基于纹理特征和垂直投影的车牌定位算法研究

Research of Vehicle License-plate Locating Method Based on Texture Characteristic and Vertical Projection

车牌定位是车牌识别中的关键步骤。为了能在复杂背景和不同光照条件下快速、准确定位车牌位置,提出了一种基于车牌纹理特征和垂直投影的车牌定位方法。该方法先根据车牌区域的纹理特性确定出多个水平候选区域,再利用车牌区域垂直投影的统计规律对候选区域进行筛选,并确定出车牌左右边界。实验结果表明,该方法定位速度快、准确率高,具有较好的实用性。

License plate location is one of the key steps of the License Plate Recognition. An algorithm for license plate location based on the combination of texture characteristic and gray scale vertical projection is proposed in order to obtain location of vehicle plate quickly and accurately under complicated background and different illumination condition. At fist the horizontal plate candidates are determined based on texture characteristic of the license area,then the statistic law of the characters of vertical projection in the license area is used to select among the horizontal plate candidates and determine the left and right borders. The results indicate that the presented method is excellent in accuracy with a good speed and is valuable in practical application.