MPEG Column: 155th MPEG Meeting

The 155th MPEG meeting took place in Geneva, Switzerland, from July 13 to 17, 2026. The official MPEG press release can be found here. This report highlights key outcomes from the meeting, with a focus on research directions relevant to the ACM SIGMM community:

  • Gaussian Splat Coding Use Cases and Current Status
  • Call for Proposals on Media Authenticity and Provenance Indication
  • Joint Call for Proposals on video compression with capability beyond VVC
  • Joint ITU-T SG 21 and ISO/IEC JTC 1/SC 29 Workshop on Media Streaming Services
  • Exploration on Systems technologies for AI-based media standards (SyfAI)

Gaussian Splat Coding Use Cases and Current Status

The previous MPEG column [MPEG154] introduced MPEG’s Gaussian Splat Coding (GSC) exploration, its two tracks (I-3DGS and A-3DGS), and a first set of 27 draft use cases. At the 155th meeting, WG 2 (Technical Requirements) approved an updated document (WG 2 N531) that drops the draft qualifier and adds two use cases.

The additions matter less for their number than their nature: both concern storage and delivery rather than compression. Use case 28 stores a static splat asset in a single file together with a cover image, thumbnail, and audio annotation, so that a capable receiver renders it interactively while a legacy receiver displays the cover image, with no modification of the file. Use case 29 is the temporal counterpart, delivering a dynamic splat track by HTTP adaptive streaming alongside synchronized audio, a pre-rendered video track serving as preview and fallback, and timed text, with representations offered per bitrate, level of detail, spherical harmonics subset, or attribute subset. The application-oriented use cases are unchanged, although the derived requirements are being refactored, notably by separating attribute subset scalability from random access.

GSC remains an exploration activity, but a busy one: 83 input contributions and nine Joint Exploration Experiments re-conducted across WG 2, WG 4 (Video Coding), WG 5 (Joint Video Experts Team, JVET), and WG 7 (3D Graphics and Haptics), with WG 1 (JPEG) now engaged on quality metrics and WG 4 examining Neural Network Coding (NNC) as a compression tool. On the fast track, GS4 (Video-based Point Cloud Compression, V-PCC, Amd. 1) and GS5 (Geometry-based Point Cloud Compression, G-PCC, Amd. 1) progress on reference software and conformance, while the JVET codec track carries five competing proposals. The Call for Proposals (CfP) still has no date, and I-3DGS planning is more mature than A-3DGS. The clearest message from the meeting is that single-frame compression is essentially solved and that the difficulty and the expected gain now lie in dynamic content.

Research aspects: Temporal coding is no longer one open question among many, but the central one, covering inter-prediction for anisotropic primitives, deformation models, and primitive correspondence across frames. Quality assessment remains unresolved: current test conditions score rendered views with peak signal-to-noise ratio (PSNR), structural similarity (SSIM), and learned perceptual image patch similarity (LPIPS) along a pose trace, a fragile proxy for artifacts such as floaters and popping; the involvement of JPEG makes this a good moment to contribute. Use case 29 gives the streaming question a concrete form: when quality varies along several orthogonal axes at once, what is the right abstraction for a representation, and what should an adaptation algorithm optimize?

Call for Proposals on Media Authenticity and Provenance Indication

At the 155th meeting, WG 2 approved a CfP on media authenticity and provenance indication with the MPEG Systems technologies (WG 2 N535), following an exploration phase in WG 3 (Systems) that produced requirements, a gap analysis, and several technical proposals (WG 3 N1842, attached to the call). The scope is the system layer: carriage and signaling of metadata that allows a receiver to verify that a media asset comes from a trusted producer and to convey provenance information, rather than the definition of a provenance language itself.

Three interfaces are addressed, namely (i) elementary streams and non-timed items, (ii) the file format level (ISO Base Media File Format (ISOBMFF) and Common Media Application Format (CMAF)), and (iii) packaged delivery (Dynamic Adaptive Streaming over HTTP (DASH), CMAF, MPEG Media Transport (MMT), and MPEG-2 Transport Stream (MPEG-2 TS)). The use cases span deepfakes and manipulated news media, forgery in insurance claims, surveillance and investigations, labeling of AI-generated content, and legitimate modifications such as editing, transcoding, ad insertion, and archival preservation. Detecting whether an asset is fake without embedded data is explicitly out of scope.

A response may be a complete solution or a single tool addressing one or more requirements, and is evaluated on requirement coverage, computational complexity, the bandwidth needed to convey the authenticity information, compatibility and backward compatibility with existing MPEG standards, and extensibility, with self-evaluation tables provided in the annexes. Proposals are submitted as input contributions to the 157th meeting in Brisbane, Australia, by January 13, 2027. Review at that meeting will produce one or more working drafts or new work item proposals, and the preliminary development plan targets Committee Draft (CD) or Committee Draft Amendment (CDAM) at the 158th meeting, Draft International Standard (DIS) or Draft Amendment (DAM) at the 159th, and Final Draft International Standard (FDIS) or Final Draft Amendment (FDAM) in early 2028.

Research aspects: The requirements make this more interesting than a signing exercise. A conventional signature breaks on any bit change, yet the call demands that verification survive transcoding, dropped scalability layers, representation switching, splicing, late binding, and loss of frames or audio, and that the unmodified remainder of a presentation stay verifiable after an authorized edit. Designing verification structures with that granularity and quantifying their overhead per segment against the added latency in live scenarios is an open problem at the intersection of cryptography and streaming systems. A second question is joint verification: establishing that a given audio track was the one the producer intended to accompany a given video, including their synchronization, cannot be achieved by signing each file separately. Finally, interoperability with provenance schemes defined elsewhere, and the question of what a receiver should do with a verification result, leave room for work on usable trust signaling.

Joint Call for Proposals on Video Compression with Capability Beyond VVC

The draft of this call was described in the previous MPEG column [MPEG154], and JVET has now issued the final version (JVET-AQ2021 [JVET-AQ2021]), approved at its 43rd meeting in Geneva in July 2026. The target is video coding technology that significantly exceeds Versatile Video Coding (VVC) in compression, implementability, applicability across content types, and features such as latency, robustness, and scalability, benchmarked against the VVC Main 10 profile. Four test cases are defined: one for improved compression without runtime limits, and three in which the aggregate encoder run time is constrained to 5x, 1x, and 0.2x that of the VVC Test Model (VTM) anchor. All are evaluated over seven categories covering (i) standard dynamic range (SDR) random access at ultra-high definition (UHD) and (ii) at high definition (HD), (iii) SDR low delay HD, (iv) high dynamic range (HDR) with perceptual quantizer (PQ) and (v) with hybrid log-gamma (HLG) transfer functions, (vi) gaming, and (vii) user-generated content. A separate track invites technology offering additional functionality, together with proposals on how its benefit should be assessed.

Formal subjective testing uses degradation category rating, with objective results reported as PSNR, multiscale SSIM (MS-SSIM), and, for PQ content, weighted PSNR. The schedule is tight: anchors have been available since May 2026, registration runs from August 1 to September 1, 2026, and the main package of bitstreams, reconstructed sequences, and binaries must reach the test coordinator on physical media by October 26, 2026. Subjective assessment then runs until late December, blind cross-checking by other proponents is mandatory, and proposals are evaluated at the 45th JVET meeting in January 2027, with an initial test model selected during 2027 and the standard targeted for October 2029. Participation is not free: up to EUR 20k per test case is charged to cover the hiring of test subjects.

Research aspects: Two design choices in the call are worth attention. First, a supplemental set of sequences is disclosed to proponents only after the decoder binaries have been submitted, and results on it are due six weeks later, which turns the call into a held-out generalization test. Read together with the ban on training on test sequences and the obligation to disclose training material, this makes out-of-domain behavior of learned coding tools measurable at scale, and reporting it well is a contribution in itself. Second, run time is aggregated as the sum over threads, which measures total compute rather than latency and therefore reads very differently for a massively parallel or GPU-resident design than for a sequential one. How to characterize the rate, distortion, and complexity trade-off fairly across such architectures, and how to value functionality such as scalability or error resilience against a plain bitrate gain, are open questions the call poses rather than answers.

Joint ITU-T SG 21 and ISO/IEC JTC 1/SC 29 Workshop on Media Streaming Services

On July 14, 2026, ITU-T SG 21 and MPEG Systems held a joint half-day workshop in Geneva, collocated with their meetings, on “Media Streaming Service, What’s next” (call for presentations, program). The premise was that after the transitions from analog to digital, enabled by MPEG-2 Systems, and from broadcast to over the top (OTT), enabled by MPEG-DASH, integrated networks, edge computing, and AI are driving another shift, and that both bodies wanted industry views before committing to new work. On challenges, Netflix spoke on the shortcomings and evolution of ISOBMFF, Bitmovin on where streaming trends meet the container, ETRI on future streaming services, and Huawei on ultra-low latency communication and streaming. On opportunities, 5G-MAG addressed standards and open source, DVB heterogeneous networks, and 3GPP SA4 delivery beyond OTT. The closing session was an open mic with questions and answers from both speakers and the audience.

The wrap-up set the existing systems standards, namely MPEG-2 TS, ISOBMFF, DASH, and CMAF as well as the volumetric, scene, and augmented reality (AR) formats, plus ongoing work on authenticity, SyfAI (see below), common metadata, and Gaussian splats, against what industry actually asked for: low latency, low overhead, AI-driven media, and open source software. The resulting agenda is an exploration of a better or new container format, an analysis of overhead, processing-friendly metadata, including JSON and ontology issues, WebCodecs integration, and ingest. Just as notable are the conclusions about process: more open access and industry involvement, faster turnaround, possibly a new home or outlet for this work, and software with interoperability testing from day one rather than reference software at the end. Three ad hoc groups were set up: (i) on MP4, DASH, and file formats, reviewing ISOBMFF against emerging transports and the delivery of AI input and output data; (ii) on vision, analyzing bottlenecks and requirements beyond ISOBMFF; and (iii) on working methods.

