Dépouillements

Objective quality assessment in free-viewpoint video production / J. Kilner in Signal processing. Image communication, Vol. 24 N° 1/2 (Janvier 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp. 3-16 Titre : Objective quality assessment in free-viewpoint video production Type de document : texte imprimé Auteurs : J. Kilner, Auteur ; J. Starck, Auteur ; J. Y. Guillemaut, Auteur Article en page(s) : pp. 3-16 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Free-viewpoint  video  Image-based  reconstruction  Image-based  rendering  Quality  assessment Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : This paper addresses the problem of objectively quantifying accuracy in free-viewpoint video production. Free-viewpoint video makes use of geometric scene reconstruction and renders novel views using the appearance sampled in multiple camera images. Previous work typically adopts an objective evaluation of geometric accuracy against ground-truth data or a subjective evaluation of visual quality in view synthesis. We consider two production scenarios, human performance capture in a highly constrained studio environment and sports production in a large-scale external environment. The accuracy of scene reconstruction is typically limited and absolute geometric accuracy does not necessarily reflect the quality of free-viewpoint rendering. A framework is introduced to quantify error at the point of view synthesis. The approach can be applied as a full-reference metric to measure fidelity to a ground-truth image or as a no-reference metric to measure the error in rendering. The framework is applied to a data set with known geometric accuracy and a comparison is presented for studio based and sports production scenarios. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] Objective quality assessment in free-viewpoint video production [texte imprimé] / J. Kilner, Auteur ; J. Starck, Auteur ; J. Y. Guillemaut, Auteur . - pp. 3-16. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp. 3-16 Mots-clés : Free-viewpoint  video  Image-based  reconstruction  Image-based  rendering  Quality  assessment Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : This paper addresses the problem of objectively quantifying accuracy in free-viewpoint video production. Free-viewpoint video makes use of geometric scene reconstruction and renders novel views using the appearance sampled in multiple camera images. Previous work typically adopts an objective evaluation of geometric accuracy against ground-truth data or a subjective evaluation of visual quality in view synthesis. We consider two production scenarios, human performance capture in a highly constrained studio environment and sports production in a large-scale external environment. The accuracy of scene reconstruction is typically limited and absolute geometric accuracy does not necessarily reflect the quality of free-viewpoint rendering. A framework is introduced to quantify error at the point of view synthesis. The approach can be applied as a full-reference metric to measure fidelity to a ground-truth image or as a no-reference metric to measure the error in rendering. The framework is applied to a data set with known geometric accuracy and a comparison is presented for studio based and sports production scenarios. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

3DTV view generation using uncalibrated pure rotating and zooming cameras / Songkran Jarusirisawad in Signal processing. Image communication, Vol. 24 N° 1/2 (Janvier 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp. 17-30 Titre : 3DTV view generation using uncalibrated pure rotating and zooming cameras Type de document : texte imprimé Auteurs : Songkran Jarusirisawad, Auteur ; Hideo Saito, Auteur Article en page(s) : pp. 17-30 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Free  viewpoint  video  View  interpolation  Projective  grid  space  Trifocal  tensor Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : This paper proposes a novel method for synthesizing free viewpoint video captured by uncalibrated pure rotating and zooming cameras. Neither intrinsic nor extrinsic parameters of our cameras are known. Projective grid space (PGS), which is the 3D space defined by the epipolar geometry of two basis cameras, is employed for weak camera calibration. Trifocal tensors are used to relate non-basis cameras to PGS. Given trifocal tensors in the initial frame, our method automatically computes trifocal tensors in the other frames. Scale invariant feature transform (SIFT) is used for finding corresponding points in a natural scene between the initial frame and the other frames. Finally, free viewpoint video is synthesized based on the reconstructed visual hull. In the experimental results, free viewpoint video captured by uncalibrated hand-held cameras is successfully synthesized using the proposed method. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] 3DTV view generation using uncalibrated pure rotating and zooming cameras [texte imprimé] / Songkran Jarusirisawad, Auteur ; Hideo Saito, Auteur . - pp. 17-30. