15 research outputs found

    Electronic Imaging & the Visual Arts. EVA 2012 Florence

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    The key aim of this Event is to provide a forum for the user, supplier and scientific research communities to meet and exchange experiences, ideas and plans in the wide area of Culture & Technology. Participants receive up to date news on new EC and international arts computing & telecommunications initiatives as well as on Projects in the visual arts field, in archaeology and history. Working Groups and new Projects are promoted. Scientific and technical demonstrations are presented

    Electronic Imaging & the Visual Arts. EVA 2014 Florence

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    Information Technologies of interest for Culture Heritage are presented: multimedia systems, data-bases, data protection, access to digital content, Virtual Galleries. Particular reference is reserved to digital images (Electronic Imaging & the Visual Arts), regarding Cultural Institutions (Museums, Libraries, Palace - Monuments, Archaeological Sites). The International Conference includes the following Sessions: Strategic Issues; EC Projects and Related Networks & Initiatives; 2D - 3D Technologies and Applications; Virtual Galleries - Museums and Related Initiatives; Access to the Culture Information. Three Workshops regard: International Cooperation; Innovation and Enterprise; e.Culture Cloud

    Methods for Light Field Display Profiling and Scalable Super-Multiview Video Coding

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    Light field 3D displays reproduce the light field of real or synthetic scenes, as observed by multiple viewers, without the necessity of wearing 3D glasses. Reproducing light fields is a technically challenging task in terms of optical setup, content creation, distributed rendering, among others; however, the impressive visual quality of hologramlike scenes, in full color, with real-time frame rates, and over a very wide field of view justifies the complexity involved. Seeing objects popping far out from the screen plane without glasses impresses even those viewers who have experienced other 3D displays before.Content for these displays can either be synthetic or real. The creation of synthetic (rendered) content is relatively well understood and used in practice. Depending on the technique used, rendering has its own complexities, quite similar to the complexity of rendering techniques for 2D displays. While rendering can be used in many use-cases, the holy grail of all 3D display technologies is to become the future 3DTVs, ending up in each living room and showing realistic 3D content without glasses. Capturing, transmitting, and rendering live scenes as light fields is extremely challenging, and it is necessary if we are about to experience light field 3D television showing real people and natural scenes, or realistic 3D video conferencing with real eye-contact.In order to provide the required realism, light field displays aim to provide a wide field of view (up to 180°), while reproducing up to ~80 MPixels nowadays. Building gigapixel light field displays is realistic in the next few years. Likewise, capturing live light fields involves using many synchronized cameras that cover the same display wide field of view and provide the same high pixel count. Therefore, light field capture and content creation has to be well optimized with respect to the targeted display technologies. Two major challenges in this process are addressed in this dissertation.The first challenge is how to characterize the display in terms of its capabilities to create light fields, that is how to profile the display in question. In clearer terms this boils down to finding the equivalent spatial resolution, which is similar to the screen resolution of 2D displays, and angular resolution, which describes the smallest angle, the color of which the display can control individually. Light field is formalized as 4D approximation of the plenoptic function in terms of geometrical optics through spatiallylocalized and angularly-directed light rays in the so-called ray space. Plenoptic Sampling Theory provides the required conditions to sample and reconstruct light fields. Subsequently, light field displays can be characterized in the Fourier domain by the effective display bandwidth they support. In the thesis, a methodology for displayspecific light field analysis is proposed. It regards the display as a signal processing channel and analyses it as such in spectral domain. As a result, one is able to derive the display throughput (i.e. the display bandwidth) and, subsequently, the optimal camera configuration to efficiently capture and filter light fields before displaying them.While the geometrical topology of optical light sources in projection-based light field displays can be used to theoretically derive display bandwidth, and its spatial and angular resolution, in many cases this topology is not available to the user. Furthermore, there are many implementation details which cause the display to deviate from its theoretical model. In such cases, profiling light field displays in terms of spatial and angular resolution has to be done by measurements. Measurement methods that involve the display showing specific test patterns, which are then captured by a single static or moving camera, are proposed in the thesis. Determining the effective spatial and angular resolution of a light field display is then based on an automated analysis of the captured images, as they are reproduced by the display, in the frequency domain. The analysis reveals the empirical limits of the display in terms of pass-band both in the spatial and angular dimension. Furthermore, the spatial resolution measurements are validated by subjective tests confirming that the results are in line with the smallest features human observers can perceive on the same display. The resolution values obtained can be used to design the optimal capture setup for the display in question.The second challenge is related with the massive number of views and pixels captured that have to be transmitted to the display. It clearly requires effective and efficient compression techniques to fit in the bandwidth available, as an uncompressed representation of such a super-multiview video could easily consume ~20 gigabits per second with today’s displays. Due to the high number of light rays to be captured, transmitted and rendered, distributed systems are necessary for both capturing and rendering the light field. During the first attempts to implement real-time light field capturing, transmission and rendering using a brute force approach, limitations became apparent. Still, due to the best possible image quality achievable with dense multi-camera light field capturing and light ray interpolation, this approach was chosen as the basis of further work, despite the massive amount of bandwidth needed. Decompression of all camera images in all rendering nodes, however, is prohibitively time consuming and is not scalable. After analyzing the light field interpolation process and the data-access patterns typical in a distributed light field rendering system, an approach to reduce the amount of data required in the rendering nodes has been proposed. This approach, on the other hand, requires rectangular parts (typically vertical bars in case of a Horizontal Parallax Only light field display) of the captured images to be available in the rendering nodes, which might be exploited to reduce the time spent with decompression of video streams. However, partial decoding is not readily supported by common image / video codecs. In the thesis, approaches aimed at achieving partial decoding are proposed for H.264, HEVC, JPEG and JPEG2000 and the results are compared.The results of the thesis on display profiling facilitate the design of optimal camera setups for capturing scenes to be reproduced on 3D light field displays. The developed super-multiview content encoding also facilitates light field rendering in real-time. This makes live light field transmission and real-time teleconferencing possible in a scalable way, using any number of cameras, and at the spatial and angular resolution the display actually needs for achieving a compelling visual experience

