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JPEG assesses responses to its Call for Proposals on Lossless Coding of Visual Events

The 107th JPEG meeting was held in Brussels, Belgium, from April 12 to 18, 2025. During this meeting, the JPEG Committee assessed the responses to its call for proposals on JPEG XE, an International Standard for lossless coding of visual events. JPEG XE is being developed under the auspices of three major standardisation organisations: ISO, IEC, and ITU. It will be the first codec developed by the JPEG committee targeting lossless representation and coding of visual events.

The following sections summarise the main highlights of the 107th JPEG meeting.

JPEG XE

This initiative focuses on a new imaging modality produced by event-based visual sensors. This effort aims to establish a standard that efficiently represents and codes events, thereby enhancing interoperability in sensing, storage, and processing for machine vision and related applications.

As a response to the JPEG XE Final Call for Proposals on lossless coding of events, the JPEG Committee received five innovative proposals for consideration. Their evaluation indicated that two among them meet the stringent requirements of the constrained case, where resources, power, and complexity are severely limited. The remaining three proposals can cater to the unconstrained case. During the 107th JPEG meeting, the JPEG Committee launched a series of Core Experiments to define a path forward based on the received proposals as a starting point for the development of the JPEG XE standard.

To streamline the standardisation process, the JPEG Committee will proceed with the JPEG XE initiative in three distinct phases. Phase 1 will concentrate on lossless coding for the constrained case, while Phase 2 will address the unconstrained case. Both phases will commence simultaneously, although Phase 1 will follow a faster timeline to enable a timely publication of the first edition of the standard. The JPEG Committee recognises the urgent industry demand for a standardised solution for the constrained case, aiming to produce a Committee Draft by as early as July 2025. The third phase will focus on lossy compression of event sequences. The discussions and preparations will be initiated soon.

In a significant collaborative effort between ISO/IEC JTC 1/SC 29/WG1 and ITU-T SG21, the JPEG Committee will proceed to specify a joint JPEG XE standard. This partnership will ensure that JPEG XE becomes a shared standard under ISO, IEC, and ITU-T, reflecting their mutual commitment to developing standards for event-based systems.

Additionally, the JPEG Committee is actively discussing and exploring lossy coding of visual events, exploring future evaluation methods for such advanced technologies. Stakeholders interested in JPEG XE are encouraged to access public documents available at jpeg.org. Moreover, a joint Ad-hoc Group on event-based vision has been formed between ITU-T Q7/21 and ISO/IEC JTC1 SC29/WG1, paving the way for continued collaboration leading up to the 108th JPEG meeting. Interested parties are invited to join the public mailing list for the event-based vision joint Ad-hoc Group to stay updated on this exciting initiative.

JPEG AI

At the 107th JPEG meeting, JPEG AI discussions focused around conformance (JPEG AI Part 4), which has now advanced to the Draft International Standard (DIS) stage. The specification defines three conformance points — namely, the decoded residual tensor, the decoded latent space tensor (also referred to as feature space), and the decoded image. Strict conformance for the residual tensor is evaluated immediately after entropy decoding, while soft conformance for the latent space tensor is assessed after tensor decoding. The decoded image conformance is measured after converting the image to the output picture format, but before any post-processing filters are applied. Regarding the decoded image, two types have been defined: conformance Type A, which implies low tolerance, and conformance Type B, which allows for moderate tolerance.

During the 107th JPEG meeting, the results of several subjective quality assessment experiments were also presented and discussed, using different methodologies and for different test conditions, from low to very high qualities, including both SDR and HDR images. The results of these evaluations have shown that JPEG AI is highly competitive and, in many cases, outperforms existing state-of-the-art codecs such as VVC Intra, AVIF, and JPEG XL. A demonstration of an JPEG AI encoder running on a Huawei Mate50 Pro smartphone with a Qualcomm Snapdragon 8+ Gen1 chipset was also presented. This implementation supports tiling, high-resolution (4K) support, and a base profile with level 20. Finally, the implementation status of all mandatory and desirable JPEG AI requirements was discussed, assessing whether each requirement had been fully met, partially addressed, or remained unaddressed. This helped to clarify the current maturity of the standard and identify areas for further refinements.

