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150 results on '"Mathias Wien"'

1. Remote expert viewing, laboratory tests or objective metrics: which one(s) to trust?

Author

Mathias Wien and Joel Jung

Subjects
Visual quality assessment, Quality metrics, Remote expert viewing, Visual media coding, Electronics, TK7800-8360
Abstract

Abstract We present a study on the validity of quality assessment in the context of the development of visual media coding schemes. The work is motivated by the need for reliable means for decision-taking in standardization efforts of MPEG and JVET, i.e., the adoption or rejection of coding tools during the development process of the coding standard. The study includes results considering three means: objective quality metrics, remote expert viewing, which is a method designed in the context of MPEG standardization, and formal laboratory visual evaluation. The focus of this work is on the comparison of pairs of coded video sequences, e.g., a proposed change and an anchor scheme at a given rate point. An aggregation of performance measurements across multiple rate points, such as the Bjøntegaard Delta rate, is out of the scope of this paper. The paper details the test setup for the subjective assessment methods and the objective quality metrics under consideration. The results of the three approaches are reviewed, analyzed, and compared with respect to their suitability for the decision-taking task. The study indicates that, subject to the chosen test content and test protocols, the results of remote expert viewing using a forced-choice scale can be considered more discriminatory than the results of naïve viewers in the laboratory tests. The results further that, in general, the well-established quality metrics, such as PSNR, SSIM, or MS-SSIM, exhibit a high rate of correct decision-making when their results are compared with both types of viewing tests. Among the learning-based metrics, VMAF and AVQT appear to be most robust. For the development process of a coding standard, the selection of the most suitable means must be guided by the context, where a small number of carefully selected objective metrics, in combination with viewing tests for unclear cases, appears recommendable.

Published
2024
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45. Special issue on Open Media Compression: Overview, Design Criteria, and Outlook on Emerging Standards

Author

Mathias Wien, Christian Timmerer, Lu Yu, and Amy Reibman

Subjects
business.industry, Computer science, Universal design, Bandwidth (computing), Provisioning, The Internet, Use case, Internet traffic, Electrical and Electronic Engineering, Virtual reality, Telecommunications, business, Mixed reality
Abstract

Universal access to and provisioning of multimedia content is now a reality. It is easy to generate, distribute, share, and consume any multimedia content, anywhere, anytime, or any device. Open media standards took a crucial role toward enabling all these use cases leading to a plethora of applications and services that have now become a commodity in our daily life. Interestingly, most of these services adopt a streaming paradigm, are typically deployed over the open, unmanaged Internet, and account for most of today’s Internet traffic. Currently, the global video traffic is greater than 60% of all Internet traffic [1] , and it is expected that this share will grow to more than 80% in the near future [2] . In addition, Nielsen’s law of Internet bandwidth states that the users’ bandwidth grows by 50% per year, which roughly fits data from 1983 to 2019 [3] . Thus, the users’ bandwidth can be expected to reach approximately 1 Gb/s by 2022. At the same time, network applications will grow and utilize the bandwidth provided, just like programs and their data expand to fill the memory available in a computer system. Most of the available bandwidth today is consumed by video applications, and the amount of data is further increasing due to already established and emerging applications, e.g., ultrahigh definition, high dynamic range, or virtual, augmented, mixed realities, or immersive media applications in general.

Published
2021

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