10,502 research outputs found
A Systematic Review of Urban Navigation Systems for Visually Impaired People
Blind and Visually impaired people (BVIP) face a range of practical difficulties when undertaking outdoor journeys as pedestrians. Over the past decade, a variety of assistive devices have been researched and developed to help BVIP navigate more safely and independently. In~addition, research in overlapping domains are addressing the problem of automatic environment interpretation using computer vision and machine learning, particularly deep learning, approaches. Our aim in this article is to present a comprehensive review of research directly in, or relevant to, assistive outdoor navigation for BVIP. We breakdown the navigation area into a series of navigation phases and tasks. We then use this structure for our systematic review of research, analysing articles, methods, datasets and current limitations by task. We also provide an overview of commercial and non-commercial navigation applications targeted at BVIP. Our review contributes to the body of knowledge by providing a comprehensive, structured analysis of work in the domain, including the state of the art, and guidance on future directions. It will support both researchers and other stakeholders in the domain to establish an informed view of research progress
A Neural System for Automated CCTV Surveillance
This paper overviews a new system, the “Owens
Tracker,” for automated identification of suspicious
pedestrian activity in a car-park.
Centralized CCTV systems relay multiple video streams
to a central point for monitoring by an operator. The
operator receives a continuous stream of information,
mostly related to normal activity, making it difficult to
maintain concentration at a sufficiently high level.
While it is difficult to place quantitative boundaries on
the number of scenes and time period over which
effective monitoring can be performed, Wallace and
Diffley [1] give some guidance, based on empirical and
anecdotal evidence, suggesting that the number of
cameras monitored by an operator be no greater than 16,
and that the period of effective monitoring may be as
low as 30 minutes before recuperation is required.
An intelligent video surveillance system should
therefore act as a filter, censuring inactive scenes and
scenes showing normal activity. By presenting the
operator only with unusual activity his/her attention is
effectively focussed, and the ratio of cameras to
operators can be increased.
The Owens Tracker learns to recognize environmentspecific
normal behaviour, and refers sequences of
unusual behaviour for operator attention. The system
was developed using standard low-resolution CCTV
cameras operating in the car-parks of Doxford Park
Industrial Estate (Sunderland, Tyne and Wear), and
targets unusual pedestrian behaviour.
The modus operandi of the system is to highlight
excursions from a learned model of normal behaviour in
the monitored scene. The system tracks objects and
extracts their centroids; behaviour is defined as the
trajectory traced by an object centroid; normality as the
trajectories typically encountered in the scene. The
essential stages in the system are: segmentation of
objects of interest; disambiguation and tracking of
multiple contacts, including the handling of occlusion
and noise, and successful tracking of objects that
“merge” during motion; identification of unusual
trajectories. These three stages are discussed in more
detail in the following sections, and the system
performance is then evaluated
Using Wii technology to explore real spaces via virtual environments for people who are blind
Purpose - Virtual environments (VEs) that represent real spaces (RSs) give people who are blind the opportunity to build a cognitive map in advance that they will be able to use when arriving at the RS. Design - In this research study Nintendo Wii based technology was used for exploring VEs via the Wiici application. The Wiimote allows the user to interact with VEs by simulating walking and scanning the space. Finding - By getting haptic and auditory feedback the user learned to explore new spaces. We examined the participants' abilities to explore new simple and complex places, construct a cognitive map, and perform orientation tasks in the RS. Originality – To our knowledge, this finding presents the first virtual environment for people who are blind that allow the participants to scan the environment and by this to construct map model spatial representations
Spatio-Temporal Information for Action Recognition in Thermal Video Using Deep Learning Model
Researchers can evaluate numerous information to ensure automated monitoring due to the widespread use of surveillance cameras in smart cities. For the monitoring of violence or abnormal behaviors in smart cities, schools, hospitals, residences, and other observational domains, an enhanced safety and security system is required to prevent any injuries that might result in ecological, economic and social losses. Automatic detection for prompt actions is vital and may help the respective departments effectively. Based on thermal imaging, several researchers have concentrated on object detection, tracking, and action identification. Few studies have simultaneously extracted spatial-temporal information from a thermal image and utilized it to recognize human actions. This research provides a novelty based on frame-level and spatial and temporal features which combines richer context temporal information to address the issue of poor efficiency and less accuracy in detecting abnormal/violent behavior in thermal monitoring devices. The model can locate (bounded box) video frame areas involving different human activities and recognize (classify) the actions. The dataset on human behavior includes videos captured with infrared cameras in both indoor and outdoor environments. The experimental results using the publicly available benchmark datasets reveal the proposed model\u27s efficiency. Our model achieves 98.5% and 94.85% accuracy on IITR Infrared Action Recognition (IITR-IAR) and Thermal Simulated Fall (TSF) datasets, respectively. In addition, the proposed method may be evaluated in more realistic conditions, such as zooming in and out etc
Semi-Supervised First-Person Activity Recognition in Body-Worn Video
Body-worn cameras are now commonly used for logging daily life, sports, and
law enforcement activities, creating a large volume of archived footage. This
paper studies the problem of classifying frames of footage according to the
activity of the camera-wearer with an emphasis on application to real-world
police body-worn video. Real-world datasets pose a different set of challenges
from existing egocentric vision datasets: the amount of footage of different
activities is unbalanced, the data contains personally identifiable
information, and in practice it is difficult to provide substantial training
footage for a supervised approach. We address these challenges by extracting
features based exclusively on motion information then segmenting the video
footage using a semi-supervised classification algorithm. On publicly available
datasets, our method achieves results comparable to, if not better than,
supervised and/or deep learning methods using a fraction of the training data.
It also shows promising results on real-world police body-worn video
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