Manel Abid - Academia.edu (original) (raw)
Papers by Manel Abid
Joint source-channel decoding (JSCD) exploits residual redundancy in compressed bitstreams to imp... more Joint source-channel decoding (JSCD) exploits residual redundancy in compressed bitstreams to improve the robustness to transmission errors of multimedia coding schemes. This paper proposes an architecture to introduce some additional side information in compressed streams to help JSCD. This architecture exploits a reference decoder already present or introduced at the encoder side. An application to the robust decoding of 3D-ESCOT encoded bitstreams generated within the Vidwav video coder is presented. The layered bitstream generated by this encoder allows SNR scalability, and moreover, when processed by a JSCD, provides increased robustness to transmission errors compared with a single layered bitstream.
de la Thèse Je remercie tout d'abord mes directrices de thèse, Béatrice Pesquet-Popescu et Maria ... more de la Thèse Je remercie tout d'abord mes directrices de thèse, Béatrice Pesquet-Popescu et Maria Trocan, pour m'avoir fait confiance et pour m'avoir guidée, encouragée, conseillée tout au long de ces trois années. Je tiens de plus à remercier Michel Kieffer pour sa précieuse collaboration au cours de ma thèse. J'adresse également mes remerciements à tous le membres de mon jury : François-Xavier Coudoux qui m'a fait l'honneur de présider ce jury, Peter Schelkens et Fabrice Labeau qui ont bien voulu accepter la charge de rapporteur et Anissa Mokraoui qui a bien voulu juger ce travail. Je souhaite de plus remercier toutes les personnes que j'ai pu côtoyer et avec lesquelles j'ai pu collaborer durant mes trois années de thèse au département TSI de Télécom Paris Tech, et plus spécifiquement, tous les membres de l'équipe multimédia. Enfin, je remercie du fond du coeur mes chers parents qui n'ont jamais cessé de croire en moi pendant toutes mes années d'études et qui m'ont toujours encouragée à aller de l'avant. Je leur dédie cette thèse.
2012 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2012
Oversampled filter banks perform simultaneously subband decomposition and redundancy introduction... more Oversampled filter banks perform simultaneously subband decomposition and redundancy introduction. This redundancy has been shown to be useful to combat channel impairments, when the subbands are transmitted over a wireless channel, as well as quantization noise. This paper describes an implementation of the maximum a posteriori estimator of the input signal from the noisy quantized subbands obtained at the output of some transmission channel. The relations between the input samples and the noisy subband samples are described using a factor graph. Belief propagation is then applied to get the posterior marginals of the input samples. The experimental results show that when the channel is clear, a least-squares estimate is satisfying. But, the proposed approach performs significantly better than a least-squares reconstruction when the channel is noisy: a gain in terms of channel SNR of more than 2 dB is observed.
This thesis aims at proposing and implementing efficient joint source-channel coding and decoding... more This thesis aims at proposing and implementing efficient joint source-channel coding and decoding schemes in order to enhance the robustness of multimedia contents transmitted over unreliable networks. In a first time, we propose to identify and exploit the residual redundancy left by wavelet video coders in the compressed bit streams. an efficient joint-source channel decoding scheme is proposed to detect and correct some of the transmission errors occurring during a noisy transmission. This technique is further applied to multiple description video streams transmitted over a mixed architecture consisting of a wired lossy part and a wireless noisy part. In a second time, we propose to use the structured redundancy deliberately introduced by multirate coding systems, such as oversampled filter banks, in order to perform a robust estimation of the input signals transmitted over noisy channels. Two efficient estimation approaches are proposed and compared. The first one exploits the l...
