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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

[en] AN EVALUATION OF AUTOMATIC FACE RECOGNITION METHODS FOR SURVEILLANCE / [pt] ESTUDO DE MÉTODOS AUTOMÁTICOS DE RECONHECIMENTO FACIAL PARA VÍDEO MONITORAMENTO

VICTOR HUGO AYMA QUIRITA 26 March 2015 (has links)
[pt] Esta dissertação teve por objetivo comparar o desempenho de diversos algoritmos que representam o estado da arte em reconhecimento facial a imagens de sequências de vídeo. Três objetivos específicos foram perseguidos: desenvolver um método para determinar quando uma face está em posição frontal com respeito à câmera (detector de face frontal); avaliar a acurácia dos algoritmos de reconhecimento com base nas imagens faciais obtidas com ajuda do detector de face frontal; e, finalmente, identificar o algoritmo com melhor desempenho quando aplicado a tarefas de verificação e identificação. A comparação dos métodos de reconhecimento foi realizada adotando a seguinte metodologia: primeiro, foi criado um detector de face frontal que permitiu o captura das imagens faciais frontais; segundo, os algoritmos foram treinados e testados com a ajuda do facereclib, uma biblioteca desenvolvida pelo Grupo de Biometria no Instituto de Pesquisa IDIAP; terceiro, baseando-se nas curvas ROC e CMC como métricas, compararam-se os algoritmos de reconhecimento; e por ultimo, as análises dos resultados foram realizadas e as conclusões estão relatadas neste trabalho. Experimentos realizados sobre os bancos de vídeo: MOBIO, ChokePOINT, VidTIMIT, HONDA, e quatro fragmentos de diversos filmes, indicam que o Inter Session Variability Modeling e Gaussian Mixture Model são os algoritmos que fornecem a melhor acurácia quando são usados em tarefas tanto de verificação quanto de identificação, o que os indica como técnicas de reconhecimento viáveis para o vídeo monitoramento automático em vídeo. / [en] This dissertation aimed to compare the performance of state-of-the-arte face recognition algorithms in facial images captured from multiple video sequences. Three specific objectives were pursued: to develop a method for determining when a face is in frontal position with respect to the camera (frontal face detector); to evaluate the accuracy for recognition algorithms based on the facial images obtained with the help of the frontal face detector; and finally, to identify the algorithm with better performance when applied to verification and identification tasks in video surveillance systems. The comparison of the recognition methods was performed adopting the following approach: first, a frontal face detector, which allowed the capture of facial images was created; second, the algorithms were trained and tested with the help of facereclib, a library developed by the Biometrics Group at the IDIAP Research Institute; third, ROC and CMC curves were used as metrics to compare the recognition algorithms; and finally, the results were analyzed and the conclusions were reported in this manuscript. Experiments conducted on the video datasets: MOBIO, ChokePOINT, VidTIMIT, HONDA, and four fragments of several films, indicate that the Inter-Session Variability Modelling and Gaussian Mixture Model algorithms provide the best accuracy on classification when the algorithms are used in verification and identification tasks, which indicates them as a good automatic recognition techniques for video surveillance applications.
52

Evaluating and Implementing JPEG XR Optimized for Video Surveillance

Yu, Lang January 2010 (has links)
<p>This report describes both evaluation and implementation of the new coming image compression standard JPEG XR. The intention is to determine if JPEG XR is an appropriate standard for IP based video surveillance purposes. Video surveillance, especially IP based video surveillance, currently has an increasing role in the security market. To be a good standard for surveillance, the video stream generated by the camera is required to be low bit-rate, low latency on the network and at the same time keep a high dynamic display range. The thesis start with a deep insightful study of JPEG XR encoding standard. Since the standard could have different settings,optimized settings are applied to JPEG XR encoder to fit the requirement of network video surveillance. Then, a comparative evaluation of the JPEG XR versusthe JPEG is delivered both in terms of objective and subjective way. Later, part of the JPEG XR encoder is implemented in hardware as an accelerator for further evaluation. SystemVerilog is the coding language. TSMC 40nm process library and Synopsys ASIC tool chain are used for synthesize. The throughput, area, power ofthe encoder are given and analyzed. Finally, the system integration of the JPEGXR hardware encoder to Axis ARTPEC-X SoC platform is discussed.</p>
53

