The growing size of organizations is making it increasingly expensive to attend meetings and difficult to retain what happened in those meetings. Meeting video capture systems exist to support video conferencing for remote participation or archiving for later review, but they have been regarded ineffective. The reason is twofold. Firstly, the conventional way of capturing video using a single static camera fails to capture focus and context. Secondly, a single static view is often monotonous, making the video onerous to review. To address these issues, often human camera operators are employed to capture effective videos with changing views, but this approach is expensive. In this thesis, we argue that camera views can be changed automatically to produce meeting videos effectively and inexpensively. We automate the camera view control by automatically determining the visual focus of attention as a function of time and moving the camera to capture it. In order to determine visual focus of attention for different meetings, we conducted experiments and interviewed television production professionals who capture meeting videos. Furthermore, television production principles were used to appropriately frame shots and switch between shots. The result of the evaluation of the automatic camera control system indicated its significant benefits over conventional static camera view. By applying television production principles various issues related to shot stability and screen motion were resolved. The performance of the automatic camera control based on television production principles also approached the performance of trained human camera crew. To further reduce the cost of the automation, we also explored the application of computer vision and audio tracking. Results of our explorations provide empirical evidence in support of the utility of camera control encouraging future research in this area. Successful application of television production principles to automatically control cameras suggest various ways to handle issues involved in the automation process.

A team of developers from Epsilon AB has developed a lightweight remote controlledquadcopter named Crazyflie. The team wants to allow a pilot to navigate thequadcopter using video from an on-board camera as the only guidance. The masterthesis evaluates the feasibility of mounting a camera module on the quadcopter andstreaming images from the camera to a computer, using the existing quadcopterradio link. Using theoretical calculations and measurements, a set of requirementsthat must be fulfilled for such a system are identified. Using the requirementsas a basis, various camera products are investigated and the findings presented.A design to fulfill the requirements, using the found products, is proposed. Theproposed design is then implemented and evaluated. It is found that the Crazyflie system has the resources necessary to transferan image stream with the quality required for navigation. Furthermore, theimplementation is found to provide the required functionality. From the evaluationseveral key factors of the design that can be changed to further improve theperformance of an implementation are identified. Ideas for future work andimprovements are proposed and possible alternative approaches are presented.

Geographical image data efficiently help people with wayfinding when in an unfamiliar environment. However, since the display modes of geographical image data such as 2D and 3D virtual reality could not meet with users' needs anymore, the new technique augmented reality (AR) has then become a better and effective solution to graphics Augmented reality is a kind of 3D display technique by computer vision, in which 3D virtual objects are combined with 3D real environment interactively, dynamically, and in real-time. It will bring more advantages especially to the display of building spatial data. The research aims to find out more spatial information by seeing-through buildings when we stay outside it. The approach is firstly to use a single camera to capture building features with serial images, and secondly to do building recognition and tracking between reference images and serial images by Speeded-Up Robust Features (SURF) algorithm. Thirdly, the relationship of points correspondence between serial images are then applied to estimate camera parameters via computer vision technique. Finally, the 3D model map of buildings can augment to building images according to the camera parameters.

Siegen, Universität, Thesis (doctoral), 2000.

A gimbal is a pivoted device that decouples movements of a platform from its payload. The payload is a camera which must be stabilized to capture video without motion disturbances. A challenge with this type of gimbal is that a wide span of cameras with different sizes and weights can be used. The change of camera has significant effect on the dynamics of the gimbal and therefore the control system must be retuned. This tuning is inconvenient, especially for someone without knowledge of control engineering. This thesis reviews suitable methods to perform an automatic controller tuning directly on the gimbal's hardware.This tuning starts by exciting the system and then using data to estimate a model. This model is then used to control the gimbal, thus removing the need for manual tuning of the system. The foundation of this thesis is a physical model of the gimbal, derived through the Lagrange equation. The physical model has undetermined parameters such as inertias, centre of gravity and friction constants. System identification is used to determine these parameters. A problem discussed is how the system should be excited in order to achieve data with as much information as possible about the dynamics. This problem is approached by formulating an optimization problem that can be used find suitable trajectories. The identified model is then used to control the gimbal. Different methods for model based-control are discussed. By using a method called feedback linearisation all of the parameter-dependant dynamics of the gimbal can be compensated for. Apart from being independent of model parameters the new outer system is also decoupled and linear. A PID controller is used for feedback control of the outer system. The uncertainty of the feedback linearisation is analysed to find the effects of model errors.To assure robustness of the closed loop system a Lyapunov redesign controller is used to compensate for these model errors. Some experimental results are also presented. The quality of the estimated model is evaluated. Additionally, the reference tracking performance of the control system is tested and results reveal issues with the estimated model's performance.

