Understanding user interactions in stereoscopic head-mounted displays

2022 Spring.Includes bibliographical references.Interacting in stereoscopic head mounted displays can be difficult. There are not yet clear standards for how interactions in these environments should be performed. In virtual reality there are a number of well designed interaction techniques; however, augmented reality interaction techniques still need to be improved before they can be easily used. This dissertation covers work done towards understanding how users navigate and interact with virtual environments that are displayed in stereoscopic head-mounted displays. With this understanding, existing techniques from virtual reality devices can be transferred to augmented reality where appropriate, and where that is not the case, new interaction techniques can be developed. This work begins by observing how participants interact with virtual content using gesture alone, speech alone, and the combination of gesture+speech during a basic object manipulation task in augmented reality. Later, a complex 3-dimensional data-exploration environment is developed and refined. That environment is capable of being used in both augmented reality (AR) and virtual reality (VR), either asynchronously or simultaneously. The process of iteratively designing that system and the design choices made during its implementation are provided for future researchers working on complex systems. This dissertation concludes with a comparison of user interactions and navigation in that complex environment when using either an augmented or virtual reality display. That comparison contributes new knowledge on how people perform object manipulations between the two devices. When viewing 3D visualizations, users will need to feel able to navigate the environment. Without careful attention to proper interaction technique design, people may struggle to use the developed system. These struggles may range from a system that is uncomfortable and not fit for long-term use, or they could be as major as causing new users to not being able to interact in these environments at all. Getting the interactions right for AR and VR environments is a step towards facilitating their widespread acceptance. This dissertation provides the groundwork needed to start designing interaction techniques around how people utilize their personal space, virtual space, body, tools, and feedback systems

Three-dimensional media for mobile devices

Cataloged from PDF version of article.This paper aims at providing an overview of the core technologies enabling the delivery of 3-D Media to next-generation mobile devices. To succeed in the design of the corresponding system, a profound knowledge about the human visual system and the visual cues that form the perception of depth, combined with understanding of the user requirements for designing user experience for mobile 3-D media, are required. These aspects are addressed first and related with the critical parts of the generic system within a novel user-centered research framework. Next-generation mobile devices are characterized through their portable 3-D displays, as those are considered critical for enabling a genuine 3-D experience on mobiles. Quality of 3-D content is emphasized as the most important factor for the adoption of the new technology. Quality is characterized through the most typical, 3-D-specific visual artifacts on portable 3-D displays and through subjective tests addressing the acceptance and satisfaction of different 3-D video representation, coding, and transmission methods. An emphasis is put on 3-D video broadcast over digital video broadcasting-handheld (DVB-H) in order to illustrate the importance of the joint source-channel optimization of 3-D video for its efficient compression and robust transmission over error-prone channels. The comparative results obtained identify the best coding and transmission approaches and enlighten the interaction between video quality and depth perception along with the influence of the context of media use. Finally, the paper speculates on the role and place of 3-D multimedia mobile devices in the future internet continuum involving the users in cocreation and refining of rich 3-D media content

Open Profiling of Quality: A Mixed Methods Research Approach for Audiovisual Quality Evaluations

