Sustainability of Digital Formats
Planning for Library of Congress Collections
Sustainability of Digital Formats
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| Introduction | Sustainability Factors | Content Categories | Format Descriptions | Contact | |
| Full name | ISO/IEC 15444-6:2003. Information technology -- JPEG 2000 image coding system -- Part 6: Compound image file format (formal name) JPEG 2000 jpm file format (common name) |
| Description | Format developed by the Joint Photographic Experts Group (JPEG) to serve document imaging. JPM files contain layered still images that use JPEG 2000 and other encodings. The format's compositing model is based on the Mixed Raster Content standard (ISO/IEC 16485). The JPM file format inherits features from its parent: JP2_FF, JPEG 2000 Part 1 (Core) jp2 File Format. The JPM standard specifies:
The specification describes a Web profile and three decompression profiles (pp. 67-68). The former has a number of constraints, e.g., on compression types and color space. The decompression profiles constrain files to the use of a single compression method: JPEG 2000, JPEG, and JBIG2. Additional information about the format is provided in Notes, below. |
| Production phase | May be used for content in initial, middle, and final states. |
| Relationship to other formats | |
| May contain | Uncompressed bitmap, not documented at this time |
| May contain | ITU-T "Group 3" FAX Compression (T.4), One Dimensional; commonly known as Modified Huffman (MH) encoding, not documented at this time |
| May contain | ITU-T "Group 3" FAX Compression (T.4), Two Dimensional; commonly known as Modified READ (MR) encoding, not documented at this time |
| May contain | ITU_G4, ITU-T "Group 4" FAX Compression (T.6); commonly known as Modified Modified READ (MMR) encoding |
| May contain | JBIG_1, JBIG1 Bitonal Image Format |
| May contain | JPEG_DCT, JPEG Lossy (DCT) Compression Encoding |
| May contain | JPEG_LS, JPEG Lossless Compression |
| May contain | J2K_EXT, JPEG 2000 Part 2, Coding Extensions |
| May contain | JBIG_2, JBIG2 Bitonal Image Format |
| May contain | Run length coding, not documented at this time |
| LC experience or existing holdings | None |
| LC preference | None established |
| Disclosure | Open standard. Developed by Joint Technical Committee ISOAEC JTC 1, Information technology, Subcommittee SC 29, Coding of audio, picture, multimedia and hypermedia information in collaboration with ITU-T. |
| Documentation | ISO/IEC 15444-6:2003. Information technology -- JPEG 2000 image coding system -- Part 6: Compound image file format. See complete list of ISO/IEC JPEG 2000 documents in JP2_FF. |
| Adoption | Although implementations of JPEG 2000 (especially J2K_C Part 1 core coding) increased in 2003 and 2004, and are expected to accelerate markedly in 2005, the compiler of this document is not aware of the extent to which JPM_FF is being implemented. |
| Licensing and patent claims | None identified in specification, which states that "some of the elements of this document may be the subject of patent rights." (p. iv) |
| Transparency | Depends upon algorithms and tools to read; will require sophistication to build tools. |
| Self-documentation | All JPEG 2000 files are made up of "boxes," as described in the Notes below, including an XML box typically used for metadata. The specification does not include any particular specification for XML data. Additional boxes inherited from JP2_FF include one for a unique identifier for the image or identifier-references to other digital objects, e.g., a UUID, and another for IPR metadata, possibly redundant with that included in the XML box. |
| External dependencies | None |
| Technical protection considerations | Like all JPEG 2000 file formats, JPM_FF provides an IPR box for rights management information that may be used as inputs to access management systems. |
| Normal rendering | Good support |
| Clarity (support for high image resolution) | Depends upon encoding; see list in Relationships to other formats, above. |
| Color maintenance | Rich support; the color space of the decompressed image data is indicated in the Color Specification box inside the Header box, which contains the ICC profile when applicable. Other color maintenance features are inherited from JP2_FF, e.g., the Palette box and the Component Mapping box. |
| Support for graphic effects and typography | No support for vector graphics. |
| Functionality beyond normal rendering | JPM data may be fragmented over several files or network resources and reassembled by a network client. Annex E of the specification explains how to construct URLs that reference sub-elements of a JPM file. Meanwhile, 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, destined to be Part 9 of the JPEG 2000 standard; see JPIP-Architecture-VCIP2003.pdf |
| Tag type | Value | Note |
| Filename Extension | jpm | As specified by Annex A.1 of the specification. |
