Sustainability of Digital Formats: Planning for Library of Congress Collections

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JPEG 2000 Part 1 (Core) jp2 File Format

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Format Description Properties Explanation of format description terms

Identification and description Explanation of format description terms

Full name ISO/IEC 15444-1:2004. Information technology -- JPEG 2000 image coding system -- Part 1: Core coding system, Annex I: JP2 file format syntax (formal name) JPEG 2000 jp2 file format (common name)
Description Wrapper developed by the Joint Photographic Experts Group (JPEG) for still images using JPEG 2000 core encoding. Its role (although not its extended capabilities) has been compared to that played by JFIF for JPG_DCT (JPEG encoding). The extended capabilities of JP2 grow out of its object-based design and its ability to wrap object types beyond JPEG 2000 core bitstreams, e.g., auxiliary opacity/transparency channels, color profile information, and other metadata. See Notes below for additional information.
Production phase May be used for content in initial, middle, and final states.
Relationship to other formats
    Subtype of ISO_BMFF, ISO Base Media File Format
    Has subtype JP2_J2K_C_LL, JP2 File Format with JPEG 2000 Core Coding, Lossless
    Has subtype JP2_J2K_C_LSY, JP2 File Format with JPEG 2000 Core Coding, Lossy
    Has subtype JP2_J2K_C_Profile_0, JP2 File with Profile 0 for JPEG 2000 Part 1, Core Coding
    Has subtype JP2_J2K_C_Profile_1, JP2 File with Profile 1 for JPEG 2000 Part 1, Core Coding
    Has subtype JP2_J2K_C_Profile_3, JP2 File with Profile 3 for JPEG 2000 Part 1, Core Coding
    Has subtype JP2_J2K_C_Profile_4, JP2 File with Profile 4 for JPEG 2000 Part 1, Core Coding
    Has subtype JP2_J2K_C_BIIF_01_00, JP2 File with BIIF Profile for JPEG 2000 Part 1, Core Coding, Version 01.00
    Has subtype JP2_J2K_C_NDNP, JP2 File with NDNP Profile for JPEG 2000 Part 1, Core Coding

Local use Explanation of format description terms

LC experience or existing holdings JP2_FF files with lossy compression are being used for the service images of maps in American Memory, where they have replaced the MrSID files used formerly to provide zoom capabilities for large images. Meanwhile, the Library and the National Endowment for the Humanities have specified JP2_J2K_C_NDNP for use as lossy-compressed service images in the National Digital Newspaper Program, launched during 2004. MXF files that wrap JPEG 2000 codestreams (bitstreams not wrapped in the file format described here) are the preservation masters in the video reformatting work carried out by the Library's Motion Picture, Broadcasting, and Recorded Sound Division at the Packard Campus. These video-frame-image codestreams are encoded with lossless J2K_C_LL.
LC preference For still images, as of 2011, the Library employs JPEG 2000 as service images and continues to create uncompressed bitmaps in TIFF files as masters. At this time, however, Library staff investigate options for creating masters for some content classes as JPEG 2000 files. Meanwhile, lossless JPEG 2000 encoding is in use for preservation master copies of video recordings. The Library of Congress Recommended Formats Statement (RFS) includes JPEG 2000 as a preferred format for photographs in digital form and other graphic images in digital form. The RFS does not specify details about the JPEG 2000 file.

Sustainability factors Explanation of format description terms

Disclosure Open standard. Developed by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 29, Coding of audio, picture, multimedia and hypermedia information incollaboration with ITU-T.

ISO/IEC 15444-1:2004. Information technology -- JPEG 2000 image coding system -- Part 1: Core coding system, Annex I: JP2 file format syntax.

See complete list of ISO/IEC JPEG 2000 documents in Format specifications below.


There is increasing implementation of JPEG 2000 in archive and library digitization of books, pictorial collections, maps, and other materials that can be reproduced as still images. A good overview was provided at the JPEG 2000 Summit held at the Library of Congress in 2011. Meanwhile, the Wellcome Library in the UK has evangelized for greater use of the format in digitization projects. Some cultural heritage institutions, including the Library of Congress, formerly used MrSID to support zoom views of large images such as maps and have now migrated to JPEG 2000 as a service format, often implemented to create JPEG_DCT (the earlier JPEG codec) images on the fly for presentation in the browser.

Many image manipulation programs and software libraries can now read and write JP2 files. Insight (Luna), ContentDM (DiMeMa), and Digitool (Ex Libris) can now use JPEG2000 and have deployed server-side transformation to deliver an image to the user within a regular web-browser. Software encoders designed for general DSP (digital signal processing) chips are now available.

Examples of significant adoption of JPEG2000 include the Digital Cinema Initiative (see Digital Cinema Initiative Package (DCP), Version 1.0) and use by the High Resolution Imaging Science Experiment (HiRISE) flying on board NASA's MARS Reconnaissance Orbiter mission.

At the same time, JPEG 2000 encoding is not generally built into still-photography camera chips nor is JPEG 2000 decoding native to Web browsers, and this has led some commentators to compare JPEG 2000 unfavorably to JPEG_DCT in terms of adoption. JPEG_DCT is native to virtually all still-image digital cameras and Web browsers. Meanwhile, however, JPEG 2000 has begun to appear as a built-in option in moving image cameras.