Den Anforderungen der Konsumenten gerecht zu werden und ihnen eine immer besser werdende Quality of Experience zu bieten, ist eine der großen Herausforderungen jeder Neuentwicklung im Bereich der Multimediasysteme. Doch proportional zur technischen Komplexität neuer Systeme, in denen Komponenten unterschiedlicher Technologien zu neuen System wie zum Beispiel mobilem 3D-Fernsehen verschmolzen werden, steigt auch die Frage, wie eine optimierte Quality of Experience eigentlich zu erreichen ist. Daher werden seit langer Zeit Nutzertests zur subjektiven Qualitätsbewertung durchgeführt. Deren Ziel über den gesamten Entwcklungsprozesses ist es, die kritischen Komponenten des Systems mit so wenig wie möglich wahrnehmbarem Einfluss auf diewahrgenommene Qualität des Nutzers zu optimieren. Bereits seit den 1970er Jahren werden hierfür Leitfäden verschiedener Standardisierungsgremien zur Verfügung gestellt, in denen unterschiedliche Evaluationsmethoden definiert sind, um die wahrgenommene Gesamtqualität des Systems mit Hilfe von Skalen quantitativ evaluieren zu können. Aktuelle Ansätze erweitern diese klassische Methoden um Sichtweise, die über die klassische Evaluation hedonistischer Gesamtqualität hinausgehen, um das Wissen über individuell zugrundeliegende Qualitätsfaktoren zu erweitern.Die vorliegende Dissertation verfolgt dabei zwei Ziele. Zum einen soll eine audiovisuelle Evaluationsmethode entwickelt werden, die eine kombinierte Analyse quantitativer und qualitativer Daten ermöglicht, um eine Verknüpfung hedonistischer Qualität und zugrundeliegender Qualitätsfaktoren zu ermöglichen. Weiter soll diese Methode innerhalb des Gebiets der mobiler 3DTV-Systeme erprobt und validiert werden.Open Profiling of Quality (OPQ) als Evaluationsmethode kombiniert quantitative Evaluation wahrgenommener Gesamtqualität und deskriptive, sensorische Analyse zur Erhebung individueller Qualitätsfaktoren. Die Methode ist für Erhebungen mit naiven Probanden geeignet. OPQ wurde unter besonderer Beachtung von Validität und Reliabilität in einem konstruktivem Ansatz entwickelt und in einer Folge von Studien während der Entwicklung eines mobilem 3DTV-Systems mit über 300 Probanden angewendet. Die Ergebnisse dieser Studien unterstreichen die sich ergänzenden Ergebnisse quantitativer und sensorischer Analysen.Neben der Entwicklung von OPQ werden in der vorliegenden Arbeit weitere Ansätze sensorischer Analyse präsentiert und miteinander verglichen. Gerade dieser Vergleich ist ein wichtiger Bestandteil der Validierung der OPQ-Methode. Um die Stärken und Schwächen jeder Methode ganzheitlich erfassen und vergleichen zu können, wurde hierfür ein Methodenvergleichsmodell entwickelt und operationalisiert, das den methodischen Beitrag der Arbeit vervollständigtTo meet the requirements of consumers and to provide them with a greater quality of experience than existing systems do is a key issue for the success of modern multimedia systems. However, the question about an optimized quality of experience becomes more and more complex as technological systems are evolving and several systems are merged into new ones, e.g. systems for mobile 3D television and video. To be able to optimize critical components of a system under development with as little perceptual errors as possible, user studies are conducted throughout the whole process. A variety of research methods for different purposes have been provided by standardization bodies since the 1970s. These methods allow researchers to evaluate the hedonic excellence of a set of test stimuli. However, a broader view to quality has been taken recently to be able to evaluate quality beyond its hedonic excellence to obtain a greater knowledge about perceived quality and its subjective quality factors that impact on the user.The goal of this thesis is twofold. The primary goal is the development of a validated mixed methods research approach for audiovisual quality evaluations. The method shall allow collecting quantitative and descriptive data during the experiment to combine evaluation of hedonic excellence and the elicitation of underlying subjective quality factors. The second goal is the application of the developed method within a series of studies in the domain of mobile 3D video and television to show its applicability.Open Profiling of Quality (OPQ) is a mixed-methods research approach which combines a quantitative, psychoperceptual evaluation of hedonic excellence and a descriptive sensory analysis of underlying quality factors based on naive participants' individual vocabulary. This combination allows defining the excellence of overall quality, understanding the characteristics of quality perception, and, eventually, constructing a link between preferences and quality attributes. The method was developed under constructive research with respect to validity and reliability of test results. A series of quality evaluation studies with more than 300 test participants was conducted along different critical components of a system for optimized mobile 3DTV content delivery over DVB-H.The results complemented each other, and, even more importantly, quantitative quality preferences were explained by sensory descriptions in all studies. Beyond the development of OPQ, the thesis proposes further research approaches, e.g. a conventional profiling in which OPQ's individual vacobulary is substituted by a fixed set of Quality ofExperience components or Descriptive Sorted Napping which combines a sorting task and a short post-task interview. All approaches are compared to Open ProVling of Quality at the end of the thesis. To be able to holistically contrast strengths and weaknesses of each method, a comparison model for audiovisual evaluation methods was developed and a Vrst conceptual operationalization of the model was applied in the comparison

