Documents disponibles écrits par cet auteur

An asymmetric post-processing for correspondence problem / Dongbo Min in Signal processing. Image communication, Vol. 25 N° 2 (02 EX.) (Février 2010) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 25 N° 2 (02 EX.) (Février 2010) . - pp. 130-142 Titre : An asymmetric post-processing for correspondence problem Type de document : texte imprimé Auteurs : Dongbo Min, Auteur ; Kwanghoon Sohn, Auteur Année de publication : 2010 Article en page(s) : pp. 130-142 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Adaptive  filtering  Asymmetric  consistency  check  Post-processing  Stereo  matching Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : This paper presents a novel approach that performs post-processing for stereo matching. We improve the performance of stereo matching by performing consistency check and adaptive filtering in an iterative filtering scheme. The consistency check is only done with asymmetric information so that very few additional computational loads are necessary. The information in the valid pixels is propagated into invalid pixels through the adaptive filtering. The proposed post-filtering method can be used in various methods for stereo matching. We demonstrate the validity of the proposed method by applying it to hierarchical belief propagation and semi-global matching. The performance of the post-processing method for hierarchical belief propagation is comparable to state-of-the-art methods in the Middlebury stereo datasets. In order to verify the performance of asymmetric consistency check, we compare it with other reliability estimation methods in the proposed post-processing scheme. Moreover, in order to verify the performance of post-filtering method in noisy environment, the proposed post-filtering method is applied to the stereo images denoised by NL-means algorithm. We find that the iterative filtering scheme reduce an error which may be caused in stereo matching for the denoised images and improve the performance of stereo matching. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] An asymmetric post-processing for correspondence problem [texte imprimé] / Dongbo Min, Auteur ; Kwanghoon Sohn, Auteur . - 2010 . - pp. 130-142. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 25 N° 2 (02 EX.) (Février 2010) . - pp. 130-142 Mots-clés : Adaptive  filtering  Asymmetric  consistency  check  Post-processing  Stereo  matching Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : This paper presents a novel approach that performs post-processing for stereo matching. We improve the performance of stereo matching by performing consistency check and adaptive filtering in an iterative filtering scheme. The consistency check is only done with asymmetric information so that very few additional computational loads are necessary. The information in the valid pixels is propagated into invalid pixels through the adaptive filtering. The proposed post-filtering method can be used in various methods for stereo matching. We demonstrate the validity of the proposed method by applying it to hierarchical belief propagation and semi-global matching. The performance of the post-processing method for hierarchical belief propagation is comparable to state-of-the-art methods in the Middlebury stereo datasets. In order to verify the performance of asymmetric consistency check, we compare it with other reliability estimation methods in the proposed post-processing scheme. Moreover, in order to verify the performance of post-filtering method in noisy environment, the proposed post-filtering method is applied to the stereo images denoised by NL-means algorithm. We find that the iterative filtering scheme reduce an error which may be caused in stereo matching for the denoised images and improve the performance of stereo matching. 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 [...]

Hardware design of motion data decoding process for H.264/AVC / Kiwon Yoo in Signal processing. Image communication, Vol. 25 N° 3 (02 ex.) (Mars 2010) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 25 N° 3 (02 ex.) (Mars 2010) . - pp. 208–223 Titre : Hardware design of motion data decoding process for H.264/AVC Type de document : texte imprimé Auteurs : Kiwon Yoo, Auteur ; Kwanghoon Sohn, Auteur Année de publication : 2010 Article en page(s) : pp. 208–223 Note générale : Electronique Langues : Anglais (eng) Mots-clés : H.264/AVC  Motion  vector  derivation  Motion  data  decoding  Hardware  design  VLSI  design Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : In H.264/AVC, motion data can be basically derived by the following two schemes: one is a typical spatial prediction scheme based on the DPCM and the other is a sophisticated spatiotemporal prediction scheme for the skipped motion data, formally referred to as a direct mode. We verified through instruction level profiling that when these schemes are combined with various H.264/AVC coding techniques, the computational burden to derive the motion data could be considerably aggravated. Specifically, its computational complexity amounts to maximally 55% of that of the overall syntax parsing process. In this paper, we aim at an efficient hardware design of the motion data decoding process for H.264/AVC, for which all the key design considerations are addressed in detail and respective rational answers are presented. As comparing the resulting hardware design with the processor-based solution, its effectiveness was clearly demonstrated. The proposed design was implemented with 43.2 K logic gates and three on-chip memories of 3584 bits using Samsung Semiconductor’s Standard Cell Library in 65 nm L6LP process technology (SS65LP), and was capable of operating the H.264/AVC high-profile video bitstream of 1080p@60fps at 100 MHz consuming 843 μW. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science/article/pii/S0923596509001362 [article] Hardware design of motion data decoding process for H.264/AVC [texte imprimé] / Kiwon Yoo, Auteur ; Kwanghoon Sohn, Auteur . - 2010 . - pp. 208–223. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 25 N° 3 (02 ex.) (Mars 2010) . - pp. 208–223 Mots-clés : H.264/AVC  Motion  vector  derivation  Motion  data  decoding  Hardware  design  VLSI  design Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : In H.264/AVC, motion data can be basically derived by the following two schemes: one is a typical spatial prediction scheme based on the DPCM and the other is a sophisticated spatiotemporal prediction scheme for the skipped motion data, formally referred to as a direct mode. We verified through instruction level profiling that when these schemes are combined with various H.264/AVC coding techniques, the computational burden to derive the motion data could be considerably aggravated. Specifically, its computational complexity amounts to maximally 55% of that of the overall syntax parsing process. In this paper, we aim at an efficient hardware design of the motion data decoding process for H.264/AVC, for which all the key design considerations are addressed in detail and respective rational answers are presented. As comparing the resulting hardware design with the processor-based solution, its effectiveness was clearly demonstrated. The proposed design was implemented with 43.2 K logic gates and three on-chip memories of 3584 bits using Samsung Semiconductor’s Standard Cell Library in 65 nm L6LP process technology (SS65LP), and was capable of operating the H.264/AVC high-profile video bitstream of 1080p@60fps at 100 MHz consuming 843 μW. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science/article/pii/S0923596509001362