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With the development of immersive media technologies, omnidirectional video service has been popularized at an accelerated speed due to the sense of presence it offered. Accurately measuring the user's subjective sense of presence on virtual reality (VR) devices are urgently required by video service providers and VR device manufacturers to further improve their quality of service. So far, there is no standardized methodology available for the conduction of the subjective experiment toward the user's sense of presence when viewing omnidirectional videos. In this paper, we designed a novel subjective assessment method, which evaluates the presence of omnidirectional videos where the scenes have been previously experienced in the real world by subjects. In this setup, subjects can easily and accurately form their sense of presence when viewing omnidirectional videos using previous observations of the real environment as references. The experimental results demonstrated that the proposed method is able to obtain reliable quantitative results toward the sense of presence.

In this work, we develop a novel no-reference (NR) quality assessment metric for stereoscopic images based on monocular and binocular features, motivated by visual perception properties of the human visual system (HVS) named binocular rivalry and binocular integration. To be more specific, we first calculate the normalized intensity feature maps of right- and left-view images through local contrast normalization, where statistical intensity features are extracted by the histogram of the normalized intensity feature map to represent monocular features. Then, we compute the disparity map of stereoscopic image, with which we extract structure feature map of stereoscopic image based on local binary pattern (LBP). We further extract statistical structure features and statistical depth features from structure feature map and disparity map by histogram to represent binocular features. Finally, we adopt support vector regression (SVR) to train the mapping function from the extracted monocular and binocular features to subjective quality scores. Comparison experiments are conducted on four large-scale stereoscopic image databases and the results demonstrate the promising performance of the proposed method in stereoscopic image quality assessment.

Emotional interactive movie is a kind of film unfolding in different ways according to the emotion the viewer experiences. The movie is made of several sequences; their combination determines the particular scenario experienced. In this paper, we describe the system and its implementation by providing combination selection criteria. We measured neurophysiological and ocular activities of 60 individuals viewing an experimental interactive short-movie composed of 12 different scenarios. For this purpose, we combined an electroencephalography headset which directly provides emotional data with an eye-tracker in order to simultaneously investigate the position of viewer’s gaze. From the collected data analysis, we propose a functional version of the emotional interactive movie, which was used in a so called “emotional cinema” during public exhibitions.

Telemedicine provides a transformative practice for access to and delivery of timely and high-quality healthcare in resource-poor settings. In a typical scenario of telesurgery, surgical tasks are performed with one surgeon situated at the patient's side and one expert surgeon from a remote site. In order to make telesurgery practice realistic and secure, reliable transmission of medical videos over large distances is essential. However, telesurgery videos that are communicated remotely in real time are vulnerable to distortions in signals due to data compression and transmission. Depending on the system and its applications, visual content received by the surgeons differs in perceived quality, which may incur implications for the performance of telesurgery tasks. To rigorously study the assessment of the quality of telesurgery videos, we performed both qualitative and quantitative research, consisting of semi-structured interviews and video quality scoring with human subjects. Statistical analyses are conducted and results show that compression artifacts and transmission errors significantly affect the perceived quality; and the effects tend to depend on the specific surgical procedure, visual content, frame rate, and the degree of distortion. The findings of the study are readily applicable to improving telesurgery systems.

Virtual reality (VR) headsets offer a large and immersive workspace for displaying visualizations with stereoscopic vision, as compared to traditional environments with monitors or printouts. The controllers for these devices further allow direct three-dimensional interaction with the virtual environment. In this paper, we make use of these advantages to implement a novel multiple and coordinated view (MCV) system in the form of a vertical stack, showing tilted layers of geospatial data. In a formal study based on a use-case from urbanism that requires cross-referencing four layers of geospatial urban data, we compared it against more conventional systems similarly implemented in VR: a simpler grid of layers, and one map that allows for switching between layers. Performance and oculometric analyses showed a slight advantage of the two spatial-multiplexing methods (the grid or the stack) over the temporal multiplexing in blitting. Subgrouping the participants based on their preferences, characteristics, and behavior allowed a more nuanced analysis, allowing us to establish links between e.g., saccadic information, experience with video games, and preferred system. In conclusion, we found that none of the three systems are optimal and a choice of different MCV systems should be provided in order to optimally engage users.

Observers’ fixations exhibit a marked bias towards certain areas on the screen when viewing scenes on computer monitors. For instance, there exists a well-known “center-bias” which means that fixations are biased towards the center of the screen during the viewing of 2D still images. In the viewing of 3D content, stereoscopic displays enhance depth perception by the mean of binocular parallax. This additional depth cue has a great influence on guiding eye movements. Relatively little is known about the impact of binocular parallax on visual attention of the 3D content displayed on stereoscopic screen. Several studies mentioned that people tend to look preferably at the objects located at certain positions in depth. But studies proving or quantifying this depth-bias are still limited. In this paper, we conducted a binocular eye-tracking experiment by showing synthetic stimuli on a stereoscopic display. Observers were required to do a free-viewing task through passive polarized glasses. Gaze positions of both eyes were recorded and the depth of eyes’ fixation was determined. The stimuli used in the experiment were designed in such a way that the center-bias and the depth-bias affect eye movements individually. Results indicate the existence of a depth-bias: objects closer to the viewer attract attention earlier than distant objects, and the number of fixations located on objects varies as a function of objects’ depth. The closest object in a scene always attracts most fixations. The fixation distribution along depth also shows a convergent behavior as the viewing time increases.

Several metrics have been proposed in literature to assess the perceptual quality of two-dimensional images. However, no similar effort has been devoted to quality assessment of stereoscopic images. Therefore, in this paper, we review the different issues related to 3D visualization, and we propose a quality metric for the assessment of stereopairs using the fusion of 2D quality metrics and of the depth information. The proposed metric is evaluated using the SAMVIQ methodology for subjective assessment. Specifically, distortions deriving from coding are taken into account and the quality degradation of the stereopair is estimated by means of subjective tests.