Alexander Raake

Technische Universität Ilmenau | TUI · Institut für Medientechnik

This paper presents a proof-of-concept study conducted to analyze the effect of simple diotic vs. spatial, position-dynamic binaural synthesis on social presence in VR, in comparison with face-to-face communication in the real world, for a sample two-party scenario. A conversational task with shared visual reference was realized. The collected data...

There is an increased interest in understanding users' behavior when exploring omnidirectional (360°) videos, especially in the presence of spatial audio. Several studies demonstrate the effect of no, mono, or spatial audio on visual saliency. However, no studies investigate the influence of higher-order (i.e., 4t h- order) Ambisonics on subjective...

This paper uses a crowdsourced dataset of online video streaming sessions to investigate opportunities to reduce the power consumption while considering QoE. For this, we base our work on prior studies which model both the end-user's QoE and the end-user device's power consumption with the help of high-level video features such as the bitrate, the...

Augmented Reality (AR) and Virtual Reality (VR) are pushing from the labs towards consumers, especially with social applications. These applications require visual representations of humans and intelligent entities. However, displaying and animating photo-realistic models comes with a high technical cost while low-fidelity representations may evoke...

In many research fields, human-annotated data plays an important role as it is used to accomplish a multitude of tasks. One such example is in the field of multimedia quality assessment where subjective annotations can be used to train or evaluate quality prediction models. Lab-based tests could be one approach to get such quality annotations. They...

Since virtual reality (VR) offers great opportunities to investigate auditory phenomena in more close to real-life scenarios, it is important to translate and extend established paradigms to consider the new technology. One major novelty in VR as opposed to classical laboratory conditions is the spatial audio setup and the added immersive visual co...

Laymen are not trained in camera control and how to use a vision mixing desk to switch between different cameras in a video production. Specific training and expert knowledge are required. In the non-professional environment, multi-camera recordings of theater performances or other stage performances are therefore difficult to realize. This can be...

AI-generated images have gained in popularity in recent years due to improvements and developments in the field of artificial intelligence. This has led to several new AI generators, which may produce realistic, funny, and impressive images using a simple text prompt. DALL-E-2, Midjourney, and Craiyon are a few examples of the mentioned approaches....

There are more and more photographic images uploaded to social media platforms such as Instagram, Flickr, or Facebook on a daily basis. At the same time, attention and consumption for such images is high, with image views and liking as one of the success factors for users and driving forces for social media algorithms. Here, "liking" can be assumed...

In a non-professional environment, multi-camera recordings of theater performances or other stage shows are difficult to realize, because amateurs are usually untrained in camera work and in using a vision mixing desk that mixes multiple cameras. This can be remedied by a production process with high-resolution cameras where recordings of image sec...

Research into multi-modal perception, human cognition, behavior, and attention can benefit from high-fidelity content that may recreate real-life-like scenes when rendered on head-mounted displays. Moreover, aspects of audiovisual perception, cognitive processes, and behavior may complement questionnaire-based Quality of Experience (QoE) evaluation...

The ability to focus ones attention in different acoustical environments has been thoroughly investigated in the past. However, recent technological advancements have made it possible to perform laboratory experiments in a more realistic manner. In order to investigate close-to-real-life scenarios, a classroom was modeled in virtual reality (VR) an...

Communication technologies play an important role in maintaining the grandparent-grandchild (GP-GC) relationship. Based on Media Richness Theory, this study investigates the frequency of use (RQ1) and perceived quality (RQ2) of established media as well as the potential use of selected innovative media (RQ3) in GP-GC relationships with a particular...

Most studies investigating the effects of environmental noise on children’s cognitive performance examine the impact of monaural noise (i.e., same signal to both ears), oversimplifying multiple aspects of binaural hearing (i.e., adequately reproducing interaural differences and spatial information). In the current study, the effects of a realistic...

In the past decade, we have witnessed an enormous growth in the demand for online video services. Recent studies estimate that nowadays, more than 1% of the global greenhouse gas emissions can be attributed to the production and use of devices performing online video tasks. As such, research on the true power consumption of devices and their energy...

Instruction at school relies heavily on oral discourse. Listening comprehension is thus of major importance for successful learning. However, in many classrooms, children’s listening is impaired by unfavourable acoustic conditions such as indoor noise and reverberation. Most studies on the effects of environmental noise on children’s speech percept...

Background: Loneliness and social isolation in older age are considered major public health concerns and research on technology-based solutions is growing rapidly. This scoping review of reviews aims to summarize the communication technologies (CTs) (review question RQ1), theoretical frameworks (RQ2), study designs (RQ3), and positive effects of t...

Telemeetings such as audiovisual conferences or virtual meetings play an increasingly important role in our professional and private lives. For that reason, system developers and service providers will strive for an optimal experience for the user, while at the same time optimizing technical and financial resources. This leads to the discipline of...

