This article presents a study on the impact of video frame losses on the quality perceived by users. Video compression standards, such as MPEG, use a sequence of frames called Group of Pictures (GOP), which is a video...This article presents a study on the impact of video frame losses on the quality perceived by users. Video compression standards, such as MPEG, use a sequence of frames called Group of Pictures (GOP), which is a video compression method which a frame is expressed in terms of one or more neighboring frames. This dependence between frames impacts directly in the quality because a loss of a reference frame prevents the decoding of other frames in GOP, thereby reducing the user-perceived quality. The assessment of quality in this article is estimated by Peak Signal Noise Ratio (PSNR), which compares the original and the received images. Computer simulations were used to show that the degradation on the quality may vary for different patterns of GOPs and type of lost frames.展开更多
Error-resilient video communication over lossy packet networks is often designed and operated based on models for the effect of losses on the reconstructed video quality. This paper analyzes the channel distortion for...Error-resilient video communication over lossy packet networks is often designed and operated based on models for the effect of losses on the reconstructed video quality. This paper analyzes the channel distortion for video over lossy packet networks and proposes a new model that, compared to previous models, more accurately estimates the expected mean-squared error distortion for different packet loss patterns by accounting for inter-frame error propagation and the correlation between error frames. The accuracy of the proposed model is validated with JVT/H.264 encoded standard test sequences and previous frame concealment, where the proposed model provides an obvious accuracy gain over previous models.展开更多
根据控制器局域网络(Controller Area Network,CAN)通信协议的要求与限制,结合CAN通信协议在铁路信号大负载运用过程中可能存在的总线数据发送过程丢帧的故障,分析原因并给出可行的解决方案。围绕实现解决方案过程中应考虑的外在因素及...根据控制器局域网络(Controller Area Network,CAN)通信协议的要求与限制,结合CAN通信协议在铁路信号大负载运用过程中可能存在的总线数据发送过程丢帧的故障,分析原因并给出可行的解决方案。围绕实现解决方案过程中应考虑的外在因素及系统性能等,提出方案实现过程中应注意的问题,旨在保证CAN总线上数据传输的合理性、安全性和系统的稳定性,提升系统运营效率。展开更多
文摘This article presents a study on the impact of video frame losses on the quality perceived by users. Video compression standards, such as MPEG, use a sequence of frames called Group of Pictures (GOP), which is a video compression method which a frame is expressed in terms of one or more neighboring frames. This dependence between frames impacts directly in the quality because a loss of a reference frame prevents the decoding of other frames in GOP, thereby reducing the user-perceived quality. The assessment of quality in this article is estimated by Peak Signal Noise Ratio (PSNR), which compares the original and the received images. Computer simulations were used to show that the degradation on the quality may vary for different patterns of GOPs and type of lost frames.
基金Project (No. Y2001005) supported by the Natural Science Foundation of Shandong Province, China
文摘Error-resilient video communication over lossy packet networks is often designed and operated based on models for the effect of losses on the reconstructed video quality. This paper analyzes the channel distortion for video over lossy packet networks and proposes a new model that, compared to previous models, more accurately estimates the expected mean-squared error distortion for different packet loss patterns by accounting for inter-frame error propagation and the correlation between error frames. The accuracy of the proposed model is validated with JVT/H.264 encoded standard test sequences and previous frame concealment, where the proposed model provides an obvious accuracy gain over previous models.
文摘根据控制器局域网络(Controller Area Network,CAN)通信协议的要求与限制,结合CAN通信协议在铁路信号大负载运用过程中可能存在的总线数据发送过程丢帧的故障,分析原因并给出可行的解决方案。围绕实现解决方案过程中应考虑的外在因素及系统性能等,提出方案实现过程中应注意的问题,旨在保证CAN总线上数据传输的合理性、安全性和系统的稳定性,提升系统运营效率。
