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The 103rd JPEG meeting was held online from April 8 to 12, 2024. During this JPEG meeting, the first learning-based standard, JPEG AI, reached the Draft International Standard (DIS) and was sent for balloting after a very successful development stage that led to performance improvements above 25% against its best-performing anchor, VVC. This high performance, combined with implementation in current mobile phones or the possibilities given by the latent representation to be used in image processing applications, leads to new opportunities and will certainly launch a new era of compression technology.

The following sections summarize the main highlights of the 103rd JPEG meeting.

JPEG AI

At its 103rd meeting the JPEG Committee produced the Draft International Standard (DIS) of the JPEG AI Part 1 Core Coding Engine which is expected to be published as an International Standard in October 2024. JPEG AI offers a coding solution for standard reconstruction with significant improvements in compression efficiency over previous image coding standards at equivalent subjective quality. The JPEG AI coding design allows for hardware/software implementation encoding and decoding, in terms of memory and computational complexity, efficient coding of images with text and graphics, support for 8- and 10-bit depth, region of interest coding, and progressive coding. To cover multiple encoder and decoder complexity-efficiency tradeoffs, JPEG AI supports a multi-branch coding architecture with two encoders and three decoders (6 possible compatible combinations) that have been jointly trained. Compression efficiency (BD-rate) gains of 12.5% to 27.9% over the VVC Intra coding anchor, for relevant encoder and decoder configurations, can be achieved with a wide range of complexity tradeoffs (7 to 216 kMAC/px at the decoder side).

The work regarding JPEG AI profiles and levels (part 2), reference software (part 3) and conformance (part 4) has started and a request for sub-division has been issued in this meeting to establish a new part on the file format (part 5). At this meeting, most of the work focused on the JPEG AI high-level syntax and improvement of several normative and non-normative tools, such as hyper-decoder activations, training dataset, progressive decoding, training methodology and enhancement filters. There are now two smartphone implementations of JPEG AI available. In this meeting, a JPEG AI demo was shown running on a Huawei Mate50 Pro with a Qualcomm Snapdragon 8+ Gen1 with high resolution (4K) image decoding, tiling, full base operating point support and arbitrary image resolution decoding.

JPEG Trust

At the 103rd meeting, the JPEG Committee produced an updated version of the Use Cases and Requirements for JPEG Trust (v2.0). This document integrates the use cases and requirements of the JPEG NFT exploration with the use cases and requirements of JPEG Trust. In addition, a new document with Terms and Definitions for JPEG Trust (v1.0) was published which incorporates all terms and concepts as they are used in the context of the JPEG Trust activities. Finally, an updated version of the JPEG Trust White Paper v1.1 has been released. These documents are publicly available on the JPEG Trust/Documentation page.

JPEG Pleno Learning-based Point Cloud coding

The JPEG Committee continued its activity on Learning-based Point Cloud Coding under the JPEG Pleno family of standards. During the 103rd JPEG meeting, comments on the Committee Draft of IS0/IEC 21794 Part 6: “Learning-based point cloud coding” were received and the activity is on track for the release of a Draft International Standard for balloting at the 104th JPEG meeting in Sapporo, Japan in July 2024. A new version of the Verification Model (Version 4.1) was released during the 103rd JPEG meeting containing an updated entropy coding module. In addition, version 2.1 of the Common Training and Test Conditions was released as a public document.

JPEG Pleno Light Field

The JPEG Pleno Light Field activity progressed at this meeting with a number of technical submissions for improvements to the JPEG PLeno Model (JPLM). The JPLM provides reference implementations for the standardized technologies within the JPEG Pleno framework. The JPEG Pleno Light Field activity has an ongoing standardization activity concerning a novel light field coding architecture that delivers a single coding mode to efficiently code all types of light fields. This novel coding mode does not need any depth information resulting in significant improvement in compression efficiency.

The JPEG Pleno Light Field is also preparing standardization activities in the domains of objective and subjective quality assessment for light fields, aiming to address other plenoptic modalities in the future. During the meeting, important decisions were made regarding the execution of multiple collaborative subjective experiments aiming at exploring various aspects of subjective light field quality assessments. Additionally, a specialized tool for subjective quality evaluation has been developed to support these experiments. The outcomes of these experiments will guide the decisions during the subjective quality assessment standardization process. They will also be utilized in evaluating proposals for the upcoming objective quality assessment standardization activities.

JPEG AIC

During the 103rd JPEG meeting, the work on visual image quality assessment continued with a focus on JPEG AIC-3, targeting a standard for a subjective quality assessment methodology for images in the range from high to nearly visually lossless quality. The activity is currently investigating three kinds of subjective image quality assessment methodologies, notably the Boosted Triplet Comparison (BTC), the In-place Double Stimulus Quality Scale (IDSQS), and the In-place Plain Triplet Comparison (IPTC), as well as a unified framework capable of merging the results of two among them.

