Using remote vision: The effects of video image frame rate on visual object recognition performance

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.The process of using remote vision was simulated in order to determine the effects of video image frame rate on the performance in visual recognition of stationary environmental hazards in the dynamic video footage of the pedestrian travel environment. The recognition performance was assessed against two different video image frame rate variations: 25 and 2 fps. The assessment included a range of objective and subjective criteria. The obtained results show that the effects of the frame rate variations on the performance are statistically insignificant. This paper belongs to the process of development of a novel system for navigation of visually impaired pedestrians. The navigation system includes a remote vision facility, and the visual recognition of the environmental hazards by the sighted human guide is a basic activity in aiding the visually impaired user of the system in mobility

Interface design for a remote guidance system for the blind: Using dual-screen displays

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The mobility for the visually impaired people is one of the main challenges that researchers are still facing around the world. Although some projects have been conducted to improve the mobility of visually impaired people, further research is still needed. One of these projects is Brunel Remote Guidance System (BRGS). BRGS is aimed to assist visually impaired users in avoiding obstacles and reaching their destinations safely by providing online instructions via a remote sighted guide. This study comes as continuation of the development process of BRGS; the main aim that has been achieved of this research is the optimisation of the interface design for the system guide terminal. This helps the sighted guide to assist the VIUs to avoid obstacles safely and comfortably in the micro-navigation, as well as to keep them on the right track to reach their destination in the macro-navigation. After using the content analysis, the performance factors and their assessments method were identified in each BRGS‘ element, which concluded that there is a lack of research on the guide terminal setup and the assessment method for the sighted guide performance. Furthermore, there are no model to assist the sighted guide performance and two-screen displays used in the literature review and similar projects. A model was designed as a platform to conduct the evaluation on sighted guide performance. Based on this model, the computer-based simulation was established and tested, which made the simulation is ready for next task; the evaluation of the sighted guide performance. The conducted study determined the effects of the two-screen displays on the recognition performance of the 80 participants in the guide terminal. The performance was measured with the context of four different resolution conditions. The study was based on a simulation technique, which is consisted of two key performance elements in order to examine the sighted guide performance; the macro-navigation element and the micro-navigation element. The results show that the two-screen displays have an effect on the performance of the sighted guide. The optimum setup for the two-screen displays for the guide terminal consisted of a big digital map screen display (4CIF [704p x 576p]) and a small video image screen display (CIF [352p x 288p]), which one of the four different resolutions. This interface design has been recommended as a final setup in the guide terminal

Precise positioning in real-time using GPS-RTK signal for visually impaired people navigation system

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 24/9/2010.This thesis presents the research carried out to investigate and achieve highly reliable and accurate navigation system of guidance for visually impaired pedestrians. The main aim with this PhD project has been to identify the limits and insufficiencies in utilising Network Real-Time Kinematic Global Navigation Satellite Systems (NRTK GNSS) and its augmentation techniques within the frame of pedestrian applications in a variety of environments and circumstances. Moreover, the system can be used in many other applications, including unmanned vehicles, military applications, police, etc. NRTK GNSS positioning is considered to be a superior solution in comparison to the conventional standalone Global Positioning System (GPS) technique whose accuracy is highly affected by the distance dependent errors such as satellite orbital and atmospheric biases. Nevertheless, NRTK GNSS positioning is particularly constrained by wireless data link coverage, delays of correction and transmission and completeness, GPS and GLONASS signal availability, etc., which could downgrade the positioning quality of the NRTK results. This research is based on the dual frequency NRTK GNSS (GPS and GLONASS). Additionally, it is incorporated into several positioning and communication methods responsible for data correction while providing the position solutions, in which all identified contextual factors and application requirements are accounted. The positioning model operates through client-server based architecture consisted of a Navigation Service Centre (NSC) and a Mobile Navigation Unit (MNU). Hybrid functional approaches were consisting of several processing procedures allowing the positioning model to operate in position determination modes. NRTK GNSS and augmentation service is used if enough navigation information was available at the MNU using its local positioning device (GPS/GLONASS receiver).The positioning model at MNU was experimentally evaluated and centimetric accuracy was generally attained during both static and kinematic tests in various environments (urban, suburban and rural). This high accuracy was merely affected by some level of unavailability mainly caused by GPS and GLONASS signal blockage. Additionally, the influence of the number of satellites in view, dilution of precision (DOP) and age corrections (AoC) over the accuracy and stability of the NRTK GNSS solution was also investigated during this research and presented in the thesis. This positioning performance has outperformed the existing GPS service. In addition, utilising a simulation evaluation facility the positioning model at MNU performance was quantified with reference to a hybrid positioning service that will be offered by future Galileo Open Service (OS) along with GPS. However, a significant difference in terms of the service availability for the advantage of the hybrid system was experienced in all remaining scenarios and environments more especially the urban areas due to surrounding obstacles and conditions. As an outcome of this research a new and precise positioning model was proposed. The adaptive framework is understood as approaching an integration of the available positioning technology into the context of surrounding wireless communication for a maintainable performance. The positioning model has the capability of delivering indeed accurate, precise and consistent position solutions, and thus is fulfilling the requirements of visually impaired people navigation application, as identified in the adaptive framework

