Dépouillements

New rate-distortion modeling and efficient rate control for H.264/AVC video coding / Yimin Zhou in Signal processing. Image communication, Vol. 24 N° 5 (Mai 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 5 (Mai 2009) . - pp. 345-356 Titre : New rate-distortion modeling and efficient rate control for H.264/AVC video coding Type de document : texte imprimé Auteurs : Yimin Zhou, Auteur ; Yu Sun, Auteur ; Zhidan Feng, Auteur Article en page(s) : pp. 345-356 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Rate  control  H.264/AVC  compression  standard  Video  coding  Rate-distortion  model  Buffer  control Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : Rate control (RC) is crucial in controlling compression bit rates and qualities for networked video applications. In this paper, we propose a new rate-distortion (R-D) model and an efficient rate control scheme for H.264/AVC video coding, which elegantly resolve the inter-dependency problem between rate-distortion optimization and rate control by eliminating the need of coding complexity prediction for an inter-frame. The objective is to achieve accurate bit rate, obtain optimal video quality while reducing quality variations and simultaneously handling buffer fullness effectively. The proposed algorithm encapsulates a number of new features, including a coding complexity measure for intra-frames, a rate-distortion model, an accurate quantization parameter (QP) estimation for intra-frames, an incremental quantization parameter calculation method for inter-frames, a proportional+integral+derivative (PID) buffer controller, and an intelligent bit-allocation-balancing technique. Our experimental results demonstrate that the proposed scheme outperforms the JVT-G012 solution by providing accurate rate regulation, effectively reducing frame skipping, and finally improving coding quality by up to 1.80 dB. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] New rate-distortion modeling and efficient rate control for H.264/AVC video coding [texte imprimé] / Yimin Zhou, Auteur ; Yu Sun, Auteur ; Zhidan Feng, Auteur . - pp. 345-356. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 5 (Mai 2009) . - pp. 345-356 Mots-clés : Rate  control  H.264/AVC  compression  standard  Video  coding  Rate-distortion  model  Buffer  control Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : Rate control (RC) is crucial in controlling compression bit rates and qualities for networked video applications. In this paper, we propose a new rate-distortion (R-D) model and an efficient rate control scheme for H.264/AVC video coding, which elegantly resolve the inter-dependency problem between rate-distortion optimization and rate control by eliminating the need of coding complexity prediction for an inter-frame. The objective is to achieve accurate bit rate, obtain optimal video quality while reducing quality variations and simultaneously handling buffer fullness effectively. The proposed algorithm encapsulates a number of new features, including a coding complexity measure for intra-frames, a rate-distortion model, an accurate quantization parameter (QP) estimation for intra-frames, an incremental quantization parameter calculation method for inter-frames, a proportional+integral+derivative (PID) buffer controller, and an intelligent bit-allocation-balancing technique. Our experimental results demonstrate that the proposed scheme outperforms the JVT-G012 solution by providing accurate rate regulation, effectively reducing frame skipping, and finally improving coding quality by up to 1.80 dB. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