Descriptive quality of experience for mobile 3D video

ilmenau.de} Perceptual quality evaluation experiments are used to assess the excellence of multimedia quality. However, these studies disregard qualitative experiential descriptions, interpretations, and impressions of quality. The goal of this paper is to identify general descriptive characteristics of experienced quality of 3D video on mobile devices. We conducted five studies in which descriptive data was collected after the psychoperceptual quality evaluation experiment. Qualitative semi-structured interviews and written attribute description tasks were conducted with over 90 naïve participants. The experiments contained an extensive and heterogeneous set of produced quality by varying content, level of depth, compression and transmission parameters, and audio and display factors for 3D. The results showed that quality of experience is constructed from four main components, 1) visual quality, 2) viewing experience, 3) content, and 4) quality of other modalities and their interactions. Author Keywords Quality perception, quality of experience, multimedia, 3

Impact of disparity error on user experience of interacting with stereoscopic 3D video content

The stereoscopic three-dimensional (3D) displays can offer immersive experience to the audience by artificially stimulating binocular stereopsis in the human visual system. The binocular disparity between the left and right view is the key factor in creating the impression of depth, distinguishing the stereo 3D video from other types of video paradigms. Taking into consideration of the imperfections of current disparity estimation algorithms, this paper focus on the impact of disparity error on the user experience of pointing and selecting stereo 3D content. The conducted user study into perception tolerance suggests that users can tolerate disparity errors to a certain degree, where the level of tolerance varies with perceived distance from the screen. In addition, the study demonstrates that for a typical interaction task, reduction of accuracy is proportional to the disparity level of targeted 3D objects

3D multiple description coding for error resilience over wireless networks

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Mobile communications has gained a growing interest from both customers and service providers alike in the last 1-2 decades. Visual information is used in many application domains such as remote health care, video –on demand, broadcasting, video surveillance etc. In order to enhance the visual effects of digital video content, the depth perception needs to be provided with the actual visual content. 3D video has earned a significant interest from the research community in recent years, due to the tremendous impact it leaves on viewers and its enhancement of the user’s quality of experience (QoE). In the near future, 3D video is likely to be used in most video applications, as it offers a greater sense of immersion and perceptual experience. When 3D video is compressed and transmitted over error prone channels, the associated packet loss leads to visual quality degradation. When a picture is lost or corrupted so severely that the concealment result is not acceptable, the receiver typically pauses video playback and waits for the next INTRA picture to resume decoding. Error propagation caused by employing predictive coding may degrade the video quality severely. There are several ways used to mitigate the effects of such transmission errors. One widely used technique in International Video Coding Standards is error resilience. The motivation behind this research work is that, existing schemes for 2D colour video compression such as MPEG, JPEG and H.263 cannot be applied to 3D video content. 3D video signals contain depth as well as colour information and are bandwidth demanding, as they require the transmission of multiple high-bandwidth 3D video streams. On the other hand, the capacity of wireless channels is limited and wireless links are prone to various types of errors caused by noise, interference, fading, handoff, error burst and network congestion. Given the maximum bit rate budget to represent the 3D scene, optimal bit-rate allocation between texture and depth information rendering distortion/losses should be minimised. To mitigate the effect of these errors on the perceptual 3D video quality, error resilience video coding needs to be investigated further to offer better quality of experience (QoE) to end users. This research work aims at enhancing the error resilience capability of compressed 3D video, when transmitted over mobile channels, using Multiple Description Coding (MDC) in order to improve better user’s quality of experience (QoE). Furthermore, this thesis examines the sensitivity of the human visual system (HVS) when employed to view 3D video scenes. The approach used in this study is to use subjective testing in order to rate people’s perception of 3D video under error free and error prone conditions through the use of a carefully designed bespoke questionnaire.Petroleum Technology Development Fund (PTDF

Goggles in the lab:Economic experiments in immersive virtual environments

This review outlines the potential of virtual reality for creating naturalistic and interactive high-immersive environments in experimental economics. After explanation of essential terminology and technical equipment, the advantages are discussed by describing the available high-immersive VR experiments concerning economic topics to give an idea of the possibilities of VR for economic experiments. Furthermore, possible drawbacks are examined, including simulator sickness, the costs of VR equipment and specialist skills. By carefully controlling a naturalistic experimental context, virtual reality brings some field into the lab. Besides, it allows for testing contexts that would otherwise be unethical or impossible. It is a promising new tool in the experimental economics toolkit