During the COVID-19 pandemic, many smaller conferences have moved entirely online and larger ones are being held as hybrid events. Even beyond the pandemic, hybrid events reduce the carbon footprint of conference travel and makes events more accessible to parts of the research community that have difficulty traveling long distances, while preservin...

An audio-only paradigm for investigating auditory selective attention has previously been transferred into a classroom-type audio-visual virtual reality (VR) environment. However, directly translating such a paradigm into VR does not promise a close-to-real life scenario, as possible benefits of the virtual environment are not utilized. In the audi...

Videoconferencing (VC) is a type of online meeting that allows two or more participants from different locations to engage in live multi-directional audio-visual communication and collaboration (e.g., via screen sharing). The COVID-19 pandemic has induced a boom in both private and professional videoconferencing in the early 2020s that elicited con...

The paper presents a conceptual, multidimensional approach to understand the technological factors that are assumed to or even have been proven to contribute to what has been coined as Zoom Fatigue (ZF) or more generally Videoconferencing Fatigue (VCF). With the advent of the Covid-19 pandemic, the usage of VC services has drastically increased, le...

The paper presents $AVQBits$ , a versatile, bitstream-based video quality model. It can be applied in several contexts such as video service monitoring, evaluation of video encoding quality, of gaming video QoE, and even of omnidirectional video quality. In the paper, it is shown that $AVQBits$ predictions closely match video quality ratings ob...

The grandparent-grandchild (GP-GC) relationship is a relevant factor for the wellbeing of both grandchildren and grandparents. Digital communication technologies play an important role in maintaining it, especially when face-to-face interactions are not possible, e.g., due to living far from each other or pandemic contact restrictions. The aim of t...

In the project ECoClass-VR, which is part of the AUDIC-TIVE priority programme, we investigate the suitability of audiovisual Immersive Virtual Environments (IVEs) for a "real-world" assessment of cognitive performance of adults and children in classroom-type environments under different visuospatial and acoustic conditions. Existing knowledge in t...

As part of the AUDICTIVE priority program, the overall objective of the ECoClass-VR project is to investigate the cognitive behavior of children in virtual, but close to real-life settings. In the first stage of this project, three validated paradigms focusing on different aspects of auditory cognition are examined and extended towards using virtua...

Recently an impressive development in immersive technologies, such as Augmented Reality (AR), Virtual Reality (VR) and 360 video, has been witnessed. However, methods for quality assessment have not been keeping up. This paper studies quality assessment of 360 video from the cross-lab tests (involving ten laboratories and more than 300 participants...

—Spatial Information (SI) and Temporal Information (TI) are frequently-used metrics to classify the spatiotemporal complexity of video content. However, they are mostly used on original video sources, and their impact on actual encoding efficiency is not known. In this paper, we propose a method to determine the compressibility of video sources, th...

Groove in music is a fundamental part of why humans entrain to it and enjoy it. Smartphones have become an important medium to listen to music. Especially when being with others, loudspeaker playback may be the method of choice. However, due to the physical limits of acoustics, for loudspeaker playback, smartphones are equipped with sub-optimal aud...

Assessing high resolution video quality is usually performed using controlled, defined, and standardized lab tests. This method of acquiring human ratings in a lab environ- ment is time-consuming and may also not reflect the typical viewing conditions. To overcome these disadvantages, crowd testing paradigms have been used for assessing video quali...

Virtual Reality/360° videos provide an immersive experience to users. Besides this, 360° videos may lead to an undesirable effect when consumed with Head-Mounted Displays (HMDs), referred to as simulator sickness/cybersickness. The Simulator Sickness Questionnaire (SSQ) is the most widely used questionnaire for the assessment of simulator sickness....

The popularity of video on-demand streaming services increased tremendously over the last years. Most services use http-based adaptive video streaming methods. Today’s movies and TV shows are typically recorded in UHD-1/4K and streamed using settings attuned to the end-device and current network conditions. Video quality prediction models can be us...

Current state-of-the-art pixel-based video quality models for 4K resolution do not have access to explicit meta information such as resolution and framerate and may not include implicit or ex- plicit features that model the related effects on perceived video quality. In this paper, we propose a meta concept to extend state- of-the-art pixel-based m...

Current state-of-the-art pixel-based video quality models for 4K resolution do not have access to explicit meta information such as resolution and framerate and may not include implicit or explicit features that model the related effects on perceived video quality. In this paper, we propose a meta concept to extend state-of-the-art pixel-based mode...

With the increasing availability of 360° video content, it becomes important to provide smoothly playing videos of high quality for end users. For this reason, we compare the influence of different Motion Interpolation (MI) algorithms on 360° video quality. After conducting a pre-test with 12 video experts in [3], we found that MI is a useful tool...

The paper presents a series of three new video quality model standards for the assessment of sequences of up to UHD/4K resolution. They were developed in a competition within the International Telecommunication Union (ITU-T), Study Group 12, in collaboration with the Video Quality Experts Group (VQEG), over a period of more than two years. A large...

