摘要
当前交通相机的自标定算法大多基于灭点或道路中的几何标识进行标定,但多灭点的检测存在不稳定及趋于无穷的"病态"条件,标识先验条件获取不精确等因素,造成自标定算法的实际应用受限.为了改进上述问题,首先根据典型道路场景,建立较稳定的单灭点标定模型;然后动态获取道路中的可标定区域及其中的几何标识,并在钻石空间中求取最佳灭点;最后利用场景中的冗余信息构造非线性约束条件,对标定参数在约束空间中进行迭代求最优,以消除标定初始条件不精确造成的标定误差.在云台相机监控的实际弯曲道场景中进行实验,同时改变相机视角及焦距进行实时算法处理,结果表明,该算法在多交通场景下的标定准确率达95%以上,优于现有算法,尤其适用于云台全方位交通相机的自标定.
Currently most of the traffic camera self-calibration algorithms are based on vanish point and geometry markers in road scene. However, for the detected multiple vanish points, there exist the unstable disadvantages and the "ill-condition" of approaches infinity. In addition, the acquired makers may not be accurate. So the practical application of traffic camera self-calibration is limited nowadays. To overcome the above problem, firstly, this paper builds a more stable self-calibration model with single vanish point based on the typical road scene;then acquires the calibration region and geometry markers dynamically, and get the optimal vanish point in diamond space;finally, use the redundant information in road scene to formulate non-linear constraints, and iterate the calibration parameters in the constraint space to get the optimal solutions. Therefore, calibration errors resulted from imprecise initial calibration conditions could be eliminated. The experiment was carried out in pan-tilt-zoom traffic camera monitoring curved road environment, where the camera angle and focal length were changed synchronously in real-time. The results show that the proposed method gets more than 95% accurate of calibration result in road scene, which is better than existing algorithms, especially it applies to the real time self-calibration of pan-tilt-zoom traffic camera.
作者
王伟
张朝阳
唐心瑶
宋焕生
崔华
Wang Wei;Zhang Chaoyang;Tang Xinyao;Song Huansheng;Cui Hua(School of Information Engineering,Chang’an University,Xi’an 710064;Anhui Science and Technology Information Industry Co.Ltd,Hefei 230088)
出处
《计算机辅助设计与图形学学报》
EI
CSCD
北大核心
2019年第11期1955-1962,共8页
Journal of Computer-Aided Design & Computer Graphics
基金
教育部联合基金(6141A02022610)
中央高校基本科研基金(300102249103)
陕西省重点研发计划重点项目(2018ZDXM-GY-047)
陕西省社会发展领域项目(2019SF-258)
关键词
自标定
灭点检测
非线性优化
云台交通相机
automatic calibration
vanishing point detection
nonlinear optimization
pan-tilt-zoom traffic camera
