Le développement croissant de la chirurgie robotique pose le problème de la formation. Cette nouvelle technologie tend à suppléer dans les procédures complexes la coelioscopie. Elle nécessite une adaptation du chirurgien. Il est, en effet, nécessaire de maîtriser à la fois le télémanipulateur et les procédures chirurgicales, qui ne sont pas de simples transpositions des gestes coelioscopiques. Initialement, nous avons réalisé un historique du développement de la chirurgie mini-invasive coelioscopique et robotique, ainsi qu'un historique de l'apprentissage de la chirurgie. Puis, nous nous sommes intéressés à l'apprentissage de la robotique. Les simulateurs de chirurgie coelioscopique sont très couramment employés dans l'apprentissage. En robotiques, ils ont fait récemment leur apparition sur le marché. Nous avons étudié la validité du simulateur dV-Trainer dans l'apprentissage de la chirurgie robotique. Nous avons démontré l'intérêt de cet outil dans l'acquisition de la gestuelle et des automatismes propres au robot. Nous avons par ailleurs étudié l'impact d'une formation en micro-chirurgie sur les performances développées en chirurgie robotique car, au cours d'une étude préliminaire nous avions constaté que les micro-chirurgiens présentaient de meilleures aptitudes sur le simulateur de chirurgie robotique que ceux sans expérience en micro-chirurgie. Dans un troisième temps, nous nous sommes intéressés à la téléchirurgie à longue distance qui est impactée par deux contraintes que sont la latence de transmission et le volume des informations à transmettre. Une première étude a étudié l'impact du délai de transmission sur les performances des chirurgiens. Une deuxième étude a consisté à réaliser une évaluation subjective par des chirurgiens de la qualité de vidéos de chirurgie robotique compressées afin de déterminer un seuil de compression maximal acceptable / The huge expansion of minimally invasive robotic devices for surgery ask the question of the training of this new technology. Progress of robotic-assisted surgical techniques allows today mini- invasive surgery to be more accurate, providing benefits to surgeons and patients for complex surgical procedures. But, it resulted from an increasing need for training and development of new pedagogical strategies. Indeed, the surgeon has to master the telemanipulator and the procedure, which is different from a simple transposition of a laparoscopic skill. The first part of this work treats about historical development of minimal invasive surgery from laparoscopy to robotic surgery. We also develop the evolution of training program in surgery. Virtual simulators provide efficient tools for laparoscopy training. The second part of this work, study some possible solutions for robotic training. We assess the validity of a new robotic virtual simulator (dV-Trainer). We demonstrate the usefulness of this tool for the acquisition of the basic gesture for robotic surgery. Then, we evaluate the impact of a previous experience in micro-surgery on robotic training. We propose a prospective study comparing the surgical performance of micro-surgeons to that of general surgeons on a robotic simulator. We want to determine if this experience in micro-surgery could significantly improve the abilities and surgeons performance in the field of basic gesture in robotic surgery. The last part of the study also looks to the future. Currently, telesurgery need sophisticated dedicated technical resources. We want to develop procedures for clinical routine used. Therefore, we evaluate the impact of the delay on the surgical procedure. Also, reducing data volume allow decreasing latency. An appropriate solution to reduce the amount of data could be found by introducing lossy compression for the transmission using the well-known MPEG-2 and H-264 standards

This thesis deals with description of lossy video compression. Theoretical part of the work describes the fundamentals of the video compression and standarts for lossy as well lossless video and still image compression. The practical part follows up with design of Java program for simulation of MPEG codec.

