Dépouillements

Algorithm analysis and architecture design for rate distortion optimized mode decision in high definition AVS video encoder / Hai bing Yin in Signal processing. Image communication, Vol. 25 N° 9 (Octobre 2010) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 25 N° 9 (Octobre 2010) . - pp. 633–647 Titre : Algorithm analysis and architecture design for rate distortion optimized mode decision in high definition AVS video encoder Type de document : texte imprimé Auteurs : Hai bing Yin, Auteur ; Honggang Qi, Auteur ; Hui Zhu Jia, Auteur Année de publication : 2012 Article en page(s) : pp. 633–647 Note générale : Electronique Langues : Anglais (eng) Mots-clés : AVS  Mode  decision  Rate  distortion  optimization  VLSI  architecture Résumé : There are abundant intra and inter prediction modes in the AVS video coding standard. Rate distortion optimized mode decision can fully utilize this flexibility to improve the spatio-temporal prediction efficiency and maximize the coding efficiency. However, the implementation complexity is dramatically high due to huge throughput burden. Hardware oriented mode decision algorithm is tailored for VLSI implementation in this work for high definition video coding. Mode preselection is employed to alleviate the dramatic throughout burden. Also, intelligent pipeline scheduling mechanism is proposed to break the intrinsic data dependency in intra prediction, which is directly related with mode decision. The proposed simplified algorithm is well-suited for hardware implementation with small performance penalty. Finally, the VLSI architecture is proposed with good trade off between circuit consumption and rate distortion performance. ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science/article/pii/S0923596510000986 [article] Algorithm analysis and architecture design for rate distortion optimized mode decision in high definition AVS video encoder [texte imprimé] / Hai bing Yin, Auteur ; Honggang Qi, Auteur ; Hui Zhu Jia, Auteur . - 2012 . - pp. 633–647. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 25 N° 9 (Octobre 2010) . - pp. 633–647 Mots-clés : AVS  Mode  decision  Rate  distortion  optimization  VLSI  architecture Résumé : There are abundant intra and inter prediction modes in the AVS video coding standard. Rate distortion optimized mode decision can fully utilize this flexibility to improve the spatio-temporal prediction efficiency and maximize the coding efficiency. However, the implementation complexity is dramatically high due to huge throughput burden. Hardware oriented mode decision algorithm is tailored for VLSI implementation in this work for high definition video coding. Mode preselection is employed to alleviate the dramatic throughout burden. Also, intelligent pipeline scheduling mechanism is proposed to break the intrinsic data dependency in intra prediction, which is directly related with mode decision. The proposed simplified algorithm is well-suited for hardware implementation with small performance penalty. Finally, the VLSI architecture is proposed with good trade off between circuit consumption and rate distortion performance. ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science/article/pii/S0923596510000986

Novel prediction schemes for error resilient video coding / Ramdas Satyan in Signal processing. Image communication, Vol. 25 N° 9 (Octobre 2010) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 25 N° 9 (Octobre 2010) . - pp. 648–659 Titre : Novel prediction schemes for error resilient video coding Type de document : texte imprimé Auteurs : Ramdas Satyan, Auteur ; Sunday Nyamweno, Auteur ; Fabrice Labeau, Auteur Année de publication : 2012 Article en page(s) : pp. 648–659 Note générale : Electronique Langues : Anglais (eng) Mots-clés : H.264/AVC  Packet  loss  Error  resilience  Video  coding Résumé : A conventional video codec uses encoder reconstruction of previous frames for motion compensated prediction. This is designed to minimize the encoder prediction error and assumes error free transmission. In this paper we use a modified prediction mechanism both at the encoder and decoder and propose techniques to improve the error resilience of H.264/AVC when transmitted over error prone networks. In our schemes we provide greater emphasis on Intra pixels during the formation of the reference frame used for prediction, thereby achieving better resilience. We also incorporate leaky prediction to further improve the robustness. We apply leaky prediction selectively at a macroblock level based on a simple mean square error metric in order to reduce the bit-rate penalty. Substantial performance gains have been observed in simulations. The effectiveness of using leaky prediction can be observed in medium and fast moving video sequences. ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science/article/pii/S0923596510000500 [article] Novel prediction schemes for error resilient video coding [texte imprimé] / Ramdas Satyan, Auteur ; Sunday Nyamweno, Auteur ; Fabrice Labeau, Auteur . - 2012 . - pp. 648–659. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 25 N° 9 (Octobre 2010) . - pp. 648–659 Mots-clés : H.264/AVC  Packet  loss  Error  resilience  Video  coding Résumé : A conventional video codec uses encoder reconstruction of previous frames for motion compensated prediction. This is designed to minimize the encoder prediction error and assumes error free transmission. In this paper we use a modified prediction mechanism both at the encoder and decoder and propose techniques to improve the error resilience of H.264/AVC when transmitted over error prone networks. In our schemes we provide greater emphasis on Intra pixels during the formation of the reference frame used for prediction, thereby achieving better resilience. We also incorporate leaky prediction to further improve the robustness. We apply leaky prediction selectively at a macroblock level based on a simple mean square error metric in order to reduce the bit-rate penalty. Substantial performance gains have been observed in simulations. The effectiveness of using leaky prediction can be observed in medium and fast moving video sequences. ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science/article/pii/S0923596510000500

