Abstract: Based on analysis of the properties of traffic accident scene，a new method of camera calibration using X-corners patterns is proposed.After several photos are obtained from different views，on the basis of the Tsai，camera is calibrated according to linear model，then its nonlinear parameters are modified based on the maximum likelihood criterion，at last the image is emendated according to new parameters.The final parameters of the model are achieved，and the experiment results demonstrate the proposed method is not only simple and accurate，but also flexible.

Key words: traffic accident scene photogrammetry, X-corners, corner detecting, camera calibration

摘要： 在分析了交通事故现场处理特点的基础上，提出了基于棋盘格模板的照相机标定方法，即从不同角度拍摄多幅含有棋盘格模板的现场图像，在Tsai两步法的基础上先对相机进行线性标定，然后基于极大似然估计进行非线性优化，最后进行图像校正，获得照相机模型参数。实验结果表明该方法标定精度高，抗噪性能稳定，标定物简单，更加灵活易用。

关键词: 交通事故现场摄影测量, 棋盘格, 角点提取, 相机标定