As an important part in the video coding technology, the rate control aims to achieve a smooth output of the code stream and adjust the quality of the video coding under a limited bandwidth. During the parallel coding...
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ISBN:
(纸本)9781538651957
As an important part in the video coding technology, the rate control aims to achieve a smooth output of the code stream and adjust the quality of the video coding under a limited bandwidth. During the parallel coding framework, the existing rate control algorithm has its limitation, that is, for the I frame, the bit prediction error is large. This drawback will lead to the result that the quality of the video coding cannot be guaranteed. Since back propagation(BP) neural network shows better performance on approximating complex nonlinear relationship and possessing the advantages of high fault tolerance, strong self-learning ability and controllable prediction error, we propose a new rate control algorithm based on BP neural network for parallel coding framework in this paper. Experimental results demonstrate that the frame-level bit prediction error based on BP neural network is smaller and more stable than the traditional method, which verifies the accuracy and feasibility of this method.
In indoor optical channels, intersymbol interference (ISI) due to the multipath propagation prevents high data rate transmission. In this paper, a new Optical Multi-Wavelength PPM (Pulse Position Modulation) has been ...
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ISBN:
(纸本)0780338715
In indoor optical channels, intersymbol interference (ISI) due to the multipath propagation prevents high data rate transmission. In this paper, a new Optical Multi-Wavelength PPM (Pulse Position Modulation) has been investigated for improving the quality of transmission. In this strategy, parallel transmission is accomplished which lowers the data rate per channel and thus reduces the effect of ISI. Furthermore, this strategy also implements parallel coding technique in the predetermined parallel branches. This parallel coding corrects errors without changing the system data rate. The simulation results show that a combination of these methods can achieve high quality transmission without reduction of the total data rate.
Time-correlated single-photon technology is emerging as an important approach to 3D Imaging. This paper presents a reconstruction algorithm that exploits data statistics and multi-scale information to deliver clean de...
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This paper describes a generalized parallelization methodology for mapping video coding algorithms onto a multiprocessing architecture, through systematic task decomposition, scheduling and performance analysis. It ex...
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ISBN:
(纸本)0819431249
This paper describes a generalized parallelization methodology for mapping video coding algorithms onto a multiprocessing architecture, through systematic task decomposition, scheduling and performance analysis. It exploits data parallelism inherent in the coding process and performs task scheduling base on task data size and access locality with the aim to hide as much communication overhead as possible. Utilizing Petri-nets and task graphs for representation and analysis, the method enables parallel video frame capturing, buffering and encoding without extra communication overhead. The theoretical speedup analysis indicates that this method offers excellent communication hiding, resulting in system efficiency well above 90%. A H.261 video encoder has been implemented on a TMS320C80 system using this method, and its performance was measured. The theoretical and measured performances are similar in that the measured speedup of the H.261 is 3.67 and 3.76 on four PP for QCIF and 352x240 video, respectively. They correspond to frame rates of 30.7 frame per second (fps) and 9.25 fps, and system efficiency of 91.8% and 94% respectively. As it is, this method is particularly efficient for platforms with small number of parallel processors.
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