The JPEG Committee has also worked on the preparation of the Part 4 of the standard (JPEG AIC-4) by initiating work on the Draft Call for Proposals on Objective Image Quality Assessment. The Final Call for Proposals on Objective Image Quality Assessment is planned to be released in January 2025, while the submission of the proposals is planned for April 2025.

JPEG XE

The JPEG Committee continued its activity on JPEG XE and event-based vision. This activity revolves around a new and emerging image modality created by event-based visual sensors. JPEG XE is about the creation and development of a standard to represent events in an efficient way allowing interoperability between sensing, storage, and processing, targeting machine vision and other relevant applications. The JPEG Committee finished the Common Test Conditions v1.0 document that provides the means to perform an evaluation of candidate technologies for efficient coding of event sequences. The Common Test Conditions define a canonical raw event format, a reference dataset, a set of key performance metrics and an evaluation methodology. In addition, the JPEG Committee also finalized the Draft Call for Proposals on lossless coding for event-based data. This call will be finalized at the next JPEG meeting in July 2024. Both the Common Test Conditions v1.0 and the Draft Call for Proposals are publicly available on jpeg.org. Standardization will start with lossless coding of event sequences as this has the most imminent application urgency in industry. However, the JPEG Committee acknowledges that lossy coding of event sequences is also a valuable feature, which will be addressed at a later stage. The Ad-hoc Group on Event-based Vision was reestablished to continue the work towards the 104th JPEG meeting. To stay informed about the activities please join the event-based imaging Ad-hoc Group mailing list.

JPEG DNA

JPEG DNA is an exploration aiming at developing a standard that provides technical solutions that are capable of representing bi-level, continuous-tone grey-scale, continuous-tone colour, or multichannel digital samples in a format representing nucleotide sequences for supporting DNA storage. A Call for Proposals was published at the 99th JPEG meeting and based on performance assessment and a descriptive analysis of the solutions that had been submitted, the JPEG DNA Verification Model was created during the 102nd JPEG meeting. A number of core experiments were conducted to validate the Verification Model, and notably, the first Working Draft of JPEG DNA was produced during the 103rd JPEG meeting. Work towards the creation of the specification will start with newly defined core experiments to improve the rate-distortion performance of Verification Model and the robustness to insertion, deletion, and substitution errors. In parallel, efforts are underway to improve the noise simulator produced at the 102nd JPEG meeting to allow the assessment of the resilience to noise in the Verification Model in more realistic conditions and to explore learning-based coding solutions.

JPEG XS

The JPEG Committee is happy to announce that the core parts of JPEG XS 3rd edition are ready for publication as International Standards. The Final Draft International Standard for Part 1 of the standard – Core coding tools – is ready, and Part 2 – Profiles and buffer models – and Part 3 – Transport and container formats – are both being prepared by ISO for immediate publication. At this meeting, the JPEG Committee continued the work on Part 4 – Conformance testing, to provide the necessary test streams and test protocols to implementers of the 3rd edition. Consultation of the Committee Draft for Part 4 took place and a DIS version was issued. The development of the reference software, contained in Part 5, continued and the reference decoder is now feature-complete and fully compliant with the 3rd edition. A Committee Draft for Part 5 was issued at this meeting. Development of a fully compliant reference encoder is scheduled to be completed by July.

Finally, new experimental results were presented on how to use JPEG XS over 5G mobile networks for the wireless transmission of low-latency and high quality 4K/8K 360 degree views with mobile devices and VR headsets. More experiments will be conducted, but first results show that JPEG XS is capable of providing immersive and excellent quality of experience in VR use cases, mainly thanks to its native low-latency and low-complexity properties.

JPEG XL

The performance of JPEG XL on HDR images was investigated and the experiments will continue. Work on a hardware implementation continues, and further improvements are made to the libjxl reference software. The second editions of Parts 1 and 2 are in the final stages of the ISO process and will be published soon.

"The JPEG AI Draft International Standard is a yet another important milestone in an age where AI is rapidly replacing previous technologies. With this achievement, the JPEG Committee has demonstrated its ability to reinvent itself and adapt to new technological paradigms, offering standardized solutions based on latest state-of-the-art technologies.” said Prof. Touradj Ebrahimi, the Convenor of the JPEG Committee.

About JPEG

The Joint Photographic Experts Group (JPEG) is a Working Group of ISO/IEC, the International Organization 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, JPEG XT and more recently, the JPEG XS, JPEG Systems, JPEG Pleno, JPEG XL, JPEG AI and JPEG Trust families of imaging standards.

The JPEG Committee nominally meets four times a year. The next 103rd JPEG Meeting will be held online from 8 to 12 April 2024. More information about JPEG and its work is available at jpeg.org or by contacting of the JPEG Communication Subgroup. If you would like to stay informed about JPEG activities, please subscribe to the jpeg- mailing lists.

Future JPEG meetings are planned as follows:

• No. 104 will be in Sapporo, Japan, from 13 to 19 July 2024
• No. 105 will be in Berlin, Germany, from 7 to 11 October 2024

A zip package containing the official JPEG logo and logos of all JPEG standards can be downloaded here.