Evaluating and Implementing JPEG XR Optimized for Video Surveillance

Yu, Lang January 2010 (has links)
This report describes both evaluation and implementation of the new coming image compression standard JPEG XR. The intention is to determine if JPEG XR is an appropriate standard for IP based video surveillance purposes. Video surveillance, especially IP based video surveillance, currently has an increasing role in the security market. To be a good standard for surveillance, the video stream generated by the camera is required to be low bit-rate, low latency on the network and at the same time keep a high dynamic display range. The thesis start with a deep insightful study of JPEG XR encoding standard. Since the standard could have different settings,optimized settings are applied to JPEG XR encoder to fit the requirement of network video surveillance. Then, a comparative evaluation of the JPEG XR versusthe JPEG is delivered both in terms of objective and subjective way. Later, part of the JPEG XR encoder is implemented in hardware as an accelerator for further evaluation. SystemVerilog is the coding language. TSMC 40nm process library and Synopsys ASIC tool chain are used for synthesize. The throughput, area, power ofthe encoder are given and analyzed. Finally, the system integration of the JPEGXR hardware encoder to Axis ARTPEC-X SoC platform is discussed.
54

Adaptive Camera Tamper Detection For Video Surveillance

Saglam, Ali 01 June 2009 (has links) (PDF)
Criminals often resort to camera tampering to prevent capture of their actions. Many surveillance systems left unattended and videos surveillance system operators lose their concentration after a short period of time. Many important Real-time automated detection of video camera tampering cases is important for timely warning of the operators. Tampering can be defined as deliberate physical actions on a video surveillance camera and is generally done by obstructing the camera view by a foreign object, displacing the camera and changing the focus of the camera lens. In automated camera tamper detection systems, low false alarm rates are important as reliability of these systems is compromised by unnecessary alarms and consequently the operators start ignoring the warnings. We propose adaptive algorithms to detect and identify such cases with low false alarms rates in typical surveillance scenarios where there is significant activity in the scene. We also give brief information about the camera tampering detection algorithms in the literature. In this thesis we compare performance of the proposed algorithms to the algorithms in the literature by experimenting them with a set of test videos.
55

Design and performance evaluation of a new spatial reuse firewire protocol [electronic resource] / by Vijay Chandramohan.

Chandramohan, Vijay. January 2003 (has links)
Title from PDF of title page. / Document formatted into pages; contains 84 pages. / Thesis (M.S.C.S.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: New generations of video surveillance systems are expected to possess a large-scale network of intelligent video cameras with built-in image processing capabilities. These systems need to be tethered for reasons of bandwidth and power requirements. To support economical installation of video cameras and to manage the huge volume of information flow in these networks, there is a need for new shared-medium daisy-chained physical and medium access control (bus arbitration) layer communication protocols. This thesis describes the design principles of Spatial reuse FireWire Protocol (SFP), a novel request/grant bus arbitration protocol, architected for an acyclic daisy-chained network topology. SFP is a new extension of the IEEE 1394b FireWire architecture. / ABSTRACT: SFP preserves the simple repeat path functionality of FireWire while offering two significant advantages: 1) SFP supports concurrent data transmissions over disjoint segments of the network (spatial reuse of bandwidth), which increases the effective throughput and 2) SFP provides support for priority traffic, which is necessary to handle real-time applications (like packet video), and mission critical applications (like event notifications between cameras) that have strict delay and jitter constraints. The delay and throughput performance of FireWire and SFP were evaluated using discrete-event queuing simulation models built with the CSIM-18 simulation library. Simulation results show that for a homogeneous traffic pattern SFP improves upon the throughput of IEEE 1394b by a factor of 2. For a traffic pattern typical of video surveillance applications, throughput increases by a factor of 7. / ABSTRACT: Simulation results demonstrate that IEEE 1394b asynchronous stream based packet transactions offer better delay performance than isochronous transactions for variable bit rate video like MPEG-2 and MPEG-4. SFP extends this observation by supporting priority traffic. QoS for packet video is provided in SFP by mapping individual asynchronous stream packets to the three priority classes. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.
56

