Sustainability of Digital Formats: Planning for Library of Congress Collections

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HD Photo, Version 1.0 (Windows Media Photo)

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Format Description Properties Explanation of format description terms

Identification and description Explanation of format description terms

Full name HD Photo, Version 1.0 (formerly Windows Media Photo)
Description

Format developed by Microsoft for continuous-tone still images that supports a wide range of features including:

  • Multiple color formats for display or print
  • Fixed or floating point, high-dynamic-range image encoding
  • Lossless or high-quality lossy compression
  • Efficient decoding for multiple resolutions and sub-regions
  • Minimal overhead for format conversion or transformations during decoding

When HD Photo was released, Microsoft stated (as reported by Softpedia News on November 18, 2006) that the format delivers "a lightweight, high-performance algorithm with a small memory footprint that enables practical, in-device encoding and decoding."

Support for HD Photo in Windows is provided by the Windows Imaging Component (WIC), an installable codec architecture introduced for Windows Vista and built in to later Windows versions. Microsoft stated that Vista represented the integration of imaging at the operating system level, reducing the level of activity required of specific applications. WIC is included with Windows Presentation Foundation (WPF), a development environment provided by Microsoft for building user interfaces.

In a July 31, 2007, press release, Microsoft Corp. announced the decision by the Joint Photographic Expert Group (JPEG) to introduce a new work item for the standardization of HD Photo which, if approved, would lead to a format tentatively titled "JPEG XR." JPEG XR was given final approval as ITU-T Recommendation T.832 in April 2009 and as ISO/IEC 29199-2 in June 2009.

Production phase Used for content in middle and final states. Although designed for potential use by camera manufacturers, neither HD Photo nor its successor, JPEG XR, was adopted for that purpose.
Relationship to other formats
    Has later version JPEG_XR, JPEG XR Image Encoding. HD Photo was standardized as JPEG XR.
    Has later version JXR, JPEG XR File Format. Defined in Annex A of the JPEG XR standard, which deliberately separates the image encoding specification from this proposed file format.
    Used by MS-XPS, Microsoft XML Paper Specification, (XPS). One of several image formats permitted in the XPS format.

Local use Explanation of format description terms

LC experience or existing holdings The Library of Congress has a very small number of files with .hdp (3 files, 9KB) and .wdp (26 files, 6MB) file extensions in its digital collections. These have likely come from archived websites..
LC preference Neither HD Photo nor Windows Media Photo are included in the Recommended Formats Statement in relation to acquisition of digital images for LC collections.

Sustainability factors Explanation of format description terms

Disclosure Developed by the Microsoft Corporation and publicly documented.
    Documentation

The container format and API were specified in the HD Photo Feature Specification (2006), made available from http://www.microsoft.com/whdc/xps/wmphoto.mspx (link from January 2008 via Internet Archive) and later from http://msdn.microsoft.com/en-us/windows/hardware/gg463400.aspx (link from October 2012 via Internet Archive). Information about the HD Photo compressed bitstream format and how to implement an encoder and decoder were part of the HD Photo Device Porting Kit 1.0 (DPK). This kit was available from http://www.microsoft.com/whdc/xps/hdphotodpk.mspx (link from January 2008 via Internet Archive) and later from http://msdn.microsoft.com/en-us/windows/hardware/gg463381.aspx (link from October 2012 via Internet Archive).

The page titled HD Photo Specification Download (last updated March 2010) has been archived by Microsoft, but lacks an active link for the download.

Adoption

Introduced in 2006, with initial dependency on the level of adoption of the Windows Vista operating/application system, made available in a general release in 2007. In December 2007, Microsoft announced the availability of plug-ins for Adobe PhotoShop. HD Photo is incorporated as a native codec into the Windows Imaging Component (WIC); see HD Photo Format Overview. HD Photo is one of several image formats that could be incorporated into Microsoft's XPS format. The compilers of this resource have not encountered indications of significant adoption of HD Photo outside Windows. For example, in https://fileinfo.com/extension/hdp (as of September 2020) the only Mac application listed is the plugin released by Microsoft for Adobe Photoshop. However, in a response to the February 2020 question How to use javascript to save jpeg-xr files on the Adobe Support Community, there was a response indicating that the plugin may not work in recent versions of Adobe Photoshop. The Wikipedia entry for JPEG XR indicates that the plugin works with Photoshop versions CS2, CS5-CS6 but is silent on later versions of Photoshop. Comments welcome.

