| 1. |
- Alqaysi, Hiba, et al.
(författare)
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Evaluating Coverage Effectiveness of Multi-Camera Domes Placement for Volumetric Surveillance
- 2017
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Ingår i: ICDSC 2017 Proceedings of the 11th International Conference on Distributed Smart Cameras. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450354875 ; , s. 49-54
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Konferensbidrag (refereegranskat)abstract
- Multi-camera dome is composed of a number of cameras arranged to monitor a half sphere of the sky. Designing a network of multi-camera domes can be used to monitor flying activities in open large area, such as birds' activities in wind parks. In this paper, we present a method for evaluating the coverage effectiveness of the multi-camera domes placement in such areas. We used GPS trajectories of free flying birds over an area of 9 km2 to analyze coverage effectiveness of randomly placed domes. The analysis is based on three criteria namely, detection, positioning and the maximum resolution captured. The developed method can be used to evaluate results of designing and optimizing dome placement algorithms for volumetric monitoring systems in order to achieve maximum coverage.
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| 2. |
- Anwar, Qaiser, et al.
(författare)
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Intelligence Partitioning as a Method for Architectural Exploration of Wireless Sensor Node
- 2016
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Ingår i: Proceedings of the International Conference on Computational Science and Computational Intelligence (CSCI), 2016.. - : IEEE Press. - 9781509055104 ; , s. 935-940
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Konferensbidrag (refereegranskat)abstract
- Embedded systems with integrated sensing, processing and wireless communication are driving future connectivity concepts such as Wireless Sensor Networks (WSNs) and Internet of Things (IoTs). Because of resource limitations, there still exists a number of challenges such as low latency and energy consumption to realize these concepts to full potential. To address and understand these challenges, we have developed and employed an intelligence partitioning method which generates different implementation alternatives by distributing processing load across multiple nodes. The task-to-node mapping has exponential complexity which is hard to compute for a large scale system. Regarding this, our method provides recommendation to handle and minimize such complexity for a large system. Experiments on a use-case concludes that the proposed method is able to identify unfavourable architecture solutions in which forward and backword communication paths exists in task-to-node mapping. These solution can be avoided for further architectural exploration, thus limiting the space for architecture exploration of a sensor node.
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| 3. |
- Fedorov, Igor, et al.
(författare)
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Placement Strategy of Multi-Camera Volumetric Surveillance System for Activities Monitoring
- 2017
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Ingår i: ICDSC 2017 Proceedings of the 11th International Conference on Distributed Smart Cameras. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450354875 ; , s. 113-118
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Konferensbidrag (refereegranskat)abstract
- The design of multi-camera surveillance system comes with many advantages, for example it facilitates as understanding how flying objects act in a given volume. One possible application is for the observation interaction of birds and calculate their trajectories around wind turbines to create promising systems for preventing bird collisions with turbine blades. However, there are also challenges, such as finding the optimal node placement and camera calibration. To address these challenges we investigated a trade-off between calibration accuracy and node requirements, including resolution, modulation transfer function, field of view and angle baseline. We developed a strategy for camera placement to achieve improved coverage for golden eagle monitoring and tracking. This strategy based on the modified resolution criterion taking into account the contrast function of the camera and the estimation of the base angle between the cameras.
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| 4. |
- Imran, Muhammad, et al.
(författare)
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Exploration of preprocessing architectures for field-programmable gate array-based thermal-visual smart camera
- 2016
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Ingår i: Journal of Electronic Imaging (JEI). - 1017-9909 .- 1560-229X. ; 25:4
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Tidskriftsartikel (refereegranskat)abstract
- Embedded smart cameras are gaining in popularity for a number of real-Time outdoor surveillance applications. However, there are still challenges, i.e., computational latency, variation in illumination, and occlusion. To solve these challenges, multimodal systems, integrating multiple imagers can be utilized. However, trade-off is more stringent requirements on processing and communication for embedded platforms. To meet these challenges, we investigated two low-complexity and high-performance preprocessing architectures for a multiple imagers' node on a field-programmable gate array (FPGA). In the proposed architectures, majority of the tasks are performed on the thermal images because of the lower spatial resolution. Analysis with different sets of images show that the system with proposed architectures offers better detection performance and can reduce output data from 1.7 to 99 times as compared with full-size images. The proposed architectures can achieve a frame rate of 53 fps, logics utilization from 2.1% to 4.1%, memory consumption 987 to 148 KB and power consumption in the range of 141 to 163 mW on Artix-7 FPGA. This concludes that the proposed architectures offer reduced design complexity and lower processing and communication requirements while retaining the configurability of the system.
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| 5. |
- Imran, Muhammad, et al.
(författare)
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Low complexity FPGA based background subtraction technique for thermal imagery
- 2015
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Ingår i: ACM International Conference Proceeding Series. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450336819 ; , s. 1-6
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Konferensbidrag (refereegranskat)abstract
- Embedded smart camera systems are gaining popularity for a number of real world surveillance applications. However, there are still challenges, i.e. variation in illumination, shadows, occlusion, and weather conditions while employing the vision algorithms in outdoor environments. For safety-critical surveillance applications, the visual sensors can be complemented with beyond-visual-range sensors. This in turn requires analysis, development and modification of existing imaging techniques. In this work, a low complexity background modelling and subtraction technique has been proposed for thermal imagery. The proposed technique has been implemented on Field Programmable Gate Arrays (FPGAs) after in-depth analysis of different sets of images, characterizing poor signal-to-noise ratio challenges, e.g. motion of high frequency background objects, temperature variation and camera jitter etc. The proposed technique dynamically updates the background on pixel level and requires a single frame storage as opposed to existing techniques. The comparison of this approach with two other approaches show that this approach performs better in different environmental conditions. The proposed technique has been modelled in Register Transfer Logic (RTL) and implementation on the latest FPGAs shows that the design requires less than 1 percent logics, 47 percent block RAMs, and consumes 91 mW power consumption on Artix-7 100T FPGA.