Rate-distortion driven decoder-side bitplane mode decision for distributed video coding / Jürgen Slowack in Signal processing. Image communication, Vol. 25 N° 9 (Octobre 2010) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 25 N° 9 (Octobre 2010) . - pp. 660–673 Titre : Rate-distortion driven decoder-side bitplane mode decision for distributed video coding Type de document : texte imprimé Auteurs : Jürgen Slowack, Auteur ; Stefaan Mys, Auteur ; Jozef Škorupa, Auteur Année de publication : 2012 Article en page(s) : pp. 660–673 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Distributed  video  coding  Mode  decision  Wyner–Ziv  coding Résumé : Distributed video coding (DVC) features simple encoders but complex decoders, which lies in contrast to conventional video compression solutions such as H.264/AVC. This shift in complexity is realized by performing motion estimation at the decoder side instead of at the encoder, which brings a number of problems that need to be dealt with. One of these problems is that, while employing different coding modes yields significant coding gains in classical video compression systems, it is still difficult to fully exploit this in DVC without increasing the complexity at the encoder side. Therefore, in this paper, instead of using an encoder-side approach, techniques for decoder-side mode decision are proposed. A rate-distortion model is derived that takes into account the position of the side information in the quantization bin. This model is then used to perform mode decision at the coefficient level and bitplane level. Average rate gains of 13–28% over the state-of-the-art DISCOVER codec are reported, for a GOP of size four, for several test sequences. ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science/article/pii/S0923596510000767 [article] Rate-distortion driven decoder-side bitplane mode decision for distributed video coding [texte imprimé] / Jürgen Slowack, Auteur ; Stefaan Mys, Auteur ; Jozef Škorupa, Auteur . - 2012 . - pp. 660–673. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 25 N° 9 (Octobre 2010) . - pp. 660–673 Mots-clés : Distributed  video  coding  Mode  decision  Wyner–Ziv  coding Résumé : Distributed video coding (DVC) features simple encoders but complex decoders, which lies in contrast to conventional video compression solutions such as H.264/AVC. This shift in complexity is realized by performing motion estimation at the decoder side instead of at the encoder, which brings a number of problems that need to be dealt with. One of these problems is that, while employing different coding modes yields significant coding gains in classical video compression systems, it is still difficult to fully exploit this in DVC without increasing the complexity at the encoder side. Therefore, in this paper, instead of using an encoder-side approach, techniques for decoder-side mode decision are proposed. A rate-distortion model is derived that takes into account the position of the side information in the quantization bin. This model is then used to perform mode decision at the coefficient level and bitplane level. Average rate gains of 13–28% over the state-of-the-art DISCOVER codec are reported, for a GOP of size four, for several test sequences. ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science/article/pii/S0923596510000767

