Researcher:
Saygılı, Görkem

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Master Student

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Görkem

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Saygılı

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Saygılı, Görkem

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2009 - 200912010 - 20113

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Researcher Of Publications: search.filters.isAuthorOfPublication.19b6d4cb-99c9-4bab-aae4-766ca3fbc12c

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    Evaluation of asymmetric stereo video coding and rate scaling for adaptive 3D video streaming
    (IEEE-Inst Electrical Electronics Engineers Inc, 2011) N/A; N/A; Department of Electrical and Electronics Engineering; Saygılı, Görkem; Gürler, Cihat Göktuğ; Tekalp, Ahmet Murat; Master Student; PhD Student; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; 26207
    It is well known that the human visual system can perceive high frequencies in 3D stereo video, even if that information is present in only one of the views. Therefore, the best perceived 3D stereo video quality may be achieved by asymmetric coding where the reference and auxiliary (right and left) views are coded at unequal PSNR. However, the questions of what is the best level of asymmetry in order to maximize the perceived quality and whether asymmetry should be achieved by spatial resolution reduction or PSNR (quality) reduction have been open issues. We conducted extensive subjective tests, which indicate that if the reference view is encoded at sufficiently high quality and the auxiliary view is encoded at a lower quality but above a certain PSNR threshold, then the degradation in 3D video quality is unnoticeable. Since asymmetric coding by PSNR reduction gives finer control over achievable PSNR values over spatial resolution reduction, asymmetry by PSNR reduction allows us to encode at a point more close to this just-noticeable asymmetry PSNR threshold; hence will be preferred over the spatial resolution reduction method. Subjective tests also indicate that below this just-noticeable asymmetry threshold, where subtle artifacts start to appear, symmetric coding performs better than asymmetric coding in terms of perceived 3D video quality. Therefore, we show that the choice between asymmetric vs. symmetric coding depends on PSNR; hence, the available total bitrate. This paper also proposes a novel asymmetric scalable stereo video coding framework to enable adaptive stereoscopic video streaming taking full advantage of these observations and subjective test results.
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    3D display dependent quality evaluation and rate allocation using scalable video coding
    (Ieee, 2009) N/A; N/A; Department of Electrical and Electronics Engineering; Saygılı, Görkem; Gürler, Cihat Göktuğ; Tekalp, Ahmet Murat; Master Student; PhD Student; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; 26207
    It is well known that the human visual system can perceive high frequency content in 3D, even if that information is present in only one of the views. Then, the best 3D perception quality may be achieved by allocating the rates of the reference (right) and auxiliary (left) views asymmetrically. However the question of whether the rate reduction for the auxiliary view should be achieved by spatial resolution reduction (coding a downsampled version of the video followed by upsampling after decoding) or quality (QP) reduction is an open issue. This paper shows that which approach should be preferred depends on the 3D display technology used at the receiver. Subjective tests indicate that users prefer lower quality (larger QP) coding of the auxiliary view over lower resolution coding if a "full spatial resolution" 3D display technology (such as polarized projection) is employed. On the other hand, users prefer lower resolution coding of the auxiliary view over lower quality coding if a "reduced spatial resolution" 3D display technology (such as parallax barrier - autostereoscopic) is used. Therefore, we conclude that for 3D IPTV services, while receiving full quality/resolution reference view, users should subscribe to differently scaled versions of the auxiliary view depending on their 3D display technology. We also propose an objective 3D video quality measure that takes the 3D display technology into account.
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    Flexible transport of 3-d video over networks
    (IEEE-Inst Electrical Electronics Engineers Inc, 2011) N/A; N/A; N/A; Department of Electrical and Electronics Engineering; Gürler, Cihat Göktuğ; Görkemli, Burak; Saygılı, Görkem; Tekalp, Ahmet Murat; PhD Student; PhD Student; Master Student; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; N/A; 26207
    Three-dimensional (3-D) video is the next natural step in the evolution of digital media technologies. Recent 3-D autostereoscopic displays can display multiview video with up to 200 views. While it is possible to broadcast 3-D stereo video (two views) over digital TV platforms today, streaming over Internet Protocol (IP) provides a more flexible approach for distribution of stereo and free-view 3-D media to home and mobile with different connection bandwidths and different 3-D displays. Here, flexible transport refers to rate-scalable, resolution-scalable, and view-scalable transport over different channels including digital video broadcasting (DVB) and/or IP. In this paper, we first briefly review the state of the art in 3-D video formats, coding methods for different transport options and video formats, IP streaming protocols, and streaming architectures. We then take a look at beyond the state of the art in 3-D video transport research, including asymmetric stereoscopic video streaming, adaptive and peer-to-peer (P2P) streaming of multiview video, view-selective streaming and future directions in broadcast of 3-D media over IP and jointly over DVB and IP.
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    Quality assessment of asymmetric stereo video coding
    (IEEE, 2010) N/A; N/A; Department of Electrical and Electronics Engineering; Saygılı, Görkem; Gürler, Cihat Göktuğ; Tekalp, Ahmet Murat; Master Student; PhD Student; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; 26207
    It is well known that the human visual system can perceive high frequencies in 3D, even if that information is present in only one of the views. therefore, the best 3D stereo quality may be achieved by asymmetric coding where the reference (right) and auxiliary (left) views are coded at unequal PSNR. However, the questions of what should be the level of this asymmetry and whether asymmetry should be achieved by spatial resolution reduction or SNR (quality) reduction are open issues. Extensive subjective tests indicate that when the reference view is encoded at sufficiently high quality, the auxiliary view can be encoded above a low-quality threshold without a noticeable degradation on the perceived stereo video quality. This low-quality threshold may depend on the 3D display; e.g., it is about 31 dB for a parallax barrier display and 33 dB for a polarized projection display. Subjective tests show that, Above this PSNR threshold value, users prefer SNR reduction over spatial resolution reduction on both parallax barrier and polarized projection displays. It is also observed that, if the auxiliary view is encoded below this threshold value, symmetric coding starts to perform better than asymmetric coding in terms of perceived 3D video quality.