The following graphics applications claim to read and write photos in the HD Photo format: XnView Classic (for Windows); XnView MP (successor to XnView, available for Windows, MacOS, and Linux). The following graphics application claims to read but not write HD Photo 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

Licensing applies to applications that create or display images, not to the images themselves. A Microsoft Web page consulted in August 2006 and no longer available in January 2007 (http://www.microsoft.com/windows/windowsmedia/licensing/wmphoto.aspx) stated, "Under most conditions, Windows Media Photo technology is available free of charge; royalties are associated only with specific licensing conditions."

According to the Wikipedia entry for HD Photo as of February 2, 2009, "A Microsoft representative stated in a January 2007 interview that in order to encourage the adoption and use of HD Photo, the specification is made available under the Microsoft Open Specification Promise, which asserts that Microsoft offers the specification for free, and will not file suit on the patented technology, and that open-source software can therefore make use of the format. However, as of Microsoft's December 4, 2007 update, HD Photo is still not among the technologies that Microsoft has listed as being covered by the Open Specification Promise."

Note: Rather than covering HD Photo's successor JPEG XR by the Open Specification Promise (OSP), Microsoft chose to use its Microsoft Community Promise. See Microsoft Community Promise (as of August 18, 2010, via Internet Archive). The Community Promise model was introduced in 2007 to support interoperability. See, for example, Community Promise for XPS - FAQ (as of March 6, 2007, via Internet Archive).

Transparency Depends upon algorithms and tools to read; will require sophistication to build tools.
Self-documentation

WMP_1_0 uses a "TIFF-like" file container to store image data in a table of Image File Directory (IFD) tags, using tag numbers from TIFF's baseline, extended, and "private" sets. Examples of tags drawn from extended and private TIFF sets: ICCProfile (34675), XMPMetadata (700), and EXIFMetadata (34665). For an overview of tags, including a listing of WMP_1_0 tags, see Tags for TIFF and Related Specifications.

The large number of possible image encodings are identified by means of GUIDs specified by Microsoft. (This contrasts with an approach based upon the placement of data in a set of tags for such features as bits per pixel, photometric interpretation, and so on.)

External dependencies None
Technical protection considerations No DRM technology; see Notes below.

Quality and functionality factors Explanation of format description terms

Still Image
Normal rendering Supported.
Clarity (high image resolution) Very high levels of image quality are supported. The Wikipedia entry for HD Photo as of February 2, 2009 reports, "HD Photo is an image codec that gives a high-dynamic-range image encoding while requiring only integer operations (with no divides) for both compression and decompression. It supports monochrome, RGB, CMYK and even n-channel color representation, using up to 16-bit unsigned integer representation, or up to 32-bit fixed point or floating point representation, and also supports RGBE (Radiance) . . . . All color representations are transformed to an internal color representation. The transformation is entirely reversible, so, by using appropriate quantizers, both lossy and lossless compression can be achieved."
Color maintenance Excellent support; files can include ICC profiles; extended color gamuts are supported.
Support for vector graphics, including graphic effects and typography HD Photo is a raster format, without support for vector graphics
Functionality beyond normal rendering Paraphrasing the Wikipedia entry for HD Photo as of February 2, 2009: An alpha channel may be present for transparency. The format allows decoding part of an image, without decoding the entire image. Full decoding is also unnecessary for certain operations such as cropping, downsampling, horizontal or vertical flips, or cardinal rotations.

File type signifiers and format identifiers Explanation of format description terms

Tag Value Note
Filename extension hdp
wdp
Both extensions are listed in Microsoft's document describing the features of HD Photo (November 16, 2006). In the Wikipedia entry for HD Photo as of February 2, 2009 the extension "wdp" is labeled "formerly." PRONOM's entry for JPEG XR [https://www.nationalarchives.gov.uk/PRONOM/fmt/590] includes the extension .wdp but not .hdp.
Internet Media Type image/vnd.ms-photo
From the Wikipedia entry for HD Photo as of February 2, 2009. Also in Microsoft's documents describing the features of Windows Media Photo (June 25, 2006) and HD Photo (November 16, 2006).
Magic numbers Hex: 49 49 BC
ASCII: II.
From the The File Extension Source for WDP.
Pronom PUID fmt/590
PRONOM includes the .wdp file extension in its entry for JPEG XR. See https://www.nationalarchives.gov.uk/PRONOM/fmt/590.
Wikidata Title ID Q11222362
See https://www.wikidata.org/wiki/Q11222362.

