3D video is a technology that has seen a tremendous attention in the recent years. Multiview Video Coding (MVC) is an extension of the popular H.264 video coding standard and is commonly used to compress 3D videos. It offers an improvement of 20% to 50% in compression efficiency over simulcast encoding of multiview videos using the conventional H.264 video coding standard. However, there are two important problems associated with it: (i) its superior compression performance comes at the cost of significantly higher computational complexity which hampers the real-world realization of MVC encoder in applications such as 3D live broadcasting and interactive Free Viewpoint Television (FTV), and (ii) compressed 3D videos can suffer from packet loss during transmission, which can degrade the viewing quality of the 3D video at the decoder. This thesis aims to solve these problems by presenting techniques to reduce the computational complexity of the MVC encoder and by proposing a consistent error concealment technique for frame losses in 3D video transmission. The thesis first analyses the complexity of the MVC encoder. It then proposes two novel techniques to reduce the complexity of motion and disparity estimation. The first method achieves complexity reduction in the disparity estimation process by exploiting the relationship between temporal levels, type of macroblocks and search ranges while the second method achieves it by exploiting the geometrical relation- ship between motion and disparity vectors in stereo frames. These two methods are then combined with other state-of-the-art methods in a unique framework where gains add up. Experimental results show that the proposed low-complexity framework can reduce the encoding time of the standard MVC encoder by over 93% while maintaining similar compression efficiency performance. The addition of new View Synthesis Prediction (VSP) modes to the MVC encoding framework improves the compression efficiency of MVC. However, testing additional modes comes at the cost of increased encoding complexity. In order to reduce the encoding complexity, the thesis, next, proposes a bayesian early mode decision technique for a VSP enhanced MVC coder. It exploits the statistical similarities between the RD costs of the VSP SKIP mode in neighbouring views to terminate the mode decision process early. Results indicate that the proposed technique can reduce the encoding time of the enhanced MVC coder by over 33% at similar compression efficiency levels. Finally, compressed 3D videos are usually required to be broadcast to a large number of users where transmission errors can lead to frame losses which can degrade the video quality at the decoder. A simple reconstruction of the lost frames can lead to inconsistent reconstruction of the 3D scene which may negatively affect the viewing experience of a user. In order to solve this problem, the thesis proposes, at the end, a consistency model for recovering frames lost during transmission. The proposed consistency model is used to evaluate inter-view and temporal consistencies while selecting candidate blocks for concealment. Experimental results show that the proposed technique is able to recover the lost frames with high consistency and better quality than two standard error concealment methods and a baseline technique based on the boundary matching algorithm.

A atenção voltada à produção de conteúdos 3D atualmente tem sido alta, em grande parte devido à aceitação e à manifestação de interesse do público para esta tecnologia. Isso reflete num maior investimento das indústrias cinematográfica, de televisores e de jogos visando trazer o 3D para suas produções e aparelhos, oferecendo modos diferentes de interação ao usuário. Com isso, novas técnicas de captura, codificação e modos de reprodução de vídeos 3D, em especial, os vídeos estereoscópicos, vêm surgindo ou sendo melhorados, visando aperfeiçoar e integrar esta nova tecnologia com a infraestrutura disponível. Entretanto, notam-se divergências nos avanços feitos no campo da codificação, com cada método de visualização estereoscópica utilizando uma técnica de codificação diferente. Isso leva ao problema da incompatibilidade entre métodos de visualização. Uma proposta é criar uma técnica que seja genérica, isto é, independente do método de visualização. Tal técnica, por meio de parâmetros adequados, codifica o vídeo estéreo sem nenhuma perda significativa tanto na qualidade quanto na percepção de profundidade, característica marcante nesse tipo de conteúdo. A técnica proposta, denominada RevGlyph, transforma um par estéreo de vídeos em um único fluxo anaglífico, especialmente codificado. Tal fluxo, além de ser compatível com o método anaglífico de visualização, é também reversível a uma aproximação do par estéreo original, garantindo a independência do método de visualização / Attention towards 3D content production has been currently high, mostly because of public acceptance and interest in this kind of technology. That reflects in more investment from film, television and gaming industries, aiming at bringing 3D to their content and devices, as well as offering different ways of user interaction. 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. One proposal 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 proposed technique, named RevGlyph, 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

A atenção voltada à produção de conteúdos 3D atualmente tem sido alta, em grande parte devido à aceitação e à manifestação de interesse do público para esta tecnologia. Isso reflete num maior investimento das indústrias cinematográfica, de televisores e de jogos visando trazer o 3D para suas produções e aparelhos, oferecendo modos diferentes de interação ao usuário. Com isso, novas técnicas de captura, codificação e modos de reprodução de vídeos 3D, em especial, os vídeos estereoscópicos, vêm surgindo ou sendo melhorados, visando aperfeiçoar e integrar esta nova tecnologia com a infraestrutura disponível. Entretanto, notam-se divergências nos avanços feitos no campo da codificação, com cada método de visualização estereoscópica utilizando uma técnica de codificação diferente. Isso leva ao problema da incompatibilidade entre métodos de visualização. Uma proposta é criar uma técnica que seja genérica, isto é, independente do método de visualização. Tal técnica, por meio de parâmetros adequados, codifica o vídeo estéreo sem nenhuma perda significativa tanto na qualidade quanto na percepção de profundidade, característica marcante nesse tipo de conteúdo. A técnica proposta, denominada RevGlyph, transforma um par estéreo de vídeos em um único fluxo anaglífico, especialmente codificado. Tal fluxo, além de ser compatível com o método anaglífico de visualização, é também reversível a uma aproximação do par estéreo original, garantindo a independência do método de visualização / Attention towards 3D content production has been currently high, mostly because of public acceptance and interest in this kind of technology. That reflects in more investment from film, television and gaming industries, aiming at bringing 3D to their content and devices, as well as offering different ways of user interaction. 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. One proposal 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 proposed technique, named RevGlyph, 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