Publications

This paper presents a method for developing a consensus vocabulary to describe and evaluate the visual experience of videos. As a first result, a vocabulary characterizing the specific look of cinema-type video is presented. Such a vocabulary can be used to relate perceptual features of professional high-end image and video quality of experience (QoE) with the underlying technical characteristics and settings of the video systems involved in the creative content production process. For the vocabulary elicitation, a combination of different survey techniques was applied in this work. As the first step, individual interviews were conducted with experts of the motion picture industry on image quality in the context of cinematography. The data obtained from the interviews was used for the subsequent Real-time Delphi survey, where an extended group of experts worked out a consensus on key aspects of the vocabulary specification. Here, 33 experts were supplied with the anonymized results of the other panelists, which they could use to revise their own assessment. Based on this expert panel, the attributes collected in the interviews were verified and further refined, resulting in the final vocabulary proposed in this paper. Besides an attribute-based sensory evaluation of high-quality image, video and film material, applications of the vocabulary are the development of dimension-based image and video quality models, and the analysis of the multivariate relationship between quality-relevant perceptual attributes and technical system parameters.

In this paper, we compare the influence of a higher-resolution Head-Mounted Display (HMD) like HTC Vive Pro on 360˚ video QoE to that obtained with a lower-resolution HMD like HTC Vive. Furthermore, we evaluate the difference in perceived quality for entertainment-type 360˚ content in 4K/6K/8K resolutions at typical high-quality bitrates. In addition, we evaluate which video parts people are focusing on while watching omnidirectional videos. To this aim we conducted three subjective tests. We used HTC Vive in the first and HTC Vive Pro in the other two tests. The results from our tests are showing that the higher resolution of the Vive Pro seems to enable people to more easily judge the quality, shown by a minor deviation between the resulting quality ratings. Furthermore, we found no significant difference between the quality scores for the highest bitrate for 6K and 8K resolution. We also compared the viewing behavior for the same content viewed for the first time with the behavior when the same content is viewed again multiple times. The different representations of the contents were explored similarly, probably due to the fact that participants are finding and comparing specific parts of the 360˚ video suitable for rating the quality.