Recognition of Tunnel Lining Cracks Based on Digital Image Processing

Abstract

Most of the tunnel projects are related to the national economy and people’s livelihood, and their operational safety is of paramount importance. Tunnel safety accidents or hidden safety hazards often start from subtleties. Therefore, the identification of tunnel cracks is a key part of tunnel safety control. The development of computer vision technology has made it possible for the automatic detection of tunnel cracks. Aiming at the problem of low recognition accuracy of existing crack recognition algorithms, this paper uses an improved homomorphic filtering algorithm to dehaze and clear the collected images according to the characteristics of tunnel images and uses an adaptive median filter to denoise the grayscaled image. The extended difference of Gaussian function is used for edge extraction, and the morphological opening and closing operations are used to remove noise. The breakpoints of the binary image are connected after removing the noise to make the image more in line with the actual situation. Aiming at the identification of tunnel crack types, the block index is proposed and used to distinguish linear cracks and network cracks. Using the histogram-like method to distinguish linear cracks in different directions can well solve the mixed crack situation in an image. Compared with the traditional method, the recognition rate of the new algorithm is increased to 94.5%, which is much higher than the traditional crack recognition algorithm. The average processing time of an image is 5.2 s which is moderate, and the crack type discrimination accuracy is more than 92%. In general, the new algorithm has good prospects for theoretical promotion and high engineering application value.

Wall Crack Detection based on Adaptive Double Threshold Greyscale Transform

“…Due to the interference of noise, the quality of the image will be reduced and the crack information in the image will become fuzzy. In this work, an adaptive median filtering technique is applied to smooth and reduce the noise of images [9] [10].…”

Mechanical properties of the combined medium-diameter anti-slide piles and tunnels under landslide loads at different sliding zone angles

“…Some researchers have classified the tunnel landslide system into three types: orthogonal, oblique, and parallel, based on the relative positions of the tunnel and landslide [3,4]. To investigate tunnel excavation, existing tunnel damage, and landslide control, researchers typically use model testing, numerical simulation, field monitoring [5,6,7,8,9], and other methods.…”

Tunnel Lining Crack Recognition Based on Improved Multiscale Retinex and Sobel Edge Detection

“…Zhu et al [10] realized the accurate identification of tunnel cracks by fusing the template-based analysis method, the linear structure analysis method based on Hough transform, and the approximate crack structure analysis method based on support vector machine, but the algorithm took a long time. Dai et al [11] used improved homomorphic filtering to process the collected images and used the XDoG edge extraction method to extract the edges of the cracks in the image. Practice has proved that this method has the advantage of fast calculation speed.…”