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JPEG explores standardization in event-based imaging

The 98th JPEG meeting was held in Sydney, Australia, from the 16th to 20th January 2023. This was a welcome return to face-to-face meetings after a long period of online meetings due to Covid-19. Interestingly, the previous face-to-face meeting of the JPEG Committee was also held in Sydney, in January 2020. The face-to-face 98th JPEG meeting was complemented with online connections to allow the remote participation of those who could not be present.

The recent calls for proposals, such as JPEG Fake Media, JPEG AI and JPEG Pleno Learning Based Point Cloud Coding, resulted in a very dynamic and participative meeting in Sydney, with multiple technical sessions and decisions. Exploration activities such as JPEG DNA and JPEG NFT also produced drafts of future calls for proposals as a consequence of reaching sufficient maturity.

Furthermore, and considering the current trends in machine-based imaging applications the JPEG Committee initiated an exploration on standardization in event-based imaging.

The following summarizes the major achievements during the 98th JPEG meeting.

New JPEG exploration in event-based imaging

The JPEG Committee has started a new exploration activity on event-based imaging named JPEG XE.

Event-based Imaging revolves around a new and emerging image modality created by event-based visual sensors. Event-based sensors are the foundation for a new class of cameras that allow the efficient capture of visual information at high speed while at the same time requiring low computational cost, a requirement which it is common in many machine vision applications. Such sensors are modeled based on the mechanisms of the human visual system for the detection of scene changes and the asynchronous capture of those changes. This means that every pixel works individually to detect scene changes and creates the associated events. If nothing happens, then no events are generated. This contrasts with conventional image sensors, where pixels are sampled in a continuous and periodic manner, with images generated regardless of any changes in the scene and a risk of reacting with delay and even missing quick changes.

The JPEG Committee recognizes that this new image modality opens doors to a large number of applications where capture and processing of visual information is needed. Currently, there is no standard format to represent event-based information, and therefore existing and emerging applications are fragmented and lack interoperability. The new JPEG XE activity focuses on establishing a scope and relevant definitions, collecting use cases and their associated requirements, and investigating the role that JPEG can play in the definition of timely standards in the near- and long-term. To start, an Ad-hoc Group has been established. To stay informed about the activities please join the event based imaging Ad-hoc Group mailing list.

JPEG Fake Media and NFT

In April 2022, the JPEG Committee released a Final Call for Proposals on JPEG Fake Media. The scope of JPEG Fake Media is the creation of a standard that can facilitate the secure and reliable annotation of media assets creation and modifications. During the 98th meeting, the JPEG Committee finalised the evaluation of the six submitted proposals and initiated the process for establishing a new standard.

The JPEG Committee also continues to explore use cases and requirements related to Non-Fungible Tokens (NFTs). Although the use cases for both topics are very different, there is a clear commonality in terms of requirements and relevant solutions. An updated version of the “Use Cases and Requirements for JPEG NFT” was produced and made publicly available for review and feedback.

To stay informed about the activities, please join the mailing list of the Ad-hoc Group and regularly check the JPEG website for the latest information.

JPEG AI

Following the creation of the JPEG AI Verification Model at the previous 97th JPEG meeting, more discussions occurred at the 98th meeting to improve the coding efficiency, and complexity, especially on the decoder side. The JPEG AI VM has several unique characteristics, such as a parallelizable context model to perform latent prediction, decoupling of prediction and sample reconstruction, and rate adaptation, among others. JPEG AI VM shows up to 31% compression gain over VVC Intra for natural content. A new JPEG AI test set was released during the 98th meeting. This is a large dataset for the evaluation of the JPEG AI VM containing 50 images, with the objective of tracking the performance improvements at every meeting. The JPEG AI Common Training and Test Conditions were updated to include this new dataset. In this meeting, it was also decided to integrate several changes into the JPEG AI VM, speeding up training, improving performance at high rates and fixing bugs. A set of core experiments were established at this meeting targeting RD performance and complexity improvements. The JPEG AI VM Software Guidelines were approved, describing the initial setup repository of JPEG AI VM, how to obtain the JPEG AI dataset, and how to run tests and training. A description of the structure of the JPEG AI VM repository was also made available.

JPEG Pleno Learning-based Point Cloud coding

The JPEG Pleno Point Cloud activity progressed at this meeting with a number of technical submissions for improvements to the VM in the area of colour coding, artefact processing and improvements to coding speed. In addition, the JPEG Committee released the “Call for Content for JPEG Pleno Point Cloud Coding” to expand on the current training and test set with new point clouds representing key use cases. Prior to the 99th JPEG Meeting, JPEG experts will promote the Call for Content as well as investigate possible advancements to the VM in the areas of auto-regressive entropy encoding, sparse tensor convolution, meta-data controlled post-filtering of colour and a flexible split geometry and colour coding framework for the VM.