Research aspects: Two of these items are directly researchable. Container overhead is asserted more often than measured, and as segments shrink toward frame level for low latency, the ratio of container to media bytes grows; a careful comparison across ISOBMFF, CMAF, and object-based transports at equal latency would inform the exploration rather than follow it. Media over QUIC (MOQ) is the bigger change, since it replaces the segment with the object as the unit of delivery and pulls streaming and real-time communication into a single design space, which reopens rate adaptation, interaction with congestion control, caching, and relay behavior, and the question of what a container still contributes when the transport itself frames media. Carrying AI input and output data alongside media, finally, links this work to coding for machines and to semantic streaming.

Exploration on Systems Technologies for AI-based Media Standards (SyfAI)

Several MPEG coding standards now put a neural network inside the decoder, among them video and feature coding for machines, AI-based point cloud coding, and neural network coding. The previous MPEG column [MPEG154] described that coding side through the MPEG-AI vision document. SyfAI, an MPEG Systems exploration started at the 153rd MPEG meeting, asks the complementary and much less glamorous question: what does the surrounding infrastructure have to do so that such content can actually be stored, delivered, and played back interoperably? The underlying shift is that a media file has traditionally been self-contained, meaning that a conforming decoder and the bitstream are sufficient. Once the decoder depends on a trained model that may be selected, delivered, or updated separately, that assumption no longer holds, and the system layer has to say how a player learns which model it needs, how that model reaches it, and how both sides can be sure they are using the same one. Work so far has advanced on the most concrete piece, namely storing video coding for machines content in the MPEG file format, while proposals for carrying compressed neural networks were sent back for clearer use cases. The more interesting development is a new thread on an AI update framework, opened jointly with WG 7, which collects five topics: (i) a format for AI parameter data, (ii) a manifest for updating parameters, (iii) a repository to serve them, (iv) integrity checking, and (v) bit exactness together with conformance.

Research aspects: Each of those topics is a research problem in its own right. Distributing and updating models alongside media turns into a delivery question that looks familiar but has not been studied: when to fetch an update, how to cache and version models, what a manifest must express about capability and compatibility, and how to treat weights as a second class of asset next to the media. Conformance is harder, because a standard normally guarantees that every decoder produces identical output, whereas neural inference varies with library and hardware, so deciding what conformance means and how to test it remains open and extends the reproducibility concerns already visible in MPEG-AI. A repository of updatable weights is also an attack surface, which is why this work sits naturally beside the media authenticity call discussed above: signing and verifying a model raises the same questions one level down from signing content. And because the choice of where a model lives affects how quickly playback can start and how smoothly a player can switch, the apparently dry container questions have measurable consequences for the quality of experience (QoE).

Concluding Remarks

Taken together, the five items show MPEG engaging early with technologies whose momentum comes from outside the committee. With Gaussian splatting, it is compressing a representation that already has a renderer and a user base, which is a better starting point than earlier attempts at three-dimensional video had, even if wider adoption will depend on capture and display ecosystems as much as on coding efficiency. The authenticity call is scoped pragmatically at establishing origin, which is achievable in the near term and provides the system-level plumbing that regulation and industry are asking for. The call for video coding beyond VVC visibly reflects deployment experience, with runtime-constrained test cases treating practicality as a first-class criterion, while questions of licensing and market uptake sit largely outside MPEG itself. In systems, the joint workshop and the new ad hoc groups show a willingness to re-examine long-standing assumptions as transports such as MOQ emerge, and SyfAI stakes out the system-level questions of the AI era before they become urgent. For our community, the result is an unusually rich set of open problems in evaluation and methodology.

The 156th MPEG meeting will be held in Hangzhou, China, from October 19 to 23, 2026. Click here for more information about MPEG meetings and ongoing developments.

References

  • [MPEG154] C. Timmerer. 2026. MPEG Column: 154th MPEG Meeting. SIGMultimedia Rec. 18, 2, Article 8 (April 2026).
  • [JVET-AQ2021] J.-R. Ohm, M. Wien, F. Bossen. 2026. Joint Call for Proposals on video compression with capability beyond VVC, JVET-AQ2021 (July 2026).

The 4th Edition of Spring School on Social XR, ACM Seasonal School organised by CWI

The 4th edition of the Spring School on Social XR organised by Distributed and Interactive Systems group (DIS) at CWI in Amsterdam took place from 20 to 23 April 2026 and attracted 31 students from various disciplines, including technology, the social sciences, and the humanities. The event was organized by Silvia Rossi, Irene Viola, Thomas Röggla, and Pablo Cesar from CWI, and Omar Niamut from TNO. Also this year, it was co-sponsored by ACM SIGMM, thanks to the founding for Special initiatives, and it has been recognised also as an ACM Europe Council Seasonal School.

Students and organisers of the 4th Spring School on Social XR, 2026

Across 11 lectures (4 of them open to public) and 3 hands‑on workshops led by 12 international instructors, participants had the possibility to have cross-domain interactions on Social XR. The program covered a broad range of topics at the intersection of immersive technology, human behavior and system design: trust and safety in social virtual environments, ethical and human-centered approaches to XR design, affective computing and mental health applications, socially intelligent and AI-driven virtual humans, haptics and tactile interaction, volumetric video technologies, mobility research in XR, and the future of communications in education and research. Together, they provided a multidisciplinary perspective that went beyond knowledge transfer: bringing together early-career researchers from diverse backgrounds to create the groundwork for new collaborations and a growing community around Social XR.

Students presenting themself during first day.

List of talks and workshops:

  • “The Future of Communications and Interaction” by Gül Akcaova and Mark Cole— workshop
  • “Towards Ethical, Human-Centered XR Experiences: From Theory to Practice” by Katrien de Moor — workshop
  • “Volumetric Video Technologies for Real-Time Immersive Communication” by Guillaume Gautier and Alexandre Mercat — workshop 
  • “Studying Mobility in eXtended Reality” by Yan Feng
  • “A Brief History of Virtual Humans” by Marco Gillies
  • “Affective Social XR and Intercorporeal Regulation: A Multi-Method Approach to Supporting Mental Health and Well-being” by Alexandra Kitson
  • “Designing Inclusive XR: Experience from Day-to-Day Industrial Research” by Marta Orduna
  • “Socially Intelligent Digital Humans” by Chirag Raman
  • “Tactile Extended Reality: The Role of Haptics in Immersive Interactive Applications” by Maria Torres Vega
  • “Trust and Safety in Social XR” by D. Yvette Wohn
  • “AI-driven Animation for Virtual Humans” by Zerrin Yumak

JPEG Column: 111th JPEG Meeting

JPEG DNA reaches Draft International Standard stage at the 111th JPEG meeting

The 111th JPEG meeting was held in virtual mode from 13 to 17 April 2026.

This meeting was marked by several major achievements. JPEG DNA, the first image format that uses a quaternary representation suitable for synthesis into nucleotide sequences to be used for storage on DNA support, reached the Draft International Standard (DIS) stage. This was ensured after a successful wet-lab experiment, including DNA synthesis/sequencing that allowed a test of reliability in real conditions.

Furthermore, the DIS stage was also reached for JPEG XE, the first International standard for coding of visual events; JPEG Pleno Light Field Quality Assessment, which establishes a model for quality evaluation of encoded light fields; JPEG Trust Media Asset Watermarking, which provides watermarking support to media asset authenticity; and JPEG Trust reference software, which will provide a valuable tool for the development of applications using this family of standards. Furthermore, JPEG Pleno Light Field coding, 2nd edition, reached the Final Draft International Stage.

The following sections summarize the main highlights of the 111th JPEG meeting.

  • JPEG DNA reaches DIS stage.
  • JPEG XE reaches DIS stage.
  • JPEG Trust part 4 – Reference Software – reaches DIS stage.
  • JPEG Pleno Light Field Quality Assessment reaches DIS.
  • JPEG XS Part 2 prepares a new amendment to define a new raw Bayer profile.
  • JPEG RF explores methodologies for quality evaluation of Gaussian Splatting coding distortions.
  • JPEG AI explores machine-oriented applications in the compressed domain.

JPEG DNA

At its 111th meeting, the JPEG Committee reached a major milestone with JPEG DNA Part 1 (ISO/IEC 25508-1) advancing to the Draft International Standard (DIS) stage. This achievement marks the culmination of a multi-year standardization effort, beginning with the Final Call for Proposals at the 99th JPEG meeting and proceeding through the creation of the Verification Model at the 102nd meeting, the first Working Draft at the 103rd meeting, the Committee Draft, and the study DIS text produced at the 108th meeting. With DIS now reached, the core technical specification for the efficient coding of images into quaternary representations suitable for archival on DNA synthetic polymers is frozen for the first edition of the standard. The JPEG Committee expects publication of Part 1 an International Standard before the end of 2026.

The DIS milestone was accompanied by the successful completion of wet-lab experiments initiated at the 109th JPEG meeting and whose synthesis and sequencing phases were carried out between the 110th and 111th meetings. The sequenced results from the independent parties have now been delivered to the JPEG Committee and analyzed. The experiments confirmed that the information recorded in the DNA solution was successfully extracted and that the corresponding compressed images were correctly decoded, in accordance with the end-to-end workflow defined in the specification, including biochemical constraints, the recovery mechanism used to cope with the noise introduced by the synthesis and sequencing processes, and the procedures for reading the encoded image information back from the synthesized oligonucleotides. These results provide concrete validation that the current specification of JPEG DNA satisfies the conditions required for applications relying on the current state of the art in DNA synthesis and sequencing and represents the first end-to-end demonstration of the standard on real biological media.

JPEG XE

The joint effort between ITU-T SG21 and ISO/IEC JTC1/SC29/WG1 on JPEG XE is ongoing, with JPEG XE Part 1 ready to become the first of a series of standards for coding of visual events. During its 111th meeting, the JPEG Committee made substantial progress on the ongoing development of the additional JPEG XE Parts 2, 3, 4, and 5. Technical discussions advanced the work on Part 2, which will define Profiles and Levels, as well as a normative buffer model to ensure safe and interoperable decoder operation across implementations. Further enhancements were made to the code of the open source reference software, which will be published under Part 3 as a proof‑of‑concept and conformance testing implementation. Preparatory work commenced for Part 4, which will establish the structure and scope of formal conformance testing and will become the focus during the coming months. Finally, consensus was reached about Part 5, where the JPEG Committee converged on an ISOBMFF‑based file format design supporting efficient storage, streaming, and precise event timestamping. The JPEG Committee, mandated for the joint effort between ISO/IEC/JTC1/SG29 and ITU-T SG21, remains committed to the development of a comprehensive and industry-aligned standard that meets the growing demand for event-based vision technologies. This collaborative approach underscores a shared vision for a unified, international standard to accelerate innovation and interoperability in this emerging field. The JPEG XE joint AHG (ITU-T SG21 and ISO/IEC JTC1 SC29 WG1) was reestablished to continue the JPEG XE standards development. If you are interested, please consider joining this public joint AHG.