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp. 17-30 Mots-clés : Free  viewpoint  video  View  interpolation  Projective  grid  space  Trifocal  tensor Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : This paper proposes a novel method for synthesizing free viewpoint video captured by uncalibrated pure rotating and zooming cameras. Neither intrinsic nor extrinsic parameters of our cameras are known. Projective grid space (PGS), which is the 3D space defined by the epipolar geometry of two basis cameras, is employed for weak camera calibration. Trifocal tensors are used to relate non-basis cameras to PGS. Given trifocal tensors in the initial frame, our method automatically computes trifocal tensors in the other frames. Scale invariant feature transform (SIFT) is used for finding corresponding points in a natural scene between the initial frame and the other frames. Finally, free viewpoint video is synthesized based on the reconstructed visual hull. In the experimental results, free viewpoint video captured by uncalibrated hand-held cameras is successfully synthesized using the proposed method. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

2D/3D freeview video generation for 3DTV system / Dongbo Min in Signal processing. Image communication, Vol. 24 N° 1/2 (Janvier 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp. 31-48 Titre : 2D/3D freeview video generation for 3DTV system Type de document : texte imprimé Auteurs : Dongbo Min, Auteur ; Donghyun Kim, Auteur ; SangUn Yun, Auteur Article en page(s) : pp. 31-48 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Occlusion  handling  Semi-N-view  &  N-depth  framework  Stereo  matching  Virtual  view  rendering Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : In this paper, we present a new method of synthesizing novel views from the virtual cameras in multiview camera configurations for three-dimensional TV (3DTV) system. We introduce a semi-N-view & N-depth framework in order to estimate disparity maps efficiently and correctly. This framework reduces redundancy on disparity estimation by using information from neighboring views. N views can be classified as reference and target images. The disparity maps on the reference images are only estimated by using the cost aggregation method with the weighted least square. The cost functions on the target images are computed by the proposed warping technique so that significant reduction of computation loads is possible. The occlusion problem, which significantly affects the quality of virtual view rendering, is handled by using cost functions computed with multiview images. The proposed method provides a 2D/3D freeview video for 3DTV system. User can select 2D/3D modes of freeview video and control 3D depth perception by adjusting several parameters in 3D freeview video. Experimental results show that the proposed method yields the accurate disparity maps and the synthesized novel view is satisfactory enough to provide seamless freeview videos for 3DTV system. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] 2D/3D freeview video generation for 3DTV system [texte imprimé] / Dongbo Min, Auteur ; Donghyun Kim, Auteur ; SangUn Yun, Auteur . - pp. 31-48. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp. 31-48 Mots-clés : Occlusion  handling  Semi-N-view  &  N-depth  framework  Stereo  matching  Virtual  view  rendering Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : In this paper, we present a new method of synthesizing novel views from the virtual cameras in multiview camera configurations for three-dimensional TV (3DTV) system. We introduce a semi-N-view & N-depth framework in order to estimate disparity maps efficiently and correctly. This framework reduces redundancy on disparity estimation by using information from neighboring views. N views can be classified as reference and target images. The disparity maps on the reference images are only estimated by using the cost aggregation method with the weighted least square. The cost functions on the target images are computed by the proposed warping technique so that significant reduction of computation loads is possible. The occlusion problem, which significantly affects the quality of virtual view rendering, is handled by using cost functions computed with multiview images. The proposed method provides a 2D/3D freeview video for 3DTV system. User can select 2D/3D modes of freeview video and control 3D depth perception by adjusting several parameters in 3D freeview video. Experimental results show that the proposed method yields the accurate disparity maps and the synthesized novel view is satisfactory enough to provide seamless freeview videos for 3DTV system. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