ITC/USA 2014 Conference Proceedings / The Fiftieth Annual International Telemetering Conference and Technical Exhibition / October 20-23, 2014 / Town and Country Resort & Convention Center, San Diego, CA / Camera technology is now ubiquitous with smartphones, laptops, automotive and industrial applications frequently utilizing high resolution imagine sensors. Increasingly there is a demand for high-definition cameras in the aerospace market - however, such cameras must have several considerations that do not apply to average consumer use including high reliability and being ruggedized for harsh environments. A significant issue is managing the large volumes of data that one or more HD cameras produce. One method of addressing this issue is to use compression algorithms that reduce video bandwidth. This can be achieved with dedicated compression units or modules within data acquisition systems. For flight test applications it is important that data from cameras is available for telemetry and coherently synchronized while also being available for storage. Ideally the data in the telemetry steam should be highly compressed to preserve downlink bandwidth while the recorded data is lightly compressed to provide maximum quality for onboard/ post flight analysis. This paper discusses the requirements for airborne applications and presents an innovative solution using Ethernet cameras with integrated compression that outputs two steams of data. This removes the need for dedicated video and compression units while offering all the features of such including switching camera sources and optimized video streams.

We address the problem of multi-view multi-target tracking using multiple stationary cameras in the application of hockey tracking and test the approach with data from two cameras. The system is based on the previous work by Okuma et al. [50]. We replace AdaBoost detection with blob detection in both image coordinate systems after background subtraction. The sets of blob-detection results are then mapped to the rink coordinate system using a homography transformation. These observations are further merged into the final detection result which will be incorporated into the particle filter. In addition, we extend the particle filter to use multiple observation models, each corresponding to a view. An observation likelihood and a reference color model are also maintained for each player in each view and are updated only when the player is not occluded in that view. As a result of the expanded coverage range and multiple perspectives in the multi-view tracking, even when the target is occluded in one view, it still can be tracked as long as it is visible from another view. The multi-view tracking data are further processed by trajectory smoothing using the Maximum a posteriori smoother. Finally, automatic camera selection is performed using the Hidden Markov Model to create personalized video programs.