JPEG Trust

There have been major advances in all parts of JPEG Trust. Recently, a 2nd edition of JPEG Trust Part 1 – Core Foundation, was published to accommodate assertions for attributions (based on The Dublin Core metadata element set, ISO 15836-1:2017) and declarations of rights (based on the W3C ODRL Information Model 2.2). JPEG Trust Part 2 – Trust profiles and reports extends the framework specified in Part 1 with extended functionalities for Trust Profiles and Trust Reports; it has now entered the DIS stage. JPEG Trust Part 3 – Media asset watermarking, incorporating specific tools and associated assessment methodologies for usage scenarios that rely on invisible watermarking of media assets, has now been released for DIS balloting. The DIS for JPEG Trust Part 4 – Reference Software was also released for balloting; this Part will be extended in the future with additional implementations and test datasets.

A first JPEG Trust Summit is planned on 12-13 November 2026 in London. More information on upcoming events related to JPEG Trust can be found here.

JPEG Pleno

The JPEG Pleno Light Field activity analyzed the DoCR for the Final Draft International Standard (FDIS) 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 112th JPEG meeting this new edition will become an International Standard (IS).

The JPEG committee made significant progress in JPEG Pleno Light Field Quality Assessment (Part 7) activities. Key developments were achieved, including the review and finalization of the DIS text for ISO/IEC 21794-7, which was approved for registration at this meeting. Core experiments on light field quality assessment were presented and discussed, contributing to the validation of subjective testing frameworks and the further development of objective metrics, including improvements to learning-based approaches.

JPEG XS

JPEG XS, the image and video compression format for transmitting visually lossless, high-quality pictures with minimal latency and low resource consumption, is currently in a mature state. Two amendments, JPEG XS Part 1 and Part 2, are expected to be published in July of 2026. JPEG XS AMD1 provides a new syntax to allow embedding of user-defined metadata at the slice-level in addition to the frame-level that was already possible. JPEG XS Part 2 amendment AMD1 provides additional levels and sublevels, as well as a new frame buffer level, to better support proxy-stream extraction use cases. At its 111th meeting, the JPEG Committee prepared another amendment (AMD2) for JPEG XS Part 2 to define a new raw Bayer profile, called CMainBayer, that supports reducing the implementation complexity compared to the MainBayer profile. It will be an inclusive profile, meaning that existing HighBayer and MainBayer implementations will be capable of decoding the newly proposed CMainBayer profile. A core experiment was issued to verify the proposed parameters and the impact on the coding performance and the potential resource savings. The plan is to issue the DAMD2 text at the next JPEG meeting in July 2026.

JPEG RF

At its 111th meeting, the JPEG committee continued its active exploration of technologies for radiance field representations. Significant progress was achieved, particularly in the areas of quality assessment and visualization methods for radiance fields, where an exploration study was presented and discussed, contributing to a deeper understanding of how radiance field content should be rendered and evaluated in subjective experiments. These discussions support the development of reliable and practical assessment frameworks in preparation for a future Call for Proposals. JPEG also initiated a new exploration focusing on the identification of suitable objective quality metrics and subjectively annotated datasets, as well as the evaluation of metrics’ performance for radiance field content. This work builds on prior efforts covering coding methods, subjective assessment protocols, and trajectory design, and aims to support the development of standardized evaluation methodologies.

In parallel, outreach activities continued to expand community engagement and support the preparation of dissemination materials, while work progresses toward revising the JPEG RF Common Test Conditions. The outcome of these efforts will guide future standardization in radiance field coding.

JPEG AI

At its 111th meeting, the JPEG Committee continued advancing JPEG AI. The Committee reviewed progress in key JPEG AI Core Experiments, including energy-consumption analysis, and bit-exact reconstruction, with results showing promising implementation trade-offs across CPU, GPU, and FPGA platforms. The FPGA implementation was identified as the most energy-efficient, while GPU execution provided the lowest latency. JPEG also reported progress on compressed-domain machine analysis, where JPEG AI latent representations enabled earth-observation segmentation with nearly ten times fewer model parameters. Further work will continue through new Core Experiments on energy consumption, bit-exact reconstruction, and objective and subjective evaluation. This activity reinforces JPEG AI’s role as the first International Standard for end-to-end learning-based image coding and as a technology relevant to both human visualization and machine-oriented applications.

Final Quote

“At the 111th meeting, five JPEG standardization projects reached DIS stage, a testimony to the commitment of its experts who work tirelessly towards the development of efficient standardized solutions that guarantee interoperability between emerging imaging products and services,” said Prof. Touradj Ebrahimi, the Convenor of the JPEG Committee.

VQEG Column: VQEG Meeting December 2025

Introduction

The Video Quality Experts Group (VQEG) fall plenary meeting took place online from December 15th to 19th 2025. More than 130 participants registered to the meeting, coming from industry and academic institutions worldwide.

The meeting was dedicated to present updates and discuss about topics related to the ongoing projects within VQEG. All the related information, minutes, and files from the meeting are available online in the VQEG meeting website, and video recordings of the meeting are available in Youtube.

Several of the addressed topics can be of interest for the SIGMM community working on quality assessment, such as the shift toward Artificial Intelligence (AI) and neural-based media processing, requiring updated evaluation methodologies; the increasing emphasis on immersive media and XR systems, including the recently published recommendation ITU-T P.1321; the growing interest in user-centric Quality of Experience (QoE) modeling, including individualized quality prediction; and the continued development of datasets, tools, and statistical frameworks for reproducible research.

Readers of these columns interested in the ongoing projects of VQEG are encouraged to subscribe to their corresponding reflectors to follow the activities going on and to get involved in them

Overview of VQEG Projects

Immersive Media Group (IMG)

The IMG group continues its focus on quality assessment for immersive technologies. In this meeting, Marta Orduna (Nokia XR Lab, Spain) and Jesús Gutiérrez (Universidad Politécnica de Madrid, Spain) reported updates on the multi-laboratory test plan and next steps for immersive communication assessment. In this sense, a major achievement of the group was the publication of the recommendation ITU-T P.1321 “Interactive test methods for subjective assessment of extended reality communications”, approved in October 2025. In addition, the following presentations related to IMG topics were delivered:

  • Felix Immohr (RWTH Aachen University, Germany) introduced the ICS-MR dataset, providing standardized conversational scenarios for evaluating mixed reality communication systems.
  • Jakob Hartbrich and William Menz (RWTH Aachen University and TU Ilmenau, Germany) analyzed how encoding parameters, such as texture resolution and polygon count influence the perceived quality of volumetric avatars, showing that texture resolution and quality level are dominant factors.
  • Daniel Zielasko (Technical University of Denmark, Denmark) presented a cross-laboratory initiative to establish standardized evaluation protocols for cybersickness, aiming to improve reproducibility and enable large-scale datasets.
  • Another contribution focused on datasets and evaluation tools. Abhinav Bhattacharya (RWTH Aachen University, Germany) introduced AMIS, a multimodal dataset for eXtended Reality (XR) research including multiple representation formats, such as talking-head videos, full-body videos, volumetric avatars, and personalized animated avatars.
  • An additional work explored teleoperation and user experience, with Shirin Rafiei (RISE, Sweden) presenting a study showing that latency and field of view significantly impact user performance, while video quality mainly affects subjective confidence.

Statistical Analysis Methods (SAM)

The group SAM presented several contributions focused on their main topics, which are data analysis, subjective evaluation, and statistical modeling:

  • Ryan Lei (Meta, USA) provided an update on AV2 common test conditions and coding gains, including both subjective and objective evaluation methodologies.
  • Lucjan Janowski (AGH University of Krakow, Poland) introduced a simulation framework for evaluating subject screening methods, demonstrating that correlation-based approaches outperform traditional kurtosis-based techniques.
  • Dietmar Saupe (University of Konstanz, Germany) proposed the use of G-test statistical methods for validating models in subjective quality datasets, improving reliability in quality scale reconstruction.
  • A discussion led by Robert Grosso (NTIA/ITS, USA) addressed open challenges in crowdsourcing-based subjective quality evaluation, including whether such approaches can replace standardized lab-based methodologies.

Joint Effort Group (JEG) – Hybrid

The group JEG addresses several areas of Video Quality Assessment (VQA), and in this meeting it provided contributions focused on advanced modeling of perceptual quality and subjective evaluation methods. In particular, Lohic Fotio Tiotsop (Politecnico di Torino, Italy) introduced a novel attention-based model for predicting individual perceived image coding quality, moving beyond Mean Opinion Score (MOS) toward personalized QoE modeling. In a second contribution, he also presented ongoing work on the evaluation of high-resolution image quality, highlighting variability in no-reference metrics and the need for subjective validation.

Emerging Technologies Group (ETG)

The ETG group continued to highlight forward-looking topics in multimedia. In this meeting:

  • Abhijay Ghildyal, Saman Zadtootaghaj, and Nabajeet Barman (Sony Interactive Entertainment, Germany and USA) proposed a non-aligned reference image quality assessment framework for novel view synthesis, addressing the challenge of quality evaluation when pixel-perfect references are unavailable.
  • Mathias Wien (RWTH Aachen University, Germany) presented updates on JVET activities, including results from a Call for Evidence (CfE) on next-generation video compression beyond Versatile Video Coding (VVC) and the outlook for future standardization.

