http://ii.tudelft.nl/iqlab/assets/1-s2.0-S0747563215001752-main.pdf

Understanding the role of social context and user factors in video Quality of Experience

Videoconferencing is becoming an essential part in everyday life. The visual channel allows us for interactions that were not possible over audio-only communication systems, such as the telephone. However, being a de-facto over-the-top service, the quality of the delivered videoconferencing experience is subject to variations, depending on network conditions. Videoconferencing systems adapt to network conditions by changing, for example, encoding bit rate of the video. For this adaptation not to hamper the benefits related to the presence of a video channel in the communication, it needs to be optimized according to a measure of the quality of experience (QoE) as perceived by the user. The latter is highly dependent on the ongoing interaction and individual preferences, which have hardly been investigated so far. In this paper, we focus on the impact that video quality has on conversations that revolve around objects that are presented over the video channel. To this end, we conducted an empirical study where groups of four people collaboratively build a Lego model over a videoconferencing system. We examine the requirements for such a task by showing when the interaction, measured by visual and auditory cues, changes depending on the encoding bit rate and loss. We then explore the impact that prior experience with the technology and affective state have on QoE of participants. We use these factors to construct predictive models that double the accuracy compared to a model based on the system factors alone. We conclude with a discussion of how these factors could be applied in real-world scenarios.

/pdf/towards-individual-qoe-for-multiparty-videoconferencing-59vht938nz.pdf

Towards Individual QoE for Multiparty Videoconferencing

Subjective assessment of quality of experience (QoE) is key to understanding user preferences with respect to multimedia fruition As such, it is a necessary step to multimedia delivery optimization, since QoE needs to take into account technology limitations as well as user satisfaction The study of QoE appreciation dates back to the twentieth century, when it exploded with the advent of CRT first and LCD displays later For a long time, this branch of research was targeted at determining user sensitivity to impairments induced in the media by suboptimal delivery The media recipient was considered a passive observer, whose appreciation of the video material was determined primarily by the degree of annoyance due to the impairments affecting it With the advent of mobile technology and Internet-based media delivery, this impairment-centric concept of QoE has shown to be incomplete The media recipient became an active user who creates content, interacts with the system, and selects the media he/she wants to have delivered As a result, elements such as visual semantics, user personality, preferences and intent, social and environmental context of media fruition also concur to the final experience assessment The role played by these elements in QoE and the cognitive/affective processes that underlie them are still to be understood, although several models of QoE appreciation have already been proposed In this paper, we review the evolution of subjective QoE assessment and models from the impairment-centric approach to a more user-centric approach We analyze relevant features and factors influencing QoE, and point out future directions for subjective QoE assessment research

How passive image viewers became active multimedia users : new trends and recent advances in subjective assessment of quality of experience

Summary This paper presents a quality of experience (QoE) conceptual model to the context of unified communications (UC) through summary, classification, and discussion of multiple influence factor...

Quality of experience for unified communications: A survey

Web real-time communication (WebRTC) based services introduce the new way of communication and collaboration. These types of services allow real-time communication with voice, video, messaging, and data sharing via browser. Their success and adoption depend on a number of different factors that influence user's experience and its quality. As WebRTC based services are growing, it is important to identify these influence factors (IFs) and investigate their impact on quality of experience (QoE). In this paper, the focus is on users' experience with WebRTC video calling. The objective is to determine the most and least influential factors in general according to examined users' opinions in the context of WebRTC video calling, and all for the successful management of QoE. With this in focus, this paper may serve as a basis for further research in the field in order to increase the utilization and adoption of WebRTC technology.

What factors influence the quality of experience for WebRTC video calls

Nowadays, Service Providers are increasingly concerned about the concept of Quality of Experience (QoE),, even more, when talking about Internet TV or WebTV, where no guarantees of delivery are provided. This paper describes the research and the results on the influence of the level of interest (on a particular sport) in the subjective quality assessment of the corresponding broadcasted media. This analysis is motivated by the work being developed in the European Project My-eDirector 2012, which has the capability to cover the London Olympic Games 2011 via the Web. Therefore, a subjective test was prepared and performed where each observer visioned and assessed the perceived video quality of a set of six sports, encoded in four different bitrate/resolution sets. From the analysis of the collected data it is possible to demonstrate that the interest level has a strong influence in the subjective assessment of the video quality. Based on these results, an empiric formula was deduced to estimate the Mean Opinion Source (MOS) as a function of bitrate and interest level.

/pdf/quality-of-experience-assessment-in-internet-tv-336ggdpeof.pdf

Quality of Experience Assessment in Internet TV

Nowadays, Service Providers are increasingly concerned about the concept of Quality of Experience (QoE),, even more, when talking about Internet TV or WebTV, where no guarantees of delivery are provided This paper describes the research and the results on the influence of the level of interest (on a particular sport) in the subjective quality assessment of the corresponding broadcasted media This analysis is motivated by the work being developed in the European Project My-eDirector 2012, which has the capability to cover the London Olympic Games 2011 via the Web Therefore, a subjective test was prepared and performed where each observer visioned and assessed the perceived video quality of a set of six sports, encoded in four different bitrate/resolution sets From the analysis of the collected data it is possible to demonstrate that the interest level has a strong influence in the subjective assessment of the video quality Based on these results, an empiric formula was deduced to estimate the Mean Opinion Source (MOS) as a function of bitrate and interest level

/pdf/quality-of-experience-assessment-in-internet-tv-2odf7svkaz.pdf

Joana Palhais

Papers

Quality of Experience Assessment in Internet TV

Quality of Experience Assessment in Internet TV