Real-time stereo-based view synthesis algorithms / Sammy Rogmans in Signal processing. Image communication, Vol. 24 N° 1/2 (Janvier 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp. 49-64 Titre : Real-time stereo-based view synthesis algorithms : a unified framework and evaluation on commodity GPUs Type de document : texte imprimé Auteurs : Sammy Rogmans, Auteur ; Jiangbo Lu, Auteur ; Philippe Bekaert, Auteur Article en page(s) : pp. 49-64 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Stereo  correspondence  View  synthesis  Image-based  rendering  Performance  evaluation  GPGPU Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : Novel view synthesis based on dense stereo correspondence is an active research problem. Despite that many algorithms have been proposed recently, this flourishing, cross-area research field still remains relatively less structured than its front-end constituent part, stereo correspondence. Moreover, so far little work has been done to assess different stereo-based view synthesis algorithms, particularly when real-time execution is enforced as a hard application constraint. In this paper, we first propose a unified framework that seamlessly connects stereo correspondence and view synthesis. The proposed framework dissects the typical algorithms into a common set of individual functional modules, allowing the comparison of various design decisions. Aligned with this algorithmic framework, we have developed a flexible GPU-accelerated software model, which contains optimized implementations of several recent real-time algorithms, specifically focusing on local cost aggregation and image warping modules. Based on this common software model running on graphics hardware, we evaluate the relative performance of various design combinations in terms of both view synthesis quality and real-time processing speed. This comparative evaluation leads to a number of observations, and hence offers useful guides to the future design of real-time stereo-based view synthesis algorithms. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] Real-time stereo-based view synthesis algorithms : a unified framework and evaluation on commodity GPUs [texte imprimé] / Sammy Rogmans, Auteur ; Jiangbo Lu, Auteur ; Philippe Bekaert, Auteur . - pp. 49-64. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp. 49-64 Mots-clés : Stereo  correspondence  View  synthesis  Image-based  rendering  Performance  evaluation  GPGPU Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : Novel view synthesis based on dense stereo correspondence is an active research problem. Despite that many algorithms have been proposed recently, this flourishing, cross-area research field still remains relatively less structured than its front-end constituent part, stereo correspondence. Moreover, so far little work has been done to assess different stereo-based view synthesis algorithms, particularly when real-time execution is enforced as a hard application constraint. In this paper, we first propose a unified framework that seamlessly connects stereo correspondence and view synthesis. The proposed framework dissects the typical algorithms into a common set of individual functional modules, allowing the comparison of various design decisions. Aligned with this algorithmic framework, we have developed a flexible GPU-accelerated software model, which contains optimized implementations of several recent real-time algorithms, specifically focusing on local cost aggregation and image warping modules. Based on this common software model running on graphics hardware, we evaluate the relative performance of various design combinations in terms of both view synthesis quality and real-time processing speed. This comparative evaluation leads to a number of observations, and hence offers useful guides to the future design of real-time stereo-based view synthesis algorithms. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

View generation with 3D warping using depth information for FTV / Yuji Mori in Signal processing. Image communication, Vol. 24 N° 1/2 (Janvier 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp. 65-72 Titre : View generation with 3D warping using depth information for FTV Type de document : texte imprimé Auteurs : Yuji Mori, Auteur ; Norishige Fukushima, Auteur ; Tomohiro Yendo, Auteur Année de publication : 2009 Article en page(s) : pp. 65-72 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Depth-image-based  rendering  Free-viewpoint  TV  3D  warping  Post-filtering Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : In this paper, we propose a new method of depth-image-based rendering (DIBR) for free-viewpoint TV (FTV). In the conventional method, we estimated the depth of an object on the virtual image plane, which is called view-dependent depth estimation, and the virtual view images are rendered using the view-dependent depth map. In this method, virtual viewpoint images are rendered with 3D warping instead of estimating the view-dependent depth, since depth estimation is usually costly and it is desirable to eliminate it from the rendering process. However, 3D warping causes some problems that do not occur in the method with view-dependent depth estimation; for example, the appearance of holes on the rendered image, and the occurrence of depth discontinuity on the surface of the object at virtual image plane. Depth discontinuity causes artifacts on the rendered image. In this paper, these problems are solved by projecting depth map to the virtual image plane and performing post-filtering on the projected depth map. In the experiments, high-quality arbitrary viewpoint images were obtained by rendering images from relatively small number of cameras. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] View generation with 3D warping using depth information for FTV [texte imprimé] / Yuji Mori, Auteur ; Norishige Fukushima, Auteur ; Tomohiro Yendo, Auteur . - 2009 . - pp. 65-72. