6 results on '"Crave, Olivier"'
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2. Distributed Temporal Multiple Description Coding for Robust Video Transmission
- Author
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Crave, Olivier, Guillemot, Christine, Pesquet-Popescu, Béatrice, and Tillier, Christophe
- Published
- 2007
- Full Text
- View/download PDF
3. Distributed Temporal Multiple Description Coding for Robust Video Transmission
- Author
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Pesquet-Popescu Béatrice, Tillier Christophe, Crave Olivier, and Guillemot Christine
- Subjects
Telecommunication ,TK5101-6720 ,Electronics ,TK7800-8360 - Abstract
Abstract The problem of multimedia communications over best-effort networks is addressed here with multiple description coding (MDC) in a distributed framework. In this paper, we first compare four video MDC schemes based on different time splitting patterns and temporal two- or three-band motion-compensated temporal filtering (MCTF). Then, the latter schemes are extended with systematic lossy description coding where the original sequence is separated into two subsequences, one being coded as in the latter schemes, and the other being coded with a Wyner-Ziv (WZ) encoder. This amounts to having a systematic lossy Wyner-Ziv coding of every other frame of each description. This error control approach can be used as an alternative to automatic repeat request (ARQ) or forward error correction (FEC), that is, the additional bitstream can be systematically sent to the decoder or can be requested, as in ARQ. When used as an FEC mechanism, the amount of redundancy is mostly controlled by the quantization of the Wyner-Ziv data. In this context, this approach leads to satisfactory rate-distortion performance at the side decoders, however it suffers from high redundancy which penalizes the central description. To cope with this problem, the approach is then extended to the use of MCTF for the Wyner-Ziv frames, in which case only the low-frequency subbands are WZ-coded and sent in the descriptions.
- Published
- 2008
4. Distributed temporal multiple description coding for robust video transmission
- Author
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Crave, Olivier, Guillemot, Christine, Pesquet-Popescu, Beatrice, and Tillier, Christophe
- Subjects
TCP/IP ,Coding theory -- Usage ,Error-correcting codes -- Usage ,Transmission Control Protocol/Internet Protocol (Computer network protocol) -- Usage ,Transmission Control Protocol/Internet Protocol (Computer network protocol) -- Analysis - Published
- 2008
5. Approches théoriques en codage vidéo robuste multi-terminal
- Author
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Crave, Olivier, Télécom ParisTech, Ecole, Laboratoire Traitement et Communication de l'Information (LTCI), Télécom ParisTech-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), Télécom ParisTech, Béatrice Pesquet-Popescu, and Christine Guillemot
- Subjects
Distributed source coding ,Codage par descriptions multiples ,[OTHER] domain_other ,Multiple description coding ,Video ,[OTHER]domain_other ,Codage de source distribué - Abstract
In this thesis, new robust video compression techniques are proposed for multi-terminal coding. We first compare four video multiple description coding schemes based on different time splitting patterns and temporal two- or three-band motion-compensated temporal filtering (MCTF). Then, the latter schemes are extended with systematic lossy description coding where the original sequence is separated into two sub-sequences, one being coded as in the latter schemes, and the other being coded with a Wyner-Ziv encoder. This amounts to having a systematic lossy Wyner-Ziv coding of every other frame of each description. This error control approach can be used as an alternative to Automatic Repeat Request (ARQ) or Forward Error Correction (FEC), i.e. the additional bitstream can be systematically sent to the decoder or can be requested, as in ARQ. When used as a FEC mechanism, the amount of redundancy is mostly controlled by the quantization of the Wyner-Ziv data. In this context, this approach leads to satisfactory rate-distortion performance at the side decoders, however suffers from high redundancy which penalizes the central description. To cope with this problem, the approach is then extended to the use of MCTF for the Wyner-Ziv frames, in which case only the low-frequency subbands are Wyner-Ziv encoded and sent in the descriptions. Next, we propose a multiple description coding scheme with side information at the receiver. It builds upon both multiple description coding principles and Slepian-Wolf coding principles. The input source is first quantized with a multiple description scalar quantizer (MDSQ) which introduces redundancy or correlation in the transmitted streams in order to take advantage of the path diversity. The resulting sequences of indexes are Slepian-Wolf encoded, that is separately encoded and jointly decoded. While the first step (MDSQ) plays the role of a channel code, the second one (Slepian-Wolf coding) plays the role of a source code, compressing the sequences of quantized indexes. In a second step, the cross-decoding of the two descriptions is proposed. This allows us to account for both the correlation with the side information as well as the correlation between the two descriptions. Then, we propose a way to improve the robustness of distributed video coding while keeping good rate-distortion performance by structuring the input sequence into groups of picture, each containing one key frame and one Wyner-Ziv frame. For each frame, two descriptions are generated by a MDSQ. This provides two balanced descriptions that contain partial information about every frame in the video input. At the central decoder, iterative decoding of the two Wyner-Ziv descriptions along with side information is performed. We study the influence of the cross-decoding and of the amount of redundancy on the performance., Cette thèse propose des techniques de compression vidéo robuste dans un contexte de codage multi-terminal. Nous proposons des schémas de codage par descriptions multiples basés sur des filtres temporels dyadiques et 3-bandes appliqués sur des séquences sous-échantillonnées. Nous commençons par présenter plusieurs méthodes pour construire des descriptions corrélées à partir de ces bancs de filtres. Puis, pour augmenter leur robustesse et leur stabilité au cours du temps, nous proposons d'introduire un codec Wyner-Ziv au sein de ces schémas redondants : les trames qui en principe ne sont pas transmises dans une description sont ici codées en Wyner-Ziv. Pour réduire la redondance, nous proposons d'appliquer un filtrage temporel compensé en mouvement sur les trames codées en Wyner-Ziv pour ne transmettre que les sous-bandes de basses fréquences. Ensuite, nous proposons un schéma de codage par descriptions multiples avec information adjacente basé sur une quantification scalaire à descriptions multiples (MDSQ). Dans un premier temps, les indices générés par la MDSQ sont codés séparément par un codeur de Slepian-Wolf et décodés séparément à l'aide d'une information adjacente qui sert également à la reconstruction des coefficients. Dans un deuxième temps, un décodage croisé est proposé pour décoder conjointement les indices et ainsi profiter de la redondance entre les descriptions. Enfin, nous proposons d'améliorer la robustesse en codage vidéo distribué tout en conservant de bonnes performances débit-distorsion en structurant la séquence d'origine en groupes d'images, chacun contenant une trame clé et une trame codée en Wyner-Ziv. Pour chaque trame, deux descriptions sont générées par un quantificateur scalaire à descriptions multiples. Cette technique permet d'obtenir deux descriptions équilibrées contenant chacune une information partielle sur chaque trame dans la vidéo d'origine. Au décodeur central, le décodage itératif de deux descriptions avec information adjacente est utilisé. Nous étudions alors l'influence du décodage croisé et du taux de redondance sur les performances.
- Published
- 2008
6. Robust Video Coding Based on Multiple Description Scalar Quantization With Side Information
- Author
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Crave, Olivier, primary, Pesquet-Popescu, Beatrice, additional, and Guillemot, Christine, additional
- Published
- 2010
- Full Text
- View/download PDF
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