Emotion Recognition in Immersive Virtual Reality: From Statistics to Affective Computing

[EN] Emotions play a critical role in our daily lives, so the understanding and recognition of emotional responses is crucial for human research. Affective computing research has mostly used non-immersive two-dimensional (2D) images or videos to elicit emotional states. However, immersive virtual reality, which allows researchers to simulate environments in controlled laboratory conditions with high levels of sense of presence and interactivity, is becoming more popular in emotion research. Moreover, its synergy with implicit measurements and machine-learning techniques has the potential to impact transversely in many research areas, opening new opportunities for the scientific community. This paper presents a systematic review of the emotion recognition research undertaken with physiological and behavioural measures using head-mounted displays as elicitation devices. The results highlight the evolution of the field, give a clear perspective using aggregated analysis, reveal the current open issues and provide guidelines for future research.This research was funded by European Commission, grant number H2020-825585 HELIOS.Marín-Morales, J.; Llinares Millán, MDC.; Guixeres Provinciale, J.; Alcañiz Raya, ML. (2020). Emotion Recognition in Immersive Virtual Reality: From Statistics to Affective Computing. Sensors. 20(18):1-26. https://doi.org/10.3390/s20185163S126201

User-based gesture vocabulary for form creation during a product design process

There are inconsistencies between the nature of the conceptual design and the functionalities of the computational systems supporting it, which disrupt the designers’ process, focusing on technology rather than designers’ needs. A need for elicitation of hand gestures appropriate for the requirements of the conceptual design, rather than those arbitrarily chosen or focusing on ease of implementation was identified.The aim of this thesis is to identify natural and intuitive hand gestures for conceptual design, performed by designers (3rd, 4th year product design engineering students and recent graduates) working on their own, without instruction and without limitations imposed by the facilitating technology. This was done via a user centred study including 44 participants. 1785 gestures were collected. Gestures were explored as a sole mean for shape creation and manipulation in virtual 3D space. Gestures were identified, described in writing, sketched, coded based on the taxonomy used, categorised based on hand form and the path travelled and variants identified. Then they were statistically analysed to ascertain agreement rates between the participants, significance of the agreement and the likelihood of number of repetitions for each category occurring by chance. The most frequently used and statistically significant gestures formed the consensus set of vocabulary for conceptual design. The effect of the shape of the manipulated object on the gesture performed, and if the sequence of the gestures participants proposed was different from the established CAD solid modelling practices were also observed.Vocabulary was evaluated by non-designer participants, and the outcomes have shown that the majority of gestures were appropriate and easy to perform. Evaluation was performed theoretically and in the VR environment. Participants selected their preferred gestures for each activity, and a variant of the vocabulary for conceptual design was created as an outcome, that aims to ensure that extensive training is not required, extending the ability to design beyond trained designers only.There are inconsistencies between the nature of the conceptual design and the functionalities of the computational systems supporting it, which disrupt the designers’ process, focusing on technology rather than designers’ needs. A need for elicitation of hand gestures appropriate for the requirements of the conceptual design, rather than those arbitrarily chosen or focusing on ease of implementation was identified.The aim of this thesis is to identify natural and intuitive hand gestures for conceptual design, performed by designers (3rd, 4th year product design engineering students and recent graduates) working on their own, without instruction and without limitations imposed by the facilitating technology. This was done via a user centred study including 44 participants. 1785 gestures were collected. Gestures were explored as a sole mean for shape creation and manipulation in virtual 3D space. Gestures were identified, described in writing, sketched, coded based on the taxonomy used, categorised based on hand form and the path travelled and variants identified. Then they were statistically analysed to ascertain agreement rates between the participants, significance of the agreement and the likelihood of number of repetitions for each category occurring by chance. The most frequently used and statistically significant gestures formed the consensus set of vocabulary for conceptual design. The effect of the shape of the manipulated object on the gesture performed, and if the sequence of the gestures participants proposed was different from the established CAD solid modelling practices were also observed.Vocabulary was evaluated by non-designer participants, and the outcomes have shown that the majority of gestures were appropriate and easy to perform. Evaluation was performed theoretically and in the VR environment. Participants selected their preferred gestures for each activity, and a variant of the vocabulary for conceptual design was created as an outcome, that aims to ensure that extensive training is not required, extending the ability to design beyond trained designers only