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp. 65-72 Mots-clés : Depth-image-based  rendering  Free-viewpoint  TV  3D  warping  Post-filtering Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : In this paper, we propose a new method of depth-image-based rendering (DIBR) for free-viewpoint TV (FTV). In the conventional method, we estimated the depth of an object on the virtual image plane, which is called view-dependent depth estimation, and the virtual view images are rendered using the view-dependent depth map. In this method, virtual viewpoint images are rendered with 3D warping instead of estimating the view-dependent depth, since depth estimation is usually costly and it is desirable to eliminate it from the rendering process. However, 3D warping causes some problems that do not occur in the method with view-dependent depth estimation; for example, the appearance of holes on the rendered image, and the occurrence of depth discontinuity on the surface of the object at virtual image plane. Depth discontinuity causes artifacts on the rendered image. In this paper, these problems are solved by projecting depth map to the virtual image plane and performing post-filtering on the projected depth map. In the experiments, high-quality arbitrary viewpoint images were obtained by rendering images from relatively small number of cameras. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

The effects of multiview depth video compression on multiview rendering / P. Merkle in Signal processing. Image communication, Vol. 24 N° 1/2 (Janvier 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp. 73-88 Titre : The effects of multiview depth video compression on multiview rendering Type de document : texte imprimé Auteurs : P. Merkle, Auteur ; Y. Morvan, Auteur ; A. Smolic, Auteur Article en page(s) : pp. 73-88 Note générale : Electronique Langues : Anglais (eng) Mots-clés : 3D  television  Multiview  video  Depth  compression  View  synthesis  rendering Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : This article investigates the interaction between different techniques for depth compression and view synthesis rendering with multiview video plus scene depth data. Two different approaches for depth coding are compared, namely H.264/MVC, using temporal and inter-view reference images for efficient prediction, and the novel platelet-based coding algorithm, characterized by being adapted to the special characteristics of depth-images. Since depth-images are a 2D representation of the 3D scene geometry, depth-image errors lead to geometry distortions. Therefore, the influence of geometry distortions resulting from coding artifacts is evaluated for both coding approaches in two different ways. First, the variation of 3D surface meshes is analyzed using the Hausdorff distance and second, the distortion is evaluated for 2D view synthesis rendering, where color and depth information are used together to render virtual intermediate camera views of the scene. The results show that—although its rate-distortion (R-D) performance is worse—platelet-based depth coding outperforms H.264, due to improved sharp edge preservation. Therefore, depth coding needs to be evaluated with respect to geometry distortions. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] The effects of multiview depth video compression on multiview rendering [texte imprimé] / P. Merkle, Auteur ; Y. Morvan, Auteur ; A. Smolic, Auteur . - pp. 73-88. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp. 73-88 Mots-clés : 3D  television  Multiview  video  Depth  compression  View  synthesis  rendering Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : This article investigates the interaction between different techniques for depth compression and view synthesis rendering with multiview video plus scene depth data. Two different approaches for depth coding are compared, namely H.264/MVC, using temporal and inter-view reference images for efficient prediction, and the novel platelet-based coding algorithm, characterized by being adapted to the special characteristics of depth-images. Since depth-images are a 2D representation of the 3D scene geometry, depth-image errors lead to geometry distortions. Therefore, the influence of geometry distortions resulting from coding artifacts is evaluated for both coding approaches in two different ways. First, the variation of 3D surface meshes is analyzed using the Hausdorff distance and second, the distortion is evaluated for 2D view synthesis rendering, where color and depth information are used together to render virtual intermediate camera views of the scene. The results show that—although its rate-distortion (R-D) performance is worse—platelet-based depth coding outperforms H.264, due to improved sharp edge preservation. Therefore, depth coding needs to be evaluated with respect to geometry distortions. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

