68th Meeting - Sydney, Australia - JPEG XT’s Lossless/Near-Lossless and Alpha Channel Coding Move to Committee Draft Stage - February 6, 2015

Document WG1N6938

JPEG XT’s Lossless/Near-Lossless and Alpha Channel Coding Move to Committee Draft Stage

The Joint Photographic Experts Group (JPEG) is a Working Group of ISO/IEC, the International Organisation for Standardization / International Electrotechnical Commission, (ISO/IEC JTC 1/SC 29/WG 1) and of the International Telecommunication Union (ITU-T SG16), responsible for the popular JPEG, JPEG 2000, JPEG XR, JPSearch and more recently, the JPEG XT, JPEG Systems and JPEG AR families of imaging standards. The WG1 group meets nominally three times a year, in Europe, North America and Asia. The latest meeting was held on February 2–6, 2015 in Sydney, Australia.

JPEG is pleased to announce that parts 8 and 9 of JPEG XT, a project on backward-compatible extensions of the well-known JPEG image compression format, have been progressed to Committee Draft stage. Part 8 of JPEG XT allows lossless compression of photographic images of eight-bit resolution and beyond, including high dynamic range images. At the same time, part 8 ensures that legacy JPEG software is able to decode such streams with minimal loss. JPEG XT part 9 adds a feature to JPEG, namely the ability to include alpha channels, i.e. transparency information to JPEG coded images. This feature especially enables webpages to include photographic images with arbitrary boundaries or transparency effects. Similar to part 8, this part ensures backward compatibility and legacy decoders will replace the transparent regions with a constant color. A reference implementation for JPEG XT part 8 can be found on the webpage of the committee, at

The JPEG committee has finalized its work on new profiles for JPEG 2000 (ISO/IEC 15444-1) designed for integrating them into the interoperable master format IMF. IMF is a file-based framework under development by SMPTE to represent high-quality versions of a given finished multimedia work destined for distribution across multiple channels and platforms, including broadcast and Internet. It is intended for professional applications worldwide. The new profiles allow resolutions up to 8192 by 6144 with newest colour spaces (e.g. ITU-T BT.2020) and up to lossless compression. It offers a flexible exchange of content across media production and distribution houses.

JPEG has been making continuous efforts to further extend interoperability and usability of the existing JPSearch standard of image search and management framework. As a result, JPEG is proud to announce that the technical development of JPOnto as an amendment of JPSearch Part 2 and JPSearch API as an amendment of JPSearch Part 3 are finalized and approved by the national bodies and now await formal publication. JPOnto provides an expandable vocabulary for describing images - or objects in images - in RDF (Resource Description Framework). A formalized vocabulary provides a standard for rich image annotations that can be interlinked with external resources and as such vastly improves interoperability. In addition, JPOnto specifies how these descriptions can be embedded within the image itself to guarantee the portability. The JPSearch API on the other hand simplifies how mobile or web-based applications interact with images and image collections by specifying a REST based interface. The API offers a standardized interface for client-server communication for apps that provide features such as metadata based search, searching for visual similar images or requesting automated image annotations. In order to fulfill mobile development needs, the interface is lightweight to minimize bandwidth usage and can be flexibly integrated with other APIs.

The JPEG Committee has launched a new activity: JPEG Pleno, which is targeting a standard framework for the representation and exchange of new imaging modalities such as light-field, point-cloud and holographic imaging. In addition to the representation it is also a target to define new tools for improved compression while providing advanced functionality support for – but not limited to – image manipulation, metadata, image access and interaction, privacy and security. This paradigm shift caused by computational imaging approaches will be as disruptive for the photography markets as the migration from analog film to digital pictures. Hence, JPEG Pleno investigates how this evolution can be properly addressed by WG1 while accounting for JPEG’s legacy. WG1 is inviting interested parties to contribute to this effort. A public workshop on JPEG Pleno will be organised at the next JPEG/MPEG joint meeting in Warsaw on June 23rd, 2015.

JPEG is integrating support for privacy protection in the codestream syntax and file formats of its standards. JPEG Privacy will enable safe sharing and storing of images seen the necessity of protecting private information contained by images but also the associated metadata (e.g. geospatial coordinates in EXIF) is increasing rapidly. JPEG Privacy is intended to incorporate support for privacy solutions within the JPEG family of standards while maintaining backward compatibility.

JPEG investigates use cases, applications and models for a low-latency, efficient or lightweight new coding system. Today’s industrial uses include JPEG 2000 (ISO/IEC 15444-1) for broadcast applications. As screen resolutions in the broadcasting as well as in consumer appliances increase, need for an advanced coding system has evolved to include low-latency and lightweight features in addition to efficient compression efficiency. .

WG1 is interested in receiving latest information on current state of the art for the coding of still images. JPEG standards have been by far the most widely used still image coding formats. Several efficient still image coding systems have been standardized, some of which have found success in niche markets. JPEG would like to collect information on alternative still image technologies to understand how they operate and how they may be used commercially. While WG1 is interested in coding efficiency, coding efficiency is one among many other important features that play a role in successful deployment of next generation still image coding. WG1 would like to use the information collected to determine opportunities for potential next generation still image codecs. This investigation may lead to a new standardization effort within the framework of JPEG.

“The JPEG XT framework provides new functionalities to JPEG while guaranteeing backward compatibility with legacy JPEG implementations. The new parts 8 and 9 will provide the long-desired functionalities to encode pictures in JPEG format with features such as lossless/near-lossless compression and alpha channel support. ” said Prof. Touradj Ebrahimi, the Convener of the JPEG committee.

The next 69th WG 1 Meeting will be held on June 22-26, 2015, in Warsaw, Poland.

More information about JPEG and its work is available at or by contacting Peter Schelkens and Fumitaka Ono of the JPEG PR subgroup at .

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