提出了一种基于图像处理的膨胀圆裂缝检测算法，将裂缝假想成被若干圆形充填的平面空间，圆的直径可以近似为裂缝宽度，通过一系列圆的坐标和直径，可以实现裂缝几何模型的建立与复原。结果表明，裂缝参数化后由图像格式转为若干个圆的坐标和直径，仍保留了裂缝的主要形态与特征，可用于裂缝或者结构健康评估的进一步分析运算，为裂缝图像检测和结构健康监测提供了参考。

An algorithm based on image processing for crack detection of expansion circle is proposed, which is named expansion circle, the crack is assumed to be a plane filled with several circular shapes, and the diameter of the circle can be approximated as the crack width. The geometrical model of the crack can be established and restored through a series of coordinates and diameters of the circle. The results show that after the parametrization of the crack, the image format is converted into the coordinates and diameters of several circles, and the main shape and characteristics of the crack are retained, which can be used as a further analysis operation for crack or structural health assessment. It provides a solution for crack image detection and structural health monitoring.