Association of Sound to Motion in Video Using Perceptual Organization

Ravulapalli, Sunil Babu 29 March 2006 (has links)
Technological developments and innovations of the first forty years of the digital era have primarily addressed either the audio or the visual senses. Consequently, designers have primarily focused on the audio or the visual aspects of design. In the perspective of video surveillance, the data under consideration has always been visual. However, in light of the new behavioral and physiological studies which established a proof of cross modality in human perception i.e. humans do not process audio and visual stimulus separately, but percieve a scene based on all stimulus available, similar cues are being used to develop a surveillance system which uses both audio and visual data available. Human beings can easily associate a particular sound to an object in the surrounding. Drawing from such studies, we demonstrate a technique by which we can isolate concurrent audio and video events and associate them based on perceptual grouping principles. Associating sound to an object can form apart of larger surveillance system by producing a better description of objects. We represent audio in the pitch-time domain and use image processing algorithms such as line detection to isolate significant events. These events and are then grouped based on gestalt principles of proximity and similarity which operates in audio. Once auditory events are isolated we can extract their periodicity. In video, we can extract objects by using simple background subtraction. We extract motion and shape periodicities of all the objects by tracking their position or the number of pixels in each frame. By comparing all the periodicities in audio and video using a simple index we can easily associate audio to video. We show results on five scenariosin outdoor settings with different kinds of human activity such as running, walking and other moving objects such as balls and cars.
57

Évaluation de stratégies pour améliorer l'observance de la biosécurité sur les fermes avicoles au Québec

