Expert evaluation of a novel light-field visualization format

Light-field visualization is continuously emerging in industrial sectors, and the appearance on the consumer market is approaching. Yet this process is halted, or at least slowed down, by the lack of proper display-independent light-field formats. Such formats are necessary to enable the efficient interchange between light-field content creation and visualization, and thus support potential future use case scenarios of this technology. In this paper, we introduce the results of a perceived quality assessment research, performed on our own novel light-field visualization format. The subjective tests, which compared conventional linear camera array visualization to our format, were completed by experts only, thus quality assessment was an expert evaluation. We aim to use the findings gathered in this research to carry out a large-scale subjective test series in the future, with non-expert observers

Objective quality evaluation of an angularly-continuous light-field format

With the rapid advances in light-field display and camera technology, research in light-field content creation, visualization, coding and quality assessment has gained momentum. While light-field cameras are already available to the consumer, light-field displays need to overcome several obstacles in order to become a commonplace. One of these challenges is the unavailability of a light-field visualization format which can be used across various light-field displays. Existing light-field representations are optimized for specific displays and converting them for visualization on a different display is a computationally expensive operation, often resulting in the degradation of perceptual quality. To this end, an intermediate, display-independent and angularly-continuous light-field representation format has been proposed recently, targeted towards large-field-of-view light-field displays. In this paper, we evaluate the said data format in terms of degradation in objective quality under three compression methods. We found that, while offering display-independence, the intermediate light-field format maintains the same objective quality in general and achieves higher objective quality in some cases compared to the conventional linear camera representation

The quality of experience of emerging display technologies

As new display technologies emerge and become part of everyday life, the understanding of the visual experience they provide becomes more relevant. The cognition of perception is the most vital component of visual experience; however, it is not the only cognition that contributes to the complex overall experience of the end-user. Expectations can create significant cognitive bias that may even override what the user genuinely perceives. Even if a visualization technology is somewhat novel, expectations can be fuelled by prior experiences gained from using similar displays and, more importantly, even a single word or an acronym may induce serious preconceptions, especially if such word suggests excellence in quality. In this interdisciplinary Ph.D. thesis, the effect of minimal, one-word labels on the Quality of Experience (QoE) is investigated in a series of subjective tests. In the studies carried out on an ultra-high-definition (UHD) display, UHD video contents were directly compared to their HD counterparts, with and without labels explicitly informing the test participants about the resolution of each stimulus. The experiments on High Dynamic Range (HDR) visualization addressed the effect of the word “premium” on the quality aspects of HDR video, and also how this may affect the perceived duration of stalling events. In order to support the findings, additional tests were carried out comparing the stalling detection thresholds of HDR video with conventional Low Dynamic Range (LDR) video. The third emerging technology addressed by this thesis is light field visualization. Due to its novel nature and the lack of comprehensive, exhaustive research on the QoE of light field displays and content parameters at the time of this thesis, instead of investigating the labeling effect, four phases of subjective studies were performed on light field QoE. The first phases started with fundamental research, and the experiments progressed towards the concept and evaluation of the dynamic adaptive streaming of light field video, introduced in the final phase