    Electronic Imaging & the Visual Arts. EVA 2017 Florence

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    The Publication is following the yearly Editions of EVA FLORENCE. The State of Art is presented regarding the Application of Technologies (in particular of digital type) to Cultural Heritage. The more recent results of the Researches in the considered Area are presented. Information Technologies of interest for Culture Heritage are presented: multimedia systems, data-bases, data protection, access to digital content, Virtual Galleries. Particular reference is reserved to digital images (Electronic Imaging & the Visual Arts), regarding Cultural Institutions (Museums, Libraries, Palace - Monuments, Archaeological Sites). The International Conference includes the following Sessions: Strategic Issues; New Sciences and Culture Developments and Applications; New Technical Developments & Applications; Museums - Virtual Galleries and Related Initiatives; Art and Humanities Ecosystem & Applications; Access to the Culture Information. Two Workshops regard: Innovation and Enterprise; the Cloud Systems connected to the Culture (eCulture Cloud) in the Smart Cities context. The more recent results of the Researches at national and international are reported in the Area of Technologies and Culture Heritage, also with experimental demonstrations of developed Activities

    State of the art 3D technologies and MVV end to end system design

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    L’oggetto del presente lavoro di tesi è costituito dall’analisi e dalla recensione di tutte le tecnologie 3D: esistenti e in via di sviluppo per ambienti domestici; tenendo come punto di riferimento le tecnologie multiview video (MVV). Tutte le sezioni della catena dalla fase di cattura a quella di riproduzione sono analizzate. Lo scopo è di progettare una possibile architettura satellitare per un futuro sistema MVV televisivo, nell’ambito di due possibili scenari, broadcast o interattivo. L’analisi coprirà considerazioni tecniche, ma anche limitazioni commerciali

