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Suche nach „[J.] [Fournier]“ hat 5 Publikationen gefunden
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    DigitalAngewandte Informatik

    Zeitschriftenartikel

    W. Chen, J. Fournier, Marcus Barkowsky, P. Le Callet

    Methodologies for Assessing 3D QoE: Standards and Explorative Studies

    ZTE Communications, vol. 11, no. 1, pp. 2-10

    2013

    Abstract anzeigen

    Mastering quality of experience (QoE) is key to the widespread adoption of stereoscopic 3DTV (S-3DTV). However, assessing QoE of S-3DTV is not straightforward. Methods for determining observer experience need to be clearly defined and sufficiently robust. In this paper, we present state-of-the-art subjective QoE assessment for S-3DTV. We present conventional stan⁃ dardized ITU recommendations for evaluating picture quality and discuss new ITU activities in the area of S-3DTV assess⁃ ment. We also present and discuss explorative studies from the literature. We then introduce ways of using conventional quality assessment for S-3DTV QoE assessment. In discussing our pro⁃ posal, we mainly focus on QoE indicators and common features of subjective assessment. Multidimensional QoE indicators need to be used in S-3DTV to highlight advantages and reveal problems. In the second part of our proposal, we discuss the re⁃ quirements for adapting ITU-R BT.500, a conventional subjec⁃ tive QoE assessment method, ITU-R BT.500, for assessing QoE of S-3DTV are presented.

    DigitalAngewandte Informatik

    Beitrag (Sammelband oder Tagungsband)

    W. Chen, J. Fournier, Marcus Barkowsky, P. Le Callet

    Quality of experience model for 3DTV

    Proceedings of IS&T/SPIE ELECTRONIC IMAGING | Stereoscopic Displays and Applications XXIII , San Francisco, CA, USA, vol. 8288, no. 59

    2012

    DOI: 10.1117/12.907873

    Abstract anzeigen

    Modern stereoscopic 3DTV brings new QoE (quality of experience) to viewers, which not only enhances the 3D sensation due to the added binocular depth, but may also induce new problems such as visual discomfort. Subjective quality assessment is the conventional method to assess the QoE. However, the conventional perceived image quality concept is not enough to reveal the advantages and the drawbacks of stereoscopic images in 3DTV. Higher-level concepts such as visual experience were proposed to represent the overall visual QoE for stereoscopic images. In this paper, both the higher-level concept quality indicator, i.e. visual experience and the basic level concepts quality indicators including image quality, depth quantity, and visual comfort are defined. We aim to explore 3D QoE by constructing the visual experience as a weight sum of image quality, depth quantity and visual comfort. Two experiments in which depth quantity and image quality are varied respectively are designed to validate this model. In the first experiment, the stimuli consist of three natural scenes and for each scene, there are four levels of perceived depth variation in terms of depth of focus: 0, 0.1, 0.2 and 0.3 diopters. In the second experiment, five levels of JPEG 2000 compression ratio, 0, 50, 100, 175 and 250 are used to represent the image quality variation. Subjective quality assessments based on the SAMVIQ method are used in both experiments to evaluate the subject's opinion in basic level quality indicators as well as the higher-level indicator. Statistical analysis of result reveals how the perceived depth and image quality variation affect different perceptual scales as well as the relationship between different quality aspects.

    DigitalAngewandte Informatik

    Beitrag (Sammelband oder Tagungsband)

    W. Chen, J. Fournier, Marcus Barkowsky, P. Le Callet

    Exploration of Quality of Experience of Stereoscopic Images: Binocular Depth

    Sixth International Workshop on Video Processing and Quality Metrics for Consumer Electronics - VPQM 2012 (Jan 2012; Scottsdale, AZ, USA)

    2012

    DigitalAngewandte Informatik

    Beitrag (Sammelband oder Tagungsband)

    W. Chen, J. Fournier, Marcus Barkowsky, P. Le Callet

    New stereoscopic video shooting rule based on stereoscopic distortion parameters and comfortable viewing zone

    Proceedings of SPIE Vol. 7863: Stereoscopic Displays and Applications XXII;

    2011

    Abstract anzeigen

    Human binocular depth perception, the most important element brought by 3DTV, is proved to be closely connected to not only the content acquisition (camera focal length, camera baseline and etc.) but also the viewing environment (viewing distance, screen size and etc.). Conventional 3D stereography rule in the literature usually consider the general viewing condition and basic human factors to guide the content acquisition, such as assuming human inter-pupil baseline as the maximum disparity. A lot of new elements or problems of stereoscopic viewing was not considered or precisely defined so that advanced shooting rule is needed to guarantee the overall quality of stereoscopic video. In this paper, we proposed a new stereoscopic video shooting rule considering two most important issues in 3DTV: stereoscopic distortion and comfortable viewing zone. Firstly, a mathematic model mapping the camera space to visualization space is established in order to geometrically estimate the stereoscopic depth distortion. Depth and shape distortion factors are defined and used to describe the stereoscopic distortion. Secondly, comfortable viewing zone (or Depth of focus) is considered to reduce the problem of visual discomfort and visual fatigue. The new shooting rule is to optimize the camera parameters (focal length, camera baseline and etc.) in order to control depth and shape distortion and also guarantee that the perceived scene is located in comfortable viewing zone as possible. However, in some scenarios, the above two conditions cannot be fulfill simultaneously, even sometimes contradict with each other so that priority should be decided. In this paper, experimental stereoscopic synthetic content generation with various sets of camera parameters and various sets of scenes representing different depth range are presented. Justification of the proposed new shooting rule is based on 3D concepts (depth rendering, visual comfort and visual experience) subjective video assessment. The results of this study will provide a new method to propose camera parameters based on management of new criteria (shape distortion and depth of focus) in order to produce optimized stereoscopic images and videos.

    DigitalAngewandte Informatik

    Beitrag (Sammelband oder Tagungsband)

    W. Chen, J. Fournier, Marcus Barkowsky, P. Le Callet

    New Requirements of Subjective Video Quality Assessment Methodologies for 3DTV

    Fifth International Workshop on Video Processing and Quality Metrics (VPQM) [Scottsdale, AZ, USA]

    2010

    Abstract anzeigen

    In this paper, the new challenges of 3DTV for subjective assessment are discussed. Conventional 2D methods have severe limitations which will be revealed. Based on the understanding of the new characteristics brought by 3DTV, changes and additions in the requirements for subjective assessment are proposed in order to develop a novel subjective video quality assessment methodology for 3DTV. In particular, depth rendering for 3D display is selected to give a further discussion. The depth rendering abilities are defined as a combination of the physical parameters and the perceptual constrains. We analyze different types of stereoscopic and multiview displays. Several problems regarding depth rendering are discussed in order to highlight the diversity and complexity of assessing 3DTV.