996 research outputs found

    New visual coding exploration in MPEG: Super-MultiView and free navigation in free viewpoint TV

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    ISO/IEC MPEG and ITU-T VCEG have recently jointly issued a new multiview video compression standard, called 3D-HEVC, which reaches unpreceded compression performances for linear,dense camera arrangements. In view of supporting future highquality,auto-stereoscopic 3D displays and Free Navigation virtual/augmented reality applications with sparse, arbitrarily arranged camera setups, innovative depth estimation and virtual view synthesis techniques with global optimizations over all camera views should be developed. Preliminary studies in response to the MPEG-FTV (Free viewpoint TV) Call for Evidence suggest these targets are within reach, with at least 6% bitrate gains over 3DHEVC technology

    Hierarchical Hole-filling For Depth-based View Synthesis In Ftv And 3d Video

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    Methods for hierarchical hole-filling and depth adaptive hierarchical hole-filling and error correcting in 2D images, 3D images, and 3D wrapped images are provided. Hierarchical hole-filling can comprise reducing an image that contains holes, expanding the reduced image, and filling the holes in the image with data obtained from the expanded image. Depth adaptive hierarchical hole-filling can comprise preprocessing the depth map of a 3D wrapped image that contains holes, reducing the preprocessed image, expanding the reduced image, and filling the holes in the 3D wrapped image with data obtained from the expanded image. These methods are can efficiently reduce errors in images and produce 3D images from a 2D images and/or depth map information.Georgia Tech Research Corporatio

    Chapter 4D Ray-Space and Ultra-Wide Area FTV

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    Ultra-wide area FTV is an FTV with very wide viewing zone where motion parallax is realized. 4D orthogonal ray-space is analyzed and applied to ultra-wide area FTV. Ray-space of “a group of rays through one point” is derived in 4D orthogonal ray-space. It is extended to obtain ray-space captured by linear arrangement cameras. View generation of ultra-wide area FTV needs rays that are not captured by real cameras. These rays are synthesized by interpolating the captured ray-space so that the intersections of the captured ray-space and the ray-space of rays emitted from a light source have the same color

    Dissipation of information in channels with input constraints

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    One of the basic tenets in information theory, the data processing inequality states that output divergence does not exceed the input divergence for any channel. For channels without input constraints, various estimates on the amount of such contraction are known, Dobrushin's coefficient for the total variation being perhaps the most well-known. This work investigates channels with average input cost constraint. It is found that while the contraction coefficient typically equals one (no contraction), the information nevertheless dissipates. A certain non-linear function, the \emph{Dobrushin curve} of the channel, is proposed to quantify the amount of dissipation. Tools for evaluating the Dobrushin curve of additive-noise channels are developed based on coupling arguments. Some basic applications in stochastic control, uniqueness of Gibbs measures and fundamental limits of noisy circuits are discussed. As an application, it shown that in the chain of nn power-constrained relays and Gaussian channels the end-to-end mutual information and maximal squared correlation decay as Θ(log⁥log⁥nlog⁥n)\Theta(\frac{\log\log n}{\log n}), which is in stark contrast with the exponential decay in chains of discrete channels. Similarly, the behavior of noisy circuits (composed of gates with bounded fan-in) and broadcasting of information on trees (of bounded degree) does not experience threshold behavior in the signal-to-noise ratio (SNR). Namely, unlike the case of discrete channels, the probability of bit error stays bounded away from 121\over 2 regardless of the SNR.Comment: revised; include appendix B on contraction coefficient for mutual information on general alphabet

    Chapter International Standardization of FTV

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    FTV (Free-viewpoint Television) is visual media that transmits all ray information of a 3D space and enables immersive 3D viewing. The international standardization of FTV has been conducted in MPEG. The first phase of FTV is multiview video coding (MVC), and the second phase is 3D video (3DV). The third phase of FTV is MPEG-FTV, which targets revolutionized viewing of 3D scenes via super multiview, free navigation, and 360-degree 3D. After the success of exploration experiments and Call for Evidence, MPEG-FTV moved MPEG Immersive project (MPEG-I), where it is in charge of video part as MPEG-I Visual. MPEG-I will create standards for immersive audio-visual services
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