| Macintosh type code | jpm\040 [jpm plus the space character] | As specified by Annex A.1 of the specification. |
| Internet Media Type | image/jpm | As specified by Annex A.1 of the specification. |
| Magic numbers | None identified | Comments welcome |
| File type brand | jpm\040 [jpm plus the space character] | When "completely defined by" Part 6 of the JPEG 2000 standard. The File Type Box is similar to the ISO_BMFF file type box. |
| Image header box | Signifier for the encoded bitstream: 0=uncompressed bitmap; 1=for ITU-T T.4 "Group 3," One Dimensional, aka Modified Huffman (MH) encoding; 2=for ITU-T T.4 "Group 3," Two Dimensional, aka Modified READ (MR) encoding; 3=for ITU-T T.6 "Group 4," aka Modified Modified READ (MMR) encoding; 4=JBIG bi-level images; 5=JPEG encoding; 6=JPEG lossless encoding; 7=JPEG 2000 wavelet encoding (no specification part number indicated); 8=JBIG2 encoding; 9=JBIG images other than bi-level; 10=run length coding |
| General | The JPEG 2000 file format family includes: • JP2_FF, JPEG 2000 Part 1 (Core) jp2 File Format • JPX_FF, JPEG 2000 Part 2 (Extensions) jpf (jpx) File Format • JPM_FF, JPEG 2000 Part 6 (Compound) jpm File Format (this document) 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. The description of this standard at the ISO Web site may be paraphrased as follows: A compound image may contain scanned images, synthetic images or both, often requiring a mix of continuous tone and bi-level compression. The JPM specification defines a binary container for a mix of continuous-tone and bi-level images, and also defines a composition model that describes how the multiple images are combined to generate a compound image, based on the multi-layer Mixed Raster Content (MRC) imaging model, defined in ISO/IEC 16485. The format is useful for applications that store multiple pages, images with mixed content, and/or images that need more structure than provided in JP2. A JPM file stores a compound image document as a sequence of pages, each of which consists of a sequence of layout objects, each of which in turn consists of an MRC mask-image object pair. A JPM file can support MRC-encoded data, binary-only objects and pages, JPEG 2000-compressed objects and pages, or a mixture of all. Each of these elements (page, layout object, mask/image object) may have a label and associated metadata. Each JPM file contains a main page collection, which is used to organize and navigate the pages in a compound image document. A key feature of JPM is its support of fragmented JPEG 2000 codestreams to enable progressive and interactive rendering in web applications. A JPM file may be self-contained in that it contains all the data needed to composite the page or pages in the file. A JPM file may also reference images and data in external files. The hierarchy is: page collections contain pages which contain layout objects which contain mask and image objects. |
| History |
URLs
Print
The file format described on this page is specified in Part 6 of the standard, cited here. Other JPEG 2000 specifications are listed in JP2_FF.
• ISO/IEC 15444-6:2003. Information technology -- JPEG 2000 image coding system -- Part 6: Compound image file format. Defines a normative but optional file format for storing compound images using the JPEG 2000 file format family architecture. A compound image is an image that may contain scanned images, synthetic images or both, and that preferably requires a mix of continuous tone and bi-level compression methods. Besides defining a binary container for a mix of continuous-tone and bi-level images, this format defines a composition model that describes how the multiple images are combined to generate a compound image. This composition model is based on the multi-layer Mixed Raster Content (MRC) imaging model, defined in ITU-T T.44 | ISO/IEC 16485. The name of the file format defined in this part of ISO/IEC 15444 is JPEG 200 Multi-layer or JPM. Part 6 includes: a binary container for multiple bi-level and continuous-tone images used to represent a compound image; a mechanism by which multiple images can be combined into a single compound image, based on the Mixed Raster Content model; a mechanism for grouping multiple images in a hierarchy of layout objects, pages and page collections; a mechanism for storing JPEG 2000 and other compressed image data formats; a mechanism by which metadata can be included in files specified by ISO/IEC 15444-6:2003.
URLs
• http://www.jpeg.org/jpeg2000/
• JPIP-Architecture-VCIP2003.pdf (http://www.ee.unsw.edu.au/~taubman/publications_files/JPIP-architecture-vcip03.pdf)
• MIME types for JPEG 2000 (http://www.rfc-editor.org/rfc/rfc3745.txt)
• DIG35 metadata information (http://www.i3a.org/i_dig35.html)
Print
• Colyer, Greg and Richard Clark. Guide to the Practical Implementation of JPEG 2000. London: British Standards Institute, 2003. ISBN: 0580412423 BSI: PD 6777:2003. Available as PDF file; link to point-of-sale at http://www.jpeg.org/jpeg2000/index.html.
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