构建多部件关系概率模型的车辆检测方法

Vehicle detection using the location relationship model between multi-components

传统车辆检测方法在处理交通复杂场景时,由于判断依据单一而容易出现车辆被误检和漏检的情况.为此,笔者提出一种基于车尾灯对和车牌之间空间位置关系概率模型的车辆检测方法.首先对道路交通视频图像进行颜色模型转换,分别得到突显车牌区域和尾灯区域的灰度图像,然后,对车牌灰度图像,通过梯度特征提取、区域梯度平滑和局部极大梯度查找几个关键步骤完成车牌的进一步准确定位,同时,对尾灯灰度图像经过阈值分割、连通域分析和面积计算几个关键步骤完成尾灯对的进一步准确定位.最后,建立尾灯和车牌在同一空域下的位置关系概率模型,并计算出该模型的概率似然度,进而判断部件所属的目标是否是同一辆车.实验结果表明,引入部件的空间位置关系概率模型,可以明显提高车辆检测的精度,且对不同型号的车辆检测鲁棒性都较好.

In view of the complex traffic and changeable weather and illumination in a scene, traditional vehicle detection method based on the single part model may result in a bad detection. So, using the spatial location relationships existing in multi-components of the vehicle, license plate and rear lamps are selected to construct the probabilistic models, through which vehicles are detected in this paper. In the new method, first, the color image of the road video is decomposed to the rear lamp gray image and license plate gray image through a different color conversion model. After that, the further identification for the license plate is accomplished through the key steps of gradient feature extraction, regional gradient smoothing and local maximum gradient search; similarly, the further identification of rear lamps is accomplished through the key steps of threshold segmentation, connected domain analysis and area calculation. Finally, With the Gaussian Mixture Model, relationships between the parts of the probability are established, and for the relationship model, if it makes the likelihood probability greater than a preset threshold, we argue that these parts belong to the same vehicle, and take the test result as the final vehicle detection result. Experimental results indicate that the new vehicle detection method has a strong adaptability, which can perfectly deal with the bad illumination conditions and target occlusion conditions, as well as a variety of vehicle types.