<p>This dissertation considers packet-switched wireless networks for transmission of variable-rate layered hybrid video streams. Target applications are video streaming and broadcasting services. The work can be divided into two main parts.</p><p>In the first part, a novel quality-scalable scheme based on coefficient refinement and encoder quality constraints is developed as a possible extension to the video coding standard H.264. After a technical introduction to the coding tools of H.264 with the main focus on error resilience features, various quality scalability schemes in previous research are reviewed. Based on this discussion, an encoder decoder framework is designed for an arbitrary number of quality layers, hereby also enabling region-of-interest coding. After that, the performance of the new system is exhaustively tested, showing that the bit rate increase typically encountered with scalable hybrid coding schemes is, for certain coding parameters, only small to moderate. The double- and triple-layer constellations of the framework are shown to perform superior to other systems.</p><p>The second part considers layered code streams as generated by the scheme of the first part. Various error propagation issues in hybrid streams are discussed, which leads to the definition of a decoder quality constraint and a segmentation of the code stream to transmit. A packetization scheme based on successive source rate consumption is drafted, followed by the formulation of the channel code rate optimization problem for an optimum assignment of available codes to the channel packets. Proper MSE-based error metrics are derived, incorporating the properties of the source signal, a terminate-on-error decoding strategy, error concealment, inter-packet dependencies, and the channel conditions. The Viterbi algorithm is presented as a low-complexity solution to the optimization problem, showing a great adaptivity of the joint source channel coding scheme to the channel conditions. An almost constant image qualiity is achieved, also in mismatch situations, while the overall channel code rate decreases only as little as necessary as the channel quality deteriorates. It is further shown that the variance of code distributions is only small, and that the codes are assigned irregularly to all channel packets.</p><p>A double-layer constellation of the framework clearly outperforms other schemes with a substantial margin. </p><p>Keywords — Digital lossy video compression, visual communication, variable bit rate (VBR), SNR scalability, layered image processing, quality layer, hybrid code stream, predictive coding, progressive bit stream, joint source channel coding, fidelity constraint, channel error robustness, resilience, concealment, packet-switched, mobile and wireless ATM, noisy transmission, packet loss, binary symmetric channel, streaming, broadcasting, satellite and radio links, H.264, MPEG-4 AVC, Viterbi, trellis, unequal error protection</p>

This dissertation considers packet-switched wireless networks for transmission of variable-rate layered hybrid video streams. Target applications are video streaming and broadcasting services. The work can be divided into two main parts. In the first part, a novel quality-scalable scheme based on coefficient refinement and encoder quality constraints is developed as a possible extension to the video coding standard H.264. After a technical introduction to the coding tools of H.264 with the main focus on error resilience features, various quality scalability schemes in previous research are reviewed. Based on this discussion, an encoder decoder framework is designed for an arbitrary number of quality layers, hereby also enabling region-of-interest coding. After that, the performance of the new system is exhaustively tested, showing that the bit rate increase typically encountered with scalable hybrid coding schemes is, for certain coding parameters, only small to moderate. The double- and triple-layer constellations of the framework are shown to perform superior to other systems. The second part considers layered code streams as generated by the scheme of the first part. Various error propagation issues in hybrid streams are discussed, which leads to the definition of a decoder quality constraint and a segmentation of the code stream to transmit. A packetization scheme based on successive source rate consumption is drafted, followed by the formulation of the channel code rate optimization problem for an optimum assignment of available codes to the channel packets. Proper MSE-based error metrics are derived, incorporating the properties of the source signal, a terminate-on-error decoding strategy, error concealment, inter-packet dependencies, and the channel conditions. The Viterbi algorithm is presented as a low-complexity solution to the optimization problem, showing a great adaptivity of the joint source channel coding scheme to the channel conditions. An almost constant image qualiity is achieved, also in mismatch situations, while the overall channel code rate decreases only as little as necessary as the channel quality deteriorates. It is further shown that the variance of code distributions is only small, and that the codes are assigned irregularly to all channel packets. A double-layer constellation of the framework clearly outperforms other schemes with a substantial margin. Keywords — Digital lossy video compression, visual communication, variable bit rate (VBR), SNR scalability, layered image processing, quality layer, hybrid code stream, predictive coding, progressive bit stream, joint source channel coding, fidelity constraint, channel error robustness, resilience, concealment, packet-switched, mobile and wireless ATM, noisy transmission, packet loss, binary symmetric channel, streaming, broadcasting, satellite and radio links, H.264, MPEG-4 AVC, Viterbi, trellis, unequal error protection