2,132 research outputs found

    The crowd as a cameraman : on-stage display of crowdsourced mobile video at large-scale events

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    Recording videos with smartphones at large-scale events such as concerts and festivals is very common nowadays. These videos register the atmosphere of the event as it is experienced by the crowd and offer a perspective that is hard to capture by the professional cameras installed throughout the venue. In this article, we present a framework to collect videos from smartphones in the public and blend these into a mosaic that can be readily mixed with professional camera footage and shown on displays during the event. The video upload is prioritized by matching requests of the event director with video metadata, while taking into account the available wireless network capacity. The proposed framework's main novelty is its scalability, supporting the real-time transmission, processing and display of videos recorded by hundreds of simultaneous users in ultra-dense Wi-Fi environments, as well as its proven integration in commercial production environments. The framework has been extensively validated in a controlled lab setting with up to 1 000 clients as well as in a field trial where 1 183 videos were collected from 135 participants recruited from an audience of 8 050 people. 90 % of those videos were uploaded within 6.8 minutes

    The Smart Phone as a Mouse

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    With the development of hardware, mobile phone has become a feature-rich handheld device. Built-in camera and Bluetooth technology are supported in most current mobile phones. A real-time image processing experiment was conducted with a SonyEricsson P910i smartphone and a desktop computer. This thesis describes the design and implementation of a system which uses a mobile phone as a PC mouse. The movement of the mobile phone can be detected by analyzing the images captured by the onboard camera and the mouse cursor in the PC can be controlled by the movement of the phone

    NAMA3DS1-COSPAD1: Subjective video quality assessment database on coding conditions introducing freely available high quality 3D stereoscopic sequences

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    Research in stereoscopic 3D coding, transmission and subjective assessment methodology depends largely on the availability of source content that can be used in cross-lab evaluations. While several studies have already been presented using proprietary content, comparisons between the studies are difficult since discrepant contents are used. Therefore in this paper, a freely available dataset of high quality Full-HD stereoscopic sequences shot with a semiprofessional 3D camera is introduced in detail. The content was designed to be suited for usage in a wide variety of applications, including high quality studies. A set of depth maps was calculated from the stereoscopic pair. As an application example, a subjective assessment has been performed using coding and spatial degradations. The Absolute Category Rating with Hidden Reference method was used. The observers were instructed to vote on video quality only. Results of this experiment are also freely available and will be presented in this paper as a first step towards objective video quality measurement for 3DTV

    MPEG-SCORM : ontologia de metadados interoperåveis para integração de padrÔes multimídia e e-learning

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    Orientador: Yuzo IanoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia ElĂ©trica e de ComputaçãoResumo: A convergĂȘncia entre as mĂ­dias digitais propĂ”e uma integração entre as TIC, focadas no domĂ­nio do multimĂ­dia (sob a responsabilidade do Moving Picture Experts Group, constituindo o subcomitĂȘ ISO / IEC JTC1 SC29), e as TICE, (TIC para a Educação, geridas pelo ISO / IEC JTC1 SC36), destacando-se os padrĂ”es MPEG, empregados na forma de conteĂșdo e metadados para o multimĂ­dia, e as TICE, aplicadas Ă  Educação a DistĂąncia, ou e-Learning (o aprendizado eletrĂŽnico). Neste sentido, coloca-se a problemĂĄtica de desenvolver uma correspondĂȘncia interoperĂĄvel de bases normativas, atingindo assim uma proposta inovadora na convergĂȘncia entre as mĂ­dias digitais e as aplicaçÔes para e-Learning, essencialmente multimĂ­dia. Para este fim, propĂ”e-se criar e aplicar uma ontologia de metadados interoperĂĄveis para web, TV digital e extensĂ”es para dispositivos mĂłveis, baseada na integração entre os padrĂ”es de metadados MPEG-21 e SCORM, empregando a linguagem XPathAbstract: The convergence of digital media offers an integration of the ICT, focused on telecommunications and multimedia domain (under responsibility of the Moving Picture Experts Group, ISO/IEC JTC1 SC29), with the ICTE (the ICT for Education, managed by the ISO/IEC JTC1 SC36), highlighting the MPEG formats, featured as content and as description metadata potentially applied to the Multimedia or Digital TV and as a technology applied to e-Learning. Regarding this, it is presented the problem of developing an interoperable matching for normative bases, achieving an innovative proposal in the convergence between digital Telecommunications and applications for e-Learning, both essentially multimedia. To achieve this purpose, it is proposed to creating a ontology for interoperability between educational applications in Digital TV environments and vice-versa, simultaneously facilitating the creation of learning metadata based objects for Digital TV programs as well as providing multimedia video content as learning objects for Distance Education. This ontology is designed as interoperable metadata for the Web, Digital TV and e-Learning, built on the integration between MPEG-21 and SCORM metadata standards, employing the XPath languageDoutoradoTelecomunicaçÔes e TelemĂĄticaDoutor em Engenharia ElĂ©tricaCAPE