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| 6. |
- Imran, Muhammad, et al.
(författare)
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Pre-processing Architecture for IR-Visual Smart Camera Based on Post-Processing Constraints
- 2016
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Konferensbidrag (refereegranskat)abstract
- In embedded vision systems, the efficiency of pre-processing architectures have a ripple effect on post-processing functions such as feature extraction, classification and recognition. In this work, we investigated a pre-processing architecture for smart camera system, integrating a thermal and vision sensors, by considering the constraints of post-processing. By utilizing the locality feature of the system, we performed pre-processing on the camera node by using FPGA and post-processing on the client device by using the microprocessor platform, NVIDIA Tegra. The study shows that for outdoor people surveillance applications with complex background and varying lighting conditions, the pre-processing architecture, which transmits thermal binary Region-of-Interest (ROI) images, offers better classification accuracy and smaller complexity as compared to alternative approaches.
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| 7. |
- Imran, Muhammad, et al.
(författare)
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STC-CAM1, IR-visual based smart camera system
- 2015
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Ingår i: ACM International Conference Proceeding Series. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450336819 ; , s. 195-196
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Konferensbidrag (refereegranskat)abstract
- Safety-critical applications require robust and real-time surveillance. For such applications, a vision sensor alone can give false positive results because of poor lighting conditions, occlusion, or different weather conditions. In this work, a visual sensor is complemented by an infrared thermal sensor which makes the system more resilient in unfavorable situations. In the proposed camera architecture, initial data intensive tasks are performed locally on the sensor node and then compressed data is transmitted to a client device where remaining vision tasks are performed. The proposed camera architecture is demonstrated as a proof-ofconcept and it offers a generic architecture with better surveillance while only performing low complexity computations on the resource constrained devices.
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| 8. |
- Lawal, Najeem, et al.
(författare)
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Design exploration of a multi-camera dome for sky monitoring
- 2016
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Ingår i: ACM International Conference Proceeding Series. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450347860 ; , s. 14-18
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Konferensbidrag (refereegranskat)abstract
- Sky monitoring has many applications but also many challenges to be addressed before it can be realized. Some of the challenges are cost, energy consumption and complex deployment. One way to address these challenges is to compose a camera dome by grouping cameras that monitor a half sphere of the sky. In this paper, we present a model for design exploration that investigates how characteristics of camera chips and objective lenses affect the overall cost of a node of a camera dome. The investigation showed that by accepting more cameras in a single node can result in a reduced total cost of the system. This concludes that by using suitable design and camera placement technique, a cost-effective solution can be proposed for massive open-area i.e. sky monitoring.
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| 9. |
- Rydblom, Staffan, 1975-
(författare)
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Measuring Water Droplets to Detect Atmospheric Icing
- 2017
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis describes the exploration of a method to measurethe droplet size and the concentration of atmospheric liquid water. The purpose is to find a cost effective technique to detect the conditions for icing on structures.Icing caused by freezing atmospheric water can be a signifi- cant problem for infrastructure such as power lines, roads and air traffic. About one third of the global installed wind power capacity is located in cold climates, where icing of rotor blades is one of the major challenges.The icing process is complex and the result depends on a combination of the aerodynamic shape of the structure or airfoil, the velocity of the air and its contained water, the temperature, the mixing of snow and water, the concentration of liquid water and the Droplet Size Distribution (DSD).The measurement method is based on a shadowgraph imag- ing system using light emitting diode (LED) light as background illumination and digital image processing. A prototype instru- ment has been constructed. The components were selected keeping the possibility of low-cost volume production in mind. The applications of a commercial instrument based on this tech- nique are e.g. real-time in-situ icing condition measurements and assimilation and verification of data in numerical weather models.The work presented shows that measurements of the size and concentration of water droplets using shadowgraph images can be used for the comparison and validation of Numerical Weather Prediction (NWP) models and other instruments. The accuracy of the particle size measurement is high. The accuracy of the concentration measurement has the potential to become high due to the single-particle measurement range calibraiton. The precision of the instrument depends mainly on the number of images that is used to find each measurement value. The real-time performance of the instrument is limited by the image retrieval and processing speed and depends on the precisionrequired.
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| 10. |
- Shallari, Irida, et al.
(författare)
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Background Modelling, Analysis and Implementation for Thermographic Images
- 2017
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Ingår i: PROCEEDINGS OF THE 2017 SEVENTH INTERNATIONAL CONFERENCE ON IMAGE PROCESSING THEORY, TOOLS AND APPLICATIONS (IPTA 2017). - : IEEE. - 9781538618424
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Konferensbidrag (refereegranskat)abstract
- Background subtraction is one of the fundamental steps in the image-processing pipeline for distinguishing foreground from background. Most of the methods have been investigated with respect to visual images, in which case challenges are different compared to thermal images. Thermal sensors are invariant to light changes and have reduced privacy concerns. We propose the use of a low-pass IIR filter for background modelling in thermographic imagery due to its better performance compared to algorithms such as Mixture of Gaussians and K-nearest neighbour, while reducing memory requirements for implementation in embedded architectures. Based on the analysis of four different image datasets both indoor and outdoor, with and without people presence, the learning rate for the filter is set to 3×10-3 Hz and the proposed model is implemented on an Artix-7 FPGA.
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