Dépouillements

An efficient high-dimensional indexing method for content-based retrieval in large image databases / I. Daoudi in Signal processing. Image communication, Vol. 24 N° 10 (Novembre 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 10 (Novembre 2009) . - pp. 775-790 Titre : An efficient high-dimensional indexing method for content-based retrieval in large image databases Type de document : texte imprimé Auteurs : I. Daoudi, Auteur ; K. Idrissi, Auteur ; S.E. Ouatik, Auteur Article en page(s) : pp. 775-790 Note générale : Electronique Langues : Anglais (eng) Mots-clés : CBIR  High-dimensional  vector  space  Region  approximation  approach  Kernel  Image  databases  Relevance  feedback Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : High-dimensional indexing methods have been proved quite useful for response time improvement. Based on Euclidian distance, many of them have been proposed for applications where data vectors are high-dimensional. However, these methods do not generally support efficiently similarity search when dealing with heterogeneous data vectors. In this paper, we propose a high-dimensional indexing method (KRA+-Blocks) as an extension of the region approximation approach to the kernel space. KRA+-Blocks combines nonlinear dimensionality reduction technique (KPCA) with region approximation approach to map data vectors into a reduced feature space. The created feature space is then used, on one hand to approximate regions, and on the other hand to provide an effective kernel distances for both filtering process and similarity measurement. In this way, the proposed approach achieves high performances in response time and in precision when dealing with high-dimensional and heterogeneous vectors. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] An efficient high-dimensional indexing method for content-based retrieval in large image databases [texte imprimé] / I. Daoudi, Auteur ; K. Idrissi, Auteur ; S.E. Ouatik, Auteur . - pp. 775-790. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 10 (Novembre 2009) . - pp. 775-790 Mots-clés : CBIR  High-dimensional  vector  space  Region  approximation  approach  Kernel  Image  databases  Relevance  feedback Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : High-dimensional indexing methods have been proved quite useful for response time improvement. Based on Euclidian distance, many of them have been proposed for applications where data vectors are high-dimensional. However, these methods do not generally support efficiently similarity search when dealing with heterogeneous data vectors. In this paper, we propose a high-dimensional indexing method (KRA+-Blocks) as an extension of the region approximation approach to the kernel space. KRA+-Blocks combines nonlinear dimensionality reduction technique (KPCA) with region approximation approach to map data vectors into a reduced feature space. The created feature space is then used, on one hand to approximate regions, and on the other hand to provide an effective kernel distances for both filtering process and similarity measurement. In this way, the proposed approach achieves high performances in response time and in precision when dealing with high-dimensional and heterogeneous vectors. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

