Videos in Context for Telecommunication and Spatial Browsing

The research presented in this thesis explores the use of videos embedded in panoramic imagery to transmit spatial and temporal information describing remote environments and their dynamics. Virtual environments (VEs) through which users can explore remote locations are rapidly emerging as a popular medium of presence and remote collaboration. However, capturing visual representation of locations to be used in VEs is usually a tedious process that requires either manual modelling of environments or the employment of specific hardware. Capturing environment dynamics is not straightforward either, and it is usually performed through specific tracking hardware. Similarly, browsing large unstructured video-collections with available tools is difficult, as the abundance of spatial and temporal information makes them hard to comprehend. At the same time, on a spectrum between 3D VEs and 2D images, panoramas lie in between, as they offer the same 2D images accessibility while preserving 3D virtual environments surrounding representation. For this reason, panoramas are an attractive basis for videoconferencing and browsing tools as they can relate several videos temporally and spatially. This research explores methods to acquire, fuse, render and stream data coming from heterogeneous cameras, with the help of panoramic imagery. Three distinct but interrelated questions are addressed. First, the thesis considers how spatially localised video can be used to increase the spatial information transmitted during video mediated communication, and if this improves quality of communication. Second, the research asks whether videos in panoramic context can be used to convey spatial and temporal information of a remote place and the dynamics within, and if this improves users' performance in tasks that require spatio-temporal thinking. Finally, the thesis considers whether there is an impact of display type on reasoning about events within videos in panoramic context. These research questions were investigated over three experiments, covering scenarios common to computer-supported cooperative work and video browsing. To support the investigation, two distinct video+context systems were developed. The first telecommunication experiment compared our videos in context interface with fully-panoramic video and conventional webcam video conferencing in an object placement scenario. The second experiment investigated the impact of videos in panoramic context on quality of spatio-temporal thinking during localization tasks. To support the experiment, a novel interface to video-collection in panoramic context was developed and compared with common video-browsing tools. The final experimental study investigated the impact of display type on reasoning about events. The study explored three adaptations of our video-collection interface to three display types. The overall conclusion is that videos in panoramic context offer a valid solution to spatio-temporal exploration of remote locations. Our approach presents a richer visual representation in terms of space and time than standard tools, showing that providing panoramic contexts to video collections makes spatio-temporal tasks easier. To this end, videos in context are suitable alternative to more difficult, and often expensive solutions. These findings are beneficial to many applications, including teleconferencing, virtual tourism and remote assistance

Video based reconstruction system for mixed reality environments supporting contextualised non-verbal communication and its study

This Thesis presents a system to capture, reconstruct and render the three-dimensional form of people and objects of interest in such detail that the spatial and visual aspects of non-verbal behaviour can be communicated.The system supports live distribution and simultaneous rendering in multiple locations enabling the apparent teleportation of people and objects. Additionally, the system allows for the recording of live sessions and their playback in natural time with free-viewpoint.It utilises components of a video based reconstruction and a distributed video implementation to create an end-to-end system that can operate in real-time and on commodity hardware.The research addresses the specific challenges of spatial and colour calibration, segmentation and overall system architecture to overcome technical barriers, the requirement of domain specific knowledge to setup and generate avatars to a consistent high quality.Applications of the system include, but are not limited to, telepresence, where the computer generated avatars used in Immersive Collaborative Virtual Environments can be replaced with ones that are faithful of the people they represent and supporting researchers in their study of human communication such as gaze, inter-personal distance and facial expression.The system has been adopted in other research projects and is integrated with a mixed reality application where, during a live linkup, a three-dimensional avatar is streamed to multiple end-points across different countries

VR Technologies in Cultural Heritage

This open access book constitutes the refereed proceedings of the First International Conference on VR Technologies in Cultural Heritage, VRTCH 2018, held in Brasov, Romania in May 2018. The 13 revised full papers along with the 5 short papers presented were carefully reviewed and selected from 21 submissions. The papers of this volume are organized in topical sections on data acquisition and modelling, visualization methods / audio, sensors and actuators, data management, restoration and digitization, cultural tourism

VR Technologies in Cultural Heritage

This open access book constitutes the refereed proceedings of the First International Conference on VR Technologies in Cultural Heritage, VRTCH 2018, held in Brasov, Romania in May 2018. The 13 revised full papers along with the 5 short papers presented were carefully reviewed and selected from 21 submissions. The papers of this volume are organized in topical sections on data acquisition and modelling, visualization methods / audio, sensors and actuators, data management, restoration and digitization, cultural tourism

Perception-driven approaches to real-time remote immersive visualization

In remote immersive visualization systems, real-time 3D perception through RGB-D cameras, combined with modern Virtual Reality (VR) interfaces, enhances the user’s sense of presence in a remote scene through 3D reconstruction rendered in a remote immersive visualization system. Particularly, in situations when there is a need to visualize, explore and perform tasks in inaccessible environments, too hazardous or distant. However, a remote visualization system requires the entire pipeline from 3D data acquisition to VR rendering satisfies the speed, throughput, and high visual realism. Mainly when using point-cloud, there is a fundamental quality difference between the acquired data of the physical world and the displayed data because of network latency and throughput limitations that negatively impact the sense of presence and provoke cybersickness. This thesis presents state-of-the-art research to address these problems by taking the human visual system as inspiration, from sensor data acquisition to VR rendering. The human visual system does not have a uniform vision across the field of view; It has the sharpest visual acuity at the center of the field of view. The acuity falls off towards the periphery. The peripheral vision provides lower resolution to guide the eye movements so that the central vision visits all the interesting crucial parts. As a first contribution, the thesis developed remote visualization strategies that utilize the acuity fall-off to facilitate the processing, transmission, buffering, and rendering in VR of 3D reconstructed scenes while simultaneously reducing throughput requirements and latency. As a second contribution, the thesis looked into attentional mechanisms to select and draw user engagement to specific information from the dynamic spatio-temporal environment. It proposed a strategy to analyze the remote scene concerning the 3D structure of the scene, its layout, and the spatial, functional, and semantic relationships between objects in the scene. The strategy primarily focuses on analyzing the scene with models the human visual perception uses. It sets a more significant proportion of computational resources on objects of interest and creates a more realistic visualization. As a supplementary contribution, A new volumetric point-cloud density-based Peak Signal-to-Noise Ratio (PSNR) metric is proposed to evaluate the introduced techniques. An in-depth evaluation of the presented systems, comparative examination of the proposed point cloud metric, user studies, and experiments demonstrated that the methods introduced in this thesis are visually superior while significantly reducing latency and throughput