Issue 52

Y. Xu et alii, Frattura ed Integrità Strutturale, 52 (2020) 1-8; DOI: 10.3221/IGF-ESIS.52.01 1 Building crack monitoring based on digital image processing Yanyan Xu, Yanxia Cai*, Dandan Li,Tierui Zhang Hengshui University, Hengshui, Hebei Province 053000, China xyy_xu@126.com , yxcyanx@yeah.net, zzaod5@163.com A BSTRACT . Building crack monitoring is of great value to the judgment of building safety. In this study, the digital image processing technology was studied and applied to the monitoring of building cracks. Crack images were collected by CCD camera, and then operations such as graying, correction, denoising and segmentation were carried out to obtain clear crack images. The obtained images were processed morphologically to further improve the quality. Finally, the width and length of cracks were calculated. In the case analysis, the results of 15 cracks measured by a microscope were taken as the standards and compared with the calculated results. The results showed that the results calculated in this study and the manual measurement results differed little, and the average errors of the width and length were 0.021 mm and 0.024 mm respectively, which suggested that the method proposed had a high reliability. The findings of this study provide a new idea for the further development of the building crack monitoring field and is conducive to the accurate assessment of building safety. K EYWORDS . Digital image processing; Building crack; Monitoring; Histogram equalization. Citation: Xu, Y.Y., Cai, Y.X., Li, D.D., Zhang, T.R., Building crack monitoring based on digital image processing, Frattura ed Integrità Strutturale, 52(2020) 1-8. Received: 06.08.2019 Accepted: 05.12.2019 Published: 01.04.2020 Copyright: © 2020 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION n the process of concrete production, due to the uneven expansion and contraction, cracks will inevitably occur in the ground. In the process of component transportation and assembly, cracks may also occur due to the influence of external environment. In the process of building use, cracks will gradually occur along with the deformation of materials. Building cracks will continue to develop and expand to destroy the integrity of the building structure, resulting in a decline in the mechanical properties of the overall structure; if serious, it may lead to shorter building life and cause safety accidents. Cracks in buildings develop slowly, and changes in the width and length can reflect the safety of buildings. Therefore, effective monitoring of cracks has important practical values [1]. With the development of technology, digital image processing has shown excellent performance in crack monitoring. Riyadi et al. [2] monitored pavement cracks with digital image processing technology, developed detection technology through the Gauss pyramid method, classified cracks and non-cracks by linear discrimination, and found that the method had an accuracy of 92.8571% and the processing time of each picture was 1.5 seconds. Kim et al. [3] combined Unmanned Aerial Vehicle (UAV) technology with digital image processing technology to realize the crack assessment of concrete structures and found that the system could successfully I