JPEG AIC

During the 98th JPEG meeting in Sydney, Australia, Exploration Study 1 on JPEG AIC was established. This exploration study will collect results from three types of previously standardized subjective evaluation methodologies in order to provide an informative reference for the JPEG AIC submissions to the Call for Contributions that are due by April 1st, 2023. Corrections and additions to the JPEG AIC Common Test Conditions were issued in order to reflect the addition of a new codec for testing content generation and a new anchor subjective quality assessment methodology.

The JPEG Committee is working on the continuation of the previous standardization efforts (AIC-1 and AIC-2) and aims at developing a new standard, known as AIC-3. The new standard will focus on the methodologies for quality assessment of images in a range that goes from high quality to near-visually lossless quality, which are not covered by any previous AIC standards.

JPEG XL

The second editions of JPEG XL Part 1 (Core coding system) and Part 2 (File format) have reached the CD stage. These second editions provide clarifications, corrections and editorial improvements that will facilitate independent implementations. Also, an updated version of the JPEG XL White Paper has been published and is freely available through jpeg.org.

JPEG Systems

The JLINK standard (19566-7:2022) is now published by ISO. JLINK specifies an image file format capable of linking multiple media elements, such as image and text in any JPEG file format. It enables enhanced curated experiences of a set of images for education, training, virtual museum tours, travelogs, and similar visually-oriented content.

The JPEG Snack (19566-8) standard is expected to be published in February 2023. JPEG Snack specifies the coding of audio, picture, multimedia and hypermedia information, enabling a rich, image-based, short-form animated experiences for social media.

The second edition of JUMBF (JPEG Universal Metadata Box Format, 19566-5) is progressing to IS stage; the second edition brings new capabilities and support for additional types of media.

JPEG DNA

The JPEG Committee has been working on an exploration for coding of images in quaternary representations particularly suitable for image archival on DNA storage. The scope of JPEG DNA is the creation of a standard for efficient coding of images that considers biochemical constraints and offers robustness to noise introduced by the different stages of the storage process that is based on DNA synthetic polymers. During the 98th JPEG meeting, a draft Call for Proposals for JPEG DNA was issued and made public, as a first concrete step towards standardisation. The draft call for proposals for JPEG DNA is complemented by a JPEG DNA Common Test Conditions document which is also made public, describing details about the dataset, operating points, anchors and performance assessment methodologies and metrics that will be used to evaluate anchors and future responses to the Call for Proposals. The final Call for Proposals for JPEG DNA is expected to be released at the conclusion of the 99th JPEG meeting in April 2023, after a set of exploration experiments have validated the procedures outlined in the draft Call for Proposals for JPEG DNA and JPEG DNA Common Test Conditions. The deadline for submission of proposals to the Call for Proposals for JPEG DNA is 2 October 2023 with a pre-registration due by 10 July 2023. The JPEG DNA international standard is expected to be published by early 2025.

JPEG XS

The JPEG Committee continued with the definition of JPEG XS 3rd edition. The primary goal of the 3rd edition is to deliver the same image quality as the 2nd edition, but with half of the required bandwidth. The Committee Draft for Part 1 (Core coding system) will proceed to ISO ballot. This means that the standard is now technically defined, and all the new coding tools are known. Most notably, Part 1 adds a temporal decorrelation coding mode to further improve the coding efficiency, while keeping the low-latency and low-complexity core aspects of JPEG XS. This new coding tool is of extreme importance for remote desktop applications and screen sharing. In addition, mathematically lossless coding can now support up to 16 bits precision (up from 12 bits). For Part 2 (Profiles and buffer models), the committee created a second Working Draft and issued further core experiments to proceed and support this work. Meanwhile, ISO approved the creation of a new edition of Part 3 (Transport and container formats) that is needed to address the changes of Part 1 and Part 2.

JPEG 2000

The JPEG committee publishes two sets of guidelines for implementers of JPEG 2000, available on jpeg.org.

The first describes an algorithm for controlling JPEG 2000 coding quality using a single number (Qfactor) between 1 (worst quality) and 100 (best quality), as is commonly done with JPEG.

The second explains how to create, parse and use HTJ2K placeholder passes and HT Sets. These features are an integral part of HTJ2K and enable mathematically lossless transcoding between HT- and J2K-based codestreams, among other applications.

"The interest in event-based imaging has been rising with several products designed and offered by the industry. The JPEG Committee believes in interoperable solutions and has initiated an exploration for standardization of event-based imaging in order to accelerate creation of an ecosystem.” 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 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, JPEG XT and more recently, the JPEG XS, JPEG Systems, JPEG Pleno, JPEG XL and JPEG AI families of imaging standards.

The JPEG Committee nominally meets four times a year. The 97th JPEG Meeting was held online from 24 to 28 October 2022. The next 99th JPEG Meeting will be online from 24 to 28 April 2023.

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 99, will be online from 24-28 April 2023
• No 100, will be in Covilhã, Portugal from 17-21 July 2023

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