Abstract: A retrograde-motion detecting method based on optical flow is proposed for retrograde-motion detection in a complex environment. Firstly, the optical flow of the movement area in each frame is calculated, and used to determine whether there may be retrograde-motion, this is called quick reporting. Then the report area is expanded, and the optical flow in the new area is calculated and tracked continuous to confirm whether it is real retrograde-motion, this is called exact reporting. To verify the effectiveness of the method, a comparison experiment with the traditional optical flow method is conducted. The results show that the better performance in terms of detection time and accuracy can be achieved using this method.

Key words: optical flow, retrograde-motion, quick report, accurate report

摘要： 提出了一种基于光流法的复杂环境逆行检测方法。计算每一帧视频图像中运动区域的光流矢量，并用于判断图像中是否存在逆行，这就是逆行的速报；扩充速报区域，并连续计算和跟踪新区域的光流矢量，用于进一步确认该事件是否为真正的逆行事件，这就是逆行的精报。为验证该算法的有效性，与传统的光流法检测逆行的效果进行了对比实验，结果表明其在逆行的检测时间和检测准确率上均比传统光流法表现更优。

关键词: 光流, 逆行, 速报, 精报