Racicot, Manon 04 1900 (has links)
La problématique de l’observance de la biosécurité est présente dans tous les types de production. Il est essentiel de définir des stratégies pour améliorer l’application des mesures de biosécurité. Cette étude décrit l’application des mesures de biosécurité à l’entrée et à la sortie de 24 bâtiments d’élevages avicoles au Québec, Canada. L’effet des audits et de caméras visibles sur l’observance a été étudié, de même que les déterminants de l’observance. De plus, la relation entre l’observance et les profils de personnalité, l’expérience et l’éducation a été décrite. L’application des mesures de biosécurité a été évaluée à l’aide de caméras cachées. L’observance à court terme (deux premières semaines) et à moyen terme (six mois plus tard) a été déterminée. Basés sur les résultats du groupe contrôle, 44 différentes erreurs lors de l’application des mesures de biosécurité ont été observées à l’entrée et la sortie des bâtiments. La plupart étaient reliées à la délimitation des zones (propre versus contaminée). La nature et la fréquence des erreurs suggèrent un manque de compréhension des principes associés aux mesures de biosécurité. Le visionnement des vidéos a révélé 3055 visites par 277 individus différents (136 employés, 123 visiteurs, 3 superviseurs et 15 éleveurs). Les résultats ont démontré que les audits n’avaient pas d’impact sur l’observance des employés. Les caméras visibles ont eu un impact, à court terme, sur le port de bottes et le respect des zones durant la visite. Par contre, six mois plus tard, l’observance avait significativement diminué, au point de ne plus être statistiquement plus élevée que le groupe contrôle. La durée et le moment de la visite, la présence de l’éleveur ou d’un observateur, la conception de l’entrée, le nombre de bâtiments, le nombre de mesures de biosécurité exigé, le type de bottes, le genre et être membre de la famille de l’éleveur étaient significativement associés à l’observance de certaines mesures. Finalement, trois traits de la personnalité étaient associés à l’observance: responsabilité, orienté vers l’action et complexité, de même que le nombre d’années d’expérience et le niveau d’éducation. Il est nécessaire d’améliorer la formation en matière de biosécurité en fournissant du matériel de formation à tous les intervenants qui démontrent pourquoi et comment appliquer les mesures de biosécurité. La formation continue devrait également aborder les problématiques reliées aux caractéristiques de visites et de fermes. Améliorer la conception des entrées de bâtiments devrait contribuer à augmenter et à maintenir l’observance. L’identification de traits de personnalité associés à l’observance peut avoir des implications sur la sélection des candidats à l’embauche ou sur l’attribution de tâches et sur la planification des programmes de formation. / Biosecurity compliance issue is present in all types of animal productions, Therefore, it is essential to define strategies to improve the implementation of biosecurity measures. This study described the application of biosecurity measures when entering and exiting 24 poultry barns in Québec, Canada. The effect of audits and visible cameras on compliance was investigated, as well as determinants of compliance. Also, the relationship between compliance and personality profiles, experience and education has been described. Application of biosecurity measures was evaluated using hidden cameras. Short term (first two weeks) and medium term (six months later) compliance were determined. Based on the control group, 44 different biosecurity breaches were observed when getting in and out of poultry barns. Most were related to area delimitation (clean versus contaminated). The nature and frequency of errors suggest a lack of understanding of biosecurity principles. Overall, video viewing revealed 3055 visits done by 277 different individuals (136 employees, 123 visitors, 3 supervisors and 15 growers). Results showed that audits did not have any impact on employee compliance. Visible cameras had a significant impact on changing boots and respecting areas during the visit for the short term period. However, six months later, compliance significantly declined and was no longer statistically higher compared to the control group. Duration and moment of the visit, presence of the grower or an observer, barn entrance design, number of barns, number of biosecurity measures requested, type of boots, gender and being a member of a grower’s family were significantly associated with compliance with some biosecurity measures. Finally, three personality traits were significantly associated with compliance: responsibility, action-oriented and complexity, as well as the number of years of experience and the level of education. There is a need to improve biosecurity training by making training material available to all poultry personnel demonstrating why and how to apply biosecurity measures. Educational meetings should also address issues related to visit and farm characteristics. Improving barn entrance design should contribute to enhance and maintain compliance. The identification of personality traits associated with compliance may have implications for the selection of job applicants or task attribution, and for developing educational materials and training programs.
58

Detekce objektů pro kamerový dohled pomocí SSD přístupu / Object detection for video surveillance using the SSD approach

Dobranský, Marek January 2019 (has links)
The surveillance cameras serve various purposes ranging from security to traffic monitoring and marketing. However, with the increasing quantity of utilized cameras, manual video monitoring has become too laborious. In re- cent years, a lot of development in artificial intelligence has been focused on processing the video data automatically and then outputting the desired no- tifications and statistics. This thesis studies the state-of-the-art deep learning models for object detection in a surveillance video and takes an in-depth look at SSD architecture. We aim to enhance the performance of SSD by updating its underlying feature extraction network. We propose to replace the initially used VGG model by a selection of modern ResNet, Xception and NASNet classifica- tion networks. The experiments show that the ResNet50 model offers the best trade-off between speed and precision, while significantly outperforming VGG. With a series of modifications, we improved the Xception model to match the ResNet performance. On top of the architecture-based improvements, we ana- lyze the relationship between SSD and a number of detected classes and their selection. We also designed and implemented a new detector with the use of temporal context provided by the video frames. This detector delivers enhanced precision while...
59

The Perceptions of Video Surveillance and Its Influence on Cargiver Stress in the Home Care Setting