Exploiting quantization and spatial correlation in virtual-noise modeling for distributed video coding / Jozef Škorupa in Signal processing. Image communication, Vol. 25 N° 9 (Octobre 2010) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 25 N° 9 (Octobre 2010) . - pp. 674–686 Titre : Exploiting quantization and spatial correlation in virtual-noise modeling for distributed video coding Type de document : texte imprimé Auteurs : Jozef Škorupa, Auteur ; Jürgen Slowack, Auteur ; Stefaan Mys, Auteur Année de publication : 2012 Article en page(s) : pp. 674–686 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Context  adaptive  Distributed  video  coding  Virtual-noise  modeling Résumé : Aiming for low-complexity encoding, video coders based on Wyner–Ziv theory are still unsuccessfully trying to match the performance of predictive video coders. One of the most important factors concerning the coding performance of distributed coders is modeling and estimating the correlation between the original video signal and its temporal prediction generated at the decoder. One of the problems of the state-of-the-art correlation estimators is that their performance is not consistent across a wide range of video content and different coding settings. To address this problem we have developed a correlation model able to adapt to changes in the content and the coding parameters by exploiting the spatial correlation of the video signal and the quantization distortion. In this paper we describe our model and present experiments showing that our model provides average bit rate gains of up to 12% and average PSNR gains of up to 0.5 dB when compared to the state-of-the-art models. The experiments suggest that the performance of distributed coders can be significantly improved by taking video content and coding parameters into account. ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science/article/pii/S092359651000055X [article] Exploiting quantization and spatial correlation in virtual-noise modeling for distributed video coding [texte imprimé] / Jozef Škorupa, Auteur ; Jürgen Slowack, Auteur ; Stefaan Mys, Auteur . - 2012 . - pp. 674–686. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 25 N° 9 (Octobre 2010) . - pp. 674–686 Mots-clés : Context  adaptive  Distributed  video  coding  Virtual-noise  modeling Résumé : Aiming for low-complexity encoding, video coders based on Wyner–Ziv theory are still unsuccessfully trying to match the performance of predictive video coders. One of the most important factors concerning the coding performance of distributed coders is modeling and estimating the correlation between the original video signal and its temporal prediction generated at the decoder. One of the problems of the state-of-the-art correlation estimators is that their performance is not consistent across a wide range of video content and different coding settings. To address this problem we have developed a correlation model able to adapt to changes in the content and the coding parameters by exploiting the spatial correlation of the video signal and the quantization distortion. In this paper we describe our model and present experiments showing that our model provides average bit rate gains of up to 12% and average PSNR gains of up to 0.5 dB when compared to the state-of-the-art models. The experiments suggest that the performance of distributed coders can be significantly improved by taking video content and coding parameters into account. ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science/article/pii/S092359651000055X

Efficient entropy coding scheme for H.264/AVC lossless video coding / Seung-Hwan Kim in Signal processing. Image communication, Vol. 25 N° 9 (Octobre 2010) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 25 N° 9 (Octobre 2010) . - pp. 687–696 Titre : Efficient entropy coding scheme for H.264/AVC lossless video coding Type de document : texte imprimé Auteurs : Seung-Hwan Kim, Auteur ; Jin Heo, Auteur ; Yo-Sung Ho, Auteur Année de publication : 2012 Article en page(s) : pp. 687–696 Note générale : Electronique Langues : Anglais (eng) Mots-clés : H.264/AVC  CAVLC  CABAC  Lossless  video  coding  Entropy  coding Résumé : Context-based adaptive variable length coding (CAVLC) and context-based adaptive binary arithmetic coding (CABAC) are entropy coding methods employed in the H.264/AVC standard. Since these entropy coders are originally designed for encoding residual data, which are zigzag scanned and quantized transform coefficients, they cannot provide adequate coding performance for lossless video coding where residual data are not quantized transform coefficients, but the differential pixel values between the original and predicted pixel values. Therefore, considering the statistical characteristics of residual data in lossless video coding, we newly design each entropy coding method based on the conventional entropy coders in H.264/AVC. From the experimental result, we have verified that the proposed method provides not only positive bit-saving of 8% but also reduced computational complexity compared to the current H.264/AVC lossless coding mode. ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science/article/pii/S0923596510000470 [article] Efficient entropy coding scheme for H.264/AVC lossless video coding [texte imprimé] / Seung-Hwan Kim, Auteur ; Jin Heo, Auteur ; Yo-Sung Ho, Auteur . - 2012 . - pp. 687–696. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 25 N° 9 (Octobre 2010) . - pp. 687–696 Mots-clés : H.264/AVC  CAVLC  CABAC  Lossless  video  coding  Entropy  coding Résumé : Context-based adaptive variable length coding (CAVLC) and context-based adaptive binary arithmetic coding (CABAC) are entropy coding methods employed in the H.264/AVC standard. Since these entropy coders are originally designed for encoding residual data, which are zigzag scanned and quantized transform coefficients, they cannot provide adequate coding performance for lossless video coding where residual data are not quantized transform coefficients, but the differential pixel values between the original and predicted pixel values. Therefore, considering the statistical characteristics of residual data in lossless video coding, we newly design each entropy coding method based on the conventional entropy coders in H.264/AVC. From the experimental result, we have verified that the proposed method provides not only positive bit-saving of 8% but also reduced computational complexity compared to the current H.264/AVC lossless coding mode. ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science/article/pii/S0923596510000470