Subjective and objective assessment of GenAI content (SOGAI)

The SOGAI group researches on subjective testing methodologies and objective metrics for assessing the quality of GenAI-generated content. In this meeting, the following topcis were presented and discussed:

5G Key Performance Indicators (5GKPI)

The 5GKPI group focuses on networked multimedia systems and QoE modeling. In this meeting, the following contributions were presented:

  • Henrique Rossi and Karan Mitra (Lulea University of Technology, Sweden) proposed a Bayesian network framework for analyzing interactivity in cloud gaming, showing that latency is the dominant factor influencing QoE.
  • Pablo Pérez (Nokia XR Lab, Spain) presented proposed updates to the QoE definition in ITU-T SG12 recommendation P.10/G.100, raising awareness within VQEG.
  • Martín Varela (Metosin, Finland / University of Malaga, Spain) discussed broader concepts of QoE at the system level, including fairness and group-level QoE metrics.
  • Finally, François Blouin (Meta, USA) and Pablo Pérez (Nokia XR Lab, Spain) reported on the status and future directions of the VQEG White Paper on QoE management.

Multimedia Experience and Human Factors (MEHF)

The MEHF group contributions address human perception and subjective evaluation challenges. In this meeting the following presentations were delivered:

Quality Assessment for Computer Vision Applications (QACoViA)

In this meeting, the QACoViA group explored deep learning approaches for image enhancement:

Other updates

Additional presentations covered diverse topics related to quality assessment of audiovisual technologies:

  • Kjell Brunnström (RISE, Sweden) presented a study on digital rear-view mirrors highlighting the importance of augmented visual cues for depth perception in automotive systems.
  • Werner Robitza (AVEQ, Germany) introduced Videoparser-ng, a fast open-source bitstream parser for model development.
  • Margaret Pinson (NTIA/ITS, USA) presented a new camera dataset (JNR-ITScam) containing information from videographers on this video dataset being filmed on modern cameras.
  • Syed Uddin (AGH University of Krakow, Poland) presented a segment-Level QoE assessment dataset for adaptive bitrate video streaming.
  • Henrique Rossi and Karan Mitra (Lulea University of Technology, Sweden) made a demonstration of ALTRUIST, a multi-platform tool to conduct subjective tests efficiently, for conducting QoE subjective tests in immersive systems.
  • In terms of standardization efforts, MPEG representatives provided an overview of AG5 activities, including updates on datasets and evaluation methodologies, and there was an ITU-T Q19 interim meeting to discuss progresses on the recommendations of no-reference metrics (J.Noref). 

Finally, as announced in the VQEG website, the next face-to-face VQEG plenary meeting was planned for May 2026.

MPEG Column: 154th MPEG Meeting

The 154th MPEG meeting took place in Santa Eulària, Spain, from April 27 to May 1, 2026. The official MPEG press release can be found here. This report highlights key outcomes from the meeting, with a focus on research directions relevant to the ACM SIGMM community:

  • Exploration on MPEG Gaussian Splat Coding (GSC)
  • Draft Joint Call for Proposals: Video Compression Beyond VVC
  • Energy-aware Streaming in MPEG-DASH
  • MPEG-AI: Vision and Scenarios for Artificial Intelligence in Multimedia
  • MPEG Roadmap

Exploration on MPEG Gaussian Splat Coding (GSC)

The MPEG WG 2 Technical Requirements group — jointly with WG 4 (Video Coding), WG 5 (JVET: Joint Video Coding Team(s) with ITU-T SG 16), and WG 7 (Coding of 3D Graphics and Haptics) — made progress toward standardizing Gaussian Splat Coding (GSC) regarding draft requirements and use cases subject to change. Gaussian splatting, first introduced in a landmark 2023 ACM SIGGRAPH paper by Kerbl et al. [Kerbl2023], represents 3D scenes as collections of anisotropic Gaussian primitives carrying geometry (x, y, z positions) and appearance attributes (opacity, scale, rotation, and spherical harmonics coefficients for view-dependent color), enabling photorealistic novel-view synthesis with real-time rendering. Because raw Gaussian splat data can be extremely large and the ecosystem of proprietary formats (.ply, .splat, .spz, etc.) is fragmented, MPEG has identified a clear need for interoperable, efficient compression standards. Two exploration tracks are currently being pursued: I-3DGS, which operates on Gaussian splats in the well-established “INRIA” format as a symmetric encode/decode pipeline, and A-3DGS, which allows alternative learned representations and training-integrated approaches.

The draft requirements, still evolving, currently cover representation, coding, and system aspects across both tracks, with an additional lightweight profile targeting resource-constrained devices such as mobile phones (Snapdragon 8 Gen 3/Elite) and HMDs (Snapdragon XR Gen2, e.g., Meta Quest 3). Among the coding requirements under consideration are lossy and lossless compression with variable bitrate, spatial and temporal random access, progressive and scalable decoding (quality, Level of Detail (LoD), attribute subsets), and error resilience. Notably, a lightweight profile currently proposes hard complexity constraints (i.e., real-time encode/decode on 2024/2025 mobile hardware, a 2GB runtime memory cap, and at most four concurrent video decoder sessions) reflecting MPEG’s intent to enable a fast-deployment path for interoperable interchange and storage of static Gaussian splat assets. Alongside the requirements, a draft set of 27 use cases has been identified, spanning consumer XR (telepresence, gaming, social media, retail), professional media (movie production, sports broadcasting, immersive journalism), industrial applications (digital twins, Building Information Modeling (BIM), structure inspection, disaster assessment), and emerging hybrid representations such as Gaussian splats attached to deformable meshes for avatar animation and rigging. Several of these use cases are motivating draft requirements around primitive ordering preservation and stable identifier signaling for external metadata associations, though the details of these provisions may still change.

Research aspects: Even at this early draft stage, the direction of MPEG’s GSC work opens a rich set of research opportunities. On the compression side, the dual-track structure raises open questions around rate-distortion-complexity optimization for both geometry-based and video-codec-based pipelines, including temporally coherent coding of dynamic (tracked and non-tracked) Gaussian sequences and attribute-group-aware progressive coding. The QoE angle is equally pressing: no widely accepted perceptual quality metric yet exists for 6DoF Gaussian splat rendering, and the community can contribute splat-artifact-aware metrics, view-consistency measures, and subjective evaluation methodologies. The envisioned lightweight profile points to a need for co-design of decoders and real-time renderers targeting mobile GPU architectures, offering opportunities in GPU-friendly bitstream layouts and LOD-driven streaming. From a systems and networking perspective, the spatial and temporal random-access provisions, combined with the breadth of use cases demanding adaptive streaming to diverse devices (HMDs, phones, TVs, browsers), map naturally onto adaptive bitrate research, ROI- and view-dependent segment delivery, and loss-resilient transmission of splat parameters. Finally, the emerging use cases around hybrid mesh-Gaussian avatars, scene editing, and semantic metadata associations introduce new multimedia content management and interactive media challenges that go well beyond traditional video streaming and are squarely within the scope of ACM SIGMM’s research community.

Draft Joint Call for Proposals: Video Compression Beyond VVC

MPEG’s Joint Video Experts Team (JVET) — operating jointly under ITU-T SG21 and ISO/IEC JTC 1/SC 29 — advanced a draft Joint Call for Proposals (CfP) for a new generation of video compression technology with capabilities that would substantially exceed those of the current Versatile Video Coding (VVC) standard (Rec. ITU-T H.266 | ISO/IEC 23090-3). The final CfP is planned for July 2026, with proposal submissions evaluated at a JVET meeting in January 2027 and a tentative target of a completed standard by October 2029. The overarching goal is to solicit compression technology that significantly improves upon VVC’s Main 10 Profile in terms of rate-distortion performance, encoder/decoder implementability, applicability to diverse content types, and additional features such as low latency, error robustness, and scalability, while explicitly recognizing that practical fast encoding is increasingly important across a growing range of applications.

The draft CfP defines four test cases. The primary test case targets improved compression without runtime constraints, spanning several content categories: SDR random-access at UHD/4K and HD resolutions, SDR low-delay HD (targeting conversational and gaming applications), HDR content under both PQ and HLG transfer functions at UHD, gaming low-delay HD, and user-generated content. Three additional test cases impose encoder runtime constraints relative to the VVC Test Model (VTM) reference encoder, enabling JVET to characterize the compression-versus-speed trade-off across submissions. Formal subjective evaluation will follow the degradation category rating (DCR) methodology per ITU-R BT.500. Importantly, the CfP explicitly addresses neural and learned components: proponents must disclose what training data was used and are prohibited from using any test sequence as training material, and source code (incl. training scripts or parameter derivation procedures) must be made available for accepted technologies entering the core experiments process. The draft notes that specific test sequences and target bitrates may still change before the final CfP is issued.

Research aspects: The runtime-constrained test cases create a natural framework for studying the compression-complexity Pareto frontier for both classical and learned codecs. The inclusion of user-generated content and gaming video as distinct categories invites research into content-adaptive coding tools and perceptual quality metrics tailored to these sources, as does the HDR coverage with its use of weighted PSNR alongside MS-SSIM. The explicit allowance for neural and learned components, with mandatory training data disclosure and source code requirements, signals that JVET anticipates hybrid and end-to-end learned codecs as serious contenders, making codec-agnostic adaptive streaming, QoE modeling for learned video codecs, and large-scale perceptual quality benchmarking timely topics for the ACM SIGMM community.

Energy-aware Streaming in MPEG-DASH

MPEG’s WG 3 (Systems/DASH) is developing a framework for integrating energy-related information into adaptive streaming workflows, currently documented as a Technology under Consideration (TuC) in the DASH specification. The proposed framework treats energy as a first-class design metric alongside QoE, latency, and throughput, and defines an end-to-end approach for assigning, aggregating, and propagating energy consumption data across the entire media delivery chain — from production and encoding through CDN distribution to the client. A key design principle is extensibility: rather than hardcoding specific metrics, the framework proposes a common registry of energy-related metrics (such as energy indices or carbon indices) identified via URNs or 4CC codes, inspired by existing registries like MP4RA and DASH-IF. Energy information may be carried through a variety of existing DASH mechanisms, including MPD descriptors at multiple granularity levels (Adaptation Set, Representation, Segment, Service Location), CMCD/CMSD extensions, metadata tracks, SAND messages, and event streams. A dedicated Energy descriptor in the MPD is proposed, analogous to existing Accessibility descriptors, to expose energy information to clients and applications for representation selection, user exposure, and reporting to back-end servers.

Concept of Energy-aware Streaming in MPEG-DASH.