All phase biorthogonal transform and its application in JPEG-like image compression / Zheng-Xin Hou in Signal processing. Image communication, Vol. 24 N° 10 (Novembre 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 10 (Novembre 2009) . - pp. 791-802 Titre : All phase biorthogonal transform and its application in JPEG-like image compression Type de document : texte imprimé Auteurs : Zheng-Xin Hou, Auteur ; Cheng-You Wang, Auteur ; Ai-Ping Yang, Auteur Article en page(s) : pp. 791-802 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Biorthogonal  transform  Image  compression  JPEG  algorithm  All  phase  biorthogonal  transform  (APBT)  Dual  biorthogonal  basis  vectors  Walsh  transform  (WT)  Discrete  cosine  transform  (DCT)  Inverse  discrete  cosine  transform  (IDCT)  Peak  signal  to  noise  ratio  (PSNR) Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : This paper proposes new concepts of the all phase biorthogonal transform (APBT) and the dual biorthogonal basis vectors. In the light of all phase digital filtering theory, three kinds of all phase biorthogonal transforms based on the Walsh transform (WT), the discrete cosine transform (DCT) and the inverse discrete cosine transform (IDCT) are proposed. The matrices of APBT based on WT, DCT and IDCT are deduced, which can be used in image compression instead of the conventional DCT. Compared with DCT-based JPEG (DCT-JPEG) image compression algorithm at the same bit rates, the PSNR and visual quality of the reconstructed images using these transforms are approximate to DCT, outgoing DCT-JPEG at low bit rates especially. But the advantage is that the quantization table is simplified and the transform coefficients can be quantized uniformly. Therefore, the computing time becomes shorter and the hardware implementation easier. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] All phase biorthogonal transform and its application in JPEG-like image compression [texte imprimé] / Zheng-Xin Hou, Auteur ; Cheng-You Wang, Auteur ; Ai-Ping Yang, Auteur . - pp. 791-802. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 10 (Novembre 2009) . - pp. 791-802 Mots-clés : Biorthogonal  transform  Image  compression  JPEG  algorithm  All  phase  biorthogonal  transform  (APBT)  Dual  biorthogonal  basis  vectors  Walsh  transform  (WT)  Discrete  cosine  transform  (DCT)  Inverse  discrete  cosine  transform  (IDCT)  Peak  signal  to  noise  ratio  (PSNR) Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : This paper proposes new concepts of the all phase biorthogonal transform (APBT) and the dual biorthogonal basis vectors. In the light of all phase digital filtering theory, three kinds of all phase biorthogonal transforms based on the Walsh transform (WT), the discrete cosine transform (DCT) and the inverse discrete cosine transform (IDCT) are proposed. The matrices of APBT based on WT, DCT and IDCT are deduced, which can be used in image compression instead of the conventional DCT. Compared with DCT-based JPEG (DCT-JPEG) image compression algorithm at the same bit rates, the PSNR and visual quality of the reconstructed images using these transforms are approximate to DCT, outgoing DCT-JPEG at low bit rates especially. But the advantage is that the quantization table is simplified and the transform coefficients can be quantized uniformly. Therefore, the computing time becomes shorter and the hardware implementation easier. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

Fast mode-decision for H.264/AVC based on inter-frame correlations / Hyunsuk Ko in Signal processing. Image communication, Vol. 24 N° 10 (Novembre 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 10 (Novembre 2009) . - pp. 803-813 Titre : Fast mode-decision for H.264/AVC based on inter-frame correlations Type de document : texte imprimé Auteurs : Hyunsuk Ko, Auteur ; Kiwon Yoo, Auteur ; Kwanghoon Sohn, Auteur Article en page(s) : pp. 803-813 Note générale : Electronique Langues : Anglais (eng) Mots-clés : H.264/AVC  Intra-prediction  Inter-prediction  Rate-distortion  optimization Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : The H.264/AVC standard yields higher coding efficiency rates than other video coding standards. This is because it uses the rate-distortion optimization (RDO) technique, which selects the optimal coding mode and a reference frame for each macroblock (MB). In order to achieve this, the encoder has to encode a given block by exhaustively using all kinds of combinations (including different intra and inter-prediction modes). As a result, the computational complexity of video coding in H.264/AVC is extremely high. In this paper, two fast intra-/inter-mode-decision algorithms are proposed to reduce the complexity of the encoder. Both of these algorithms are based on the inter-frame correlation among adjacent pictures. For the fast intra-mode-decision, we used the intra-mode of the most-correlated MB at the reference frame to encode the current MB and the stationary property of the current MB was used for the fast inter-mode-decision. The simulation results show that the proposed algorithms significantly reduced the computational complexity with a negligible loss of PSNR and a slight increase in bitrate. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] Fast mode-decision for H.264/AVC based on inter-frame correlations [texte imprimé] / Hyunsuk Ko, Auteur ; Kiwon Yoo, Auteur ; Kwanghoon Sohn, Auteur . - pp. 803-813. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 10 (Novembre 2009) . - pp. 803-813 Mots-clés : H.264/AVC  Intra-prediction  Inter-prediction  Rate-distortion  optimization Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : The H.264/AVC standard yields higher coding efficiency rates than other video coding standards. This is because it uses the rate-distortion optimization (RDO) technique, which selects the optimal coding mode and a reference frame for each macroblock (MB). In order to achieve this, the encoder has to encode a given block by exhaustively using all kinds of combinations (including different intra and inter-prediction modes). As a result, the computational complexity of video coding in H.264/AVC is extremely high. In this paper, two fast intra-/inter-mode-decision algorithms are proposed to reduce the complexity of the encoder. Both of these algorithms are based on the inter-frame correlation among adjacent pictures. For the fast intra-mode-decision, we used the intra-mode of the most-correlated MB at the reference frame to encode the current MB and the stationary property of the current MB was used for the fast inter-mode-decision. The simulation results show that the proposed algorithms significantly reduced the computational complexity with a negligible loss of PSNR and a slight increase in bitrate. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

