| 1. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Andersson, Jonathan, et al.
(författare)
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Exploring the Impact of Menu Systems, Interaction Methods, and Sitting or Standing Posture on User Experience in Virtual Reality
- 2023
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Ingår i: 2023 IEEE Gaming, Entertainment, and Media Conference, GEM 2023. - : Institute of Electrical and Electronics Engineers (IEEE). - 9798350315400
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Konferensbidrag (refereegranskat)abstract
- Virtual Reality (VR) has become an increasingly crucial aspect in both commercial and industrial settings. However, the user experience of the user interfaces and interaction methods in the VR environment is often overlooked. This paper aims to explore different menu systems, interaction methods, and the user’s sitting or standing posture on user experience and cybersickness in VR applications. An experiment with two menu systems and two interaction methods in an implemented VR application was conducted with 20 participants. The results found that traditional, top-down, panel menus with motion controls are the best combination regarding the user experience. Sitting posture provides less severe simulator sickness symptoms than standing.
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| 3. |
- Elwardy, Majed, et al.
(författare)
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ACR360 : A Dataset on Subjective 360° Video Quality Assessment Using ACR Methods
- 2023
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Ingår i: 2023 16th International Conference on Signal Processing and Communication System, ICSPCS 2023 - Proceedings. - : Institute of Electrical and Electronics Engineers (IEEE). - 9798350333510
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Konferensbidrag (refereegranskat)abstract
- The recent advances in immersive technologies have been essential in the development of a wide range of novel standalone and networked immersive media applications. The concepts of virtual reality, augmented reality, and mixed reality relate to different compositions of real and computer-generated virtual objects. In this context, 360° video streaming has become increasingly popular offering improved immersive experiences when viewed on a head-mounted display (HMD). An important component in the development of novel immersive media systems are subjective tests in which participants assess the quality of experience of representative test stimuli. In this paper, the annotated ACR360 dataset is presented which is publicly available on GitHub. The ACR360 dataset contains a wide range of psychophysical and psychophysiological data that was collected in Subjective tests on 360° video quality. The test stimuli were shown on an HMD and rated according to the absolute category rating (ACR) and modified ACR (MACR) methods. To support an easy exploration and utilization of the ACR360 dataset by the research community, its structure on GitHub is described and a comprehensive illustration of analysis options are provided for each data category. The ACR360 dataset may be used for conducting meta-analysis in combination with other datasets to improve precision and to pursue research questions that cannot be answered by an individual study. © 2023 IEEE.
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| 4. |
- Elwardy, Majed, et al.
(författare)
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Comparison of ACR Methods for 360° Video Quality Assessment Subject to Participants' Experience with Immersive Media
- 2020
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Ingår i: 2020 14th International Conference on Signal Processing and Communication Systems, ICSPCS 2020 - Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. - 9781728199726
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Konferensbidrag (refereegranskat)abstract
- Watching 360° videos on head-mounted displays (HMDs) has become more popular in recent years. As such, subjective quality assessment of 360° videos on HMDs is needed to obtain a ground truth on the quality as perceived by users. Due to the lack of standardized methods, the absolute category rating (ACR) with hidden reference (ACR-HR) method for conventional videos has also been used for subjective quality assessment of 360° videos on HMDs. A modified ACR (M-ACR) method tailored for assessing 360° videos on HMDs has recently been proposed. In this paper, we compare the ACR-HR and M-ACR with hidden reference (M-ACR-HR) method regarding subjective quality assessment of 360° videos on HMDs. The comparison is conducted subject to participants' experience with watching immersive media on HMDs. The findings include: 1) Average rating times to cast opinion scores is lower for the ACR-HR method irrespective of participants' experience, 2) Mean opinion scores are similar for both methods irrespective of participants' experience, 3) The M-ACR-HR method is more reliable, especially with experts and participants with no experience, 4) Discomfort is significantly lower for the ACR-HR method, especially, for participants with no experience. © 2020 IEEE.
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| 5. |
- Elwardy, Majed, et al.
