Abstract: In order to detect the location information of the license plate in the image quickly and conveniently, this paper proposes a license plate location algorithm based on image contour features. This algorithm is based on the correlation function in the OpenCV database. Firstly, using image preprocessing operations to enhance images, and then the license plate is located by contour search and area filtering. Then, the eligible contour is filtered according to the pixel information and width height ratio of the license plate. Finally, using the green border to frame the license plate and display and save the image after positioning.

Key words: Contour features; OpenCV database; License plate positioning algorithm

摘要： 为了方便快捷地检测到图片中汽车牌照的位置信息，文章提出了一种基于图像轮廓特 征的车牌定位算法。此算法基于 OpenCV 数据库中的相关函数，首先使用图像预处理操作来 增强图像，然后采用轮廓查找、面积筛选的方式定位车牌，接着根据车牌的像素信息和宽高 比例等特征筛选出符合条件的轮廓，最后使用绿色框线将车牌框选并显示和保存定位完成的 图像。

关键词: 轮廓特征；OpenCV 数据库；车牌定位算法