February 28, 2023
The ITS Video Quality Research group yesterday hosted virtual meetings of the No-Reference (NR) Metrics (NORM) working group, one of the current Video Quality Experts Group (VQEG) projects. VQEG is an international multi-stakeholder forum where algorithm developers and industry users meet twice a year to plan and execute validation tests of objective perceptual quality metrics for standardization purposes. Understanding that the most impactful open issues in video quality assessment cannot be resolved by any single organization in isolation, the ITS Video Quality Research program has supported this collaboration and open sharing of information among industry, academia, and government since 1997. VQEG is currently co-chaired by ITS’s Margaret H. Pinson and Kjell Brunnström of the RISE Research Institute of Sweden AB.
ITS’s work with VQEG leverages the research of a renowned video quality research program that is entering its fifth decade of collaborating directly with stakeholders on the development of strong, unbiased, internat ional standards for critical and emerging video technologies. ITS video quality research publications, open source software (including the No-Reference (NR) Metric Framework), and independent analyses of new video technologies help U.S. industry and advance the U.S. Department of Commerce’s strategic goal of driving U.S. innovation and global competitiveness.
Mrs. Pinson’s most recent IEEE Transactions on Broadcasting article, “The Precision and Repeatability of Media Quality Comparisons: Measurements and New Statistical Methods,” provides a comprehensive overview of NR metrics for image quality analysis (IQA) and video quality analysis (VQA) and proposes a paradigm for collaboratively developing NR metrics that will significantly advance the science, benefiting commercial network operators as well as mission critical communications.
To facilitate and foster collaborative research and development in the area of consumer video processing and quality measurement, ITS hosts the Consumer Digital Video Library (CDVL), where subjective video quality datasets and studio quality video sequences are openly shared for research and development purposes. The VQEG NORM working group, an open collaborative for developing NR metrics for monitoring visual service quality, intends to make all its work public and royalty-free.
How to enable in-service estimates of video quality for live video streaming systems was one of the two most popular topics at the Fall 2022 VQEG meeting, held virtually in December. The other was how to address quality problems with virtual reality and other immersive media technologies. Working groups continue to meet on these and other VQEG topics throughout the year, implementing a highly collaborative and iterative approach to developing, defining, and deploying algorithms, methods, and tools that help address the rapid evolution of multimedia technologies and move the industry forward.
Some of the more innovative studies undertaken by VQEG participants seek improved video technologies for health care—for example, researchers at the Institut National des Sciences Appliquées de Rennes (INSA Rennes) are using video quality assessment techniques to develop a potential new therapy technique for people with autism spectrum disorder (ASD). And the Université d’Orléans is developing a metric that could improve hospital response times, by identifying image quality problems that would require a patient to return to the imaging department for additional scans.
On the last day of the Fall 2022 meeting, VQEG attendees finalized discussions on proposed improvements to International Telecommunication Union Telecommunication Standardization Sector (ITU-T) Recommendations P.910, P.911, and P.913, which U.S. industry relies upon in order to develop modern video systems for cameras, video streaming services, monitors, etc. However, rapid advances in video technology have left P.910 and P.911 partly obsolete, and the focus of P.913 has by default changed from emerging technologies to mainstream technologies—such as internet video streamed to mobile devices.
VQEG held regular meetings to develop a proposal to merge P.910, P.911, and P.913 into a single Recommendation. The proposed edits include improved techniques that have been vetted by international experts over the past decade of VQEG meetings. The updated Rec. will provide new tools to help U.S. industry make optimal trade-offs between consumer perception of video quality, wireless bandwidth, and power consumption—without hiring an expert in video quality assessment. ITS submitted the VQEG proposal as a U.S. contribution to ITU-T Study Group 12. Discussions will continue during an ITU-T Study Group 12 Rapporteur Group Meeting, to be co-located with the spring VQEG meeting, which will be hosted by Sony Interactive Entertainment (SIE) in San Mateo, CA.
The focus of yesterday’s VQEG NORM virtual meeting was to develop an NR metric that estimates the optimal compression resolution for a given bit rate and level of video quality. This NR metric would let live video streaming services deploy the adaptive bit rate (ABR) coding strategies. On-demand video streaming services use ABR to dynamically adjust the video stream as the network bandwidth and error rates change. On-demand video streaming services also optimize resolution, bit rate, and quality, but most of the decisions are made ahead of time using large banks of servers. The proposed NR metric would extend ABR to live video streaming. Another use case is priority access and other managed networks, which could use the proposed NR metric to consider the impact of increasing or decreasing bandwidth allocations on user experience.
This effort builds on the ITU-T Rec. P.910 metrics, Spatial Information (SI) and Temporal Information (TI). These NR metrics were developed by ITS in 1994 and remain popular with U.S. industry for research and development purposes. In the past few years, ITS hosted a series of VQEG NORM meetings that clarify aspects of the SI and TI metrics that had become ambiguous due to advances in video technology from 1994 to present.