This paper presents an efficient bandwidth allocation method for the two-layer video coding of different spatial resolution. We first find a model of distortion-bitrate relationship for the MPEG-2 spatialscalable cod...
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This paper presents an efficient bandwidth allocation method for the two-layer video coding of different spatial resolution. We first find a model of distortion-bitrate relationship for the MPEG-2 spatial scalable coding in a fixed total bitrate system. Then we propose an adaptive bitrate allocation method for a constant distortion ratio between two layers with the given total bandwidth. In the proposed method, approximated model parameters are used for simple implementation. The validity of the approximation is proven in terms of the convergence to the desired distortion ratio. It is shown by simulation that the proposed bitrate allocation method can keep almost a constant distortion ratio between two layers in comparison to a tired bitrate allocation method.
spatial scalability is a critical feature in geometry-based point cloud compression (G-PCC). The current design of geometry reconstructions for spatial scalability applies points in fixed positions (center of nodes) a...
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ISBN:
(纸本)9781665475921
spatial scalability is a critical feature in geometry-based point cloud compression (G-PCC). The current design of geometry reconstructions for spatial scalability applies points in fixed positions (center of nodes) and ignores the connection of points in regions. This work analyses the correlation between neighbours' occupancy and locally optimal reconstruction points within a node using the Pearson Product Moment Correlation Coefficient (PPMCC). Then we propose a geometry reconstruction method based on predicting the neighbours' weights. Geometry reconstruction points are calculated by applying weights inverse to distance to different categories of neighbours (face neighbours, edge neighbours, corner neighbours). Compared to the state-of-the-art G-PCC, performance improvement of 1.03dB in D1-PSNR and 2.90dB in D2-PSNR, on average, can be observed using the proposed method. Meanwhile, a simplified method is available to satisfy different complexity requirements.
A flexible and effective macroblock-based framework for hybrid spatial and fine-grain SNR scalable video coding is proposed in this paper. In the proposed framework, the base layer is of low resolution and is generall...
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ISBN:
(纸本)0819444111
A flexible and effective macroblock-based framework for hybrid spatial and fine-grain SNR scalable video coding is proposed in this paper. In the proposed framework, the base layer is of low resolution and is generally encoded at low bit rates with traditional prediction based coding schemes. Two enhancement layers, i.e., the low-resolution enhancement layer and the high-resolution enhancement layer, are generated to improve the video quality of the low-resolution base layer and evolve smoothly from low resolution to high resolution video with increasingly better quality, respectively. Since bit plane coding and drifting control techniques are applied to the two enhancement layers, each enhancement bitstream is fine-grain scalable and can be arbitrarily truncated to fit in the available channel bandwidth. In order to improve the coding efficiency and reduce the drifting errors at the high-resolution enhancement layer, five macroblock coding modes with different forms of motion compensation and reconstruction, are proposed in this paper. Furthermore, a mode decision algorithm is developed to select the appropriate coding mode for each macroblock at the high-resolution enhancement layer. Compared with the traditional spatial scalable coding scheme, the proposed framework not only provides the spatial scalability but also provides the fine granularity quality scalability at the same resolution.
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