The Advanced Camera for Surveys (ACS) Fornax Cluster Survey is a Hubble Space Telescope programme that imaged 43 early-type galaxies in the Fornax cluster, using the ACS F475W (~g) and F850LP (~z) bandpasses. We use this data set, which spans a range of ~600 in blue luminosity down to M_B ~ -16 mag, to study and characterize the properties of central galactic nuclei by fitting ellipses to the galaxy isophotes and examining their 1-dimensional surface brightness profiles. To test the robustness of this method, we perform a similar analysis with 2-dimensional surface brightness profile fitting using GALFIT, and find acceptable agreement between the derived structural parameters from the two techniques. We determine 72% of our sample (31 galaxies) to be nucleated, a significant increase from 28% found in the ground-based study of Ferguson et al. (1989). This high frequency of nucleation suggests that the creation of a compact nuclear component is a common outcome in early-type galaxy formation. Only three of the nuclei (10%) are observed to be significantly offset (by > 0.5") from their host galaxy photocentres, and a trend of increasing offset in fainter galaxies is observed, which indicates that nucleus formation timescales and/or pathways may vary with host luminosity. The nuclei are found to be larger and approximately 50 times brighter than typical globular clusters from our Fornax sample, and to follow different half-light surface brightness versus magnitude scaling relations. The colours of the nuclei are characteristic of intermediate to old stellar populations, and those residing in galaxies with B_T > 13 mag are observed to correlate with the nucleus luminosities. Both nucleus and galaxy colours become redder with increasing host luminosity, although the trend with the nuclei is steeper, and the nuclei in the brightest galaxies are found to be redder than their hosts. However, the majority of nuclei are bluer than their hosts, having an average colour difference of 0.27 +/- 0.25 mag. Comparison of our results to the complementary ACS Virgo Cluster Survey (ACSVCS) study of nuclei Côté et al. (2006), which examined 100 early-type galaxies in the Virgo cluster, yields strikingly similar results. Both samples show similar frequency of nucleation (68% in the ACSVCS), a constant nucleus-to-galaxy luminosity ratio (with a mean value of 0.41% +/- 0.04% derived from the combined samples), as well as excellent agreement in the nucleus luminosity functions and sizes (with median values of 6 pc in g and 7 pc in z in both studies). Since the Fornax cluster presents a much denser environment than Virgo, such consistency between the properties of the nuclei indicates that their formation and evolution may be influenced by local factors more than environmental ones. In particular, a constant nucleus-to-galaxy luminosity ratio suggests that a host galaxy's luminosity (or, more likely, mass) may be a key element in determining the properties of its nucleus. Since simulations have found the two main theorized nucleus formation pathways to be effective on different mass scales (with dissipationless infall of star clusters being more efficient in lower-mass galaxies, and in-situ gas accretion in higher-mass hosts), we propose that both processes may both in fact be responsible for nucleus formation, but varying in relative importance along the galaxy luminosity function. / Graduate

Although the deep seafloor represents the largest biome on the planet, its benthos has remained understudied because of logistical difficulties and the cost of access. Long-term, time-series information is needed to understand the small-scale and inter-annual variations required to build predictive models of ecological processes. In this thesis, we employed three newly developed observatory systems, which coupled in situ imagery with environmental data to examine ecological processes in three deep-sea benthic habitats: 1) Megabenthic surface bioturbation on the upper continental slope (400m depth) near Barkley Canyon, off Vancouver Island, 2) Thermal response in polynoid taxa at Main Endeavour Hydrothermal Vent Field (2,100m depth) on the Juan de Fuca Ridge and 3) Behavioural rhythms and bacterial mat growth in Saanich Inlet (100m), a fjord in southern Vancouver Island. To ensure that the imagery collected was useful for quantitative hypothesis testing by a single observer, we employed a step-wise methodological approach, taking advantage of previously acquired knowledge and, in two cases, the interactive nature of cabled observatories, to tailor the sampling frequency to the variables of interest. The application of a diverse array of image analysis techniques and statistical models, easily extendable to other systems, was also demonstrated. The results obtained while conducting the protocol optimization phase described organism and community level responses to environmental variations. Using a remotely operated camera connected to the NEPTUNE Canada cabled observatory, we estimated that total surface sediment turnover by sea urchins and flatfish, the two most important megafaunal contributors, within the field of view required 93 to 125 days in the absence of phytodetrital accumulations. When employing a camera-temperature array system, the most frequently observed mobile megafaunal species, two polynoid taxa, were not found to exploit the recorded temperature gradients suggesting that they employed a thermoconforming strategy to cope with thermal variability. In the aphotic, mostly hypoxic benthos of Saanich Inlet, strong behavioural entrainment, neither diel nor tidal, was not observed. However, significant changes in species composition and bacterial mat substratum coverage were observed following intrusion of oxygenated waters, a yearly event resulting from specific bathymetric features and oceanographic dynamics of this fjord. A Bayesian approach to data modeling was found to be particularly well suited to protocol optimization purposes as complex models could be more easily and intuitively implemented. The further application of our multi-disciplinary step-wise approach will reduce the time required to approach new ecological questions and improve integration of studies carried in different locations. By carefully choosing ecosystem functions which can be used as indicators of change, the current baseline state of the system can be described. Informed long-term monitoring initiatives can then be implemented in order to quantify global ocean responses to anthropogenic factors such as climate change, resource extraction or eutrophication. / Graduate

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