基于 Hough 变换及可信度的车牌旋转角度检测

车牌角度矫正是汽车牌照识别的一个重要步骤。采用Hough变换法检测车牌的倾斜角度。首先对汽车牌照图像预处理，再提取车牌上下边框的边缘信息，利用Hough变换对提取的边缘信息进行变换，从而获得车牌上下边框的拟合直线及其倾斜角度，并引入可信度，以度量检测结果的优劣，最终获得较精确的汽车牌照的倾斜角度。实验结果表明，该法抗干扰能力强，检测精度高。

License plate rotation angle detection based on Hough transform

License plate Angle correction is an important step of car license plate recognition .This article uses the Hough Transform method to detect the angle of the car license plate .In order to extract the frame information from the edge of the plate ,we should pretreat the car license plate images at the beginning ,then use the Hough transform to transform the extracting information of edge to get the line of the car license plate and its frame fitting line Angle . At the same time , we can introduce credibility to measure the pros and cons of test results .Finally we can get a pre-cise angle of the car license plate .The experiments show that this method can resist interference and have a good effect.The angle of car license plate measured has high credibility , reliability, and good results.