Sustainability of Digital Formats: Planning for Library of Congress Collections
Sustainability of Digital Formats: Planning for Library of Congress Collections |
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| Introduction | Sustainability Factors | Content Categories | Format Descriptions | Contact | |
| Full name | JXR File Format [Annex A in JPEG XR Image Coding System – Image coding specification. [ITU-T T.832 and ISO/IEC 29199-2] |
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| Description |
JPEG XR (JPEG extended range) is a still-image compression standard and file format for continuous tone photographic images, based on technology originally developed by Microsoft under the name HD Photo (formerly Windows Media Photo). This description is for the TIFF-like file format specified in Annex A of the specification for JPEG XR Image Encoding System, published as ITU-T T.832 and ISO/IEC 29199-2. See JPEG XR pages on the JPEG website and JPEG_XR for information on the JPEG XR Image Encoding. |
| Production phase | Used for content in middle and final states. Although designed for potential use by camera manufacturers, The JXR format does not appear to have been adopted for that purpose. Comments welcome. |
| Relationship to other formats | |
| Contains | JPEG_XR, JPEG XR Image Encoding. |
| Has earlier version | WMP_01, HD Photo. The JXR file format is based on the format introduced by Microsoft as Windows Media Photo and then shortly afterwards, with the release of Windows Vista, renamed as HD Photo. |
| Affinity to | TIFF_6, TIFF, Revision 6.0. The JPEG XR specification does not list the TIFF 6.0 specification or the EXIF 2.2 (JEITA CP-3451) specification among normative references, but mentions both in section A.7 for its TIFF-based use of the IFD Entry structure for Image File Directories, which is described in the TIFF 6.0 specification. |
| LC experience or existing holdings | The Library of Congress has not acquired any photographs in this file format apart from a very small number of images acquired through web crawling. |
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| LC preference | Neither JXR or the associated JPEG XR encoding is listed in the Library of Congress Recommended Formats Statement (RFS) for Still Image content in its collections. |
| Disclosure | The JXR file format is specified in Annex A of an international standard, maintained under the auspices of ISO/IEC JTC1/SC29/WG1 and co-published as ITU-T T.832 and ISO/IEC 29199-2. |
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| Documentation |
The most complete source for documentation of JPEG XR is available from the JPEG website at https://jpeg.org/jpegxr/. See full list of related specifications at Workplan & Specs of JPEG XR. The JXR file format is described in Annex A of ITU-T T.832, available online at https://www.itu.int/rec/T-REC-T.832/en; as of September 2020, the latest edition is the 4th edition, approved in June 2019. |
| Adoption |
Neither the JPEG XR encoding nor the JXR file format have been adopted widely. They are supported in Microsoft's Windows Imaging Component (WIC) and many Microsoft applications can read or write JXR files. For example, in Windows 10, Microsoft Photos, Photo Gallery Viewer, and Snip & Sketch all open JXR images and Microsoft Office 2016 applications, such as Word and PowerPoint, were able to import JXR files, although the .jxr extension did not appear anywhere on the dropdown menu when inserting the file. Comments welcome. In April 2013, Microsoft announced the availability of plug-ins for Adobe Photoshop. See blog post from April 11, 2013 titled JPEG XR Photoshop Plugin and Source Code. However, in the illuminating comment thread to the blog post, a September 2014 question and answer make it clear that, at that time, there was no plan to update the plugins for compatibility with the new Adobe Photoshop CC product line. Since the download pages for Photoshop plugins for Windows and MacOS have not been updated since 2013, it seems probable that, as of September 2020, there is no plugin compatible with current versions of Photoshop. According to the Wikipedia entry for JPEG XR, the plugins work with Photoshop versions CS2, CS5-CS6. Comments welcome. See JPEG_XR for information about the jxrlib reference software for encoding and decoding the image payload of a JXR file. The following third-party graphics applications claim to read and write JXR files: LeadTools SDK; ImageMagick (uses jxrlib); Aconvert Online (e.g., JXR to JPG and JPG to JXR); gimp-jxr (plugin for GIMP); XnView Classic (for Windows) and XnView MP (successor to XnView, available for Windows, MacOS, and Linux) [see XnView | Formats. The following graphics application claims to read but not write JPEG XR images: IrfanView (for Windows only). Applications that claim to handle JPEG XR images may also handle images in Windows Media Photo and HD Photo formats. Comments welcome. |
