基于改进的投影法的目标标识定位算法研究

军事对抗中,需要准确识别目标标识,以车辆识别中车牌精确定位为例进行研究。通过结合利用跳变法和投影法,提出一种基于改进的投影法的车牌定位。由进行车牌水平定位的跳变法和进行车牌垂直定位的投影法两个步骤组成。其中,像素在车牌水平方向的区域内会产生明显跳变,先通过跳变法确定车牌的水平区域。由于车牌一般位于图像的下半部分,所以从图像的1/2高度到4/5高度,1/3宽度到4/5宽度处扫描,减少背景区干扰。然后在车牌的水平区域再进行垂直投影,得到车牌的准确位置。实验结果证明,该方法不仅可以有效提高定位速度,还能够由于减少背景区的干扰而提高定位准确度。

License Plate Location Algorithm Based on Improved Projection Method

In the military confrontation,there is a need to identify the enemy vehicles accurately, this paper studies the precise location of license plate in the vehicle recognition.By combining the use of hopping method and projection method,an improved projection method for license plate location is presented. It is divided into two stages:using hopping method to do license plate horizontal positioning and using projection method to do license plate vertical positioning. Among them,the license plate area of pixels in the horizontal direction have obvious transition,it is necessary to use hopping method to determine the level area of the license plate first. Because of the plate is typically located in the lower half of the image,scanning the image height from of 1/2 to 4/5,the image width from 1/3 to 4/5,the background interference is reduced. Then vertical projection at the level area of the license plate is done to obtain the exact location of the license plate. Experimental results show that this method not only can effectively improve the positioning speed,but also can reduce the interference due to the background area to improve the positioning accuracy.