The April 2026 update reported significant progress on two related fronts. A 5G-MAG workshop co-organized with 3GPP SA4 and Greening of Streaming (March 2026) highlighted growing industry consensus around practical energy measurement, surfacing findings such as the dominant role of device eco-mode settings and content brightness over codec or resolution choices in determining end-device energy consumption, and the challenge of reproducible cloud-based energy measurement. In parallel, 3GPP’s Rel-20 study on media energy consumption exposure (FS_Energy_Ph2_MED) reached 80% completion and is expected to conclude in June 2026, with normative work to follow. Notably, 3GPP’s current draft conclusions focus on generic architectural enablers, specifically a new Energy Information Application Function, while explicitly deferring media-layer and client-driven energy optimization to external bodies such as MPEG, SVTA, and DVB. This positions MPEG-DASH’s manifest-based energy signaling work as the natural venue for maturing the streaming-level mechanisms that 3GPP may later reference.

Research aspects: This work opens several timely directions. Energy-aware ABR algorithm design, i.e., jointly optimizing QoE and energy across representation selection, CDN choice, and client device settings, is a natural extension of the existing adaptive streaming research agenda. The proposed metrics registry and MPD-level signaling create opportunities for dataset construction and benchmarking, building on emerging open datasets such as COCONUT [Tashtarian2024] and VEED [Linder2024]. The finding that device-side factors (eco-mode, display brightness) dominate energy consumption over codec and bitrate choices challenges some common assumptions and calls for more holistic QoE-energy modeling. Finally, the cross-SDO coordination between MPEG, 3GPP, IETF (GREEN working group), and Greening of Streaming presents opportunities for the ACM SIGMM community to contribute to the design of interoperable, standardized energy reporting APIs for streaming services.

MPEG-AI: Vision and Scenarios for Artificial Intelligence in Multimedia

The first edition of ISO/IEC TR 23888-1 serves as the foundational vision document for the MPEG-AI series (ISO/IEC 23888). The document maps out how AI and neural network technologies interact with multimedia standardization along two complementary axes: (i) AI as a multimedia coding tool (e.g., AI-based video compression, 3D point cloud coding) and (ii) multimedia as input for AI consumption (e.g., video coding optimized for machine vision tasks). Under this umbrella, the document surveys six technical areas. In AI-based video coding, neural network components are explored as hybrid additions to VVC-style codecs, covering in-loop filters, intra prediction, super-resolution via reference picture resampling, and content-adaptive postfilters transmitted via SEI messages using the Neural Network Coding standard (NNC, ISO/IEC 15938-17). In AI-based 3D graphics coding, the focus is on dynamic point clouds for immersive (XR, gaming) and machine-oriented (autonomous navigation, BIM) applications, where sparsity and geometric irregularity pose unique challenges beyond those faced by image/video AI codecs. AI model compression (NNC) addresses the bandwidth-efficient deployment and incremental updating of neural network weights to devices, with use cases ranging from adaptive streaming ABR models to federated learning and postfilter delivery. Video coding for machines (VCM) targets compression optimized for downstream AI tasks such as object detection, tracking, and content moderation, with applications in surveillance, intelligent transportation, smart cities, and industrial inspection. Feature coding for machines (FCM) extends this to split-inference architectures where intermediate feature maps — rather than reconstructed video — are compressed and transmitted between edge devices and servers. Finally, distributed AI media description addresses the interoperable representation and API-level exchange of AI inference results (e.g., bounding boxes, segmentation masks) between networked media analyzers, as specified in the MPEG-IoMT suite.

ISO/IEC TR 23888-1: AI as a multimedia coding tool and multimedia as input for AI consumption.

Research aspects: The hybrid codec paradigm raises open questions around joint optimization of traditional and learned tools and complexity-aware training for mobile targets. The VCM and FCM tracks call for new task-oriented quality metrics capturing machine-task performance as a function of bitrate, an area where the multimedia and computer vision communities can collaborate. The split-inference and feature coding scenarios introduce latency-constrained compression problems for edge-to-cloud pipelines, which naturally connect to adaptive streaming and IoT research. Finally, the reproducibility and bit-exactness challenges highlighted in the document — hardware-dependent inference, non-deterministic training, and the absence of standardized evaluation environments — present an opportunity for the community to develop shared benchmarking infrastructure for learned multimedia codecs.

MPEG Roadmap

MPEG released an updated roadmap at its 154th meeting, reflecting the current status and near-term trajectory of its standardization activities across three broad pillars. Under Media Coding, work nearing completion includes MPEG Immersive Video v.2, Feature Coding for Machines, Solid Point Cloud Coding, and Dynamic Mesh Compression, while longer-horizon efforts cover AI Graphics Compression, Video Coding for Machines, Lenslet video coding, and — directly relevant to this report — both Video-based and Geometry-based Gaussian Splat Coding tracks. Under Systems and Tools, near-term deliverables include DASH v.7, Green metadata v.4, and Carriage of Haptics Data, with CMAF v.4 and File Format (ISOBMFF) v.10 on a slightly longer timeline. The Beyond Media pillar continues to advance genomic data search and biomedical waveform coding (BWC), alongside media authenticity and provenance indication — underscoring MPEG’s expanding scope well beyond traditional audiovisual applications.

MPEG Roadmap as of April 2026.

Research aspects: The roadmap highlights several intersecting research opportunities. The convergence of volumetric and neural representations (i.e., point clouds, dynamic meshes, Gaussian splats, and lenslet video; all progressing in parallel) raises open questions around unified rate-distortion frameworks and cross-format QoE evaluation for 6DoF experiences. The simultaneous progression of Video Coding for Machines and Feature Coding for Machines alongside traditional human-centric codecs calls for research into adaptive pipelines that can serve both human and machine consumers from a shared bitstream. The Green metadata track connects directly to the energy-aware streaming work discussed above, underscoring the need for end-to-end energy modeling that spans codec choice, packaging, delivery, and consumption. Finally, the Beyond Media thread (e.g., particularly genomic data and biomedical waveforms) signals an expanding definition of “multimedia” that the ACM SIGMM community may wish to engage with as compression, retrieval, and QoE methods developed for audiovisual content find applicability in life sciences.

Concluding Remarks

The 154th MPEG meeting in Santa Eularia reflects a standards body in active transition, broadening its scope from traditional audiovisual compression toward a richer landscape that encompasses neural scene representations, AI-native codecs, energy-aware delivery, and even biomedical data. The Gaussian Splat Coding exploration, the next-generation video compression Call for Proposals, the MPEG-AI vision document, and the energy-aware streaming framework each address distinct but interconnected challenges: how to represent, compress, deliver, and consume increasingly complex and diverse media efficiently and sustainably. For the ACM SIGMM community, this meeting offers both a map of where industry standardization is heading and a set of open research problems (i.e., spanning perceptual quality assessment, learned compression, edge inference, green streaming, and immersive media delivery) where academic contributions can meaningfully shape the next generation of multimedia standards.

The 155th MPEG meeting will be held in Geneva, Switzerland, from July 13 to 17, 2026. Click here for more information about MPEG meetings and ongoing developments.

References

  • [Kerbl, 2023] Bernhard Kerbl, Georgios Kopanas, Thomas Leimkuehler, and George Drettakis. 2023. 3D Gaussian Splatting for Real-Time Radiance Field Rendering. ACM Trans. Graph. 42, 4, Article 139 (August 2023), 14 pages. https://doi.org/10.1145/3592433
  • [Tashtarian, 2024] Farzad Tashtarian, Daniele Lorenzi, Hadi Amirpour, Samira Afzal, and Christian Timmerer. 2024. COCONUT: Content Consumption Energy Measurement Dataset for Adaptive Video Streaming. In Proceedings of the 15th ACM Multimedia Systems Conference (MMSys ’24). Association for Computing Machinery, New York, NY, USA, 346–352. https://doi.org/10.1145/3625468.3652179
  • [Linder, 2024] Sandro Linder, Samira Afzal, Christian Bauer, Hadi Amirpour, Radu Prodan, and Christian Timmerer. 2024. VEED: Video Encoding Energy and CO2 Emissions Dataset for AWS EC2 instances. In Proceedings of the 15th ACM Multimedia Systems Conference (MMSys ’24). Association for Computing Machinery, New York, NY, USA, 332–338. https://doi.org/10.1145/3625468.3652178

JPEG Column: 110th JPEG Meeting in Sydney, Australia

JPEG Trust Media Asset Watermarking reaches Committee Draft stage at the 110th JPEG meeting

The 110th JPEG meeting was held in Sydney, Australia, from 11 to 16 January 2026.

This meeting was marked by several major achievements: JPEG Trust Part 3 Media Asset Watermarking that will extend JPEG Trust Core Foundation providing signalling capabilities for content authenticity, provenance, integrity, intellectual property rights, and labelling using watermarking. Furthermore, the first event-based codec, JPEG XE, reached the Draft International Standard stage.

In addition, the JPEG Committee celebrated the 25th birthday of the successful JPEG 2000 standard with a social event where members who had served the Committee shared their experience during the development of this important family of standards.

The following sections summarise the main highlights of the 110th JPEG meeting:

  • JPEG Trust Part 3: Media Asset Watermarking to provide watermarking support for media asset authenticity.
  • JPEG XE Part 1: core coding system is under DIS ballot.
  • JPEG AIC prepares large-scale subjective experiment.
  • JPEG 2000 defines a set of hardware-focused profiles for professional video streaming.
  • JPEG XS Part 2 new amendement defines additional levels and sublevels, ands a new frame buffer level.
  • JPEG RF activity approves new Use Cases and Requirements.
  • JPEG AI focus on implementation aspects and on extending its applicability across devices and use cases.
  • JPEG DNA completes wet-lab experiments, including DNA synthesis/sequencing.
  • JPEG Pleno Light Field Quality Assessment examines the performance of the proposed metrics.
  • JPEG 2000 25th Anniversary Celebrations.
The former convenor of the JPEG Committee, Daniel Lee, addressing JPEG 2000 development during the JPEG 2000 25th Anniversary Celebration.

JPEG Trust

Current technologies, especially the rise of generative AI, make synthetic creation and modification of media assets easy for general users. Media artefacts such as synthetic images and video increase the risks of online piracy, cyber security fraud, copyright breach, advertising misrepresentation and the spread of mis- and disinformation.

