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

Computational intelligence approaches to robotics, automation, and control [Volume guest editors]

No abstract available

Mobile Robots Navigation

Mobile robots navigation includes different interrelated activities: (i) perception, as obtaining and interpreting sensory information; (ii) exploration, as the strategy that guides the robot to select the next direction to go; (iii) mapping, involving the construction of a spatial representation by using the sensory information perceived; (iv) localization, as the strategy to estimate the robot position within the spatial map; (v) path planning, as the strategy to find a path towards a goal location being optimal or not; and (vi) path execution, where motor actions are determined and adapted to environmental changes. The book addresses those activities by integrating results from the research work of several authors all over the world. Research cases are documented in 32 chapters organized within 7 categories next described

Computational intelligence approaches to robotics, automation, and control [Volume guest editors]

No abstract available

Bio-Inspired Information Extraction In 3-D Environments Using Wide-Field Integration Of Optic Flow

A control theoretic framework is introduced to analyze an information extraction approach from patterns of optic flow based on analogues to wide-field motion-sensitive interneurons in the insect visuomotor system. An algebraic model of optic flow is developed, based on a parameterization of simple 3-D environments. It is shown that estimates of proximity and speed, relative to these environments, can be extracted using weighted summations of the instantaneous patterns of optic flow. Small perturbation techniques are utilized to link weighting patterns to outputs, which are applied as feedback to facilitate stability augmentation and perform local obstacle avoidance and terrain following. Weighting patterns that provide direct linear mappings between the sensor array and actuator commands can be derived by casting the problem as a combined static state estimation and linear feedback control problem. Additive noise and environment uncertainties are incorporated into an offline procedure for determination of optimal weighting patterns. Several applications of the method are provided, with differing spatial measurement domains. Non-linear stability analysis and experimental demonstration is presented for a wheeled robot measuring optic flow in a planar ring. Local stability analysis and simulation is used to show robustness over a range of urban-like environments for a fixed-wing UAV measuring in orthogonal rings and a micro helicopter measuring over the full spherical viewing arena. Finally, the framework is used to analyze insect tangential cells with respect to the information they encode and to demonstrate how cell outputs can be appropriately amplified and combined to generate motor commands to achieve reflexive navigation behavior

"Enriching 360-degree technologies through human-computer interaction: psychometric validation of two memory tasks"

This doctoral dissertation explores the domain of neuropsychological assessment, with the objective of gaining a comprehensive understanding of an individual's cognitive functioning and detecting possible impairments. Traditional assessment tools, while possessing inherent value, frequently exhibit a deficiency in ecological validity when evaluating memory, as they predominantly concentrate on short-term, regulated tasks. To overcome this constraint, immersive technologies, specifically virtual reality and 360° videos, have surfaced as promising instruments for augmenting the ecological validity of cognitive assessments. This work examines the potential advantages of immersive technologies, particularly 360° videos, in enhancing memory evaluation. First, a comprehensive overview of contemporary virtual reality tools employed in the assessment of memory, as well as their convergence with conventional assessment measures has been provided. Then, the present study utilizes cluster and network analysis techniques to categorize 360° videos according to their content and applications, thereby offering significant insights into the potential of this nascent medium. The study introduces then a novel platform, Mindscape, that aims to address the existing technological disparity, thereby enhancing the accessibility of clinicians and researchers in developing cognitive tasks within immersive environments. The conclusion of the thesis encompasses the psychometric validation of two memory tasks, which have been specifically developed with Mindscape to assess episodic and spatial memory. The findings demonstrate disparities in cognitive performance between individuals diagnosed with Mild Cognitive Impairment and those without cognitive impairments, underscoring the interrelated nature of cognitive processes and the promising prospects of virtual reality technology in improving the authenticity of real-world experiences. Overall, this dissertation aims to respond to the demand for practical and ecologically valid neuropsychological assessments within the dynamic field of neuropsychology. It achieves this by integrating user-friendly platforms and immersive cognitive tasks into its methodology. By highlighting a shift in the field of neuropsychology towards prioritizing functional and practical assessments over theoretical frameworks, this work indicates a changing perspective within the discipline. This study highlights the potential of comprehensive and purpose-oriented assessment methods in cognitive evaluations, emphasizing the ongoing significance of research in fully comprehending the capabilities of immersive technologies