5,138 research outputs found

    Online Audio-Visual Multi-Source Tracking and Separation: A Labeled Random Finite Set Approach

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    The dissertation proposes an online solution for separating an unknown and time-varying number of moving sources using audio and visual data. The random finite set framework is used for the modeling and fusion of audio and visual data. This enables an online tracking algorithm to estimate the source positions and identities for each time point. With this information, a set of beamformers can be designed to separate each desired source and suppress the interfering sources

    Mobile Augmented Reality: User Interfaces, Frameworks, and Intelligence

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    Mobile Augmented Reality (MAR) integrates computer-generated virtual objects with physical environments for mobile devices. MAR systems enable users to interact with MAR devices, such as smartphones and head-worn wearables, and perform seamless transitions from the physical world to a mixed world with digital entities. These MAR systems support user experiences using MAR devices to provide universal access to digital content. Over the past 20 years, several MAR systems have been developed, however, the studies and design of MAR frameworks have not yet been systematically reviewed from the perspective of user-centric design. This article presents the first effort of surveying existing MAR frameworks (count: 37) and further discuss the latest studies on MAR through a top-down approach: (1) MAR applications; (2) MAR visualisation techniques adaptive to user mobility and contexts; (3) systematic evaluation of MAR frameworks, including supported platforms and corresponding features such as tracking, feature extraction, and sensing capabilities; and (4) underlying machine learning approaches supporting intelligent operations within MAR systems. Finally, we summarise the development of emerging research fields and the current state-of-the-art, and discuss the important open challenges and possible theoretical and technical directions. This survey aims to benefit both researchers and MAR system developers alike.Peer reviewe

    Context Aided Tracking with Adaptive Hyperspectral Imagery

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    A methodology for the context-aided tracking of ground vehicles in remote airborne imagery is developed in which a background model is inferred from hyperspectral imagery. The materials comprising the background of a scene are remotely identified and lead to this model. Two model formation processes are developed: a manual method, and method that exploits an emerging adaptive, multiple-object-spectrometer instrument. A semi-automated background modeling approach is shown to arrive at a reasonable background model with minimal operator intervention. A novel, adaptive, and autonomous approach uses a new type of adaptive hyperspectral sensor, and converges to a 66% correct background model in 5% the time of the baseline {a 95% reduction in sensor acquisition time. A multiple-hypothesis-tracker is incorporated, which utilizes background statistics to form track costs and associated track maintenance thresholds. The context-aided system is demonstrated in a high- fidelity tracking testbed, and reduces track identity error by 30%

    INTELLIGENT VIDEO SURVEILLANCE OF HUMAN MOTION: ANOMALY DETECTION

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    Intelligent video surveillance is a system that can highlight extraction and video summarization that require recognition of the activities occurring in the video without any human supervision. Surveillance systems are extremely helpful to guard or protect you from any dangerous condition. In this project, we propose a system that can track and detect abnormal behavior in indoor environment. By concentrating on inside house enviromnent, we want to detect any abnormal behavior between adult and toddler to avoid abusing to happen. In general, the frameworks of a video surveillance system include the following stages: background estimator, segmentation, detection, tracking, behavior understanding and description. We use training behavior profile to collect the description and generate statistically behavior to perform anomaly detection later. We begin with modeling the simplest actions like: stomping, slapping, kicking, pointed sharp or blunt object that do not require sophisticated modeling. A method to model actions with more complex dynamic are then discussed. The results of the system manage to track adult figure, toddler figure and harm object as third subject. With this system, it can bring attention of human personnel security. For future work, we recommend to continue design methods for higher level representation of complex activities to do the matching anomaly detection with real-time video surveillance. We also propose the system to embed with hardware solution for triggered the matching detection as output

    Aspects of User Experience in Augmented Reality

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    Occlusion handling in multiple people tracking

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    Object tracking with occlusion handling is a challenging problem in automated video surveillance. Occlusion handling and tracking have always been considered as separate modules. We have proposed an automated video surveillance system, which automatically detects occlusions and perform occlusion handling, while the tracker continues to track resulting separated objects. A new approach based on sub-blobbing is presented for tracking objects accurately and steadily, when the target encounters occlusion in video sequences. We have used a feature-based framework for tracking, which involves feature extraction and feature matching

    Motion-Augmented Inference and Joint Kernels in Structured Learning for Object Tracking and Integration with Object Segmentation

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    Video object tracking is a fundamental task of continuously following an object of interest in a video sequence. It has attracted considerable attention in both academia and industry due to its diverse applications, such as in automated video surveillance, augmented and virtual reality, medical, automated vehicle navigation and tracking, and smart devices. Challenges in video object tracking arise from occlusion, deformation, background clutter, illumination variation, fast object motion, scale variation, low resolution, rotation, out-of-view, and motion blur. Object tracking remains, therefore, as an active research field. This thesis explores improving object tracking by employing 1) advanced techniques in machine learning theory to account for intrinsic changes in the object appearance under those challenging conditions, and 2) object segmentation. More specifically, we propose a fast and competitive method for object tracking by modeling target dynamics as a random stochastic process, and using structured support vector machines. First, we predict target dynamics by harmonic means and particle filter in which we exploit kernel machines to derive a new entropy based observation likelihood distribution. Second, we employ online structured support vector machines to model object appearance, where we analyze responses of several kernel functions for various feature descriptors and study how such kernels can be optimally combined to formulate a single joint kernel function. During learning, we develop a probability formulation to determine model updates and use sequential minimal optimization-step to solve the structured optimization problem. We gain efficiency improvements in the proposed object tracking by 1) exploiting particle filter for sampling the search space instead of commonly adopted dense sampling strategies, and 2) introducing a motion-augmented regularization term during inference to constrain the output search space. We then extend our baseline tracker to detect tracking failures or inaccuracies and reinitialize itself when needed. To that end, we integrate object segmentation into tracking. First, we use binary support vector machines to develop a technique to detect tracking failures (or inaccuracies) by monitoring internal variables of our baseline tracker. We leverage learned examples from our baseline tracker to train the employed binary support vector machines. Second, we propose an automated method to re-initialize the tracker to recover from tracking failures by integrating an active contour based object segmentation and using particle filter to sample bounding boxes for segmentation. Through extensive experiments on standard video datasets, we subjectively and objectively demonstrate that both our baseline and extended methods strongly compete against state-of-the-art object tracking methods on challenging video conditions
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