The JPEG Trust International Standard (ISO/IEC 21617-1) provides a framework for establishing trust in media assets, and has now been extended to include Part 3: Media Asset Watermarking (ISO/IEC 21617-3), to provide watermarking support for media asset authenticity.

This new part of the JPEG Trust framework provides a mechanism to empower businesses, governments and institutions to support critical use cases from labelling AI-generated media assets to Digital Rights Management and source tracing. This is in addition to its many applications in helping secure media asset authenticity.

In a major milestone achieved during the 110th JPEG meeting in Sydney, Part 3: Media Asset Watermarking reached the Committee Draft stage. It is expected that this standard will have a significant positive impact globally, as it directly responds to the urgent calls for watermarking functionality by governments around the world in response to the proliferation of AI-generated content online.

JPEG XE

JPEG XE is a joint effort between ITU-T SG21 and ISO/IEC JTC1/SC29/WG1 and will become the first internationally endorsed specification by major standardization bodies ITU-T, ISO, and IEC, for coding of events. It aims to establish a robust and interoperable format for efficient representation and coding of events in the context of machine vision and related applications. To expand the reach of JPEG XE, the JPEG Committee has closely coordinated its activities with the MIPI Alliance with the intention of developing a cross-compatible coding mode, allowing MIPI ESP signals to be decoded effectively by JPEG XE decoders.

Currently, JPEG XE Part 1, which defines the core coding system, is under DIS ballot and the JPEG Committee is awaiting the results. In the meantime, work started on Parts 2 and 3, which will define the Profiles and levels, and the Reference software, respectively. For both parts, a Committee Draft (CD) was created and their consultation was requested. The Profiles and levels in Part 2 will provide strict definitions to allow safe and correct interoperability between vendor specific implementations of the standard. The software for Part 3 will serve as a proof of concept implementation of an encoder and decoder of JPEG XE. The plan is to make the software free and open source to allow the community easy access to the JPEG XE technology.

Finally, work on Part 4 was also initiated to provide official and well-defined conformance tests. This will help vendors to verify interoperability and conformance to the standard.

The JPEG Committee remains committed to the development of a comprehensive and industry-aligned standard that meets the growing demand for event-based vision technologies. The collaborative approach between multiple standardisation organisations underscores a shared vision for a unified, international standard to accelerate innovation and interoperability in this emerging field. The JPEG XE public and joint AHG (ITU-T SG21 and ISO/IEC JTC1 SC29 WG1) was reestablished to continue the work. If you are interested, please consider joining the joint AHG.

JPEG AIC

The JPEG AIC-3 standard, which specifies a methodology for fine-grained subjective image quality assessment in the range from good quality up to mathematically lossless, is ready to be published as International Standard ISO/IEC 29170-3 in February this year. An implementation of the corresponding data analysis has been provided in MATLAB and will be ported to Python. For the current JPEG AIC-4 effort and evaluation of the responses to the call for Objective Image Quality Assessment, an image dataset for the large-scale subjective experiment was finalized, consisting of 18,000 compressed images for 70 source images and 17 codecs, including several learning-based methods. The crowdsourcing experiment is expected to take several weeks.

JPEG 2000

The JPEG Committee has initiated the development of a new standard to collect the growing number of profiles for its flexible JPEG 2000 image codec. As part of the activity, which is expected to be completed within the next 18 months, an initial set of hardware-focused profiles for professional video streaming coder are being codified. These profiles use the unique capabilities of the High-Throughput JPEG 2000 block coder, specified in Rec. ITU-T T.814 | ISO/IEC 15444-15, to shrink the hardware resources needed to tackle modern high-frame rate and high-resolution images.

JPEG XS

JPEG XS, the image and video compression format for transmitting visually lossless, high-quality pictures with minimal latency and low resource consumption, is a fundamental game-changer for real-time video transmission in live, professional, and broadcast applications. In this context, the JPEG Committee created an AMD1 for JPEG XS Part 2 to define some additional levels and sublevels, as well as a new frame buffer level. These additions each address specific requirements that came from the respective industry sectors that rely on JPEG XS. This new AMD1 for Part 2 was issued for DIS balloting. In the meantime, the ballot results for AMD1 for JPEG XS Part 1 were processed, and an FDIS ballot was initiated. Both AMDs are expected to be published before the end of this year.

JPEG RF

At the 110th JPEG meeting, JPEG RF made significant progress against its mandates, formally approving the Use Cases and Requirements for JPEG Radiance Fields v1.0 and requesting its public release on the JPEG website. Substantial technical discussions advanced the evaluation and assessment pipeline for radiance fields, covering both coding-only and joint instantiation and coding approaches. The Working Group also approved Exploration Study 7, including the study on pair-wise comparison assessment methodologies for radiance fields. In addition, next steps were agreed for outreach activities to engage additional stakeholders.

JPEG AI

During the 110th JPEG meeting, JPEG AI was focused on implementation aspects and on extending its applicability across devices and use cases. First, the Use Cases and Requirements document was updated, introducing a new video streaming and storage use case that positions JPEG AI as a deterministic still-image coding engine that can be integrated into video coding pipelines.

A new core experiment addresses the bit-exact reference frame reconstruction requirement. Moreover, other core experiments were defined to analyze power consumption on heterogeneous CPU–GPU/FPGA platforms and to retrain JPEG AI in the RGB domain for fair comparison with other codecs. Looking ahead, JPEG AI plans to develop mobile-ready encoder and decoder implementations, investigate error-resilience properties, and continue benchmarking JPEG AI against state-of-the-art learnt image codecs using solid and robust test conditions.

JPEG DNA

The wet-lab experiments, including DNA synthesis/sequencing, designed at the 109th JPEG meeting were completed, and the synthesized results have been delivered to the JPEG Committee as DNA molecules. As a next step, independent parties are carrying out sequencing separately, and the sequenced results are expected to be available by the next JPEG meeting, when the JPEG DNA, a.k.a. ISO/IEC 25508-1, will reach the DIS stage.

JPEG Pleno

During the 110th JPEG meeting, the JPEG Committee reviewed the outcomes of the subjective quality assessment conducted on the evaluation dataset with the aim to examine the performance of the proposals submitted in response to the Call for Proposals on objective metrics for JPEG Pleno Light Field Quality Assessment. The performance of submitted metrics was analysed across scenes with diverse spatial and angular resolutions and for both coding-only and joint coding and view-synthesis artefacts, highlighting differences in behaviour across distortion categories. Learning-based proposals were recognized as a promising direction, particularly when cross-validated on the evaluation dataset, while also raising considerations related to training, data dependency, and reproducibility. The evaluation phase was formally closed, with agreement to retain a set of well-established full-reference metrics as reference anchors and to pursue a combined technical direction integrating end-to-end and hybrid learning-based approaches. Finally, responsibilities across task forces were consolidated, and next steps were defined to continue the objective quality assessment work towards a first version of a working draft.

Highlights of JPEG 2000 25th Anniversary Celebrations, Sydney, 14 January 2026

The 110th JPEG meeting in Sydney offered a fitting occasion to mark the 25th anniversary of JPEG 2000 standardization. Opening the celebration, Prof. Touradj Ebrahimi, JPEG convenor, noted that it was in Sydney during the 12th JPEG meeting in 1997 that JPEG 2000 proposals were evaluated, culminating in the publication of the standard in December 2000.

The program featured a video message from Prof. Michael Marcellin, a key contributor to several core technologies adopted by JPEG 2000 and chair of the subsequent software verification model effort. He highlighted the successful deployment of JPEG 2000 for digital distribution of motion pictures and the essential standards work involved in defining the digital cinema profiles that enabled this adoption.

Prof. David Taubman, whose long-standing leadership and technical contributions continue to shape JPEG 2000 development, delivered a presentation highlighting the coding tools that underpin the format’s highly scalable and accessible codestreams. He also outlined recent progress in High Throughput JPEG 2000 (HTJ2K), including implementations achieving high performance, full float lossless compression for OpenEXR and FPGA based realizations delivering high speed, low latency coding.

Messages from Prof. Majid Rabbani and Dr. Daniel Lee—both instrumental in guiding the JPEG 2000 standardisation process—paid tribute to the dedication, expertise, and collaborative spirit of the many JPEG members who contributed to the standard’s success. Daniel, who served as JPEG convenor during the JPEG 2000 standardisation period, further underscored JPEG’s essential role as a collaborative international forum for developing standards with global reach.

The celebration concluded with an address by Dr. Pierre Anthony Lemieux, co-chair of the JPEG 2000 activity, who highlighted the format’s enduring flexibility as a key factor in its longevity. He noted that this flexibility allows end users to expand the capabilities of their workflows without the burden of switching to a different codec. Dr. Lemieux also emphasised the importance of ongoing maintenance activities, which allow JPEG 2000 to evolve to meet the shifting needs of its users, including current work on defining HTJ2K profiles and levels. He finished by stressing the importance of open source tools and libraries in driving adoption.

A sustained commitment to meeting industry needs and continued maintenance of the standard remains central to the ongoing and future success of JPEG 2000.

Final Quote

“Reaching Committee Draft for JPEG Trust Part 3: Media Asset Watermarking is a pivotal step toward restoring confidence in digital media at a moment when generative AI makes convincing manipulation accessible to anyone. This milestone equips industries and public institutions with interoperable, standards-based watermarking to support authenticity, provenance, integrity, rights signalling, and clear labelling, helping to curb mis- and disinformation, strengthen digital rights management, and enable reliable source tracing at a global scale.” said Prof. Touradj Ebrahimi, the Convenor of the JPEG Committee.

Music Meets Science at ACM Multimedia 2025

Multimedia research is framed through algorithms, datasets, and systems, but at its heart lies content that is deeply human. Few forms of content illustrate this better than classical music. Long before music becomes data to be recorded, generated, searched, or retrieved, it is imagined by composers and brought to life by performers. At ACM Multimedia 2025 in Dublin, this human origin of multimedia took centre stage in a unique social event that bridged classical music and multimedia content analysis. This event was the fourth supported by ACM SIGMM in the framework of Music Meets Science program (at CBMI’2022, CBMI’2023, CBMI’2024).

