针对ORB(oriented FAST and rotated BRIEF)算法中存在匹配精确率低的问题,提出了一种基于LK(Lucas-Kanade)光流改进的ORB图像匹配方法。首先对待处理的图像进行直方图均衡化,然后在Oriented FAST特征点检测的同时用LK光流对其进行跟踪...针对ORB(oriented FAST and rotated BRIEF)算法中存在匹配精确率低的问题,提出了一种基于LK(Lucas-Kanade)光流改进的ORB图像匹配方法。首先对待处理的图像进行直方图均衡化,然后在Oriented FAST特征点检测的同时用LK光流对其进行跟踪,并将跟踪的特征点进行Rotated BRIEF描述,最后在特征匹配筛选环节利用RANSAC(Random Sampling Consistency)算法进行误匹配的剔除。实验结果表明,改进算法在公开数据集中的平均匹配精度为90.9%,平均特征匹配及误匹配的剔除共耗时为18ms,与原始ORB算法相比,在时间基本一致的前提下,有效的提高了匹配的精度。展开更多
针对多视觉任务中传输成本高、解码端计算压力大的问题,提出一种自适应可伸缩视频编码(adaptive scalable video coding,ASVC)传输框架,将视频分为语义层和背景层,分别传输语义和背景信息。此外,提出一种自适应压缩算法,构建了C4.5决策...针对多视觉任务中传输成本高、解码端计算压力大的问题,提出一种自适应可伸缩视频编码(adaptive scalable video coding,ASVC)传输框架,将视频分为语义层和背景层,分别传输语义和背景信息。此外,提出一种自适应压缩算法,构建了C4.5决策树模型分析网络环境对视频进行压缩的决策判定,并对帧序列进行光流分析,在保留变化显著的帧基础上引入插值机制保持图像的平滑性。仿真结果表明,ASVC方法在不同码率环境下表现更高的识别精准率,视频质量和传输效率的显著提升。展开更多
We have numerically and experimentally investigated the flow rate measurement of the pipeline based on the optical fiber.Employing the large eddy simulation(LES)model,we have quantitatively analyzed the pressure fluct...We have numerically and experimentally investigated the flow rate measurement of the pipeline based on the optical fiber.Employing the large eddy simulation(LES)model,we have quantitatively analyzed the pressure fluctuation of the pipe wall caused by the turbulent flow in the pipeline.The simulation results have shown that the standard deviation of pressure fluctuation was quadratic with the flow rate.We have verified the theoretical model by using a distributed optical fiber acoustic sensing(DAS)system in the flow rate range from 0.61 m/s to 2.42 m/s.The experimental results were consistent with the simulation results very well.Furthermore,to improve the measuring error at the low flow rate,we have employed the composite adaptive denoising algorithm to eliminate the background noise and system noise.The final results have shown that the minimum goodness of fit was improved from 0.962 to 0.997,and the variation of the quadratic coefficient significantly decreased by 93.25%.The measured flow rate difference was only 0.84%between different sensing points in repeated experiments.展开更多
文摘针对ORB(oriented FAST and rotated BRIEF)算法中存在匹配精确率低的问题,提出了一种基于LK(Lucas-Kanade)光流改进的ORB图像匹配方法。首先对待处理的图像进行直方图均衡化,然后在Oriented FAST特征点检测的同时用LK光流对其进行跟踪,并将跟踪的特征点进行Rotated BRIEF描述,最后在特征匹配筛选环节利用RANSAC(Random Sampling Consistency)算法进行误匹配的剔除。实验结果表明,改进算法在公开数据集中的平均匹配精度为90.9%,平均特征匹配及误匹配的剔除共耗时为18ms,与原始ORB算法相比,在时间基本一致的前提下,有效的提高了匹配的精度。
文摘针对多视觉任务中传输成本高、解码端计算压力大的问题,提出一种自适应可伸缩视频编码(adaptive scalable video coding,ASVC)传输框架,将视频分为语义层和背景层,分别传输语义和背景信息。此外,提出一种自适应压缩算法,构建了C4.5决策树模型分析网络环境对视频进行压缩的决策判定,并对帧序列进行光流分析,在保留变化显著的帧基础上引入插值机制保持图像的平滑性。仿真结果表明,ASVC方法在不同码率环境下表现更高的识别精准率,视频质量和传输效率的显著提升。
基金supported in part by the National Natural Science Foundation of China(Grant No.U22A20206)the Key Research and Development Plan Project of Hubei Province,China(Grant No.2022BAA004)Zhejiang Provincial Market Supervision Bureau Young Eagle Plan Project,China(Grant No.CY2022228).
文摘We have numerically and experimentally investigated the flow rate measurement of the pipeline based on the optical fiber.Employing the large eddy simulation(LES)model,we have quantitatively analyzed the pressure fluctuation of the pipe wall caused by the turbulent flow in the pipeline.The simulation results have shown that the standard deviation of pressure fluctuation was quadratic with the flow rate.We have verified the theoretical model by using a distributed optical fiber acoustic sensing(DAS)system in the flow rate range from 0.61 m/s to 2.42 m/s.The experimental results were consistent with the simulation results very well.Furthermore,to improve the measuring error at the low flow rate,we have employed the composite adaptive denoising algorithm to eliminate the background noise and system noise.The final results have shown that the minimum goodness of fit was improved from 0.962 to 0.997,and the variation of the quadratic coefficient significantly decreased by 93.25%.The measured flow rate difference was only 0.84%between different sensing points in repeated experiments.
