为解决车辆压线行驶或发生交通事故时占用多个车道而无法采集到完整的车辆图像问题,基于SURF(speed up robust features)算法和最佳缝合线的思想,提出一种车道图像序列拼接方法。首先根据车辆运动轨迹提出寻找最优对应图像算法,用于找...为解决车辆压线行驶或发生交通事故时占用多个车道而无法采集到完整的车辆图像问题,基于SURF(speed up robust features)算法和最佳缝合线的思想,提出一种车道图像序列拼接方法。首先根据车辆运动轨迹提出寻找最优对应图像算法,用于找出近似同步拍摄图像;然后用SURF检测图像中的关键点对图像进行粗配准,用RANSAC方法去除误配准点实现精配准;最后利用最佳缝合线方法沿图像的重叠区域进行分割拼接。实验表明:利用车道图像序列拼接方法能找出近似同步拍摄图像,准确计算出图像的重叠区域,避免缝合线经过运动区域,解决了拼接过程中产生的重影、裂缝等问题,合成了质量较高的多车道图像,以此确保获得完整的车辆图像。展开更多
To prevent a vehicle from departing the lane in assistant or automatic steering, real-time vision-based detection of lane is studied. The system architecture, detecting principle and lane model are described. Then the...To prevent a vehicle from departing the lane in assistant or automatic steering, real-time vision-based detection of lane is studied. The system architecture, detecting principle and lane model are described. Then the detecting algorithm of the lane image is discussed in detail. In this algorithm, several proper sub-windows in one image are first selected as the processing regions. To every sub-window, by means of such steps as appropriate pre-processing, edge detection and Hough transform, etc., the lane description features are extracted. Experimental results reveal that this detection method is of good real-time, high recognition reliability and strong robustness, etc., which can provide the decision-making foundation for the following automatic or assistant steering to some extent.展开更多
In this paper, evacuation experiments are carried out to study pedestrian movement behaviors in building bottleneck. An image processing method based on mean-shift algorithm is used to extract pedestrian movement traj...In this paper, evacuation experiments are carried out to study pedestrian movement behaviors in building bottleneck. An image processing method based on mean-shift algorithm is used to extract pedestrian movement trajectory. Based on the extracted trajectory, we analyze the microscopic movement characteristics of pedestrians such as lane formation, change of velocity and distance between two sequential pedestrians. A pedestrian lane is a group of pedestrians moving in a column. The lane formation is verified by the pedestrian trajectory and distribution of pedestrian’s lateral positions (x direction in the paper): lane number changes from one to two, three or even more with the increasing bottleneck width when pedestrians pass through the bottleneck. By analyzing the pedestrian movement behaviors in the same pedestrian lane, we find three typical movement modes in the bottleneck: time-lag acceleration, synchronous acceleration, and avoiding deceleration. Through analyzing the time intervals when successive pedestrians pass through the bottleneck, we find that most pedestrians adjust their velocities according to the distance to the forward pedestrians. Results also indicate that due to different cultures, pedestrians flux in China and Germany may have some differences besides their similarities.展开更多
文摘为解决车辆压线行驶或发生交通事故时占用多个车道而无法采集到完整的车辆图像问题,基于SURF(speed up robust features)算法和最佳缝合线的思想,提出一种车道图像序列拼接方法。首先根据车辆运动轨迹提出寻找最优对应图像算法,用于找出近似同步拍摄图像;然后用SURF检测图像中的关键点对图像进行粗配准,用RANSAC方法去除误配准点实现精配准;最后利用最佳缝合线方法沿图像的重叠区域进行分割拼接。实验表明:利用车道图像序列拼接方法能找出近似同步拍摄图像,准确计算出图像的重叠区域,避免缝合线经过运动区域,解决了拼接过程中产生的重影、裂缝等问题,合成了质量较高的多车道图像,以此确保获得完整的车辆图像。
文摘To prevent a vehicle from departing the lane in assistant or automatic steering, real-time vision-based detection of lane is studied. The system architecture, detecting principle and lane model are described. Then the detecting algorithm of the lane image is discussed in detail. In this algorithm, several proper sub-windows in one image are first selected as the processing regions. To every sub-window, by means of such steps as appropriate pre-processing, edge detection and Hough transform, etc., the lane description features are extracted. Experimental results reveal that this detection method is of good real-time, high recognition reliability and strong robustness, etc., which can provide the decision-making foundation for the following automatic or assistant steering to some extent.
基金supported by the National Natural Science Foundation of China (Grant No. 91024025)the NCET Project (Grant No. 08-0518)
文摘In this paper, evacuation experiments are carried out to study pedestrian movement behaviors in building bottleneck. An image processing method based on mean-shift algorithm is used to extract pedestrian movement trajectory. Based on the extracted trajectory, we analyze the microscopic movement characteristics of pedestrians such as lane formation, change of velocity and distance between two sequential pedestrians. A pedestrian lane is a group of pedestrians moving in a column. The lane formation is verified by the pedestrian trajectory and distribution of pedestrian’s lateral positions (x direction in the paper): lane number changes from one to two, three or even more with the increasing bottleneck width when pedestrians pass through the bottleneck. By analyzing the pedestrian movement behaviors in the same pedestrian lane, we find three typical movement modes in the bottleneck: time-lag acceleration, synchronous acceleration, and avoiding deceleration. Through analyzing the time intervals when successive pedestrians pass through the bottleneck, we find that most pedestrians adjust their velocities according to the distance to the forward pedestrians. Results also indicate that due to different cultures, pedestrians flux in China and Germany may have some differences besides their similarities.