Music Meets Science explores musical spaces across centuries and styles, from the dynamic Folia of Vivaldi and Handel’s Passacaglia to works by Schubert and contemporary composers from around the world. The goal here is to bring a wide range of music performed by some of the original content creators, our classical musicians, to the multimedia research community, who explore and mine this content. It brings fundamental cultural values to the young researchers in Multimedia, opening their minds to classical and contemporary music which oscillates with the rhythm of centuries.

The concert took place on 29 October, starting at 8:00 PM, during the Welcome Reception of ACM Multimedia 2025. It was attended by over 1,000 delegates of all ages from doctoral students to senior researchers. The programme featured music by Irish composer Garth Knox and a new composition by Finnish composer Jarno Vanhanen, written especially for ACM Multimedia. The performance was delivered by internationally acclaimed French musicians of the new generation: François Pineau-Benois (violin) and Olivier Marin (viola), see Figure 1. Together, they invited the audience to experience music not only as sound, but as rich multimedia content shaped by structure, expression, interpretation, and context.

Figure 1. François Pineau-Benois (violin), Oliver Marin (viola) performing Jarno Vanhanen’s “Aurora Borealis” duet.

By embedding live performance within a major multimedia conference, Music Meets Science highlights the importance of integrating creative arts into the research ecosystem. As multimedia research continues to advance, from content understanding to generation, events like this remind us that artistic practice is not just an application domain, but a source of inspiration. Strengthening the dialogue between creative arts and multimedia research can deepen our understanding of content, context, and meaning, and enrich the future directions of the field.

The MediaEval Benchmark Looks Back at a Successful Fifteenth Edition, and Forward to its Sweet Sixteen

Introduction

The Benchmarking Initiative for Multimedia Evaluation (MediaEval) organizes interesting and engaging tasks related to multimedia data. MediaEval is proud to be supported by SIGMM. Tasks involve analyzing and exploring multimedia collections, as well as accessing the information that they contain. MediaEval emphasizes challenges that have a human or social aspect in order to support our goal of making multimedia a positive force in society. Participants in MediaEval are encouraged to submit effective, but also creative solutions to MediaEval tasks: We carry out quantitative evaluation of the submissions, but also go beyond the scores in order to obtain insight into the tasks, data, metrics. 

Participation in MediaEval is open to any team that wishes to sign up. Registration has just opened and information is available on the MediaEval 2026 website: https://multimediaeval.github.io/editions/2026 The workshop will take place in Amsterdam, Netherlands and online coordinated with ACM ICMR https://icmr2026.org

In this column, we present a short report on MediaEval 2025, which culminated with the annual workshop in Dublin, Ireland between CBMI (https://www.cbmi2025.org) and ACM Multimedia (https://acmmm2025.org). Then, we provide an outlook to MediaEval 2026, which will be the sixteenth edition of MediaEval.

A Keynote on Metascience

The workshop kicked off with a keynote on metascience for machine learning. The metascience initiative (https://metascienceforml.github.io) strives to promote discussion and development of the scientific underpinnings of machine learning. It looks at the way in which machine learning is done and examines the full range of relevant aspects, from methodologies and mindsets. The keynote was delivered by Jan van Gemert, head of the Computer Vision Lab (https://www.tudelft.nl/ewi/over-de-faculteit/afdelingen/intelligent-systems/pattern-recognition-bioinformatics/computer-vision-lab) at Delft University of Technology. He discussed the “growing pains” of the field of deep learning and the importance of the scientific method for keeping the field on course. He invited the audience to consider the question of the power of benchmarks for hypothesis-driven science in machine learning and deep learning.

Tasks at MediaEval 2025

The MediaEval 2025 tasks reflect the benchmark’s continued emphasis on human-centered and socially relevant multimedia challenges, spanning healthcare, media, memory, and responsible use of generative AI.

Several tasks this year focused on the human aspects of multimodal analysis, combining visual, textual, and physiological signals. The Medico Task challenges participants in building visual question answering models for the interpretation of gastrointestinal images, aiming to support clinical decision-making through interpretable multimodal explanations. The Memorability Task focuses on modeling long-term memory for short movie excerpts and commercial videos, requiring participants to predict how memorable a video is, whether viewers are familiar with it, and, in some cases, to leverage EEG signals alongside visual features. Multimodal understanding is further explored in the MultiSumm Task, where participants are provided with collections of multimodal web content describing food sharing initiatives in different cities and are asked to generate summaries that satisfy specific informational criteria, with evaluation exploring both traditional and emerging LLM-based assessment approaches.

The remaining two tasks emphasize the societal impact of multimedia technology in real-world settings. In the NewsImagesTask, participants worked with large collections of international news articles and images, either retrieving suitable thumbnail images or generating thumbnails for articles. The Synthetic Images Task addressed the growing prevalence of AI-generated content online, asking participants to detect synthetic or manipulated images and localize manipulated areas. The task used data created by state-of-the-art generative models as well as images collected from real-world online settings. We gratefully acknowledge the support of AI-CODE (https://aicode-project.eu), a European project focused on topics related to these two tasks.

MediaEval in Motion

MediaEval is especially proud of participants who return over the years, improving their approaches and contributing insights. We would like to highlight two previous participants who became so interested and involved in MediaEval tasks that they decided to join the task organization team and help organize the tasks. Iván Martín-Fernández, PhD student at Universidad Politécnica de Madrid, became a task organizer for the Memorability task and Lucien Heitz, PhD Student, University of Zurich, became a task organizer for NewsImages. 

One aspect of the MediaEval Benchmark I value most is its effort to go beyond metric-chasing and embark on a “quest for insights,” as the organizers put it, to help us better understand the tasks and encourage creative, innovative solutions. This spirit motivated me to participate in the 2023 Memorability Task in Amsterdam. The experience was so enriching that I wanted to become more involved in the community. In 2025, I was invited to join the Memorability Task organizing team, which gave me the chance to contribute to and help foster this innovative research effort. Thanks to SIGMM’s sponsorship, I was able to attend the event in Dublin, which further enhanced the experience. Working alongside Martha and Gabi as a student volunteer is always a pleasure. As my PhD studies come to an end, I’m proud to say that MediaEval has been a core part of my research, and I’m sure it will remain so in the immediate future. See you in Amsterdam in June!

Iván Martín-Fernández, PhD Student, GTHAU – Universidad Politécnica de Madrid

I ‘graduated’ from being a participant in the previous NewsImages challenge to now taking over the organization duties of the 2025 iteration of the task. It was an incredible journey and learning experience. Big thank you to the main MediaEval organizers for their tireless support and input for shaping this new task that combines image retrieval and generation. The recent benchmark event presented an amazing platform to share and discuss our research. We got so many great submissions from teams around the globe. I was truly overwhelmed by the feedback. Getting involved with the organization of a challenge task is something I can highly recommend to all participants. It allows you to take on an active role and bring new ideas to the table on what problems to tackle next.

Lucien Heitz, PhD Student, University of Zurich

MediaEval continues its tradition of awarding a “MediaEval Distinctive Mention” to teams that dive deeply into the data, the algorithms, and the evaluation procedure. Going above and beyond in this way makes important contributions to our understanding of the task and how to make meaningful progress. Moving the state of the art forward requires improving the scores on a pre-defined benchmark task such as the tasks offered by MediaEval. However, MediaEval Distinctive Mentions underline the importance of research that does not necessarily improve scores on a given task, but rather makes an overall contribution to knowledge.

We were happy to serve as student volunteers at MediaEval 2025. In addition, we participated as a team in the NewsImage task, contributing to two subtasks, and were honored to receive a Distinctive Mention. 

Xiaomeng had previously participated in the same task at MediaEval 2023. Compared to the 2023 edition, she observed notable evolution in both the data and task design. These changes reflect the organizers’ careful consideration of recent advances in modeling techniques as well as the practical applicability of the datasets, which proved to be highly inspiring. 

Bram participated in MediaEval for the first time and particularly found the discussions with colleagues about the challenges very rewarding. The NewsImage retrieval subtask additionally got him to learn how to deal with larger datasets. 

We tried to incorporate deeper reflections on our results into our presentation. Specifically, we showed how certain types of articles are particularly suited for image generation and identified the news categories where retrieval was most effective. 

Xiaomeng Wang and Bram Bakker PhD Students, Data Science – Radboud University

The people whose work is highlighted in this section are grateful to have received support from SIGMM in order to be able to attend the MediaEval workshop in person. 

Outlook to MediaEval 2026

The 2025 workshop concluded with participants collaborating with the task organizers to start to develop “benchmark biographies”, which are living documents that describe benchmarking tasks. Combining elements from data sheets and model cards, benchmark biographies document motivation, history, datasets, evaluation protocols, and baseline results to support transparency, reproducibility, and reuse by the broader research community. We plan to continue work on these benchmark biographies as we move toward MediaEval 2026. 

Further, in the 2026 edition, we will offer again the tasks that were held in 2025 to provide an opportunity for teams who were not able to participate in 2025. We especially encourage “Quest for Insight” papers that examine characteristics of the data and the task definitions, the strengths and weaknesses of particular types of approaches, observations about the evaluation procedure, and the implications of the task. 
We look forward to seeing you in Amsterdam for MediaEval and also ACM ICMR. Don’t forget to check out the MediaEval website (https://multimediaeval.github.io) and register your team if you are interested in participating in 2026.

MPEG Column: 153rd MPEG Meeting

The 153rd MPEG meeting took place online from January 19-23, 2026. The official MPEG press release can be found here. This report highlights key outcomes from the meeting, with a focus on research directions relevant to the ACM SIGMM community:

  • MPEG Roadmap
  • Exploration on MPEG Gaussian Splat Coding (GSC)
  • MPEG Immersive Video 2nd edition (new white paper)

MPEG Roadmap

MPEG released an updated roadmap showing continued convergence of immersive and “beyond video” media with deployment-ready systems work. Near-term priorities include 6DoF experiences (MPEG Immersive Video v2 and 6DoF audio), volumetric representations (dynamic meshes, solid point clouds, LiDAR, and emerging Gaussian splat coding), and “coding for machines,” which treats visual and audio signals as inputs to downstream analytics rather than only for human consumption.

