车号识别中的补偿光源

公路交通基础建设的不断发展和车辆管理体制的不断完善，为以视觉监控为基础的智能交通系统的实际应用打下了良好基础。在智能交通系统中，车牌自动识别系统是一个非常重要的发展方向。由于对车辆的监控是全天候的，车牌识别系统必须满足这种工作要求。在监控过程中存在自然光线不足的情况(夜晚，阴雨天等)，也就是存在逆光环境中对车牌的识别问题，这样就需要补偿光源。目前大多采用大功率泛光灯作补偿光源。由于泛光灯自身的特点，使效果不能达到理想。文章从汽车车灯的光谱及人眼的光谱光视效率曲线等方面详细分析了逆光条件下车牌识别中补偿光源的选取。并经实验证明此选取方法具有很好的效果。

The Compensatory Light for Car Plate Recognition

In the intelligent traffic system, the automatic recognition system of the car plate is an important development field. This system must satisfy the requirement of all-day long inspection. In the course of inspection, the lack of natural light(such as at night, in rainy day...) could be a problem, that is to say there could be backlighting problem, and this problem can be solved by using compensatory light. By now, the high-power floodlight has been adopted. Because of its own characteristics of the floodlight, the satisfied (result) cannot be obtained. In the present thesis, how to select the right light is analyzed, including car lights' spectra and visual response, and so on. The results of the practices are very satisfied.