Object tracking in surveillance videos using compressed domain features from scalable bit-streams / K. Mehmood in Signal processing. Image communication, Vol. 24 N° 10 (Novembre 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 10 (Novembre 2009) . - pp. 814-824 Titre : Object tracking in surveillance videos using compressed domain features from scalable bit-streams Type de document : texte imprimé Auteurs : K. Mehmood, Auteur ; M. Mrak, Auteur ; J. Calic, Auteur Article en page(s) : pp. 814-824 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Object  tracking  Scalable  video  coding  Compressed  domain  analysis  Motion  vectors Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : Recent developments in the video coding technology brought new possibilities of utilising inherently embedded features of the encoded bit-stream in applications such as video adaptation and analysis. Due to the proliferation of surveillance videos there is a strong demand for highly efficient and reliable algorithms for object tracking. This paper presents a new approach for the fast compressed domain analysis utilising motion data from the encoded bit-streams in order to achieve low-processing complexity of object tracking in the surveillance videos. The algorithm estimates the trajectory of video objects by using compressed domain motion vectors extracted directly from standard H.264/MPEG-4 Advanced Video Coding (AVC) and Scalable Video Coding (SVC) bit-streams. The experimental results show comparable tracking precision when evaluated against the standard algorithms in uncompressed domain, while maintaining low computational complexity and fast processing time, thus making the algorithm suitable for real time and streaming applications where good estimates of object trajectories have to be computed fast. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] Object tracking in surveillance videos using compressed domain features from scalable bit-streams [texte imprimé] / K. Mehmood, Auteur ; M. Mrak, Auteur ; J. Calic, Auteur . - pp. 814-824. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 10 (Novembre 2009) . - pp. 814-824 Mots-clés : Object  tracking  Scalable  video  coding  Compressed  domain  analysis  Motion  vectors Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : Recent developments in the video coding technology brought new possibilities of utilising inherently embedded features of the encoded bit-stream in applications such as video adaptation and analysis. Due to the proliferation of surveillance videos there is a strong demand for highly efficient and reliable algorithms for object tracking. This paper presents a new approach for the fast compressed domain analysis utilising motion data from the encoded bit-streams in order to achieve low-processing complexity of object tracking in the surveillance videos. The algorithm estimates the trajectory of video objects by using compressed domain motion vectors extracted directly from standard H.264/MPEG-4 Advanced Video Coding (AVC) and Scalable Video Coding (SVC) bit-streams. The experimental results show comparable tracking precision when evaluated against the standard algorithms in uncompressed domain, while maintaining low computational complexity and fast processing time, thus making the algorithm suitable for real time and streaming applications where good estimates of object trajectories have to be computed fast. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

