探讨研究X射线探伤底片的自动定级方法，运用X射线成像和数字图像处理技术，通过对预处理后X射线探伤底片图像的特征提取，得到产品焊缝内部缺陷的状态特征，结合人工神经网络方法实现模式识别，建立状态识别模型，并依据识别模型，完成产品焊缝内部缺陷的自动分类识别。

The automatic grading methods for Xray inspection negative were researched. First Xray imaging and digital image processing technology were used, through the features capturing on postpretreatment Xray inspection negatives image, the state characteristics of products welding lines internal faults were obtained. Then, combine with artificial neural network to realize mode identification, state identification model was established. And finally the automatic grading identification of the welding lines internal faults was completed based on the identification model.