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Suche nach „[V.] [Ricordel]“ hat 4 Publikationen gefunden
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    DigitalAngewandte Informatik

    Beitrag (Sammelband oder Tagungsband)

    M. Urvoy, Marcus Barkowsky, J. Gutiérrez, R. Cousseau, Y. Koudota, V. Ricordel, P. Le Callet, N. García

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

    2012 Fourth International Workshop on Quality of Multimedia Experience

    2012

    Abstract anzeigen

    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.

    DigitalAngewandte Informatik

    Beitrag (Sammelband oder Tagungsband)

    Wang, J., Marcus Barkowsky, V. Ricordel, P. Le Callet

    Clarifying how defocus blur and disparity affect the perceived depth

    Proceedings of the First Sino-French Workshop on Education and Research collaborations in Information and Communication Technologies (SIFWICT) 2011, Nantes, France

    2011

    Abstract anzeigen

    Human visual system takes advantage of different cues simultaneously to provide us the perception of depth. When 3D images are shown on a planar stereoscopic display, binocular disparity becomes a pre-eminent depth cue. But it induces simultaneously the conflict between accommodation and vergence, which is often considered as a main reason for visual discomfort. If we limit this visual discomfort by decreasing the disparity, the apparent depth also decreases. We propose to decrease the (binocular) disparity of 3D presentations, and to reinforce (monocular) cues to compensate the loss of perceived depth and keep an unaltered apparent depth. The influence of a monocular depth cue, blur, on the apparent depth of stereoscopic scenes was studied in our recent work. We conducted a subjective experiment using a two-alternative forced choice task. Observers were required to identify the larger perceived depth in a pair of 3D images with/without blur. By fitting the result to a psychometric function, we obtained points of subjective equality in terms of disparity. We found that when blur is added to the background of the image, the viewer can perceive larger depth comparing to the images without any blur in the background. The increase of perceived depth can be considered as a function of the relative distance between the foreground and background, while it is insensitive to the distance between the viewer and the depth plane at which the blur is added.

    DigitalAngewandte Informatik

    Beitrag (Sammelband oder Tagungsband)

    Wang, J., Marcus Barkowsky, V. Ricordel, P. Le Callet

    Quantifying how the Combination of Blur and Disparity affects the Perceived Depth

    Proceedings of SPIE Vol. 7865: Human Vision and Electronic Imaging XVI

    2011

    Abstract anzeigen

    The influence of a monocular depth cue, blur, on the apparent depth of stereoscopic scenes will be studied in this paper. When 3D images are shown on a planar stereoscopic display, binocular disparity becomes a pre-eminent depth cue. But it induces simultaneously the conflict between accommodation and vergence, which is often considered as a main reason for visual discomfort. If we limit this visual discomfort by decreasing the disparity, the apparent depth also decreases. We propose to decrease the (binocular) disparity of 3D presentations, and to reinforce (monocular) cues to compensate the loss of perceived depth and keep an unaltered apparent depth. We conducted a subjective experiment using a two- alternative forced choice task. Observers were required to identify the larger perceived depth in a pair of 3D images with/without blur. By fitting the result to a psychometric function, we obtained points of subjective equality in terms of disparity. We found that when blur is added to the background of the image, the viewer can perceive larger depth comparing to the images without any blur in the background. The increase of perceived depth can be considered as a function of the relative distance between the foreground and background, while it is insensitive to the distance between the viewer and the depth plane at which the blur is added.

    DigitalAngewandte Informatik

    Beitrag (Sammelband oder Tagungsband)

    Wang, J., Marcus Barkowsky, V. Ricordel, P. Le Callet

    Quantifying how the combination of blur and disparity affects the perceived depth

    Proceedings of SPIE Vol. 7865: Human Vision and Electronic Imaging XVI

    2011