    Synchronized Illumination Modulation for Digital Video Compositing

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    Informationsaustausch ist eines der GrundbedĂŒrfnisse der Menschen. WĂ€hrend frĂŒher dazu Wandmalereien,Handschrift, Buchdruck und Malerei eingesetzt wurden, begann man spĂ€ter, Bildfolgen zu erstellen, die als sogenanntes ”Daumenkino” den Eindruck einer Animation vermitteln. Diese wurden schnell durch den Einsatz rotierender Bildscheiben, auf denen mit Hilfe von Schlitzblenden, Spiegeln oder Optiken eine Animation sichtbar wurde, automatisiert – mit sogenannten Phenakistiskopen,Zoetropen oder Praxinoskopen. Mit der Erfindung der Fotografie begannen in der zweiten HĂ€lfte des 19. Jahrhunderts die ersten Wissenschaftler wie Eadweard Muybridge, Etienne-Jules Marey und Ottomar AnschĂŒtz, Serienbildaufnahmen zu erstellen und diese dann in schneller Abfolge, als Film, abzuspielen. Mit dem Beginn der Filmproduktion wurden auch die ersten Versuche unternommen, mit Hilfe dieser neuen Technik spezielle visuelle Effekte zu generieren, um damit die Immersion der Bewegtbildproduktionen weiter zu erhöhen. WĂ€hrend diese Effekte in der analogen Phase der Filmproduktion bis in die achtziger Jahre des 20.Jahrhunderts recht beschrĂ€nkt und sehr aufwendig mit einem enormen manuellen Arbeitsaufwand erzeugt werden mussten, gewannen sie mit der sich rapide beschleunigenden Entwicklung der Halbleitertechnologie und der daraus resultierenden vereinfachten digitalen Bearbeitung immer mehr an Bedeutung. Die enormen Möglichkeiten, die mit der verlustlosen Nachbearbeitung in Kombination mit fotorealistischen, dreidimensionalen Renderings entstanden, fĂŒhrten dazu, dass nahezu alle heute produzierten Filme eine Vielfalt an digitalen Videokompositionseffekten beinhalten. ...Besides home entertainment and business presentations, video projectors are powerful tools for modulating images spatially as well as temporally. The re-evolving need for stereoscopic displays increases the demand for low-latency projectors and recent advances in LED technology also offer high modulation frequencies. Combining such high-frequency illumination modules with synchronized, fast cameras, makes it possible to develop specialized high-speed illumination systems for visual effects production. In this thesis we present different systems for using spatially as well as temporally modulated illumination in combination with a synchronized camera to simplify the requirements of standard digital video composition techniques for film and television productions and to offer new possibilities for visual effects generation. After an overview of the basic terminology and a summary of related methods, we discuss and give examples of how modulated light can be applied to a scene recording context to enable a variety of effects which cannot be realized using standard methods, such as virtual studio technology or chroma keying. We propose using high-frequency, synchronized illumination which, in addition to providing illumination, is modulated in terms of intensity and wavelength to encode technical information for visual effects generation. This is carried out in such a way that the technical components do not influence the final composite and are also not visible to observers on the film set. Using this approach we present a real-time flash keying system for the generation of perspectively correct augmented composites by projecting imperceptible markers for optical camera tracking. Furthermore, we present a system which enables the generation of various digital video compositing effects outside of completely controlled studio environments, such as virtual studios. A third temporal keying system is presented that aims to overcome the constraints of traditional chroma keying in terms of color spill and color dependency. ..

