Optimized Data Representation for Interactive Multiview Navigation

In contrary to traditional media streaming services where a unique media content is delivered to different users, interactive multiview navigation applications enable users to choose their own viewpoints and freely navigate in a 3-D scene. The interactivity brings new challenges in addition to the classical rate-distortion trade-off, which considers only the compression performance and viewing quality. On the one hand, interactivity necessitates sufficient viewpoints for richer navigation; on the other hand, it requires to provide low bandwidth and delay costs for smooth navigation during view transitions. In this paper, we formally describe the novel trade-offs posed by the navigation interactivity and classical rate-distortion criterion. Based on an original formulation, we look for the optimal design of the data representation by introducing novel rate and distortion models and practical solving algorithms. Experiments show that the proposed data representation method outperforms the baseline solution by providing lower resource consumptions and higher visual quality in all navigation configurations, which certainly confirms the potential of the proposed data representation in practical interactive navigation systems

Novel Distortion Metric for Depth Coding of 3D Video

In state-of-the-art HEVC-based 3D video codec, multiview video plus associated depth maps are used. In order to achieve better coding performance, instead of the conventional sum of squared errors (SSE), view synthesis optimization (VSO) is proposed and included in the anchor encoder software to calculate view synthesis distortion in rate-distortion optimization (RDO) of depth coding. The anchor VSO achieves high rate-distortion (RD) performance. However, it requires partial rendering and is quite complex and time-consuming. On the other hand, simple SSE metric is fast but RD performance is low. In this paper, we propose a new distortion metric to be used in RDO for depth coding. The complexity of the proposed method is slightly higher than SSE, while its RD performance remains competitive. With a good trade-off between complexity and performance, the proposed method can replace the conventional SSE metric in RDO for depth coding, and can be used as a low-complexity alternative to the anchor VSO. © 2013 IEEE