Abstract: This paper applies wavelet transform to X-ray image edge detection after analyzing the characteristics of X-ray image and presents an algorithm of edge detection on the basis of maximum of wavelet transform modulus.The defect edges are detected by quadratic B-spline and Mallat algorithm which is used in the wavelet decomposition.The blocked threshold is mentioned to ascertain the points of modulus maximum and the defects edges are obtained.Experiment results show that the proposed algorithm has good anti-noise property and that the defect edges detection has strong continuity.

Key words: edge detection, wavelet transform, X-ray image, modulus maximum

摘要： 分析了X射线探伤图像的特点，将小波变换技术应用到X射线图像的边缘检测中，提出了基于小波变换的模极大值边缘检测算法，利用二次B样条小波，采用Mallat快速算法进行小波分解，采用分块阈值选取方法确定模极大值点，给出缺陷边缘。实验结果表明，该方法去噪效果好，检测出的缺陷边缘具有较强的连续性。

关键词: 边缘检测, 小波变换, X射线图像, 模极大值