(författare)
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Evaluation of Simulator Sickness for 360 degrees Videos on an HMD Subject to Participants' Experience with Virtual Reality
- 2020
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Ingår i: IEEE CONFERENCE ON VIRTUAL REALITY AND 3D USER INTERFACES WORKSHOPS (VRW 2020). - : Institute of Electrical and Electronics Engineers Inc.. - 9781728165325 ; , s. 477-484
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Konferensbidrag (refereegranskat)abstract
- Virtual reality (VR) has seen tremendous advances in head-mounted displays (HMDs), optics, media quality, and other improvements that facilitate immersive experiences. With the occurrence of new technologies like Cloud VR and networked VR video services, applications such as 360° video streaming are becoming more popular within the broader consumer markets. As a result, VR content is accessible to customers with rather different levels of experiences with immersive media, i.e., never, sometimes, or often use of VR. The question, therefore, arises to which degree simulator sickness is induced to viewers depending on their experiences with VR on HMDs. In this paper, simulator sickness is evaluated for 360° videos that were shown on an HTC Vive Pro HMD to participants having different levels of experience with VR on HMDs. The modified absolute category rating with hidden reference (M-ACR-HR) method was used in a subjective experiment for video quality assessment within two subsequent sessions along with a simulator sickness questionnaire (SSQ). A statistical analysis of the SSQ scores is performed to reveal the relationship between simulator sickness and participants' experiences with VR regarding: (1) Individual symptoms, (2) Pairwise comparison of symptoms, and (3) Symptom clusters of nausea, oculomotor, disorientation, and total score. It is shown that the simulator sickness symptoms, in general, are slightly or rarely perceived across the different experience levels for the selected 360° videos. The results indicate that the reported simulator sickness increases in the second session for participants that never used VR on HMDs. Sufficiently long breaks between sessions should therefore be accounted for in the M-ACR-HR method to avoid that simulator sickness influences quality rating. © 2020 IEEE.
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| 6. |
- Elwardy, Majed, 1988-, et al.
(författare)
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Impact of Participants' Experiences with Immersive Multimedia on 360 degrees Video Quality Assessment
- 2019
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Ingår i: 13th International Conference on Signal Processing and Communication Systems, ICSPCS 2019 - Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. - 9781728121949
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Konferensbidrag (refereegranskat)abstract
- In this paper, we study the impact that the level of experience of participants with immersive multimedia has on 360° video quality assessment. An extensive subjective experiment using the modified absolute category rating with hidden reference (M-ACR-HR) method was conducted. The opinion scores obtained from the participants in this experiment along with other sensor data support this study. The statistical analysis is performed in terms of screening participants' distribution of opinion scores for consistency, average rating time, box plots related to mean opinion scores (MOSs) and differential MOS (DMOS). Detailed results for MOS and DMOS are also provided for reference and test sequences covering a wide range of qualities. Major findings include: (1) Screening detects many outliers for participants with no experience, (2) Average rating times show that experts learn the quality assessment task fast, (3) Participants with no experience provide lower opinion scores in average, (4) DMOS may alleviate the bias in quality rating caused by different levels of experience. © 2019 IEEE.
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| 7. |
- Elwardy, Majed, et al.
(författare)
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On Head Movements in Repeated 360 degrees Video Quality Assessment for Standing and Seated Viewing on Head Mounted Displays
- 2021
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Ingår i: 2021 IEEE CONFERENCE ON VIRTUAL REALITY AND 3D USER INTERFACES ABSTRACTS AND WORKSHOPS (VRW 2021). - : IEEE. - 9781665440578 ; , s. 71-74
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Konferensbidrag (refereegranskat)abstract
- Watching 360 degrees videos on head mounted displays (HMDs) allows viewers to explore scenes in all directions. In this paper, we focus on investigating the head movements of two participants for standing and seated viewing of a total of 720 360 degrees videos on HMDs. The head movements were recorded in a 360 degrees video quality assessment experiment which was repeated after a long and short break between sessions to study changes in viewing behavior over time. The analysis of the head movement data is provided as histograms of head rotations, head speed, head turns, and head trajectories. It is shown that the participants have their own distinct exploration behavior for standing viewing which becomes less different for seated viewing.
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| 8. |
- Elwardy, Majed, et al.
