We present a novel client-driven multi-view video streaming system that allows a user watch 3-D video interactively with significantly reduced bandwidth requirements by transmitting a small number of views selected ac...
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ISBN:
(纸本)9781424414369
We present a novel client-driven multi-view video streaming system that allows a user watch 3-D video interactively with significantly reduced bandwidth requirements by transmitting a small number of views selected according to his/her head position. The proposed scheme can be used to efficiently stream a dense set of multi-view sequences (light-fields) or wider baseline multi-view sequences together with depth information. The user's head position is tracked and predicted into the future to select the views that best match the user's current viewing angle dynamically. Prediction of future head positions is needed so that views matching the predicted head positions can be requested from the server ahead of time in order to account for delays due to network transport and stream switching. Highly compressed, lower quality versions of some other views are also requested in order to provide protection against having to display the wrong view when the current user viewpoint differs from the predicted viewpoint. The proposed system makes use of multi-view coding (MVC) and scalable video coding (SVC) concepts together to obtain improved compress ion efficiency while providing flexibility in bandwidth allocation to the selected views. Rate-distortion performance of the proposed system is demonstrated under different experimental conditions.
In multiviewcoding, motion information of different views forming the multiview video is correlated. The multiview extension of High Efficiency Video coding (MV-HEVC) that is currently under development is defined to...
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ISBN:
(纸本)9781479947584
In multiviewcoding, motion information of different views forming the multiview video is correlated. The multiview extension of High Efficiency Video coding (MV-HEVC) that is currently under development is defined to allow multi-view coding with minimal changes to HEVC. This is realized by simply adding the reconstructed base view picture to the reference picture list of the dependent views. MV-HEVC specification is restricted from low-level operations with motion information, thus redundancy in motion information between views is not utilized. This paper proposes to use the temporal motion vector prediction mechanism of HEVC to enable the prediction of motion vectors from the inter-view reference picture;similar to the concept of Motion Field Mapping mechanism in the scalable extension of HEVC. In order to compensate for the disparity, it is also proposed to signal a global disparity value for motion field adjustment. Global disparity is estimated at the encoder side for each slice and signaled to the decoder side at the slice header. Simulations conducted in the MV-HEVC configuration of 3D-HTM v6.0 show that the proposed method brings 1.1 % of dBR for view 1 and 0.8% for view 2 which results in 0.6% gain on average of all views.
We present a novel and efficient multi-view depth map enhancement method proposed as a post-processing of initially estimated depth maps. The proposed method is based on edge, motion and scene depth-range adaptive med...
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ISBN:
(纸本)9781424456536
We present a novel and efficient multi-view depth map enhancement method proposed as a post-processing of initially estimated depth maps. The proposed method is based on edge, motion and scene depth-range adaptive median filtering and allows for an improved quality of virtual view synthesis. To enforce the spatial, temporal and inter-view coherence in the multi-view depth maps, the median filtering is applied to 4-dimensional windows that consist of the spatially neighboring depth map values taken at different viewpoints and time instants. A fast iterative block segmentation approach is adopted to adaptively shrink these windows in the presence of edges and motion for preservation of sharpness and realistic rendering and for improvement of the compression efficiency. We show that our enhancement method leads to a reduction of the coding bit-rate required for representation of the depth maps and also leads to a gain in the quality of synthesized views at arbitrary virtual viewpoints.
Steered Mixture-of-Experts (SMoE) is a novel framework for representing multidimensional image modalities. In this paper, we propose a coding methodology for SMoE models that is readily extendable to any dimensional S...
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ISBN:
(数字)9781510620766
ISBN:
(纸本)9781510620766
Steered Mixture-of-Experts (SMoE) is a novel framework for representing multidimensional image modalities. In this paper, we propose a coding methodology for SMoE models that is readily extendable to any dimensional SMoE model, thus representing any image modality of any dimension. We evaluate the coding performance of SMoE models of light field video, a 5D image modality, i.e. time, two angular, and two spatial dimensions. The coding consists of the exploiting the redundancy between the parameters of SMoE models, i.e. a set of multivariate Gaussian distributions. We compare the performance of three multi-view HEVC (MV-HEVC) con figurations that differ in terms of random access. Each subaperture view from the light field video is interpreted as a single view in MV-HEVC. Experiments validate that excellent coding performance compared to MV-HEVC for low-to midrange bitrates in terms of PSNR and SSIM with bitrate savings up to 75%.
Distortion drift, including intra and inter, is a big problem of data hiding in MVC video streams. Based on the analysis of the coding structure of MVC, we proposed a video steganography algorithm without inter and in...
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ISBN:
(纸本)9781479939046
Distortion drift, including intra and inter, is a big problem of data hiding in MVC video streams. Based on the analysis of the coding structure of MVC, we proposed a video steganography algorithm without inter and intra distortion drift. We embed the data in the B4-frame to prevent the inter distortion drift, then modified the QDCT coefficients of all the 4×4 luma blocks and compensated them to prevent intra distortion drift. The algorithm has lower complexity and greater embedding capacity than the current algorithms. Experimental results confirm the embedding capacity and complexity superiority of the proposed algorithm while keeping the similar human visual effect in terms of PSNR and SSIM index.
Widespread and affordable broadband access opens up opportunities for delivery of new streaming services. However, what is expected to fundamentally change the way that people use the network is the ability to produce...
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ISBN:
(纸本)9789639799363
Widespread and affordable broadband access opens up opportunities for delivery of new streaming services. However, what is expected to fundamentally change the way that people use the network is the ability to produce, and seamlessly deliver and share their own multimedia content. SEA consortium is confident that in a few years everyone will be multimedia content producer, mediator and consumer, and aims to provide the means to distribute A/V user-centric services, with superior quality and flexibility, in a trusted and personalized way.
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