    Online Specificity: Live Event Artworks and the Inner Continuity of the Network.

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    This practice-based research analyses the encounter of Net/Web artworks, their materiality and their space-time condition. I analyse a selection of online-specific artworks to examine their materiality and experiential features in an investigation into how they can offer a varied encounter atypical to offline artworks. The research suggests that these encounters have the potential to disturb a familiar linear or chronological sense of space-time. In line with this enquiry, the research explores qualities found in online-specific artworks that are analogous with the encounter of durĂ©e (i.e. duration). This concept was first theorised by Henri Bergson in 1886 as an experience of time with a heterogeneous nature that takes place in the inner self of human experience. I examine this theory to consider whether online-specific artworks are more capable of precipitating experiences associated with durĂ©e and its understanding of memory. In order to do so, I examine the materiality of these artworks (e.g. HTML/CSS) and their temporal existence in the network duration when online users establish a net connection to retrieve them (e.g. URL, HTTP). This research analyses the state of the network as a heterogeneous reality, as described by network theorist Tiziana Terranova (2004), in order to explore how such qualities impact the encounter of online-specific artworks as inherent assets of the network duration. The thesis proposes that the transitory reality of these time-based artworks are only operative in the live stream of the information flux that resides in the virtual state of the network. As a result, such encounters are analysed through a new notion of event described in the research as live events. From this perspective, the research explores similar experiential aspects that are shared between online-specific artworks and offline time-based artworks (e.g. Standing Wave (1920) by Naum Gabo) due to a live encounter during their temporal activation. Subsequently, this research analyses the materiality of telecommunication technology, especially within the protocol system (e.g. TCP/IP) operative in the architecture of the Net/Web to illustrate the transitory reality of online-specific artworks. Furthermore, through a genealogy of historical references the research selects a number of offline and online artworks to analyse their experiential aspect in relation to their time experience, materiality and method of realisation. The nature of web-based artworks and their encounter is recognised in the research through the iterative possibility of their ‘assets’ in the network and their potential capability to introduce new memory experiences specific to an online encounter

    Quality of experience in telemeetings and videoconferencing: a comprehensive survey

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    Telemeetings such as audiovisual conferences or virtual meetings play an increasingly important role in our professional and private lives. For that reason, system developers and service providers will strive for an optimal experience for the user, while at the same time optimizing technical and financial resources. This leads to the discipline of Quality of Experience (QoE), an active field originating from the telecommunication and multimedia engineering domains, that strives for understanding, measuring, and designing the quality experience with multimedia technology. This paper provides the reader with an entry point to the large and still growing field of QoE of telemeetings, by taking a holistic perspective, considering both technical and non-technical aspects, and by focusing on current and near-future services. Addressing both researchers and practitioners, the paper first provides a comprehensive survey of factors and processes that contribute to the QoE of telemeetings, followed by an overview of relevant state-of-the-art methods for QoE assessment. To embed this knowledge into recent technology developments, the paper continues with an overview of current trends, focusing on the field of eXtended Reality (XR) applications for communication purposes. Given the complexity of telemeeting QoE and the current trends, new challenges for a QoE assessment of telemeetings are identified. To overcome these challenges, the paper presents a novel Profile Template for characterizing telemeetings from the holistic perspective endorsed in this paper
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