基于直线段特征单元提取的隧道砼衬砌接缝去除算法

Lining Seam Elimination Algorithm in Tunnel Concrete Lining Based on Line Feature Unit Extraction

由于部分隧道砼衬砌表面图像中固有衬砌接缝与裂缝灰度值相似且线性一致,衬砌接缝处易产生起砂、空鼓、掉块及渗漏水,已有的裂缝检测算法提取单一的裂缝存在缺陷。提出基于直线段特征单元提取的隧道砼衬砌表面衬砌接缝去除算法。在裂缝聚类特征粗检测的基础上,首先通过改进的累计概率霍夫变换检测出显著的直线特征;然后利用像素点的延伸搜索计算来提取衬砌接缝可处理的最小直线段特征单元线;最后根据单元线标记信息及定区域内单元线特征去除部分衬砌接缝,并运用渗流去噪算法得到隧道砼衬砌表面真实裂缝。实验结果表明,提出的算法弥补了已有隧道砼衬砌表面裂缝检测技术的不足,能够精确、快速、有效地去除相似线性特征对单一的真实裂缝检测的干扰,具有较强的鲁棒性。

Due to the brightness similarity and linear consistency between surface cracks and inherent lining seams in some tunnel concrete lining,lining seams are prone to sugaring,hollowing,localized rock fall and water leakage.The existing crack detection algorithms cannot accurately extract single cracks.This paper proposed a lining seam elimination algorithm based on the extraction of line feature unit in tunnel concrete lining.Firstly,on the basis of the clustering characteristics detection which is similar to cracks,the significant linear characteristics have been detected by progressive probabilistic hough ransform（PPHT）.Secondly,the minimum line feature processing unit of lining seam,which is called Unit-Line,has been extracted by the search calculation of pixel extension.Finally,according to the marking information of the Unit-Line characteristics and the Unit-Line characteristics in fixed area,apart of the lining seams can be removed,and the real surface cracks in tunnel concrete lining can be obtained by the percolation de-noising.The experimental results show that the proposed surface lining seam elimination algorithm based on the extraction of line feature unit,which has strong robustness,fills the gap in the existing technology of tunnel concrete lining surface cracks detection,and the interference of similar linear characteristics to the single real cracks detection can be removed accurately,quickly and effectively.