An efficient macroblock-based diverse and flexible prediction modes selection for hyperspectral images coding / Fan Zhao in Signal processing. Image communication, Vol. 25 N° 9 (Octobre 2010) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 25 N° 9 (Octobre 2010) . - pp. 697–708 Titre : An efficient macroblock-based diverse and flexible prediction modes selection for hyperspectral images coding Type de document : texte imprimé Auteurs : Fan Zhao, Auteur ; Guizhong Liu, Auteur ; Xing Wang, Auteur Année de publication : 2012 Article en page(s) : pp. 697–708 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Hyperspectral  images  Compression  coding  H.264/AVC  Prediction  mode  Correlation  coefficients Résumé : In this paper, an efficient macroblock-based diverse and flexible prediction modes selection algorithm is proposed for coding hyperspectral images, which is inspired by the prediction scheme of H264/AVC. Here, different modes are specified for the corresponding macroblocks (16×16 pixel regions of a band) of hyperspectral images other than the whole band image using only one reference band image for prediction. Only the 4×4 mode is employed for the intra-band prediction in view of the fact that correlation coefficients of pixels separated by not more than four pixels in the spatial domain are greater than 0.65 at most cases. The optimal reference band is determined by the fast reference band selection algorithm; thereafter, the best partition of the candidate macroblock in the optimal reference band is further selected for inter-band prediction of the current macroblock. Thus, the stronger correlation in the spectral direction or in the spatial domain is utilized for the prediction of the given macroblock. With a comparably low memory requirement, the prediction coding scheme is proposed to speed up the implemental process using the fast reference band selection algorithm, the integer DCT and the quantization, which just needs the multiplication and bit-shifts operations. Several AVIRIS images are used to evaluate the performance of the algorithm. The proposed scheme outperforms the state-of-the-art 3D-based compression algorithms at lower rates. Moreover, compared with the method by using all the prediction modes of H.264/AVC, about 80% encoding time can be saved by our method under the same experimental condition. ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science/article/pii/S0923596510000871 [article] An efficient macroblock-based diverse and flexible prediction modes selection for hyperspectral images coding [texte imprimé] / Fan Zhao, Auteur ; Guizhong Liu, Auteur ; Xing Wang, Auteur . - 2012 . - pp. 697–708. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 25 N° 9 (Octobre 2010) . - pp. 697–708 Mots-clés : Hyperspectral  images  Compression  coding  H.264/AVC  Prediction  mode  Correlation  coefficients Résumé : In this paper, an efficient macroblock-based diverse and flexible prediction modes selection algorithm is proposed for coding hyperspectral images, which is inspired by the prediction scheme of H264/AVC. Here, different modes are specified for the corresponding macroblocks (16×16 pixel regions of a band) of hyperspectral images other than the whole band image using only one reference band image for prediction. Only the 4×4 mode is employed for the intra-band prediction in view of the fact that correlation coefficients of pixels separated by not more than four pixels in the spatial domain are greater than 0.65 at most cases. The optimal reference band is determined by the fast reference band selection algorithm; thereafter, the best partition of the candidate macroblock in the optimal reference band is further selected for inter-band prediction of the current macroblock. Thus, the stronger correlation in the spectral direction or in the spatial domain is utilized for the prediction of the given macroblock. With a comparably low memory requirement, the prediction coding scheme is proposed to speed up the implemental process using the fast reference band selection algorithm, the integer DCT and the quantization, which just needs the multiplication and bit-shifts operations. Several AVIRIS images are used to evaluate the performance of the algorithm. The proposed scheme outperforms the state-of-the-art 3D-based compression algorithms at lower rates. Moreover, compared with the method by using all the prediction modes of H.264/AVC, about 80% encoding time can be saved by our method under the same experimental condition. ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science/article/pii/S0923596510000871

Exemplaires

Bibliothèque Ecole Nationale Polytechnique d'Alger

Accueil

Se connecter

Météo

Adresse