Notes Explanation of format description terms

General

Regarding compression: The summation for compression from the Wikipedia entry for Windows Media Photo on September 13, 2006 was as follows. "uses a reversible color space conversion, a reversible lapped biorthogonal transform and a non-arithmetic entropy encoding scheme, which is very efficient in preserving high frequency image data. This makes the algorithm retain a higher image quality at high compression ratios. The transform operation needs 3 multiply and add operations and 7 add or shift operations at the highest quality level and in the highest performance mode, 1 multiply and add operation and 4 add or shifts are required per pixel, giving the codec a high performance. Windows Media Photo processes images in 16x16 macroblocks." The Wikipedia entry for HD Photo as of February 2, 2009 offers more detail.

Regarding digital rights management: In a comment on blog post consulted in August 2006, HD Photo Program Manager Bill Crow commented:

  • Windows Media DRM is ideal for publishing audio and video, but is really not that useful for still photography. Most commercial scenarios for digital photos require that the customer receive direct access to the image, which basically defeats the approach used by Windows Media DRM (where the goal is to protect the content all the way to the glass or speakers). Also, Windows Media DRM is designed for a "few to many" publishing model; the DRM license generation technology does not easily allow anyone to generate their own DRM licenses.
  • While we are looking at DRM for photos for possible support in the future, the initial implementation was deliberately been designed to be simple, lightweight and easy for partners to implement directly in devices. That said, you can currently use Windows Document Rights Management for very effective management of rights access to digital photos.
  • We're investigating more comprehensive solutions to manage digital photo access rights, copyright protection and provenance guarantees as features for future versions of Windows Media Photo.

Other notes: Bill Crow's own blog is informative; here are some excerpts from 2006:

  • From July 5, 2006: Our current encoder tools include a choice between the sample applications that are part of the Windows Media Photo Device Porting Kit (DPK) or an encoder utility based on the Windows Imaging Components (WIC) interfaces that we developed internally for our own testing purposes. Both tools are command line utilities, and each has its own specific strengths.
  • From June 21, 2006: The fundamental goal with a high dynamic range, wide gamut pixel format is to never discard image information that falls outside the visible range. The entire tonal spectrum is always retained, regardless of the current exposure or color adjustments. Using fixed point or floating point values, pixel information is encoded using an extended numerical range. The visible portion of the numerical range is a subset of the total numerical range that can be encoded with fixed point or floating point values. . . . If color or exposure adjustment pushes a pixel value outside the visible range, rather than losing this value (as is the case with unsigned integer representations), the numerical value is still retained. If a subsequent adjustment brings that pixel value back into the visible range, the correct numerical value is fully recovered. This dramatically eliminates the issues and concerns with "flattening" a file. Most color or exposure adjustments are completely reversible, eliminating the need to restart with the original RAW file or an intermediate layered editing file.
  • From November 17, 2006: For the immediate future, we will still use the Windows Media Photo name to refer to the implementation of HD Photo in Microsoft products that are already shipping. This includes the initial release of Windows Vista, the XML Paper Specification (XPS), .NET Framework 3.0, and Windows Imaging Component (WIC). With the new name, the spec now adds support for a new file extension - .hdp. However, the various Windows implementations won't recognize this new extension until some updates have been released at some point in the future. (No, I don't know exactly when that will be.) So we're recommending implementers stick with the current .wdp extension. You can "future-proof" your application by also adding support for the new .hdp extension.
History

The image-coding technology used in WMP_1_0 was incubated in Microsoft Research and developed by Microsoft’s Core Media Processing team. Windows Media Photo was announced at the Windows Hardware Engineering Conference (WinHEC) in May 2006; see Microsoft shows off JPEG rival, a May 24, 2006 article from c|net. See Welcome! post for a new blog devoted to the format. The name was changed to HD Photo later in 2006. See Introducing HD Photo, a blog post from November 17, 2006. In July 2007, Microsoft Corp issued a press release announcing that its HD Photo file format would be considered for standardization by the Joint Photographic Expert Group (JPEG), tentatively to be titled JPEG XR.

A brief history of HD Photo, from Barry Pearson has a detailed annotated history of the progression from Windows Media Photo, through renaming as HD Photo, to standardization as JPEG XR. The link is via the Internet Archive, in order to reduce the number of dead links.


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Last Updated: 10/16/2020