A two-pass rate control algorithm for H.264/AVC high definition video coding / Dongdong Zhang in Signal processing. Image communication, Vol. 24 N° 5 (Mai 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 5 (Mai 2009) . - pp. 357-367 Titre : A two-pass rate control algorithm for H.264/AVC high definition video coding Type de document : texte imprimé Auteurs : Dongdong Zhang, Auteur ; King Ngi Ngan, Auteur ; Zhenzhong Chen, Auteur Article en page(s) : pp. 357-367 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Two-pass  Rate  control  Constant  quality  High  definition  video  coding Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : In this paper, we propose a novel two-pass rate control algorithm to achieve constant quality for H.264/AVC high definition video coding. With the first-pass collected rate and distortion information and the built model of scene complexity, the encoder can determine the expected distortion which could be achieved in the second-pass encoding under the target bit rate. According to the built linear distortion-quantizer (D-Q) model, before encoding one frame, the quantization parameter can be solved to realize constant quality encoding. After encoding one frame, the model parameters will be updated with linear regression method to ensure the prediction accuracy of the quantization parameter of next encoded frame with the same coding type. In order to obtain the expected distortion of each frame under the target bit rate, a GOP-level bit allocation scheme is also designed to adjust the target bit rate of each GOP based on the scene complexity of the GOP in the second-pass encoding. In addition, the effect of scene change on the updating of D-Q model is considered. The model will be re-initialized at the scene change to minimize modeling error. The experimental results show that compared with the latest two-pass rate control algorithm, our proposed algorithm can significantly improve the bit control accuracy at comparable coding performance in terms of constant quality and average PSNR. On average, the improvement of bit control accuracy achieved about 90%. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] A two-pass rate control algorithm for H.264/AVC high definition video coding [texte imprimé] / Dongdong Zhang, Auteur ; King Ngi Ngan, Auteur ; Zhenzhong Chen, Auteur . - pp. 357-367. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 5 (Mai 2009) . - pp. 357-367 Mots-clés : Two-pass  Rate  control  Constant  quality  High  definition  video  coding Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : In this paper, we propose a novel two-pass rate control algorithm to achieve constant quality for H.264/AVC high definition video coding. With the first-pass collected rate and distortion information and the built model of scene complexity, the encoder can determine the expected distortion which could be achieved in the second-pass encoding under the target bit rate. According to the built linear distortion-quantizer (D-Q) model, before encoding one frame, the quantization parameter can be solved to realize constant quality encoding. After encoding one frame, the model parameters will be updated with linear regression method to ensure the prediction accuracy of the quantization parameter of next encoded frame with the same coding type. In order to obtain the expected distortion of each frame under the target bit rate, a GOP-level bit allocation scheme is also designed to adjust the target bit rate of each GOP based on the scene complexity of the GOP in the second-pass encoding. In addition, the effect of scene change on the updating of D-Q model is considered. The model will be re-initialized at the scene change to minimize modeling error. The experimental results show that compared with the latest two-pass rate control algorithm, our proposed algorithm can significantly improve the bit control accuracy at comparable coding performance in terms of constant quality and average PSNR. On average, the improvement of bit control accuracy achieved about 90%. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

A low-complexity rate allocation algorithm for joint source-channel video coding / Simone Milani in Signal processing. Image communication, Vol. 24 N° 5 (Mai 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 5 (Mai 2009) . - pp. 368-383 Titre : A low-complexity rate allocation algorithm for joint source-channel video coding Type de document : texte imprimé Auteurs : Simone Milani, Auteur ; Giancarlo Calvagno, Auteur Article en page(s) : pp. 368-383 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Video  coding  H.264/AVC  Joint  source-channel  coding  Bit  allocation  R-D  parameterization  Low  complexity Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : The problem of enabling robust video transmission over lossy networks has become increasingly important because of the growing interest in video delivery over unreliable channels such as wireless networks. The more the coding process relies on an intensive use of prediction to improve the coding gain, the more the reconstructed sequence proves to be sensitive to information losses. As a matter of fact, it is necessary to introduce some redundant data in order to increase the robustness of the coded bit stream. A possible solution can be found filling a matrix structure with RTP packets and applying a Forward Error Correction (FEC) code on its rows. However, the matrix size and the chosen FEC code affect the performance of the coding system. The paper proposes a novel adaptation technique that tunes the amount of redundant information included in the packet stream and differs from previously proposed solutions since it relies on the percentage of null quantized transform coefficients in place of the activity or the Mean Square Error (MSE). This strategy is then integrated in a joint source-channel coder rate allocation algorithm that shares the available bits between the H.264/AVC coder and the channel coder according to the significance of the frame in the decoding process. Experimental results show that the presented approach significantly improves the quality of the reconstructed sequences at the decoder with respect to activity-based strategies and requires a low computational complexity. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] A low-complexity rate allocation algorithm for joint source-channel video coding [texte imprimé] / Simone Milani, Auteur ; Giancarlo Calvagno, Auteur . - pp. 368-383. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 5 (Mai 2009) . - pp. 368-383 Mots-clés : Video  coding  H.264/AVC  Joint  source-channel  coding  Bit  allocation  R-D  parameterization  Low  complexity Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : The problem of enabling robust video transmission over lossy networks has become increasingly important because of the growing interest in video delivery over unreliable channels such as wireless networks. The more the coding process relies on an intensive use of prediction to improve the coding gain, the more the reconstructed sequence proves to be sensitive to information losses. As a matter of fact, it is necessary to introduce some redundant data in order to increase the robustness of the coded bit stream. A possible solution can be found filling a matrix structure with RTP packets and applying a Forward Error Correction (FEC) code on its rows. However, the matrix size and the chosen FEC code affect the performance of the coding system. The paper proposes a novel adaptation technique that tunes the amount of redundant information included in the packet stream and differs from previously proposed solutions since it relies on the percentage of null quantized transform coefficients in place of the activity or the Mean Square Error (MSE). This strategy is then integrated in a joint source-channel coder rate allocation algorithm that shares the available bits between the H.264/AVC coder and the channel coder according to the significance of the frame in the decoding process. Experimental results show that the presented approach significantly improves the quality of the reconstructed sequences at the decoder with respect to activity-based strategies and requires a low computational complexity. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

