基于亚像素级的墙面裂缝宽度检测方法研究

针对目前计算墙面裂缝宽度精度低的问题，提出一种基于亚像素级裂缝宽度计算方法。该方法在提取裂缝区域的基础上，运用基于中轴线垂线的裂缝宽度测量方法，结合多项式拟合裂缝边缘，提取裂缝左右边缘亚像素坐标点，从而运用欧式距离方法计算出亚像素级裂缝宽度，并且与像素级计算宽度的方法进行了对比。实验的结果表明，该算法计算结果更加精确，可用于多种类型的墙面裂缝宽度测量，其中纵向、横向和交叉裂缝测量的平均相对误差分别为3.02%、2.44%和3.72%，相比于像素级方法，平均误差分别减少了1.87%、1.95%和2.07%，具有较强的泛化能力以及稳定性。

Research on detection method of wall crack width based on sub-pixel level

Aiming at the problem of low accuracy in calculating the width of wall cracks, a sub-pixel based crack width calculation method is proposed. On the basis of extracting the crack area, this method uses the crack width measurement method based on the vertical line of the central axis, combined with polynomial fitting the crack edge, and extracts the sub-pixel coordinate points of the left and right edges of the crack, so as to calculate the sub-pixel crack width by using the Euclidean distance method, and compares it with the pixel level calculation method. The experimental results show that the algorithm is more accurate and can be used to measure the width of various types of wall cracks. The average relative errors of longitudinal, transverse and cross cracks are 3.02%, 2.44% and 3.72% respectively. Compared with the pixel level method, the average errors are reduced by 1.87%, 1.95% and 2.07% respectively, it has strong generalization ability and stability.