Dans cet article, nous introduisons une méthode de reconstruction du signal d'entrée d'un banc de... more Dans cet article, nous introduisons une méthode de reconstruction du signal d'entrée d'un banc de filtres suréchantillonnés (BFS) lorsque les sous bandes générées à sa sortie sont quantifiées et transmises sur un canal bruité. Nous exploitons la redondance introduite par le BFS et le caractère borné du bruit de quantification pour construire un estimateur cohérent corrigeant les erreurs de transmission. Pour cela, nous réalisons une estimation au sens du maximum de vraisemblance des indices de quantification transmis sur le canal, en nous restreignant aux indices correspondant à des signaux appartenant au sous-espace des signaux que le banc de filtres (BdF) peut générer et qui sont compatibles avec les erreurs de quantification. Aucun test d'hypothèse ou réglage de seuil de détection d'erreur n'est nécessaire, contrairement aux méthodes présentées dans [1, 2]. Le signal reconstruit à l'aide de la technique proposée est de bien meilleure qualité que le signal reconstruit à l'aide d'un estimateur classique. En considérant un facteur de suréchantillonage de 3/2, une modulation BPSK des indices binarisés et un canal à bruit blanc additif gaussien, un gain d'environ 8 dB en rapport signal-à-bruit (RSAB) sur le signal est obtenu pour un RSAB sur le canal de 7 dB.
Http Www Theses Fr, Oct 5, 2012
2011 19th European Signal Processing Conference, Aug 1, 2011
This paper introduces a reconstruction approach for the input signal of an oversampled filter ban... more This paper introduces a reconstruction approach for the input signal of an oversampled filter bank (OFB) when the sub-bands generated at its output are quantized and transmitted over a noisy channel. This approach exploits the redundancy introduced by the OFB and the fact that the quantization noise is bounded. A maximum-likelihood estimate of the input signal is evaluated, which only considers the vectors of quantization indexes corresponding to subband signals that could have been generated by the OFB and that are compliant with the quantization errors. When considering an OFB with an oversampling ratio of 3/2 and a transmission of quantized subbands on an AWGN channel, compared to a classical decoder, the performance gains are up to 9 dB in terms of SNR for the reconstructed signal, and 3 dB in terms of channel SNR.
16th IFAC Symposium on System Identification, 2012
Complex Systems Design & Management, 2015
2010 2nd European Workshop on Visual Information Processing (EUVIP), 2010
In this paper, we study the problem of image denoising by using an adaptive lifting scheme. Such ... more In this paper, we study the problem of image denoising by using an adaptive lifting scheme. Such a scheme can adapt itself well to the analyzed signal, which allows to keep important information for denoising applications. However, it results in a non-isometric transform which can be an important limitation as most of the denoising approaches rely on the estimation of the noise energy in the subbands. A previous study has been done to evaluate the subband energies of an uncorrelated signal, in the wavelet domain when using such an adaptive scheme. Based on this previous work, we propose in this paper an estimation of the noise energies in the subband and use it to perform image denoising. Experimental results illustrate that this approach is more effective, in image denoising, than the classical non adaptive lifting schemes both considering objective and subjective image quality measures.
This paper introduces a reconstruction approach for the input signal of an oversampled filter ban... more This paper introduces a reconstruction approach for the input signal of an oversampled filter bank (OFB) when the sub-bands generated at its output are quantized and transmitted over a noisy channel. This approach exploits the redundancy introduced by the OFB and the fact that the quantization noise is bounded. A maximum-likelihood estimate of the input signal is evaluated, which only considers the vectors of quantization indexes corresponding to subband signals that could have been generated by the OFB and that are compliant with the quantization errors. When considering an OFB with an oversampling ratio of 3/2 and a transmission of quantized subbands on an AWGN channel, compared to a classical decoder, the performance gains are up to 9 dB in terms of SNR for the reconstructed signal, and 3 dB in terms of channel SNR.
In this paper, we propose a joint source-channel (JSC) decoding scheme for 3D ESCOT-based video c... more In this paper, we propose a joint source-channel (JSC) decoding scheme for 3D ESCOT-based video coders, such as Vidwav. The embedded bitstream generated by such coders is very sensitive to transmission errors unavoidable on wireless channels. The proposed JSC decoder employs the residual redundancy left in the bitstream by the source coder combined with bit reliability information provided by the channel or channel decoder to correct transmission errors. When considering an AWGN channel, the performance gains are in average 4 dB in terms of PSNR of the reconstructed frames, and 0.7 dB in terms of channel SNR. When considering individual frames, the obtained gain is up to 15 dB in PSNR.