Interface design for a remote guidance system for the blind : using dual-screen displays

The mobility for the visually impaired people is one of the main challenges that researchers are still facing around the world. Although some projects have been conducted to improve the mobility of visually impaired people, further research is still needed. One of these projects is Brunel Remote Guidance System (BRGS). BRGS is aimed to assist visually impaired users in avoiding obstacles and reaching their destinations safely by providing online instructions via a remote sighted guide. This study comes as continuation of the development process of BRGS; the main aim that has been achieved of this research is the optimisation of the interface design for the system guide terminal. This helps the sighted guide to assist the VIUs to avoid obstacles safely and comfortably in the micro-navigation, as well as to keep them on the right track to reach their destination in the macro-navigation. After using the content analysis, the performance factors and their assessments method were identified in each BRGS‘ element, which concluded that there is a lack of research on the guide terminal setup and the assessment method for the sighted guide performance. Furthermore, there are no model to assist the sighted guide performance and two-screen displays used in the literature review and similar projects. A model was designed as a platform to conduct the evaluation on sighted guide performance. Based on this model, the computer-based simulation was established and tested, which made the simulation is ready for next task; the evaluation of the sighted guide performance. The conducted study determined the effects of the two-screen displays on the recognition performance of the 80 participants in the guide terminal. The performance was measured with the context of four different resolution conditions. The study was based on a simulation technique, which is consisted of two key performance elements in order to examine the sighted guide performance; the macro-navigation element and the micro-navigation element. The results show that the two-screen displays have an effect on the performance of the sighted guide. The optimum setup for the two-screen displays for the guide terminal consisted of a big digital map screen display (4CIF [704p x 576p]) and a small video image screen display (CIF [352p x 288p]), which one of the four different resolutions. This interface design has been recommended as a final setup in the guide terminal.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Adaptive, reliable, and accurate positioning model for location-based services

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This thesis presents a new strategy in achieving highly reliable and accurate position solutions fulfilling the requirements of Location-Based Services (LBS) pedestrians’ applications. The new strategy is divided into two main parts. The first part integrates the available positioning technology within the surrounding LBS application context by introducing an adaptive LBS framework. The context can be described as a group of factors affecting the application behaviour; this includes environmental states, available resources and user preferences. The proposed adaptive framework consists of several stages, such as defining the contextual factors that have a direct effect on the positioning performance, identifying preliminary positioning performance requirements associated with different LBS application groups, and introducing an intelligent positioning services selection function. The second part of this work involves the design and development of a novel positioning model that is responsible for delivering highly reliable, accurate and precise position solutions to LBS users. This new model is based on the single frequency GPS Standard Positioning Service (SPS). Additionally, it is incorporated within the adaptive LBS framework while providing the position solutions, in which all identified contextual factors and application requirements are accounted. The positioning model operates over a client-server architecture including two main components, described as the Localisation Server (LS) and the Mobile Unit (MU). Hybrid functional approaches were developed at both components consisting of several processing procedures allowing the positioning model to operate in two position determination modes. Stand-alone mode is used if enough navigation information was available at the MU using its local positioning device (GPS/EGNOS receiver). Otherwise, server-based mode is utilised, in which the LS intervenes and starts providing the required position solutions. At the LS, multiple sources of GPS augmentation services were received using the Internet as the sole augmentation data transportation medium. The augmentation data was then processed and integrated for the purpose of guaranteeing the availability of valid and reliable information required for the provision of accurate and precise position solutions. Two main advanced position computation methods were developed at the LS, described as coordinate domain and raw domain. The positioning model was experimentally evaluated. According to the reported results, the LS through the developed position computation methods, was able to provide position samples with an accuracy of less than 2 meters, with high precision at 95% confidence level; this was achieved in urban, rural, and open space (clear satellite view) navigation environments. Additionally, the integrity of the position solutions was guaranteed in such environments during more than 90% of the navigation time, taking into consideration the identified integrity thresholds (Horizontal Alert Limits (HAL)=11 m). This positioning performance has outperformed the existing GPS/EGNOS service which was implemented at the MU in all scenarios and environments. In addition, utilising a simulation evaluation facility the developed positioning model performance was quantified with reference to a hybrid positioning service that will be offered by future Galileo Open Service (OS) along with GPS/EGNOS. Using the statistical t-test, it was concluded that there is no significant difference in terms of the position samples’ accuracy achieved from the developed positioning model and the hybrid system at a particular navigation environment described as rural area. The p-value was 0.08 and the level of significance used was 0.05. However, a significant difference in terms of the service integrity for the advantage of the hybrid system was experienced in all remaining scenarios and environments more especially the urban areas due to surrounding obstacles and conditions

Revisión de la literatura de modelos matemáticos para el tránsito de personas con discapacidad visual a través de rutas accesibles y seguras

