针对多数研究中车道线检测的准确性和实时性难以有效平衡的问题,提出了一种应用区域划分的车道线识别方法。首先通过改进的大津(OTSU)算法提取边缘图像,再在所得边缘图像的基础上,利用改进的概率霍夫变换(PPHT)提取车道标识线上的特征点...针对多数研究中车道线检测的准确性和实时性难以有效平衡的问题,提出了一种应用区域划分的车道线识别方法。首先通过改进的大津(OTSU)算法提取边缘图像,再在所得边缘图像的基础上,利用改进的概率霍夫变换(PPHT)提取车道标识线上的特征点,并采用最小二乘法(LSM)对特征点点集进行直线拟合,最后通过提出的路面干扰线规避算法检测所有拟合得到的直线段并筛选可能的车道线。在实验方面,引入三种算法作为对比,并利用提出的准确性评价模型对500幅典型道路场景图中的车道线识别结果进行评估,同时统计在处理一段长为1 min 26 s的道路视频时每帧图像序列的平均耗时。实验结果表明所提算法的查准率、查全率、F量测值均优于对比算法,且达到实时处理的要求。展开更多
Vehicle license plate (VLP) character segmentation is an important part of the vehicle license plate recognition system (VLPRS).This paper proposes a least square method (LSM) to treat horizontal tilt and vertical til...Vehicle license plate (VLP) character segmentation is an important part of the vehicle license plate recognition system (VLPRS).This paper proposes a least square method (LSM) to treat horizontal tilt and vertical tilt in VLP images.Auxiliary lines are added into the image (or the tilt-corrected image) to make the separated parts of each Chinese character to be an interconnected region.The noise regions will be eliminated after two fusing images are merged according to the minimum principle of gray values. Then,the characters are segmented by projection method (PM) and the final character images are obtained.The experimental results show that this method features fast processing and good performance in segmentation.展开更多
提出了一种无需气象数据,直接用对流层天顶总延迟(zenith total delay,ZTD)推导大气可降水量(precipitable water vapor,PWV)的新方法。该方法从GPS反演大气水汽的反演方程出发,基于最小二乘法建立ZTD推算PWV的模型。结果表明,就BJFS测...提出了一种无需气象数据,直接用对流层天顶总延迟(zenith total delay,ZTD)推导大气可降水量(precipitable water vapor,PWV)的新方法。该方法从GPS反演大气水汽的反演方程出发,基于最小二乘法建立ZTD推算PWV的模型。结果表明,就BJFS测站而言,模型推算的PWV与GPS反演的PWV的均方根(root mean square,RMS)值为4.5 mm,两者存在一个微小的系统偏差,但相关系数高达0.982。在不研究其数值大小只研究其趋势变化时,可以用模型直接推算PWV,这可为气象学短期预报提供一定参考。展开更多
文摘针对多数研究中车道线检测的准确性和实时性难以有效平衡的问题,提出了一种应用区域划分的车道线识别方法。首先通过改进的大津(OTSU)算法提取边缘图像,再在所得边缘图像的基础上,利用改进的概率霍夫变换(PPHT)提取车道标识线上的特征点,并采用最小二乘法(LSM)对特征点点集进行直线拟合,最后通过提出的路面干扰线规避算法检测所有拟合得到的直线段并筛选可能的车道线。在实验方面,引入三种算法作为对比,并利用提出的准确性评价模型对500幅典型道路场景图中的车道线识别结果进行评估,同时统计在处理一段长为1 min 26 s的道路视频时每帧图像序列的平均耗时。实验结果表明所提算法的查准率、查全率、F量测值均优于对比算法,且达到实时处理的要求。
基金Scientific Research Fund of Hunan Province,PRC (No.07JJ6141)Scientific Research Fund of Hunan Provincial Education Department,PRC (No.05C720).
文摘Vehicle license plate (VLP) character segmentation is an important part of the vehicle license plate recognition system (VLPRS).This paper proposes a least square method (LSM) to treat horizontal tilt and vertical tilt in VLP images.Auxiliary lines are added into the image (or the tilt-corrected image) to make the separated parts of each Chinese character to be an interconnected region.The noise regions will be eliminated after two fusing images are merged according to the minimum principle of gray values. Then,the characters are segmented by projection method (PM) and the final character images are obtained.The experimental results show that this method features fast processing and good performance in segmentation.
文摘提出了一种无需气象数据,直接用对流层天顶总延迟(zenith total delay,ZTD)推导大气可降水量(precipitable water vapor,PWV)的新方法。该方法从GPS反演大气水汽的反演方程出发,基于最小二乘法建立ZTD推算PWV的模型。结果表明,就BJFS测站而言,模型推算的PWV与GPS反演的PWV的均方根(root mean square,RMS)值为4.5 mm,两者存在一个微小的系统偏差,但相关系数高达0.982。在不研究其数值大小只研究其趋势变化时,可以用模型直接推算PWV,这可为气象学短期预报提供一定参考。
