
  
This byte sequence represents a box of type "<code>jP </code>" (JPEG 2000 signature), which contains an arbitrary 4-byte signature (<code>0d 0a 87 0a</code>).
+
This byte sequence represents a box of type "<code>jP&nbsp;&nbsp;</code>" (JPEG 2000 signature), which contains an arbitrary 4-byte signature (<code>0d 0a 87 0a</code>).
  
 
== Specifications ==
 
== Specifications ==

Revision as of 16:19, 30 July 2013

File Format
Name JPEG 2000
Ontology
Extension(s) .jp2, .jpf, .jpx, .jpm, .mj2, others
MIME Type(s) image/jp2, image/jpx, image/jpm, video/mj2

JPEG 2000 (or JPEG2000) is standard that defines a wavelet-based raster image compression format, and a family of associated file formats, protocols, etc.

For details about specific formats, see:

Contents

Disambiguation

JPEG 2000 is sometimes incorrectly used as a synonym for JP2, and vice versa. Although JP2 might be the most important part of the JPEG 2000 standard, it is only one small part of it.

In some contexts, JPEG 2000 is used to mean the compressed codestream format, instead of the whole standard.

The terms JPEG 2000 and JPEG2000 (with and without a space) seem to be used interchangeably. The parts of the official specification that are freely available use only JPEG 2000, so that is probably the preferred form. But it must have been settled on late in the standardization process: even some of the committee drafts prefer JPEG2000.

Details

The JPEG 2000 standard consists of many parts, including:

Format

At the highest level, JPEG 2000 files (JP2, JPX, JPM, and MJ2, but not the codestream format) consist of a hierarchical sequence of tagged "boxes". It is the same format used by Quicktime and MPEG-4, but with different terminology.

Identification

Most JPEG 2000-related files (but not the codestream format) begin with bytes 00 00 00 0c 6a 50 20 20 0d 0a 87 0a.

This byte sequence represents a box of type "jP  " (JPEG 2000 signature), which contains an arbitrary 4-byte signature (0d 0a 87 0a).

Specifications

See also the articles about the specific file formats. Most of the official JPEG 2000 specification is not freely available, but the committee drafts are. (Exception: Specifications for the high-level parts of the JP2 and JPX formats are freely available.)

Software

Sample files

Links

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