Neri-Candelaria, Asuncion 01 January 2017 (has links)
Given the stress involved in caring for elders, the propensity for abuse among the older adult population continues to be a problem, as the number of caregivers providing care in the home is increasing to meet the demand of an increasing population of older adults. One solution is to implement video surveillance in the home. The purpose of this phenomenological, retrospective and prospective study was to describe the perceptions and experiences of caregivers that affect stress in the home care setting and to describe participants' perceptions about the impact of video surveillance in the home environment on caregiver stress and elder abuse. Using a lens of critical ecological framework and privacy theory, the research questions inquired about the specific experiences of stress and the perceptions of the use of home surveillance of caregivers in the home. A sample of 9 older adult home caregivers were recruited from the United Jewish Council of the East Side Home Attendant Service Corp. Findings revealed that increased family, community, and agency involvement and support may offset the feelings of isolation of the home care environment and ensure the caregiver is given opportunities to engage in strategies designed to help cope with the inherent stressors of the job. In addition, video camera surveillance in the home care setting may provide social support through observation of the situation in the home, supporting both social control on the behavior of the caregiver and direct evidence of quality of care for the caregiver. The findings of the study help to highlight effective intervention strategies based on the specific stressors and stress relievers identified, serving to reduce the potential for older adult abuse and neglect in the home care setting.
60

電視監視器新聞的真實再現與釋義 / The representation and interpretation of CCTV news.

張詠晴, Chang, Yuan Ching Unknown Date (has links)
本研究透過監視器在電視新聞發展歷程中的特殊性和新聞價值,以及監視器新聞的緣起和發展,結合電視新聞的相關理論和實證研究了解監視器影像和電視新聞媒體媒合以後,電視監視器新聞的敘事方式和其所再現的社會景觀以及社會文化意涵。 透過內容分析法,本研究發現,多數監視器新聞以目擊事件現場為「賣點」,呈現對犯罪事件和特殊奇觀的現場感,然而也有不少新聞在監視器鏡頭外,用特殊的剪輯和運鏡技巧或是帶有情緒性的口語配音進行後製,加深觀眾的「共感氛圍」。在「求真」之外,也追求在視聽訊息上的感官化,並透過選擇新聞題材以及後製加工帶給觀眾強大的視覺衝擊力和感染力。 監視器新聞主題中以暴力和犯罪為主,其次則為奇觀新聞。以感官化的手法呈現與社會安全相關的主題,以犯罪暴力為主題的監視器新聞人物,大多為社會上的邊緣團體,且多發生在都市區;奇觀新聞則以一般民眾為主,背景大多為非都市區;監視器新聞以一般市井小民為主要報導對象,公眾人物在監視器新聞裡十分罕見。監視器新聞再現的時空,突破新聞記者採訪佈線「時空」的限制。 監視器新聞的畫面來源和主要受訪者皆為警方,且多為採用「單面報導」的方式,也就是說,警方掌握監視器畫面以及享有對監視器畫面的主要詮釋權,顯示了公共攝影的社會控制和詮釋的不對等關係。在監視器新聞主題中也看到了符合社會奇觀的主題,「記錄不容錯過的精彩生活片段」似乎成了監視器在社會中扮演的另類角色。 當監視器與電視新聞媒合以後,電視新聞觀眾面對的是更多重、更奪目的真實形式。這些影像以「軟性化」或「衝突性」題材為主,而不是以訴諸理性或是傳達資訊的方式。監視器新聞帶出了公共危險的社會意象,對於邊緣團體化約、淺碟化的敘述,可能加深觀眾對於邊緣團體的刻板印象。整體而言,監視器新聞是一種去脈絡化的敘事形式,透過後製的音效和影像編輯,呈現緊張、懸疑和驚聳的氣氛,因此,監視器新聞所再現的都市空間形象是危險的、充滿不確定性的,為一種高社會犯罪率的隱喻。

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