Research aspects: The most promising research opportunities sit at the intersections: renderer and device-aware rate-distortion-complexity optimization for volumetric content; adaptive streaming and packaging evolution (e.g., MPEG-DASH / CMAF) for interactive 6DoF services under tight latency constraints; and cross-cutting themes such as media authenticity and provenance, green and energy metadata, and exploration threads on neural-network-based compression and compression of neural networks that foreshadow AI-native multimedia pipelines.

MPEG Gaussian Splat Coding (GSC)

Gaussian Splat Coding (GSC) is MPEG’s effort to standardize how 3D Gaussian Splatting content, scenes represented as sparse “Gaussian splats” with geometry plus rich attributes (scale and rotation, opacity, and spherical-harmonics appearance for view-dependent rendering), is encoded, decoded, and evaluated so it can be exchanged and rendered consistently across platforms. The main motivation is interoperability for immersive media pipelines: enabling reproducible results, shared benchmarks, and comparable rate-distortion-complexity trade-offs for use cases spanning telepresence and immersive replay to mobile XR and digital twins, while retaining the visual strengths that made 3DGS attractive compared to heavier neural scene representations.

The work remains in an exploration phase, coordinated across ISO/IEC JTC 1/SC 29 groups WG 4 (MPEG Video Coding) and WG 7 (MPEG Coding for 3D Graphics and Haptics) through Joint Exploration Experiments covering datasets and anchors, new coding tools, software (renderer and metrics), and Common Test Conditions (CTC). A notable systems thread is “lightweight GSC” for resource-constrained devices (single-frame, low-latency tracks using geometry-based and video-based pipelines with explicit time and memory targets), alongside an “early deployment” path via amendments to existing MPEG point-cloud codecs to more natively carry Gaussian-splat parameters. In parallel, MPEG is testing whether splat-specific tools can outperform straightforward mappings in quality, bitrate, and compute for real-time and streaming-centric scenarios.

Research aspects: Relevant SIGMM directions include splat-aware compression tools and rate-distortion-complexity optimization (including tracked vs. non-tracked temporal prediction); QoE evaluation for 6DoF navigation (metrics for view and temporal consistency and splat-specific artifacts); decoder and renderer co-design for real-time and mobile lightweight profiles (progressive and LOD-friendly layouts, GPU-friendly decode); and networked delivery problems such as adaptive streaming, ROI and view-dependent transmission, and loss resilience for splat parameters. Additional opportunities include interoperability work on reproducible benchmarking, conformance testing, and practical packaging and signaling for deployment.

MPEG Immersive Video 2nd edition (white paper)

The second edition of MPEG Immersive Video defines an interoperable bitstream and decoding process for efficient 6DoF immersive scene playback, supporting translational and rotational movement with motion parallax to reduce discomfort often associated with pure 3DoF viewing. The second edition primarily extends functionality (without changing the high-level bitstream structure), adding capabilities such as capture-device information, additional projection types, and support for Simple Multi-Plane Image (MPI), alongside tools that better support geometry and attribute handling and depth-related processing.

Architecturally, MIV ingests multiple (unordered) camera views with geometry (depth and occupancy) and attributes (e.g., texture), then reduces inter-view redundancy by extracting patches and packing them into 2D “atlases” that are compressed using conventional video codecs. MIV-specific metadata signals how to reconstruct views from the atlases. The standard is built as an extension of the common Visual Volumetric Video-based Coding (V3C) bitstream framework shared with V-PCC, with profiles that preserve backward compatibility while introducing a new profile for added second-edition functionality and a tailored profile for full-plane MPI delivery.

Research aspects: Key SIGMM topics include systems-efficient 6DoF delivery (better view and patch selection and atlas packing under latency and bandwidth constraints); rate-distortion-complexity-QoE optimization that accounts for decode and render cost (especially on HMD and mobile) and motion-parallax comfort; adaptive delivery strategies (representation ladders, viewport and pose-driven bit allocation, robust packetization and error resilience for atlas video plus metadata); renderer-aware metrics and subjective protocols for multi-view temporal consistency; and deployment-oriented work such as profile and level tuning, codec-group choices (HEVC / VVC), conformance testing, and exploiting second-edition features (capture device info, depth tools, Simple MPI) for more reliable reconstruction and improved user experience.

Concluding Remarks

The meeting outcomes highlight a clear shift toward immersive and AI-enabled media systems where compression, rendering, delivery, and evaluation must be co-designed. These developments offer timely opportunities for the ACM SIGMM community to contribute reproducible benchmarks, perceptual metrics, and end-to-end streaming and systems research that can directly influence emerging standards and deployments.

The 154th MPEG meeting will be held in Santa Eulària, Spain, from April 27 to May 1, 2026. Click here for more information about MPEG meetings and ongoing developments.

ACM SIGMM Multimodal Reasoning Workshop

The ACM SIGMM Multimodal Reasoning Workshop was held on 8–9 November 2025 at Indian Institute of Technology Patna (IIT Patna) in Hybrid mode. Organised by Dr. Sriparna Saha, faculty member of the Department of Computer Science and Engineering, IIT Patna and supported by ACM SIGMM, the two-day event brought together researchers, students, and practitioners to discuss the foundations, methods, and applications of multimodal reasoning and generative intelligence. The workshop registered 108 participants and featured invited talks, tutorials, and hands-on sessions by national and international experts. Sessions covered topics ranging from trustworthy AI, LLM fine-tuning, temporal and multimodal reasoning, to knowledge-grounded visual question answering and healthcare applications.

Inauguration:

 During the inauguration, Dr. Sriparna Saha welcomed participants and acknowledged the presence and support of Prof. Jimson Mathew (Dean of Student Affairs, IIT Patna), Prof. Rajiv Ratn Shah (IIIT Delhi) and all speakers. The organising committee expressed gratitude to ACM SIGMM for its financial support, which made the workshop possible. Felicitations were exchanged, and the inauguration concluded with words of encouragement for active participation and interdisciplinary collaboration.

Session summaries and highlights:

Day 1:

 The first day began with an inaugural session followed by a series of engaging talks and tutorials. Prof. Rajiv Ratn Shah (Associate Professor, IIIT Delhi, India) delivered the opening talk on “Tackling Multimodal Challenges with AI: From User Behavior to Content Generation,” highlighting the role of multimodal data in understanding user behaviour, enabling AI-driven content generation, and building region-specific applications such as voice conversion and video dubbing for Indic languages. Prof. Sriparna Saha (Associate Professor, Department of Computer Science and Engineering, IIT Patna, India) then presented “Harnessing Generative Intelligence for Healthcare: Models, Methods, and Evaluations,” discussing safe, domain-specific AI systems for healthcare, multimodal summarisation for low-resource languages, and evaluation frameworks like M3Retrieve and multilingual trust benchmarks. The afternoon sessions featured hands-on tutorials and technical talks. Ms. Swagata Mukherjee (Research Scholar, IIT Patna, India) conducted a tutorial on “Advanced Prompting Techniques for Large Language Models,” covering zero/few-shot prompting, chain-of-thought reasoning, and iterative refinement strategies. Mr. Rohan Kirti (Research Scholar, IIT Patna, India) led a tutorial on “Exploring Multimodal Reasoning: Text & Image Embeddings, Augmentation, and VQA,” demonstrating text–image fusion using models such as CLIP, VILT, and PaliGemma. Prof. José G. Moreno (Associate Professor, IRIT, France) presented “Visual Question Answering about Named Entities with Knowledge-Based Explanation (ViQuAE),” introducing a benchmark for explainable, knowledge-grounded VQA. The day concluded with Prof. Chirag Agarwal (Assistant Professor, University of Virginia, USA) delivering a talk on “Trustworthy AI in the Era of Frontier Models,” which emphasised fairness, safety, and alignment in multimodal and LLM systems.

Day 2:

 The second day continued with high-level technical sessions and tutorials. Prof. Ranjeet Ranjan Jha (Assistant Professor, Department of Mathematics, IIT Patna, India) opened with a talk on “Bridging Deep Learning and Multimodal Reasoning: Generative AI in Real-World Contexts,” tracing the evolution of deep learning into multimodal generative models and discussing ethical and computational challenges in deployment. Prof. Adam Jatowt (Professor, Department of Computer Science, University of Innsbruck, Austria) followed with a presentation on “Analyzing and Improving Temporal Reasoning Capabilities of Large Language Models,” showcasing benchmarks such as BiTimeBERT, TempRetriever, and ComplexTempQA, while proposing methods to enhance time-sensitive reasoning. The final technical session featured Mr. Syed Ibrahim Ahmad (Research Scholar, IIT Patna, India) conducted a tutorial on “LLM Fine-Tuning,” which covered PEFT approaches, QLoRA, quantization, and optimization techniques to fine-tune large models efficiently.

Valedictory session:

 The valedictory session marked the formal close of the workshop. Dr. Sriparna Saha thanked speakers, participants and the organising team for active engagement across technical talks and tutorials. Participants shared positive feedback on the depth and practicality of sessions. Certificates were distributed to attendees. Final remarks encouraged continued research, collaboration and dissemination of resources. Dr. Saha reiterated gratitude to ACM SIGMM for financial support.

Outcomes, observations and suggested actions:

  • Multimodal reasoning remains an interdisciplinary challenge that benefits from close collaboration between multimedia, NLP, and application domain experts.
  • Trustworthiness, safety, and evaluation (benchmarks and metrics) are critical for moving multimodal models from demonstration to practice especially in healthcare and other high-stakes domains.
  • Practical methods for model adaptation (PEFT, quantization) make large models accessible for research groups with limited compute.
  • Datasets and retrieval resources that combine multimodal inputs with external knowledge (as in ViQuAE) are valuable for advancing explainable VQA and grounded reasoning.
  • The community should prioritise regional and language-diverse resources (Indic languages, code-mixed data) to ensure equitable benefits from multimodal AI.
  • SIGMM and ACM venues can play a role in fostering collaborations via special projects, regional hackathons, grand challenges, and multimodal benchmark initiatives.

Outreach & social media:

 The workshop generated significant visibility on LinkedIn and other professional networks. Photos and session highlights were widely shared by participants and organisers, acknowledging ACM SIGMM support and the quality of the technical programme.

Acknowledgements:  The organising committee thanks all speakers, attendees, student volunteers, and ACM SIGMM for financial and logistic support that enabled the workshop.