Earlier indications of adoption were reported in the Guide to the Practical Implementation of JPEG 2000 (2003, see Useful references below): "Some of the aerial photography on the street-mapping web site is provided by a JPEG 2000 back-end system, chosen for its ability to extract small regions from very large images at high speed. Yahoo! Messenger, an instant-messaging client with video capabilities, also uses JPEG 2000, to achieve high compression and hence higher resolution and frame-rate. In both cases, the use of JPEG 2000 is not typically manifest to the end-user." See also Peter Murray's 2004 presentation Adoption of JPEG 2000 by Libraries and Archives.

    Licensing and patents Licensing is associated with the encoding; see J2K_C.
Transparency See J2K_C
Self-documentation A small set of metadata is required: basic image data (height, width, number of components, bit-depth); color specification (see notes on color maintenance below), and a flag indicating the presence or absence of intellectual property information. This may be supplemented by optional information, e.g., capture or dispay resolution (relating pixel size to physical size) and by data presented in three optional boxes: (1) a box for XML data (specific recommendations regarding XML are provided in Part 2 of the standard and pertain to JPX but may be used in JP2 as well), (2) an IPR box (see technical protection considerations just below), and (3) a UUID box which provides for an object identifier or identifier-references to other digital objects (described by one commentator as providing a generic mechanism for extending the file format to include application-specific data).
External dependencies None
Technical protection considerations Like the rest of the members of the JPEG 2000 file format family, JP2_FF provides an IPR box for rights management information that may be used as inputs to access management systems. Additional related elements are covered by part 8 of the specification, JPEG 2000 image coding system: Secure JPEG 2000. The compilers of this Web site have not investigated Secure JPEG 2000.

Quality and functionality factors Explanation of format description terms

Still Image
Normal rendering Good support
Clarity (high image resolution) See J2K_C
Color maintenance Rich support, further extended in JPX. In JP2_FF, the color space of the decompressed image data is indicated in the Color Specification box inside the JP2 Header box, which contains the ICC profile when applicable. If the color spaces sRGB, sYCC, or the defined greyscale space are used, this is indicated by a number. For palettized images, the Palette box holds the look-up table and the Component Mapping box defines which codestream components map to which palette components or bypass the palette. The resulting components are called channels in the standard to distinguish them from the initial codestream components. Finally, the Channel Definition box maps codestream components (if unpalettized) or channels to color components, allowing them to be permuted if desired and enabling support for alphachannels (opacity) as well as color channels. Note that J2K_C provides information about actual color encoding.
Support for vector graphics, including graphic effects and typography No support for vector graphics.
Support for multispectral bands Not supported in JP2_FF; support is provided in JPX_FF.
Functionality beyond normal rendering The JPEG 2000 family offers many extended functionalities, some of which grow out of the options of scalability offered by the various encodings, and which extend to the interactivity provided by JPIP, Part 9 of the JPEG 2000 standard; see JPEG 2000 Interactive Protocol.

File type signifiers and format identifiers Explanation of format description terms

Tag Value Note
Filename extension jp2
Internet Media Type image/jp2
From the File Extension Source; the first MIME is also provided by
Magic numbers Hex: 00 00 00 0C 6A 50 20 20 0D 0A 87 0A 00 00 00 14 66 74 79 70 6A 70 32
From the File Extension Source; Annex I of the official specification indicates that this string includes the Signature Box identifier and contents and the File Type Box identifier.
File type brand (ISO Base Media File Format) jp2\040 [jp2 plus the space character]
Value in the File Type Box, which is similar to the ISO_BMFF file type box.
Uniform Type Identifier (Mac OS) jp2\040
As specified by Annex I.2.1 of the specification.
Pronom PUID x-fmt/392
Wikidata Title ID Q27979401

Notes Explanation of format description terms


The JPEG 2000 file format family includes:

  • JP2_FF, JPEG 2000 Part 1 (Core) jp2 File Format (this document)
  • JPX_FF, JPEG 2000 Part 2 (Extensions) jpf (jpx) File Format
  • JPM_FF, JPEG 2000 Part 6 (Compound) jpm File Format

The family is descended from QuickTime. This lineage is shared with ISO_BMFF and its offshoots, which include MP4_FF_2, MP4_FF_AVCE, and MJ2_FF, itself a wrapper for JPEG 2000 core-encoded images that represent sets of film or video frames.

From Guide to the Practical Implementation of JPEG 2000, cited in Useful references below: "JP2 was designed to be inherently extensible. The extended file formats that are defined in later parts of the standard all incorporate a degree of backwards-compatibility with JP2: for each extended format it is possible to construct extended files that also conform to JP2. (A JP2 reader would ignore any extensions that it did not understand.) Thus, the definition of JP2 in Part 1 can also be considered an implicit definition of an architecture known informally as the JP family . . . . A JP family file is a sequence of boxes. [These are called atoms in the QuickTime specification. -- ed] A box consists of a 4-byte length field followed by a 4-byte type field followed by the content of the box. The content is defined for each box type and may include boxes. A box whose content consists only of boxes is called a superbox. There are two special values of the length field. A value of zero means that the box extends to the end of the file. A value of 1 means that the true length of the box follows the type field (before the content) in an 8-byte extended length field; this permits boxes up to (264 - 1) bytes in length. The length includes the whole box from the start of the length field to the end of the content."


Format specifications Explanation of format description terms

Useful references


Books, articles, etc.

Last Updated: Tuesday, 28-Feb-2017 14:16:20 EST