Publikationen


Suche nach „[Y.] [Koudota]“ hat 4 Publikationen gefunden
Suchergebnis als PDF
    DigitalF: Angewandte Informatik

    Beitrag (Sammelband oder Tagungsband)

    K. Berger, Y. Koudota, Marcus Barkowsky, P. Le Callet

    Subjective Quality Assessment Comparing UHD and HD Resolution in HEVC Transmission Chain

    2015 Seventh International Workshop on Quality of Multimedia Experience (QoMEX)

    2015

    Abstract anzeigen

    Ultra High Definition Television (UHDTV) is an emerging broadcasting system, aiming to replace the current High Definition Television (HDTV) in the near future. One aspect of UHDTV is to allow for higher resolutions, notably UHD1, which requires a four times increased datarate for uncompressed transmission compared to Full-HD resolution. As bandwidth for transmission channels in television broadcast is often a fixed value, this study provides information about the perceived quality for transmitting UHD1 content compared to Full-HD content at the same bitrate encoded with HEVC. Content influence is tested with 15 video contents and 4 bitrates are individually chosen per content to span the range of the perceptual scale. The methodology of Absolute Category Rating with Hidden Reference (ACR-HR) is used to collect votes from 24 viewers. The statistical analysis of the collected data shows that, in most cases, there is no significant quality difference between videos transmitted in Full-HD and UHD1 resolution but that the results strongly depend on the content type and on the capture quality. It is also shown that the required bitrate for achieving a chosen broadcast quality level varies with content by a factor of about 14 in HEVC coding.

    DigitalF: Angewandte Informatik

    Beitrag (Sammelband oder Tagungsband)

    J. Li, Y. Koudota, Marcus Barkowsky, H. Primon, P. Le Callet

    Comparing Upscaling Algorithms From Hd To Ultra Hd By Evaluating Preference Of Experience

    2014 Sixth International Workshop on Quality of Multimedia Experience (QoMEX)

    2014

    Abstract anzeigen

    As the next generation of TV, Ultra High Definition Television (UHDTV) is attracting more and more people's attention as it provides a new viewing experience. Considering content delivery, due to the lack of Ultra HD resources, a direct question for the industry is that whether the state-of-the-art upscaling algorithms can be utilized to upscale the current HD or Full HD resources to UHD, gaining benefit from the higher resolution but without losing the high quality viewing experience. To investigate this, in this study, we upscaled 720p and 1080p sequences to UHD resolution by different upscaling algorithms. Paired Comparison methodology was used in the subjective experiment to evaluate their performances. The results showed that for the case of fast motion content, viewers' preference on different upscaled video sequences is not significantly different. In general conditions, the low complexity upscaling algorithms (e.g., lanczos-3) performed better than the high complexity algorithms (e.g., Robust Super Resolution algorithm). A novel upscaling algorithm adapted to UHD is recommended to be developed based on the mechanisms of human visual system.

    DigitalF: Angewandte Informatik

    Beitrag (Sammelband oder Tagungsband)

    Marcus Barkowsky, N. Staelens, L. Janowski, Y. Koudota, M. Leszczuk, M. Urvoy, P. Hummelbrunner, I. Sedano, K. Brunnström

    Subjective experiment dataset for joint development of hybrid video quality measurement algorithms

    QoEMCS 2012 ‐ Third Workshop on Quality of Experience for Multimedia Content Sharing, Berlin

    2012

    Abstract anzeigen

    The application area of an objective measurement algorithm for video quality is always limited by the scope of the video datasets that were used during its development and training. This is particularly true for measurements which rely solely on information available at the decoder side, for example hybrid models that analyze the bitstream and the decoded video. This paper proposes a framework which enables researchers to train, test and validate their algorithms on a large database of video sequences in such a way that the ‐ often limited ‐ scope of their development can be taken into consideration. A freely available video database for the development of hybrid models is described containing the network bitstreams, parsed information from these bitstreams for easy access, the decoded video sequences, and subjectively evaluated quality scores.

    DigitalF: Angewandte 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.