JPEG Trust

Building on the publication of JPEG Trust (ISO/IEC 21617) Part 1 – Core Foundation in January 2025, the JPEG Committee approved a Draft International Standard (DIS) for a 2nd edition of Part 1 – Core Foundation during the 107th JPEG meeting. This Part 1 – Core Foundation 2nd edition incorporates the signalling of identity and intellectual property rights to address three particular challenges:

• achieving transparency, through the signaling of content provenance
• identifying content that has been generated either by humans, machines or AI systems, and
• enabling interoperability, for example, by standardising machine-readable terms of use of intellectual property, especially AI-related rights reservations.

Additionally, the JPEG Committee is currently developing Part 2 – Trust Profiles Catalogue. Part 2 provides a catalogue of trust profile snippets that can be used either on their own or in combination for the purpose of constructing trust profiles, which can then be used for assessing the trustworthiness of media assets in given usage scenarios. The Trust Profiles Catalogue also defines a collection of conformance points, which enables interoperability across usage scenarios through the use of associated trust profiles.

The Committee continues to develop JPEG Trust Part 3 – Media asset watermarking to build out additional requirements for identified use cases, including the emerging need to identify AIGC content.

Finally, during the 107th meeting, the JPEG Committee initiated a Part 4 – Reference software, which will provide reference implementations of JPEG Trust to which implementers can refer to in developing trust solutions based on the JPEG Trust framework.

JPEG AIC

The JPEG AIC Part 3 standard (ISO/IEC CD 29170-3), has received a revised title “Information technology — JPEG AIC Assessment of image coding — Part 3: Subjective quality assessment of high-fidelity images”. At the 107th JPEG meeting, the results of the last Core Experiments for the standard and the comments on the Committee Draft of the standard were addressed. The draft text was thoroughly revised and clarified, and has now advanced to the Draft International Standard (DIS) stage.

Furthermore, Part 4 of JPEG AIC deals with objective quality metrics, also of high-fidelity images, and at the 107th JPEG meeting, the technical details regarding anchor metrics as well as the testing and evaluation of proposed methods were discussed and finalised. The results have been compiled in the document “Common Test Conditions on Objective Image Quality Assessment”, available on the JPEG website. Moreover, the corresponding Final Call for Proposals on Objective Image Quality Assessment (AIC-4) has been issued. Proposals are expected at the end of Summer 2025. The first Working Draft for Objective Image Quality Assessment (AIC-4) is planned for April 2026.

JPEG Pleno

The JPEG Pleno Light Field activity discussed the DoCR for the submitted Committee Draft (CD) of the 2nd edition of ISO/IEC 21794-2 (“Plenoptic image coding system (JPEG Pleno) Part 2: Light field coding”). This 2nd edition integrates AMD1 of ISO/IEC 21794-2 (“Profiles and levels for JPEG Pleno Light Field Coding”) and includes the specification of a third coding mode entitled Slanted 4D Transform Mode and its associated profile. It is expected that at the 108th JPEG meeting this new edition will advance to the Draft International Standard (DIS) stage.

Software tools have been created and tested to be added as Common Test Condition Tools to a reference software implementation for the standardized technologies within the JPEG Pleno framework, including the JPEG Pleno Part 2 (ISO/IEC 21794-2).

In the framework of the ongoing standardisation effort on quality assessment methodologies for light fields, significant progress was achieved during the 107th JPEG meeting. The JPEG Committee finalised the Committee Draft (CD) of the forthcoming standard ISO/IEC 21794-7 entitled JPEG Pleno Quality Assessment – Light Fields, representing an important step toward the establishment of reliable tools for evaluating the perceptual quality of light fields. This CD incorporates recent refinements to the subjective light field assessment framework and integrates insights from the latest core experiments.

The Committee also approved the Final Call for Proposals (CfP) on Objective Metrics for JPEG Pleno Quality Assessment – Light Fields. This initiative invites proposals of novel objective metrics capable of accurately predicting perceived quality of compressed light field content. The detailed submission timeline and required proposal components are outlined in the released final CfP document. To support this process, updated versions of the Use Cases and Requirements (v6.0) and Common Test Conditions (v2.0) related to this CfP were reviewed and made available. Moreover, several task forces have been established to address key proposal elements, including dataset preparation, codec configuration, objective metric evaluation, and the subjective experiments.