View synthesis prediction for multiview video coding / Sehoon Yea in Signal processing. Image communication, Vol. 24 N° 1/2 (Janvier 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp. 89-100 Titre : View synthesis prediction for multiview video coding Type de document : texte imprimé Auteurs : Sehoon Yea, Auteur ; Anthony Vetro, Auteur Article en page(s) : pp. 89-100 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Multiview  video  coding  View  synthesis  Prediction  Depth  3DTV  Free-viewpoint  video Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : We propose a rate-distortion-optimized framework that incorporates view synthesis for improved prediction in multiview video coding. In the proposed scheme, auxiliary information, including depth data, is encoded and used at the decoder to generate the view synthesis prediction data. The proposed method employs optimal mode decision including view synthesis prediction, and sub-pixel reference matching to improve prediction accuracy of the view synthesis prediction. Novel variants of the skip and direct modes are also presented, which infer the depth and correction vector information from neighboring blocks in a synthesized reference picture to reduce the bits needed for the view synthesis prediction mode. We demonstrate two multiview video coding scenarios in which view synthesis prediction is employed. In the first scenario, the goal is to improve the coding efficiency of multiview video where block-based depths and correction vectors are encoded by CABAC in a lossless manner on a macroblock basis. A variable block-size depth/motion search algorithm is described. Experimental results demonstrate that view synthesis prediction does provide some coding gains when combined with disparity-compensated prediction. In the second scenario, the goal is to use view synthesis prediction for reducing rate overhead incurred by transmitting depth maps for improved support of 3DTV and free-viewpoint video applications. It is assumed that the complete depth map for each view is encoded separately from the multiview video and used at the receiver to generate intermediate views. We utilize this information for view synthesis prediction to improve overall coding efficiency. Experimental results show that the rate overhead incurred by coding depth maps of varying quality could be offset by utilizing the proposed view synthesis prediction techniques to reduce the bitrate required for coding multiview video. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] View synthesis prediction for multiview video coding [texte imprimé] / Sehoon Yea, Auteur ; Anthony Vetro, Auteur . - pp. 89-100. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp. 89-100 Mots-clés : Multiview  video  coding  View  synthesis  Prediction  Depth  3DTV  Free-viewpoint  video Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : We propose a rate-distortion-optimized framework that incorporates view synthesis for improved prediction in multiview video coding. In the proposed scheme, auxiliary information, including depth data, is encoded and used at the decoder to generate the view synthesis prediction data. The proposed method employs optimal mode decision including view synthesis prediction, and sub-pixel reference matching to improve prediction accuracy of the view synthesis prediction. Novel variants of the skip and direct modes are also presented, which infer the depth and correction vector information from neighboring blocks in a synthesized reference picture to reduce the bits needed for the view synthesis prediction mode. We demonstrate two multiview video coding scenarios in which view synthesis prediction is employed. In the first scenario, the goal is to improve the coding efficiency of multiview video where block-based depths and correction vectors are encoded by CABAC in a lossless manner on a macroblock basis. A variable block-size depth/motion search algorithm is described. Experimental results demonstrate that view synthesis prediction does provide some coding gains when combined with disparity-compensated prediction. In the second scenario, the goal is to use view synthesis prediction for reducing rate overhead incurred by transmitting depth maps for improved support of 3DTV and free-viewpoint video applications. It is assumed that the complete depth map for each view is encoded separately from the multiview video and used at the receiver to generate intermediate views. We utilize this information for view synthesis prediction to improve overall coding efficiency. Experimental results show that the rate overhead incurred by coding depth maps of varying quality could be offset by utilizing the proposed view synthesis prediction techniques to reduce the bitrate required for coding multiview video. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