Low memory implementation of generic hierarchical transforms for parent–children tree (PCT) production and its application in image compression / Xiongming Zhang in Signal processing. Image communication, Vol. 24 N° 5 (Mai 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 5 (Mai 2009) . - pp. 384-396 Titre : Low memory implementation of generic hierarchical transforms for parent–children tree (PCT) production and its application in image compression Type de document : texte imprimé Auteurs : Xiongming Zhang, Auteur ; Lizhi Cheng, Auteur ; Huanzhang Lu, Auteur Article en page(s) : pp. 384-396 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Image  compression  Hierarchical  transform  Low-memory  implementation  Parent–children  tree Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : This paper presents a unified approach for low-memory and on-the-fly implementation of generic hierarchical transforms (GHTs) suited for parent–children tree (PCT) production, called the stripe-based hierarchical transform (SBHT). Here, the term “generic” means that totally different FBs may appear in different decomposition levels. This approach generates the exactly same subband coefficients as the traditional global implementation of GHTs with a low memory budget that is unrelated to the input signal length and only dependent on the GHT. The SBHT lends itself to the PCT-based image coding algorithm in the sense that the basic data unit generated by the SBHT is row-based collections of PCT structures, the most widely used data entity in subband coding. To demonstrate the SBHT's application in image coding, a PCT coder based on the LLEC is proposed to encode the PCTs generated by the SBHT. No intermediate buffering is needed between the SBHT and the codec. The experiments show that when the GHT is configured appropriately, the proposed coder provides competitive coding efficiency relative to the SPIHT and JPEG2000 with a very low memory budget and low computation complexity. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] Low memory implementation of generic hierarchical transforms for parent–children tree (PCT) production and its application in image compression [texte imprimé] / Xiongming Zhang, Auteur ; Lizhi Cheng, Auteur ; Huanzhang Lu, Auteur . - pp. 384-396. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 5 (Mai 2009) . - pp. 384-396 Mots-clés : Image  compression  Hierarchical  transform  Low-memory  implementation  Parent–children  tree Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : This paper presents a unified approach for low-memory and on-the-fly implementation of generic hierarchical transforms (GHTs) suited for parent–children tree (PCT) production, called the stripe-based hierarchical transform (SBHT). Here, the term “generic” means that totally different FBs may appear in different decomposition levels. This approach generates the exactly same subband coefficients as the traditional global implementation of GHTs with a low memory budget that is unrelated to the input signal length and only dependent on the GHT. The SBHT lends itself to the PCT-based image coding algorithm in the sense that the basic data unit generated by the SBHT is row-based collections of PCT structures, the most widely used data entity in subband coding. To demonstrate the SBHT's application in image coding, a PCT coder based on the LLEC is proposed to encode the PCTs generated by the SBHT. No intermediate buffering is needed between the SBHT and the codec. The experiments show that when the GHT is configured appropriately, the proposed coder provides competitive coding efficiency relative to the SPIHT and JPEG2000 with a very low memory budget and low computation complexity. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

