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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Reversão anaglífica em vídeos estereoscópicos / Anaglyphic reversion in stereoscopic videos

Rodrigues, Felipe Maciel 24 May 2016 (has links)
A atenção voltada à produção de conteúdos 3D atualmente tem sido alta, grande parte devido à aceitação e à manifestação de interesse do público para esta tecnologia. Novas técnicas de captação e codificação e modos de reprodução de vídeos 3D, particularmente vídeos estereoscópicos, vêm surgindo ou sendo melhorados, visando aperfeiçoar e integrar esta nova tecnologia com a infraestrutura disponível. No entanto, em relação a avanços na área de codificação, nota-se a ausência de uma técnica compatível com mais de um método de visualização de vídeos estereoscópicos - para cada método de visualização há uma técnica de codificação diferente, o que inviabiliza ao usuário escolher o método que deseja visualizar o conteúdo. Uma abordagem para resolver este problema é desenvolver uma técnica genérica, isto é, uma técnica que seja independentemente do método de visualização, que através de parâmetros adequados, produza um vídeo estereoscópico sem perda significativa de qualidade ou a percepção de profundidade, que é a característica marcante desse tipo de conteúdo. O método proposto neste trabalho, chamado HaaRGlyph, transforma um vídeo esterescópico em um único fluxo contendo um anáglifo, codificado de modo especial. Esse fluxo além de ser compatível com o método de visualização anaglífica é também reversível à uma aproximação do par estéreo original, possibilitando a independência de visualização. Além disso, a HaaRGlyph atinge maiores taxas de compressão do que o trabalho relacionado. / Attention towards 3D content production has been currently high, mostly because of public acceptance and interest in this kind of technology. Therefore, new capturing techniques, coding and playback modes for 3D video, particularly stereoscopic video, have been emerging or being enhanced, focusing on improving and integrating this new kind of technology with the available infrastructure. However, regarding advances in the coding area, there are conflicts because each stereoscopic visualization method uses a different coding technique. That leads to incompatibility between those methods. An approach to tackle this problem is to develop a generic technique, that is, a technique that is appropriate regardless the visualization method. Such technique, with suitable parameters, outputs a stereoscopic video with no significant loss of quality or depth perception, which is the remarkable feature of this kind of content. The method proposed in this work, named HaaRGlyph, transforms a stereo pair of videos into a single anaglyph stream, coded in a special manner. Such stream is not only compliant with the anaglyph visualization method but also reversible to something close to the original stereo pair, allowing visualization independence. Moreover, HaarGlyph achieves higher compression rates than related work.
2

Reversão anaglífica em vídeos estereoscópicos / Anaglyphic reversion in stereoscopic videos

Felipe Maciel Rodrigues 24 May 2016 (has links)
A atenção voltada à produção de conteúdos 3D atualmente tem sido alta, grande parte devido à aceitação e à manifestação de interesse do público para esta tecnologia. Novas técnicas de captação e codificação e modos de reprodução de vídeos 3D, particularmente vídeos estereoscópicos, vêm surgindo ou sendo melhorados, visando aperfeiçoar e integrar esta nova tecnologia com a infraestrutura disponível. No entanto, em relação a avanços na área de codificação, nota-se a ausência de uma técnica compatível com mais de um método de visualização de vídeos estereoscópicos - para cada método de visualização há uma técnica de codificação diferente, o que inviabiliza ao usuário escolher o método que deseja visualizar o conteúdo. Uma abordagem para resolver este problema é desenvolver uma técnica genérica, isto é, uma técnica que seja independentemente do método de visualização, que através de parâmetros adequados, produza um vídeo estereoscópico sem perda significativa de qualidade ou a percepção de profundidade, que é a característica marcante desse tipo de conteúdo. O método proposto neste trabalho, chamado HaaRGlyph, transforma um vídeo esterescópico em um único fluxo contendo um anáglifo, codificado de modo especial. Esse fluxo além de ser compatível com o método de visualização anaglífica é também reversível à uma aproximação do par estéreo original, possibilitando a independência de visualização. Além disso, a HaaRGlyph atinge maiores taxas de compressão do que o trabalho relacionado. / Attention towards 3D content production has been currently high, mostly because of public acceptance and interest in this kind of technology. Therefore, new capturing techniques, coding and playback modes for 3D video, particularly stereoscopic video, have been emerging or being enhanced, focusing on improving and integrating this new kind of technology with the available infrastructure. However, regarding advances in the coding area, there are conflicts because each stereoscopic visualization method uses a different coding technique. That leads to incompatibility between those methods. An approach to tackle this problem is to develop a generic technique, that is, a technique that is appropriate regardless the visualization method. Such technique, with suitable parameters, outputs a stereoscopic video with no significant loss of quality or depth perception, which is the remarkable feature of this kind of content. The method proposed in this work, named HaaRGlyph, transforms a stereo pair of videos into a single anaglyph stream, coded in a special manner. Such stream is not only compliant with the anaglyph visualization method but also reversible to something close to the original stereo pair, allowing visualization independence. Moreover, HaarGlyph achieves higher compression rates than related work.
3