Joint source-channel decoding (JSCD) exploits residual redundancy in compressed bitstreams to imp... more Joint source-channel decoding (JSCD) exploits residual redundancy in compressed bitstreams to improve the robustness to transmission errors of multimedia coding schemes. This paper proposes an architecture to introduce some additional side information in compressed streams to help JSCD. This architecture exploits a reference decoder already present or introduced at the encoder side. An application to the robust decoding of 3D-ESCOT encoded bitstreams generated within the Vidwav video coder is presented. The layered bitstream generated by this encoder allows SNR scalability, and moreover, when processed by a JSCD, provides increased robustness to transmission errors compared with a single layered bitstream.
de la Thèse Je remercie tout d'abord mes directrices de thèse, Béatrice Pesquet-Popescu et Maria ... more de la Thèse Je remercie tout d'abord mes directrices de thèse, Béatrice Pesquet-Popescu et Maria Trocan, pour m'avoir fait confiance et pour m'avoir guidée, encouragée, conseillée tout au long de ces trois années. Je tiens de plus à remercier Michel Kieffer pour sa précieuse collaboration au cours de ma thèse. J'adresse également mes remerciements à tous le membres de mon jury : François-Xavier Coudoux qui m'a fait l'honneur de présider ce jury, Peter Schelkens et Fabrice Labeau qui ont bien voulu accepter la charge de rapporteur et Anissa Mokraoui qui a bien voulu juger ce travail. Je souhaite de plus remercier toutes les personnes que j'ai pu côtoyer et avec lesquelles j'ai pu collaborer durant mes trois années de thèse au département TSI de Télécom Paris Tech, et plus spécifiquement, tous les membres de l'équipe multimédia. Enfin, je remercie du fond du coeur mes chers parents qui n'ont jamais cessé de croire en moi pendant toutes mes années d'études et qui m'ont toujours encouragée à aller de l'avant. Je leur dédie cette thèse.
2012 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2012
Oversampled filter banks perform simultaneously subband decomposition and redundancy introduction... more Oversampled filter banks perform simultaneously subband decomposition and redundancy introduction. This redundancy has been shown to be useful to combat channel impairments, when the subbands are transmitted over a wireless channel, as well as quantization noise. This paper describes an implementation of the maximum a posteriori estimator of the input signal from the noisy quantized subbands obtained at the output of some transmission channel. The relations between the input samples and the noisy subband samples are described using a factor graph. Belief propagation is then applied to get the posterior marginals of the input samples. The experimental results show that when the channel is clear, a least-squares estimate is satisfying. But, the proposed approach performs significantly better than a least-squares reconstruction when the channel is noisy: a gain in terms of channel SNR of more than 2 dB is observed.
This thesis aims at proposing and implementing efficient joint source-channel coding and decoding... more This thesis aims at proposing and implementing efficient joint source-channel coding and decoding schemes in order to enhance the robustness of multimedia contents transmitted over unreliable networks. In a first time, we propose to identify and exploit the residual redundancy left by wavelet video coders in the compressed bit streams. an efficient joint-source channel decoding scheme is proposed to detect and correct some of the transmission errors occurring during a noisy transmission. This technique is further applied to multiple description video streams transmitted over a mixed architecture consisting of a wired lossy part and a wireless noisy part. In a second time, we propose to use the structured redundancy deliberately introduced by multirate coding systems, such as oversampled filter banks, in order to perform a robust estimation of the input signals transmitted over noisy channels. Two efficient estimation approaches are proposed and compared. The first one exploits the l...