| Licensing and patents | See JPEG_XR |
| Transparency | See JPEG_XR. |
| Self-documentation |
Descriptive metadata can be incorporated in the TIFF-like file format defined in Annex A of the JPEG XR specification, using tags defined for this purpose in the TIFF_6 specification and other specifications that build on the TIFF Image File Directory (IFD) syntax structure. Descriptive tags listed specifically in Annex A correspond to: image description; equipment make; equipment model; page name and number; date and time of creation; artist name; computer/operating system used at time of creation; copyright notice; color space Annex A specifically mentions that JXR images can optionally include metadata in two forms widely used for images: EXIF 2.2 (JEITA CP-3451) and XMP (ISO 16684-1). An EXIF IFD can be incorporated into the TIFF-like JXR format. Its presence can be indicated using the tag widely used tag for this purpose, 34665 (0x8769). XMP can be incorporated into using the tag widely used tag for this purpose, 700 (0x02BC). In addition, although not mentioned in the JPEG XR specification, the tag conventionally used for IPTC data, 33723 (0x83BB), might be incorporated into a JXR file. However, applications might not recognize it or preserve it on output. Comments welcome. See also Tags for TIFF, DNG, and Related Specifications. Tags identified as "used by HD Photo" are also used for JXR files. |
| External dependencies | None. |
| Technical protection considerations | This file format does not have built-in support for encryption. See JPEG XR for information about proposals for introducing encryption to the JPEG XR codestream. |
| Still Image | |
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| Normal rendering | See JPEG_XR for characteristics of the image encoding in a file with the .jxr extension. |
| Clarity (high image resolution) | See JPEG_XR for characteristics of the image encoding. Note that not all bit-depths and color representations permitted in a JPEG XR codestream are required to be supported by applications that read or write files with the .jxr extension |
| Color maintenance | ICC color profile data can be incorporated in the TIFF-like file format defined in Annex A of the JPEG XR specification (JXR), using the tag defined for this purpose in the TIFF/EP specification, 34675 (0x8773). |
| Support for vector graphics, including graphic effects and typography | See JPEG_XR. |
| Support for multispectral bands | See JPEG_XR. |
| Tag | Value | Note |
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| Filename extension | jxr wdp |
The extension .jxr is suggested in the specification (Annex A of ITU-T T.832 (V4) [2019]) and specified in IANA registration. The extension .wdp (inherited from the extension for Windows Media Photo) is listed in the PRONOM record for JPEG XR with PUID: fmt/590 and in the JPEG XR Codec Overview Microsoft provides in its documentation for the Windows Imaging Component (WIC). |
| Internet Media Type | image/jxr image/vnd.ms-photo |
There is a 2019 IANA registration for image/jxr, which was added to the ITU-T T.832 specification in its 3rd edition (2016) in the form of a provisional registration. image/vnd.ms-photo is listed as an alternative in the Wikipedia entry for JPEG XR. |
| Magic numbers | ASCII: II Hex: 4949BC |
See IANA registration. |
| File signature | ASCII: WMPHOTO Hex: 574D50484F544F00 |
Within the image codestream, a JPEG XR IMAGE_HEADER data structure begins with this 64-bit syntax element GDI_SIGNATURE. See IANA registration for image/jxr. Notice that the 7-byte ASCII value is followed by a byte with value zero, as shown in the Hex value. |
| Pronom PUID | fmt/590 |
See https://www.nationalarchives.gov.uk/PRONOM/fmt/590. PRONOM includes .wdp and .jxr as file extensions in its entry for JPEG XR. |
| Wikidata Title ID | Q1064039 |
See https://www.wikidata.org/wiki/Q1064039. |
| General |
See JPEG_XR. |
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| History |
See JPEG_XR. |
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