MPEG-4 Part 25 / Blagica Jovanova in Signal processing. Image communication, Vol. 24 N° 1/2 (Janvier 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp. 101-114 Titre : MPEG-4 Part 25 : a graphics compression framework for XML-based scene graph formats Type de document : texte imprimé Auteurs : Blagica Jovanova, Auteur ; Marius Preda, Auteur ; Françoise Preteux, Auteur Article en page(s) : pp. 101-114 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Compression  Standards  3D  graphics  MPEG-4  Extensible  markup  language  (XML)  Collaborative  design  activity  (COLLADA)  Extensible  3D  graphics  (X3D)  Extensible  MPEG-4  Textual  (XMT) Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : This paper introduces a new model for applying 3D graphics compression to arbitrary scene graphs, recently adopted by MPEG in Part 25 of the MPEG-4 standard. The goal of the model is twofold: to liberate the powerful MPEG compression techniques from the scene graph representation based on BIFS and to position the compression as a transparent layer in the 3D graphics chain, thus making it easy to integrate in third party authoring tools or end-user applications. In addition, intrinsic features of the compression tools such as progressive decoding or streaming are preserved. Currently implemented on top of COLLAborative Design Activity (COLLADA) and eXtensible 3D (X3D), the proposed model will leverage the deployment of MPEG-4 compression for 3D graphics. The software implementation, publicly available under ISO license, is introduced and reports and analyses of the compression results on large database are outlined in the document. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] MPEG-4 Part 25 : a graphics compression framework for XML-based scene graph formats [texte imprimé] / Blagica Jovanova, Auteur ; Marius Preda, Auteur ; Françoise Preteux, Auteur . - pp. 101-114. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp. 101-114 Mots-clés : Compression  Standards  3D  graphics  MPEG-4  Extensible  markup  language  (XML)  Collaborative  design  activity  (COLLADA)  Extensible  3D  graphics  (X3D)  Extensible  MPEG-4  Textual  (XMT) Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : This paper introduces a new model for applying 3D graphics compression to arbitrary scene graphs, recently adopted by MPEG in Part 25 of the MPEG-4 standard. The goal of the model is twofold: to liberate the powerful MPEG compression techniques from the scene graph representation based on BIFS and to position the compression as a transparent layer in the 3D graphics chain, thus making it easy to integrate in third party authoring tools or end-user applications. In addition, intrinsic features of the compression tools such as progressive decoding or streaming are preserved. Currently implemented on top of COLLAborative Design Activity (COLLADA) and eXtensible 3D (X3D), the proposed model will leverage the deployment of MPEG-4 compression for 3D graphics. The software implementation, publicly available under ISO license, is introduced and reports and analyses of the compression results on large database are outlined in the document. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

Peer-to-peer visualization of very large 3D landscape and city models using MPEG-4 / Romain Cavagna in Signal processing. Image communication, Vol. 24 N° 1/2 (Janvier 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp.115-121 Titre : Peer-to-peer visualization of very large 3D landscape and city models using MPEG-4 Type de document : texte imprimé Auteurs : Romain Cavagna, Auteur ; Jérôme Royan, Auteur ; Patrick Gioia, Auteur Article en page(s) : pp.115-121 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Peer-to-peer  Virtual  reality  Real-time  navigation  Streaming  Interoperability  MPEG-4 Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : The recent availability of broadband Internet access and web-based visualization techniques is paving the way for a large scale use of 3D landscape and city models in a great variety of professional and mass market services. To make such services appealing to a large audience, these 3D models must reach a sufficient level of realism and accuracy. Many solutions are now available to automatically generate 3D models of huge urban environments. Geographic information system (GIS) databases (i.e., terrain elevation grids, orthophotographs, buildings, footprint and height) provide a good basis for generating such models at affordable cost with minimum human intervention. However, the growing size of the generated representations will favor streaming over download-and-play. Moreover, the new market for virtual worlds is likely to be soon demanding interoperability. The goal of this paper is to show how solutions based on hierarchical level of detail (LOD) models and view-dependent progressive streaming can efficiently be implemented using the MPEG-4 AFX standard in peer-to-peer network architectures, solving both streaming and interoperability issues. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] Peer-to-peer visualization of very large 3D landscape and city models using MPEG-4 [texte imprimé] / Romain Cavagna, Auteur ; Jérôme Royan, Auteur ; Patrick Gioia, Auteur . - pp.115-121. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp.115-121 Mots-clés : Peer-to-peer  Virtual  reality  Real-time  navigation  Streaming  Interoperability  MPEG-4 Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : The recent availability of broadband Internet access and web-based visualization techniques is paving the way for a large scale use of 3D landscape and city models in a great variety of professional and mass market services. To make such services appealing to a large audience, these 3D models must reach a sufficient level of realism and accuracy. Many solutions are now available to automatically generate 3D models of huge urban environments. Geographic information system (GIS) databases (i.e., terrain elevation grids, orthophotographs, buildings, footprint and height) provide a good basis for generating such models at affordable cost with minimum human intervention. However, the growing size of the generated representations will favor streaming over download-and-play. Moreover, the new market for virtual worlds is likely to be soon demanding interoperability. The goal of this paper is to show how solutions based on hierarchical level of detail (LOD) models and view-dependent progressive streaming can efficiently be implemented using the MPEG-4 AFX standard in peer-to-peer network architectures, solving both streaming and interoperability issues. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