At this meeting, ISO/IEC 21794-6 (“Plenoptic image coding system (JPEG Pleno) Part 6: Learning-based point cloud coding”) progressed to the balloting of the Final Draft International Standard (FDIS) stage. Balloting will end on the 12th of June 2025 with the publication of the International Standard expected for August 2025.

The JPEG Committee held a workshop on Future Challenges in Compression of Holograms for XR Applications organised on April 16th, covering major applications from holographic cameras to holographic displays. The 2nd workshop for Future Challenges in Compression of Holograms for Metrology Applications is planned for July.

JPEG DNA

The JPEG Committee continues to develop JPEG DNA, an ambitious initiative to standardize the representation of digital images using DNA sequences for long-term storage. Following a Call for Proposals launched at its 99th JPEG meeting, a Verification Model was established during the 102nd JPEG meeting, then refined through core experiments that led to the first Working Draft at the 103rd JPEG meeting.

At its 105th JPEG meeting, JPEG DNA was officially approved as a new ISO/IEC project (ISO/IEC 25508), structured into four parts: Core Coding System, Profiles and Levels, Reference Software, and Conformance. The Committee Draft (CD) of Part 1 was produced at the 106th JPEG meeting.

During the 107th JPEG meeting, the JPEG Committee reviewed the comments received on the CD of JPEG DNA standard and prepared a Disposition of Comments Report (DoCR). The goal remains to reach International Standard (IS) status for Part 1 by April 2026.

On this occasion, the official JPEG DNA logo was also unveiled, marking a new milestone in the visibility and identity of the project.

JPEG XS

The development of the third edition of the JPEG XS standard is nearing its final stages, marking significant progress for the standardisation of high-performance video coding. Notably, Part 4, focusing on conformance testing, has been officially accepted by ISO and IEC for publication. Meanwhile, Part 5, which provides reference software, is presently at Draft International Standard (DIS) ballot stage.

In a move that underscores the commitment to accessibility and innovation in media technology, both Part 4 and Part 5 will be made publicly available as free standards. This decision is expected to facilitate widespread adoption and integration of JPEG XS in relevant industries and applications.

Looking to the future, the JPEG Committee is exploring enhancements to the JPEG XS standard, particularly in supporting a master-proxy stream feature. This feature enables a high-fidelity master video stream to be accompanied by a lower-resolution proxy stream, ensuring minimal overhead. Such functionalities are crucial in optimising broadcast and content production workflows.

JPEG RF

The JPEG RF activity issued the proceedings of the Joint JPEG/MPEG Workshop on Radiance Fields which was held on the 31st of January and featured world-renowned speakers discussing Neural Radiance Fields (NeRF) and 3D Gaussian Splatting (3DGS) from the perspective of both academia, industry, and standardisation groups. Video recordings and all related material were made publicly available on the JPEG website. Moreover, an improved version of the JPEG RF State of the Art and Challenges document was proposed, including an updated review of coding techniques for radiance fields as well as newly identified use cases and requirements. The group also defined an exploration study to investigate protocols for subjective and objective quality assessment, which are considered to be crucial to advance this activity towards a coding standard for radiance fields.

"A cost-effective and interoperable event-based vision ecosystem requires an efficient coding standard. The JPEG Committee embraces this new challenge by initiating a new standardisation project to achieve this objective.” 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 SG21, formerly SG16), responsible for the popular JPEG, JPEG 2000, JPEG XR, JPSearch, JPEG Systems, JPEG XT and more recently, the JPEG XS, JPEG Pleno, JPEG XL, JPEG AI, JPEG Trust and JPEG DNA families of imaging standards.

The JPEG Committee nominally meets four times a year. The next 108th JPEG Meeting will be held in Dajeon, Korea, from 28 June to 4 July 2025. 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. 108 will be in Daejeon, Korea, from 28 June to 4 July 2025
• No. 109 will be in Nuremberg, Germany, from 11 to 17 October 2025

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