Esta investigación parte del análisis de los problemas de accesibilidad que tienen las personas con discapacidad para transitar a través de la ciudad. En particular, para las personas con discapacidad visual transitar, navegar y orientarse resulta un reto particularmente difícil porque sus sentidos no perciben la misma información que un peatón sin discapacidad visual. En el Perú un 61.7% de las personas con discapacidad visual no utiliza ningún elemento de apoyo para movilizarse, además presentan dificultades para adquirirlos por su elevado costo. El principal elemento de apoyo para el tránsito de personas con discapacidad visual es el bastón blanco; sin embargo, ese objeto tiene un rango limitado de acción. Por esta razón se han desarrollado soluciones que permitan que dichas personas transiten de manera segura a través de la ciudad. Entre estas soluciones se encuentran los dispositivos electrónicos que sirven para detectar obstáculos, los dispositivos para navegación mediante radio señales, algoritmos de optimización para encontrar rutas seguras y accesibles y los sistemas de apoyo para navegación que incluye tecnología de inteligencia artificial, Big Data e Internet of Things (IoT). La revisión de la literatura de este trabajo de investigación revela que la solución que utiliza el IoT es la que cubre la mayoría de aspectos de la problemática de tránsito para personas invidentes (detección de obstáculos, navegación y accesibilidad). Asimismo, que en dicha solución también se utilizan algoritmos de optimización que permiten a los usuarios acceder a distintos destinos y que han presentado indicadores de rendimiento que sugieren que estas herramientas de optimización benefician a las personas con discapacidad visual en su movilidad e independencia. Por último, se debe considerar que estas herramientas de optimización deben utilizarse considerando las limitaciones o preferencias de las personas con discapacidad visual, no solo consiste en encontrar la ruta más corta, sino en la medida de los posible encontrar la ruta más segura y accesible.Trabajo de investigació

Review of substitutive assistive tools and technologies for people with visual impairments: recent advancements and prospects

YesThe development of many tools and technologies for people with visual impairment has become a major priority in the field of assistive technology research. However, many of these technology advancements have limitations in terms of the human aspects of the user experience (e.g., usability, learnability, and time to user adaptation) as well as difficulties in translating research prototypes into production. Also, there was no clear distinction between the assistive aids of adults and children, as well as between “partial impairment” and “total blindness”. As a result of these limitations, the produced aids have not gained much popularity and the intended users are still hesitant to utilise them. This paper presents a comprehensive review of substitutive interventions that aid in adapting to vision loss, centred on laboratory research studies to assess user-system interaction and system validation. Depending on the primary cueing feedback signal offered to the user, these technology aids are categorized as visual, haptics, or auditory-based aids. The context of use, cueing feedback signals, and participation of visually impaired people in the evaluation are all considered while discussing these aids. Based on the findings, a set of recommendations is suggested to assist the scientific community in addressing persisting challenges and restrictions faced by both the totally blind and partially sighted people

ASSISTIVE TECHNOLOGIES ON MOBILE DEVICES FOR PEOPLE WITH VISUAL IMPAIRMENTS

Spatial understanding and cognitive mapping are challenging tasks for people with visual impairments. The goal of this work is to leverage computer vision and spatial understanding techniques along with audio-haptic proprioceptive interaction paradigms for assisting people with visual impairments in spatial comprehension and memorization. Abstract space exploration in the field of assistive didactics is tackled through tactile exploration and audio feedback resulting in two solutions. The first one focuses on math learning in primary education while the second one focuses on function graph tactile exploration and sonification. In the field of spatial comprehension during way-finding for people with visual impairments, computer vision and spatial reasoning techniques are used for detecting visual cues such as zebra pedestrian crossings and for safely guiding the user with respect to the detected elements. Suitable interaction paradigms based on sonification and haptic feedback are designed to assist the user efficiently and quickly during the navigation

Engaging older adults with age-related macular degeneration in the design and evaluation of mobile assistive technologies

Ongoing advances in technology are undoubtedly increasing the scope for enhancing and supporting older adults’ daily living. The digital divide between older and younger adults, however, raises concerns about the suitability of technological solutions for older adults, especially for those with impairments. Taking older adults with Age-Related Macular Degeneration (AMD) – a progressive and degenerative disease of the eye – as a case study, the research reported in this dissertation considers how best to engage older adults in the design and evaluation of mobile assistive technologies to achieve sympathetic design of such technologies. Recognising the importance of good nutrition and the challenges involved in designing for people with AMD, this research followed a participatory and user-centred design (UCD) approach to develop a proof–of–concept diet diary application for people with AMD. Findings from initial knowledge elicitation activities contribute to the growing debate surrounding the issues on how older adults’ participation is initiated, planned and managed. Reflections on the application of the participatory design method highlighted a number of key strategies that can be applied to maintain empathic participatory design rapport with older adults and, subsequently, lead to the formulation of participatory design guidelines for effectively engaging older adults in design activities. Taking a novel approach, the final evaluation study contributed to the gap in the knowledge on how to bring closure to the participatory process in as positive a way as possible, cognisant of the potential negative effect that withdrawal of the participatory process may have on individuals. Based on the results of this study, we ascertain that (a) sympathetic design of technology with older adults will maximise technology acceptance and shows strong indicators for affecting behaviour change; and (b) being involved in the design and development of such technologies has the capacity to significantly improve the quality of life of older adults (with AMD)