(författare)
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On the Consistency of 360° Video Quality Assessment in Repeated Subjective Tests : A Pilot Study
- 2024
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Ingår i: EAI Endorsed Transactions on Industrial Networks and Intelligent Systems. - : European Alliance for Innovation. - 2410-0218. ; 11:1, s. 1-22
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Tidskriftsartikel (refereegranskat)abstract
- Immersive media such as virtual reality, augmented reality, and 360° video have seen tremendous technological developments in recent years. Furthermore, the advances in head-mounted displays (HMDs) offer the users increased immersive experiences compared to conventional displays. To develop novel immersive media systems and services that satisfy the expectations of the users, it is essential to conduct subjective tests revealing users’ perceived quality of immersive media. However, due to the new viewing dimensions provided by HMDs and the potential of interacting with the content, a wide range of subjective tests are required to understand the many aspects of user behavior in and quality perception of immersive media. The ground truth obtained by such subjective tests enable the development of optimized immersive media systems that fulfill the expectations of the users. This article focuses on the consistency of 360° video quality assessment to reveal whether users’ subjective quality assessment of such immersive visual stimuli changes fundamentally over time or is kept consistent for each user. A pilot study was conducted under pandemic conditions with participants given the task of rating the quality of 360° video stimuli on an HMD in standing and seated viewing. The choice of conducting a pilot study is motivated by the fact that immersive media impose high cognitive load on the participants and the need to keep the number of participants under pandemic conditions as low as possible. To gain insight into the consistency of the participants’ 360° video assessment over time, three sessions were held for each participant and each viewing condition with long and short breaks between sessions. In particular, the opinion scores and head movements were recorded for each participant and each session in standing and seated viewing. The statistical analysis of this data leads to the conjecture that the quality rating stays consistent throughout these sessions with each participant having their own quality assessment signature. The head movements, indicating the participants’ scene exploration during the quality assessment task, also remain consistent for each participant according their individual narrower or wider scene exploration signature. These findings are more pronounced for standing viewing than for seated viewing. This work supports the role of pilot studies being a useful approach of conducting pre-tests on immersive media quality under opportunity-limited conditions and for the planning of subsequent full subjective tests with a large panel of participants. The annotated RQA360 dataset containing the data recorded in the repeated subjective tests is made publicly available to the research community. © 2024. M. Elwardy et al., licensed to EAI. This is an open access article distributed under the terms of the CC BY-NC-SA 4.0, which permits copying, redistributing, remixing, transformation, and building upon the material in any medium so long as the original work is properly cited. doi:10.4108/eetinis.v11i1.4323. All Rights Reserved.
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| 9. |
- Elwardy, Majed, et al.
(författare)
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On the Opinion Score Consistency in Repeated 360° Video Quality Assessment for Standing and Seated Viewing on Head-Mounted Displays
- 2021
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Ingår i: 2021 15th International Conference on Signal Processing and Communication Systems, ICSPCS 2021 - Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. - 9781665436991
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Konferensbidrag (refereegranskat)abstract
- The development of immersive media systems and services relies on subjective tests that provide ground truth on the quality of experience as perceived by humans. In this paper, we investigate the opinion score consistency through a repeated subjective 360° video quality assessment experiment. The test stimuli are presented on a head-mounted display with participants given the task to rate the video quality in three repeated sessions for both standing and seated viewing. The statistical analysis of the data from the subjective tests aims at revealing if participants change their rating behavior over time or keep their opinion scores given to the test stimuli in standing and seated viewing consistent in a statistical sense. The experimental results are reported in terms of histograms of opinion scores, skewness and kurtosis of opinion scores, mean opinion scores, standard deviation of opinion scores (SOS), SOS fitting functions, and analysis of variance tests. The statistical analysis supports the conjecture that each participant has its own but consistent rating behavior throughout the respective sessions for standing and seated viewing. The finding that the quality rating behavior of the individual participant does not fundamentally change over time may, e.g., assist in scheduling subjective tests under pandemic conditions where experimental campaigns may need to be stalled for an unknown period of time. © 2021 IEEE.
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| 10. |
- Elwardy, Majed, et al.
(författare)
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SSV360 : A Dataset on Subjetive Quality Assessment of 360° Videos for Standing and Seated Viewing on an HMD
- 2022
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Ingår i: Proceedings - 2022 IEEE Conference on Virtual Reality and 3D User Interfaces Abstracts and Workshops, VRW 2022. - : IEEE Computer Society. - 9781665484022 ; , s. 189-194
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Konferensbidrag (refereegranskat)abstract
- In this paper, we introduce the SSV360 dataset containing psy-chophysical and psychophysiological data gathered in a pilot study on the effect of standing and seated viewing of 360° videos on subjective quality assessment. The stimuli were shown to the participants on a head-mounted display for both viewing conditions. The ground truth contained in the SSV360 dataset may support, e.g., benchmarking of immersive media processing algorithms and developing of objective perceptual quality metrics. © 2022 IEEE.
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