Dans cet article, nous introduisons une méthode de reconstruction du signal d'entrée d'un banc de... more Dans cet article, nous introduisons une méthode de reconstruction du signal d'entrée d'un banc de filtres suréchantillonnés (BFS) lorsque les sous bandes générées à sa sortie sont quantifiées et transmises sur un canal bruité. Nous exploitons la redondance introduite par le BFS et le caractère borné du bruit de quantification pour construire un estimateur cohérent corrigeant les erreurs de transmission. Pour cela, nous réalisons une estimation au sens du maximum de vraisemblance des indices de quantification transmis sur le canal, en nous restreignant aux indices correspondant à des signaux appartenant au sous-espace des signaux que le banc de filtres (BdF) peut générer et qui sont compatibles avec les erreurs de quantification. Aucun test d'hypothèse ou réglage de seuil de détection d'erreur n'est nécessaire, contrairement aux méthodes présentées dans [1, 2]. Le signal reconstruit à l'aide de la technique proposée est de bien meilleure qualité que le signal reconstruit à l'aide d'un estimateur classique. En considérant un facteur de suréchantillonage de 3/2, une modulation BPSK des indices binarisés et un canal à bruit blanc additif gaussien, un gain d'environ 8 dB en rapport signal-à-bruit (RSAB) sur le signal est obtenu pour un RSAB sur le canal de 7 dB.
Http Www Theses Fr, Oct 5, 2012
2011 19th European Signal Processing Conference, Aug 1, 2011
This paper introduces a reconstruction approach for the input signal of an oversampled filter ban... more This paper introduces a reconstruction approach for the input signal of an oversampled filter bank (OFB) when the sub-bands generated at its output are quantized and transmitted over a noisy channel. This approach exploits the redundancy introduced by the OFB and the fact that the quantization noise is bounded. A maximum-likelihood estimate of the input signal is evaluated, which only considers the vectors of quantization indexes corresponding to subband signals that could have been generated by the OFB and that are compliant with the quantization errors. When considering an OFB with an oversampling ratio of 3/2 and a transmission of quantized subbands on an AWGN channel, compared to a classical decoder, the performance gains are up to 9 dB in terms of SNR for the reconstructed signal, and 3 dB in terms of channel SNR.
16th IFAC Symposium on System Identification, 2012
Complex Systems Design & Management, 2015
2010 2nd European Workshop on Visual Information Processing (EUVIP), 2010
In this paper, we study the problem of image denoising by using an adaptive lifting scheme. Such ... more In this paper, we study the problem of image denoising by using an adaptive lifting scheme. Such a scheme can adapt itself well to the analyzed signal, which allows to keep important information for denoising applications. However, it results in a non-isometric transform which can be an important limitation as most of the denoising approaches rely on the estimation of the noise energy in the subbands. A previous study has been done to evaluate the subband energies of an uncorrelated signal, in the wavelet domain when using such an adaptive scheme. Based on this previous work, we propose in this paper an estimation of the noise energies in the subband and use it to perform image denoising. Experimental results illustrate that this approach is more effective, in image denoising, than the classical non adaptive lifting schemes both considering objective and subjective image quality measures.
This paper introduces a reconstruction approach for the input signal of an oversampled filter ban... more This paper introduces a reconstruction approach for the input signal of an oversampled filter bank (OFB) when the sub-bands generated at its output are quantized and transmitted over a noisy channel. This approach exploits the redundancy introduced by the OFB and the fact that the quantization noise is bounded. A maximum-likelihood estimate of the input signal is evaluated, which only considers the vectors of quantization indexes corresponding to subband signals that could have been generated by the OFB and that are compliant with the quantization errors. When considering an OFB with an oversampling ratio of 3/2 and a transmission of quantized subbands on an AWGN channel, compared to a classical decoder, the performance gains are up to 9 dB in terms of SNR for the reconstructed signal, and 3 dB in terms of channel SNR.
In this paper, we propose a joint source-channel (JSC) decoding scheme for 3D ESCOT-based video c... more In this paper, we propose a joint source-channel (JSC) decoding scheme for 3D ESCOT-based video coders, such as Vidwav. The embedded bitstream generated by such coders is very sensitive to transmission errors unavoidable on wireless channels. The proposed JSC decoder employs the residual redundancy left in the bitstream by the source coder combined with bit reliability information provided by the channel or channel decoder to correct transmission errors. When considering an AWGN channel, the performance gains are in average 4 dB in terms of PSNR of the reconstructed frames, and 0.7 dB in terms of channel SNR. When considering individual frames, the obtained gain is up to 15 dB in PSNR.