On performance of lossless compression for HDR image quantized in color space / Tao Fang in Signal processing. Image communication, Vol. 24 N° 5 (Mai 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 5 (Mai 2009) . - pp. 397-404 Titre : On performance of lossless compression for HDR image quantized in color space Type de document : texte imprimé Auteurs : Tao Fang, Auteur Article en page(s) : pp. 397-404 Note générale : Electronique Langues : Anglais (eng) Mots-clés : HDR  image  Lossless  compression  Image  compression  RGBE  LogLuv  JPEG  JPEG  2000  JPEG-LS Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : High dynamic range (HDR) image requires a higher number of bits per color channel than traditional images. This brings about problems to storage and transmission. Color space quantization has been extensively studied to achieve bit encodings for each pixel and still yields prohibitively large files. This paper explores the possibility of further compressing HDR images quantized in color space. The compression schemes presented in this paper extends existing lossless image compression standards to encode HDR images. They separate HDR images in their bit encoding formats into images in grayscale or RGB domain, which can be directly compressed by existing lossless compression standards such as JPEG, JPEG 2000 and JPEG-LS. The efficacy of the compression schemes is illustrated by presenting extensive results of encoding a series of synthetic and natural HDR images. Significant bit savings of up to 53% are observed when comparing with original HDR formats and HD Photo compressed version. This is beneficial to the storage and transmission of HDR images. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] On performance of lossless compression for HDR image quantized in color space [texte imprimé] / Tao Fang, Auteur . - pp. 397-404. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 5 (Mai 2009) . - pp. 397-404 Mots-clés : HDR  image  Lossless  compression  Image  compression  RGBE  LogLuv  JPEG  JPEG  2000  JPEG-LS Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : High dynamic range (HDR) image requires a higher number of bits per color channel than traditional images. This brings about problems to storage and transmission. Color space quantization has been extensively studied to achieve bit encodings for each pixel and still yields prohibitively large files. This paper explores the possibility of further compressing HDR images quantized in color space. The compression schemes presented in this paper extends existing lossless image compression standards to encode HDR images. They separate HDR images in their bit encoding formats into images in grayscale or RGB domain, which can be directly compressed by existing lossless compression standards such as JPEG, JPEG 2000 and JPEG-LS. The efficacy of the compression schemes is illustrated by presenting extensive results of encoding a series of synthetic and natural HDR images. Significant bit savings of up to 53% are observed when comparing with original HDR formats and HD Photo compressed version. This is beneficial to the storage and transmission of HDR images. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

Selective VS-MRF-ME and intra coding in H.264 based on spatiotemporal continuity of motion field / Liquan Shen in Signal processing. Image communication, Vol. 24 N° 5 (Mai 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 5 (Mai 2009) . - pp. 405-414 Titre : Selective VS-MRF-ME and intra coding in H.264 based on spatiotemporal continuity of motion field Type de document : texte imprimé Auteurs : Liquan Shen, Auteur ; Zhi Liu, Auteur ; Zhaoyang Zhang, Auteur Article en page(s) : pp. 405-414 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Video  coding  H.264  Motion  continuity  Variable  size  motion  estimation  Multiple-frame  motion  estimation  Intra  coding Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : The new video coding standard, H.264 uses variable size motion estimation (VS-ME), multiple reference frame motion estimation (MRF-ME) and spatial-based intra prediction with selectable block size in inter frame coding. These tools have achieved significant coding efficiency compared to coding a macroblock (MB) only based on motion-compensation in regular size with single reference frame. However, these new features also give rise to an exhaustive computation in the coding procedure since there are so many combinations of coding modes and reference frames to be tried. In this paper, a fast motion estimation algorithm based on the selective VS-MRF-ME and intra prediction is proposed to reduce H.264 coding computational complexity. The basic idea of the method is to utilize the spatiotemporal property of motion field in predicting where VS-MRF-ME and intra prediction are needed, and only in these regions VS-MRF-ME and intra coding are enabled. The motion field is generated by motion vectors from 16×16 motion estimation on the nearest reference frame. Simulation results show that the proposed algorithm can save 50% computational complexity on average, with negligible loss of coding efficiency. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] Selective VS-MRF-ME and intra coding in H.264 based on spatiotemporal continuity of motion field [texte imprimé] / Liquan Shen, Auteur ; Zhi Liu, Auteur ; Zhaoyang Zhang, Auteur . - pp. 405-414. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 5 (Mai 2009) . - pp. 405-414 Mots-clés : Video  coding  H.264  Motion  continuity  Variable  size  motion  estimation  Multiple-frame  motion  estimation  Intra  coding Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : The new video coding standard, H.264 uses variable size motion estimation (VS-ME), multiple reference frame motion estimation (MRF-ME) and spatial-based intra prediction with selectable block size in inter frame coding. These tools have achieved significant coding efficiency compared to coding a macroblock (MB) only based on motion-compensation in regular size with single reference frame. However, these new features also give rise to an exhaustive computation in the coding procedure since there are so many combinations of coding modes and reference frames to be tried. In this paper, a fast motion estimation algorithm based on the selective VS-MRF-ME and intra prediction is proposed to reduce H.264 coding computational complexity. The basic idea of the method is to utilize the spatiotemporal property of motion field in predicting where VS-MRF-ME and intra prediction are needed, and only in these regions VS-MRF-ME and intra coding are enabled. The motion field is generated by motion vectors from 16×16 motion estimation on the nearest reference frame. Simulation results show that the proposed algorithm can save 50% computational complexity on average, with negligible loss of coding efficiency. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

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