The streaming of gaming content, both passive and interactive, has increased manifolds in recent years. Gaming contents bring with them some peculiarities which are normally not seen in traditional 2D videos, such as the artificial and synthetic nature of contents or repetition of objects in a game. In addition, the perception of gaming content by...

Besides classical videos, videos of gaming matches, entire tournaments or individual sessions are streamed and viewed all over the world. The increased popularity of Twitch or YoutubeGaming shows the importance of additional research on gaming videos. One important pre-condition for live or offline encoding of gaming videos is the knowledge of game...

During the last years, the number of 360 ◦ videos available for streaming has rapidly increased, leading to the need for 360 ◦ streaming video quality assessment. In this paper, we report and publish results of three subjective 360 ◦ video quality tests, with conditions used to reflect real-world bitrates and resolutions including 4K, 6K and 8K, re...

Existing works in the field of quality assessment focus separately on gaming and non-gaming content. Along with the traditional modeling approaches, deep learning based approaches have been used to develop quality models, due to their high prediction accuracy. In this paper, we present a deep learning based quality estimation model considering both...

The chapter outlines the concepts of Sound Quality and Quality of Experience (QoE). Building on these, it describes a conceptual model of sound quality perception and experience during active listening in a spatial-audio context. The presented model of sound quality perception considers both bottom-up (signal-driven) as well as top-down (hypothesis...

Recent deep colorization works predict the semantic information implicitly while learning to colorize black-and-white photographic images. As a consequence, the generated color is easier to be overflowed, and the semantic faults are invisible. As human experience in coloring, the human first recognize which objects and their location in the photo,...

With the coming of age of virtual/augmented reality and interactive media, numerous definitions, frameworks, and models of immersion have emerged across different fields ranging from computer graphics to literary works. Immersion is oftentimes used interchangeably with presence as both concepts are closely related. However, there are noticeable int...

Video streaming providers spend huge amounts of processing time to get a quality-optimized encoding. While the quality-related impact may be known to the service provider, the impact on video quality is hard to assess, when no reference is available. Here, bitstream-based video quality models may be applicable, delivering estimates that include enc...

With the increasing requirement of users to view high-quality videos with a constrained bandwidth, typically realized using HTTP-based adaptive streaming, it becomes more and more important to determine the quality of the encoded videos accurately, to assess and possibly optimize the overall streaming quality. In this paper, we describe a bitstream...

As video streaming accounts for the majority of Internet traffic, monitoring its quality is of importance to both Over the Top (OTT) providers as well as Internet Service Providers (ISPs). While OTTs have access to their own analytics data with detailed information, ISPs often have to rely on automated network probes for estimating streaming qualit...

With the coming of age of virtual/augmented reality and interactive media, numerous definitions, frameworks, and models of immersion have emerged across different fields ranging from computer graphics to literary works. Immersion is oftentimes used interchangeably with presence as both concepts are closely related. However, there are noticeable int...

Nowadays, with recent advances in virtual reality technology, it is easily possible to integrate real objects into virtual environments by creating an exact virtual replication and enabling interaction with them by mapping the obtained tracking data of the real to the virtual objects. The primary goal of our study is to develop a system to investig...

Users may experience symptoms of simulator sickness while watching 360°/VR videos with Head-Mounted Displays (HMDs). At present, practically no solution exists that can efficiently eradicate the symptoms of simulator sickness from virtual environments. Therefore, in the absence of a solution, it is required to at least quantify the amount of sickn...

In recent years, with the introduction of powerful HMDs such as Oculus Rift, HTC Vive Pro, the QoE that can be achieved with VR/360° videos has increased substantially. Unfortunately, no standardized guidelines, methodologies and protocols exist for conducting and evaluating the quality of 360° videos in tests with human test subjects. In this pape...

In recent years, with the introduction of powerful HMDs such as Oculus Rift, HTC Vive Pro, the QoE that can be achieved with VR/360° videos has increased substantially. Unfortunately, no standardized guidelines, methodologies and protocols exist for conducting and evaluating the quality of 360° videos in tests with human test subjects. In this pape...

Today's video streaming providers, e.g. Youtube, Netflix or Amazon Prime, are able to deliver high resolution and high-quality content to end users. To optimize video quality and to reduce transmission bandwidth, new encoders and smarter encoding schemes are required. Encoding optimization forms an important part of this effort in reducing bandwidt...

4K television screens or even with higher resolutions are currently available in the market. Moreover video streaming providers are able to stream videos in 4K resolution and beyond. Therefore, it becomes increasingly important to have a proper understanding of video quality especially in case of 4K videos. To this effect, in this paper, we present...

Considering modern cameras, increasing image resolutions and thousands of images uploaded to sharing platforms there is still reason to have a deeper look into image compression. Especially lossy image compression is always a trade-off between file-size and image quality, where high quality is usually preferred