A Hybrid Approach For Full Frame Loss Concealment Of Multiview Video

Bilen, Cagdas 01 August 2007 (has links) (PDF)
Multiview video is one of the emerging research areas especially among the video coding community. Transmission of multiview video over an error prone network is possible with efficient compression of these videos. But along with the studies for efficiently compressing the multiview video, new error concealment and error protection methods are also necessary to overcome the problems due to erroneous channel conditions in practical applications. In packet switching networks, packet losses may lead to block losses in a frame or the loss of an entire frame in an encoded video sequence. In recent years several algorithms are proposed to handle the loss of an entire frame efficiently. However methods for full frame losses in stereoscopic or multiview videos are limited in the literature. In this thesis a stereoscopic approach for full frame loss concealment of multiview video is proposed. In the proposed methods, the redundancy and disparity between the views and motion information between the previously decoded frames are used to estimate the lost frame. Even though multiview video can be composed of more than two views, at most three view are utilized for concealment. The performance of the proposed algorithms are tested against monoscopic methods and the conditions under which the proposed methods are superior are investigated. The proposed algorithms are applied to both stereoscopic and multiview video.
4

Robust watermarking techniques for stereoscopic video protection / Méthodes de tatouage robuste pour la protection de l’imagerie numerique 3D

Chammem, Afef 27 May 2013 (has links)
La multiplication des contenus stéréoscopique augmente les risques de piratage numérique. La solution technologique par tatouage relève ce défi. En pratique, le défi d’une approche de tatouage est d'atteindre l’équilibre fonctionnel entre la transparence, la robustesse, la quantité d’information insérée et le coût de calcul. Tandis que la capture et l'affichage du contenu 3D ne sont fondées que sur les deux vues gauche/droite, des représentations alternatives, comme les cartes de disparité devrait également être envisagée lors de la transmission/stockage. Une étude spécifique sur le domaine d’insertion optimale devient alors nécessaire. Cette thèse aborde les défis mentionnés ci-dessus. Tout d'abord, une nouvelle carte de disparité (3D video-New Three Step Search- 3DV-SNSL) est développée. Les performances des 3DV-NTSS ont été évaluées en termes de qualité visuelle de l'image reconstruite et coût de calcul. En comparaison avec l'état de l'art (NTSS et FS-MPEG) des gains moyens de 2dB en PSNR et 0,1 en SSIM sont obtenus. Le coût de calcul est réduit par un facteur moyen entre 1,3 et 13. Deuxièmement, une étude comparative sur les principales classes héritées des méthodes de tatouage 2D et de leurs domaines d'insertion optimales connexes est effectuée. Quatre méthodes d'insertion appartenant aux familles SS, SI et hybride (Fast-IProtect) sont considérées. Les expériences ont mis en évidence que Fast-IProtect effectué dans la nouvelle carte de disparité (3DV-NTSS) serait suffisamment générique afin de servir une grande variété d'applications. La pertinence statistique des résultats est donnée par les limites de confiance de 95% et leurs erreurs relatives inférieurs er <0.1 / The explosion in stereoscopic video distribution increases the concerns over its copyright protection. Watermarking can be considered as the most flexible property right protection technology. The watermarking applicative issue is to reach the trade-off between the properties of transparency, robustness, data payload and computational cost. While the capturing and displaying of the 3D content are solely based on the two left/right views, some alternative representations, like the disparity maps should also be considered during transmission/storage. A specific study on the optimal (with respect to the above-mentioned properties) insertion domain is also required. The present thesis tackles the above-mentioned challenges. First, a new disparity map (3D video-New Three Step Search - 3DV-NTSS) is designed. The performances of the 3DV-NTSS were evaluated in terms of visual quality of the reconstructed image and computational cost. When compared with state of the art methods (NTSS and FS-MPEG) average gains of 2dB in PSNR and 0.1 in SSIM are obtained. The computational cost is reduced by average factors between 1.3 and 13. Second, a comparative study on the main classes of 2D inherited watermarking methods and on their related optimal insertion domains is carried out. Four insertion methods are considered; they belong to the SS, SI and hybrid (Fast-IProtect) families. The experiments brought to light that the Fast-IProtect performed in the new disparity map domain (3DV-NTSS) would be generic enough so as to serve a large variety of applications. The statistical relevance of the results is given by the 95% confidence limits and their underlying relative errors lower than er<0.1
5

Robust watermarking techniques for stereoscopic video protection

Chammem, Afef 27 May 2013 (has links) (PDF)
The explosion in stereoscopic video distribution increases the concerns over its copyright protection. Watermarking can be considered as the most flexible property right protection technology. The watermarking applicative issue is to reach the trade-off between the properties of transparency, robustness, data payload and computational cost. While the capturing and displaying of the 3D content are solely based on the two left/right views, some alternative representations, like the disparity maps should also be considered during transmission/storage. A specific study on the optimal (with respect to the above-mentioned properties) insertion domain is also required. The present thesis tackles the above-mentioned challenges. First, a new disparity map (3D video-New Three Step Search - 3DV-NTSS) is designed. The performances of the 3DV-NTSS were evaluated in terms of visual quality of the reconstructed image and computational cost. When compared with state of the art methods (NTSS and FS-MPEG) average gains of 2dB in PSNR and 0.1 in SSIM are obtained. The computational cost is reduced by average factors between 1.3 and 13. Second, a comparative study on the main classes of 2D inherited watermarking methods and on their related optimal insertion domains is carried out. Four insertion methods are considered; they belong to the SS, SI and hybrid (Fast-IProtect) families. The experiments brought to light that the Fast-IProtect performed in the new disparity map domain (3DV-NTSS) would be generic enough so as to serve a large variety of applications. The statistical relevance of the results is given by the 95% confidence limits and their underlying relative errors lower than er<0.1

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