基于单目视觉的变焦测距方法  

Zoom ranging method based on monocular vision

作　　者：秦峰 张雷 尚玉龙 QIN Feng;ZHANG Lei;SHANG Yulong(School of Electrical and Information Engineering,Jiangsu University of Technology,Changzhou 213001,China)

机构地区：[1]江苏理工学院电气信息工程学院,江苏常州213001

出　　处：《江苏理工学院学报》2024年第2期83-92,共10页Journal of Jiangsu University of Technology

基　　金：国家自然科学基金青年基金项目“混合车联网架构下基于连通性的路侧单元部署与频谱共享技术研究”(61901196)。

摘　　要：文章提出了一种基于数字变焦的单目测距检测方法,以解决传统基于车牌的单目方法中最大检测距离的限制问题。首先,通过单摄像头采集车辆图像,利用图像的数字变焦(插值)算法,对图像进行处理;然后,定位目标车辆的车牌,并得到像素宽度;最后,通过距离检测公式估计距离。显然,较远的成像距离可能会使部分像素信息丢失,从而导致像素宽度的方差变化较大,因此,需要将像素宽度的方差与计算确认的阈值进行比较,以确定是否需要进行插值处理。在有插值和无插值的情况下,通过最小二乘法得到像素宽度和距离之间的关系函数。实验结果表明,拟合方法的平均估算误差约为3%,在此估算精度下,有效真实距离可达30m,而传统方法只能达到15m。因此,在保证估计精度的前提下,提出的方法提高了单目测距的最大检测距离。In this paper,a digital zoom based monocular distance detection method is proposed to deal with the limitation of maximum detection distance in traditional monocular method.Firstly,the image of vehicle is cap-tured by the single camera,the digital zoom(interpolation)is exploited to process the image.Then,the license plate of the target vehicle is localized,and the pixel width of the license plate is obtained.Finally,the distance is estimated by the distance detection formular.It is apparent that a longer imaging distance may cause some pixel information to be lost,resulting in a larger variation in the variance of pixel width.Therefore,the variance of the pixel width needs to be compared with the threshold confirmed by the calculation to determine whether interpola-tion processing is required.In the case of interpolation and no interpolation,the relation function between pixel width and distance is obtained by least square method.The experimental results show that the average estimation error of the proposed method is around 3%,under this estimation accuracy,the maximum estimated distance can reach 30 meters,while the traditional method can only reach 15 meters.Therefore,under the premise of ensuring the estimation accuracy,the proposed method improves the maximum detection distance of the monocular dis-tance.

关 键 词：单目视觉 数字变焦 最小二乘 小孔成像 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]