First color image pre-processing, and use ROBERT detection operator image edge detection, edge information extraction, followed by expansion of corrosion, remove the loopholes, the image itself is characterized by a combination plate were analyzed to extract the license plate area. 先对彩色图像进行预处理,然后使用ROBERT检测算子对图像进行边缘检测,提取边缘信息,之后进行膨胀腐蚀,去除漏洞,对图像结合车牌本身特征进行分析,提取出车牌区域。