    Quality of Experience in Immersive Video Technologies

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    Over the last decades, several technological revolutions have impacted the television industry, such as the shifts from black & white to color and from standard to high-definition. Nevertheless, further considerable improvements can still be achieved to provide a better multimedia experience, for example with ultra-high-definition, high dynamic range & wide color gamut, or 3D. These so-called immersive technologies aim at providing better, more realistic, and emotionally stronger experiences. To measure quality of experience (QoE), subjective evaluation is the ultimate means since it relies on a pool of human subjects. However, reliable and meaningful results can only be obtained if experiments are properly designed and conducted following a strict methodology. In this thesis, we build a rigorous framework for subjective evaluation of new types of image and video content. We propose different procedures and analysis tools for measuring QoE in immersive technologies. As immersive technologies capture more information than conventional technologies, they have the ability to provide more details, enhanced depth perception, as well as better color, contrast, and brightness. To measure the impact of immersive technologies on the viewersâ QoE, we apply the proposed framework for designing experiments and analyzing collected subjectsâ ratings. We also analyze eye movements to study human visual attention during immersive content playback. Since immersive content carries more information than conventional content, efficient compression algorithms are needed for storage and transmission using existing infrastructures. To determine the required bandwidth for high-quality transmission of immersive content, we use the proposed framework to conduct meticulous evaluations of recent image and video codecs in the context of immersive technologies. Subjective evaluation is time consuming, expensive, and is not always feasible. Consequently, researchers have developed objective metrics to automatically predict quality. To measure the performance of objective metrics in assessing immersive content quality, we perform several in-depth benchmarks of state-of-the-art and commonly used objective metrics. For this aim, we use ground truth quality scores, which are collected under our subjective evaluation framework. To improve QoE, we propose different systems for stereoscopic and autostereoscopic 3D displays in particular. The proposed systems can help reducing the artifacts generated at the visualization stage, which impact picture quality, depth quality, and visual comfort. To demonstrate the effectiveness of these systems, we use the proposed framework to measure viewersâ preference between these systems and standard 2D & 3D modes. In summary, this thesis tackles the problems of measuring, predicting, and improving QoE in immersive technologies. To address these problems, we build a rigorous framework and we apply it through several in-depth investigations. We put essential concepts of multimedia QoE under this framework. These concepts not only are of fundamental nature, but also have shown their impact in very practical applications. In particular, the JPEG, MPEG, and VCEG standardization bodies have adopted these concepts to select technologies that were proposed for standardization and to validate the resulting standards in terms of compression efficiency

    Situated Displays in Telecommunication

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    In face to face conversation, numerous cues of attention, eye contact, and gaze direction provide important channels of information. These channels create cues that include turn taking, establish a sense of engagement, and indicate the focus of conversation. However, some subtleties of gaze can be lost in common videoconferencing systems, because the single perspective view of the camera doesn't preserve the spatial characteristics of the face to face situation. In particular, in group conferencing, the `Mona Lisa effect' makes all observers feel that they are looked at when the remote participant looks at the camera. In this thesis, we present designs and evaluations of four novel situated teleconferencing systems, which aim to improve the teleconferencing experience. Firstly, we demonstrate the effectiveness of a spherical video telepresence system in that it allows a single observer at multiple viewpoints to accurately judge where the remote user is placing their gaze. Secondly, we demonstrate the gaze-preserving capability of a cylindrical video telepresence system, but for multiple observers at multiple viewpoints. Thirdly, we demonstrated the further improvement of a random hole autostereoscopic multiview telepresence system in conveying gaze by adding stereoscopic cues. Lastly, we investigate the influence of display type and viewing angle on how people place their trust during avatar-mediated interaction. The results show the spherical avatar telepresence system has the ability to be viewed qualitatively similarly from all angles and demonstrate how trust can be altered depending on how one views the avatar. Together these demonstrations motivate the further study of novel display configurations and suggest parameters for the design of future teleconferencing systems

    Bowdoin Orient v.95, no.1-34 (1965-1966)

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    https://digitalcommons.bowdoin.edu/bowdoinorient-1960s/1006/thumbnail.jp

    The media, resistance and civil society

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    The relationship between the media and social/political mobilisation is a specifically modem phenomenon, contemporaneous with and responding to dominant capitalist communications. Today the trend towards concentration marches forth, policies of privatisation and deregulation of the media reveal a world-wide trend towards the commodification of information, culture and hence, of democracy. We are witnessing the privatisation of access to information and culture with the shrinking of public space in communications. My research begins from the standpoint that we can not ignore that we still live in deeply unequal capitalist societies, driven by profit and competition operating on a global scale. It is also undeniable that we live in a media dominated world with many different ideas and identities in circulation at any one time. We need to understand the former to appreciate the latter - the relation between individual autonomy, freedom and rational action on the one hand and the social construction of identity and behaviour on the other. The mainstream media as part of the political and economic infrastructure of society both disguise inequalities and frustrate any attempts to contest or reveal them. As a consequence dissident or oppressed groups have had to seek alternative means to be heard and to mobilise. These means include both organisation (investigated here in the form of the voluntary sector) and communication (including mainstream and 'alternative' media) within civil society. My research investigates why it is felt there is an ever pressing need to present oppositional views, how strategies of organisation and communication have been deployed and with what success. This research examines the relationship between the media and resistance - either as a dominant social force which through uniformity of representation encourages digression, or as a means of forging other identities and developing alternative political projects
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