Depth-image-based rendering for 3DTV service over T-DMB / Young Kyung Park in Signal processing. Image communication, Vol. 24 N° 1/2 (Janvier 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp. 122-136 Titre : Depth-image-based rendering for 3DTV service over T-DMB Type de document : texte imprimé Auteurs : Young Kyung Park, Auteur ; Kwanghee Jung, Auteur ; Youngjin Oh, Auteur Article en page(s) : pp. 122-136 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Depth-image-based  rendering  Depth  image  Adaptive  smoothing  Look-up  table  Terrestrial-digital  multimedia  broadcasting  Three-dimensional  television Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : In this paper, we present a depth-image-based rendering (DIBR) technique for three-dimensional television (3DTV) service over terrestrial-digital multimedia broadcasting (T-DMB). 3DTV service over T-DMB is very attractive because the single user environment of T-DMB is suitable to glassless 3D viewing. However, the bit budget for the transmission of additional data in 3DTV service is very limited in T-DMB. DIBR can resolve this problem because the depth information as the additional data can be compressed effectively. However, DIBR has also some problems such as the backward compatibility with the conventional T-DMB, a large computational cost for rendering virtual images and generation of holes by disocclusion. To solve these problems, we first present the service architecture for DIBR-based 3DTV service over T-DMB, which can maintain the backward compatibility with the conventional T-DMB. Second, we propose a new depth preprocessing method based on adaptive smoothing. In the proposed depth preprocessing method, two adaptive smoothing filters of the discontinuity-preserving smoothing and the gradient direction-based smoothing are sequentially conducted. As a result, both the reduction of bitrates required for the depth transmission and the reduction of the holes can be achieved. Finally, we present look-up table (LUT)-based simultaneous method for generating an auto-stereoscopic image so that problems of the limited memory and the large computational cost can be resolved in T-DMB player. Various experiments show that the proposed DIBR technique can be efficiently employed for 3DTV service over T-DMB. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] Depth-image-based rendering for 3DTV service over T-DMB [texte imprimé] / Young Kyung Park, Auteur ; Kwanghee Jung, Auteur ; Youngjin Oh, Auteur . - pp. 122-136. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 1/2 (Janvier 2009) . - pp. 122-136 Mots-clés : Depth-image-based  rendering  Depth  image  Adaptive  smoothing  Look-up  table  Terrestrial-digital  multimedia  broadcasting  Three-dimensional  television Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : In this paper, we present a depth-image-based rendering (DIBR) technique for three-dimensional television (3DTV) service over terrestrial-digital multimedia broadcasting (T-DMB). 3DTV service over T-DMB is very attractive because the single user environment of T-DMB is suitable to glassless 3D viewing. However, the bit budget for the transmission of additional data in 3DTV service is very limited in T-DMB. DIBR can resolve this problem because the depth information as the additional data can be compressed effectively. However, DIBR has also some problems such as the backward compatibility with the conventional T-DMB, a large computational cost for rendering virtual images and generation of holes by disocclusion. To solve these problems, we first present the service architecture for DIBR-based 3DTV service over T-DMB, which can maintain the backward compatibility with the conventional T-DMB. Second, we propose a new depth preprocessing method based on adaptive smoothing. In the proposed depth preprocessing method, two adaptive smoothing filters of the discontinuity-preserving smoothing and the gradient direction-based smoothing are sequentially conducted. As a result, both the reduction of bitrates required for the depth transmission and the reduction of the holes can be achieved. Finally, we present look-up table (LUT)-based simultaneous method for generating an auto-stereoscopic image so that problems of the limited memory and the large computational cost can be resolved in T-DMB player. Various experiments show that the proposed DIBR technique can be efficiently employed for 3DTV service over T-DMB. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

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