A secure media streaming mechanism combining encryption, authentication, and transcoding / Luntian Mou in Signal processing. Image communication, Vol. 24 N° 10 (Novembre 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 10 (Novembre 2009) . - pp. 825-833 Titre : A secure media streaming mechanism combining encryption, authentication, and transcoding Type de document : texte imprimé Auteurs : Luntian Mou, Auteur ; Tiejun Huang, Auteur ; Longshe Huo, Auteur Article en page(s) : pp. 825-833 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Media  streaming  Media-aware  encryption  Sender  authentication  Secure  transcoding  Intelligent  mid-network  proxy Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : Technology advancements are allowing more and more new media applications and services to be delivered over the Internet. Many of these applications and services require flexibility in media distribution as well as security in protecting the confidentiality of media content and ensuring its authenticity. However, achieving flexibility and achieving security are conventionally conflicting with each other. This is mainly because that security is traditionally implemented in a media-unaware manner that naturally prevents flexible handling of the media content during its distribution. This paper shows that the two goals can be simultaneously accomplished by making an overall plan and taking into consideration all the factors: coding, encryption, packetization, authentication, and transcoding. It emphasizes sender authentication, which is a big security issue for media streaming, but somehow left unresolved. We propose a secure media streaming mechanism which supports media-aware encryption, sender authentication and secure transcoding. Multimedia Application Routing Server (MARS) is especially used as an intelligent mid-network proxy with the ability to perform tasks of sender authentication and secure transcoding. A prototype system for securely streaming AVS media using MARS demonstrates the performance, thus proves the practicality of the proposed secure media streaming mechanism. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] A secure media streaming mechanism combining encryption, authentication, and transcoding [texte imprimé] / Luntian Mou, Auteur ; Tiejun Huang, Auteur ; Longshe Huo, Auteur . - pp. 825-833. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 10 (Novembre 2009) . - pp. 825-833 Mots-clés : Media  streaming  Media-aware  encryption  Sender  authentication  Secure  transcoding  Intelligent  mid-network  proxy Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : Technology advancements are allowing more and more new media applications and services to be delivered over the Internet. Many of these applications and services require flexibility in media distribution as well as security in protecting the confidentiality of media content and ensuring its authenticity. However, achieving flexibility and achieving security are conventionally conflicting with each other. This is mainly because that security is traditionally implemented in a media-unaware manner that naturally prevents flexible handling of the media content during its distribution. This paper shows that the two goals can be simultaneously accomplished by making an overall plan and taking into consideration all the factors: coding, encryption, packetization, authentication, and transcoding. It emphasizes sender authentication, which is a big security issue for media streaming, but somehow left unresolved. We propose a secure media streaming mechanism which supports media-aware encryption, sender authentication and secure transcoding. Multimedia Application Routing Server (MARS) is especially used as an intelligent mid-network proxy with the ability to perform tasks of sender authentication and secure transcoding. A prototype system for securely streaming AVS media using MARS demonstrates the performance, thus proves the practicality of the proposed secure media streaming mechanism. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

Efficient coding of motion vector and mode information for H.264/AVC / Dong-Shik Lee in Signal processing. Image communication, Vol. 24 N° 10 (Novembre 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 10 (Novembre 2009) . - pp. 834-839 Titre : Efficient coding of motion vector and mode information for H.264/AVC Type de document : texte imprimé Auteurs : Dong-Shik Lee, Auteur ; Young-Mo Kim, Auteur Article en page(s) : pp. 834-839 Note générale : Electronique Langues : Anglais (eng) Mots-clés : H.264  Quadtree  Motion  vector  Type  code  Header  information Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : This paper aims to reduce the size of header in H.264; therefore we only focus on compressing the larger header data into small one. H.264/AVC is the newest video coding standard, which adopts some new techniques to improve the compression efficiency. However, H.264 gets larger header than those of previous standards because the techniques exploit in detail the content of input image. The most parts of header are composed of macroblock type (mb_type) and motion vector difference (mvd), and there are redundancies in the header of H.264. Especially, when mode 8 is selected during mode decision at macroblock level, all four sub-macroblock data are transferred into bitstream. Building the idea above, we propose the scheme using the type code and quadtree to solve the problems. Experimental results show that our algorithm achieved lower total number of encoded bits over JM14.2 up to 31.87% bit reduction at QP 40 on average. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] Efficient coding of motion vector and mode information for H.264/AVC [texte imprimé] / Dong-Shik Lee, Auteur ; Young-Mo Kim, Auteur . - pp. 834-839. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 10 (Novembre 2009) . - pp. 834-839 Mots-clés : H.264  Quadtree  Motion  vector  Type  code  Header  information Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : This paper aims to reduce the size of header in H.264; therefore we only focus on compressing the larger header data into small one. H.264/AVC is the newest video coding standard, which adopts some new techniques to improve the compression efficiency. However, H.264 gets larger header than those of previous standards because the techniques exploit in detail the content of input image. The most parts of header are composed of macroblock type (mb_type) and motion vector difference (mvd), and there are redundancies in the header of H.264. Especially, when mode 8 is selected during mode decision at macroblock level, all four sub-macroblock data are transferred into bitstream. Building the idea above, we propose the scheme using the type code and quadtree to solve the problems. Experimental results show that our algorithm achieved lower total number of encoded bits over JM14.2 up to 31.87% bit reduction at QP 40 on average. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

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