A study on photogrammetric algorithm for crack width measurement

2014 ◽  
pp. 581-586
Author(s):  
S Nishiyama ◽  
T Tsubosaka ◽  
T Kikuchi ◽  
T Yano
Keyword(s):  
Crack Width ◽  
Width Measurement

CRACK WIDTH MEASUREMENT USING MULTISCALE LOG KERNEL

2018 ◽  
Vol 74 (2) ◽  
pp. I_30-I_39
Author(s):  
Kenji KAGITANI ◽  
Koji OSHIKIRI ◽  
Taro KIKUCHI ◽  
Shou MAKINO ◽  
Yoshito SEINO ◽  
...  
Keyword(s):  
Crack Width ◽  
Width Measurement

scholarly journals Analysis of Fine Crack Images Using Image Processing Technique and High-Resolution Camera

2021 ◽  
Vol 11 (20) ◽  
pp. 9714
Author(s):  
Hoseong Jeong ◽  
Baekeun Jeong ◽  
Myounghee Han ◽  
Dooyong Cho
Keyword(s):  
Image Processing ◽  
Crack Width ◽  
Focal Length ◽  
Great Influence ◽  
Health And Safety ◽  
Digital Camera ◽  
Processing Technique ◽  
Image Processing Technique ◽  
Width Measurement ◽  
Working Distance

Visual inspections are performed to investigate cracks in concrete infrastructure. These activities require manpower or equipment such as articulated ladders. Additionally, there are health and safety issues because some structures have low accessibility. To deal with these problems, crack measurement with digital images and digital image processing (DIP) techniques have been adopted in various studies. The objective of this experimental study is to evaluate the optical limit of digital camera lenses as working distance increases. Three different lenses and two digital cameras were used to capture images of lines ranging from 0.1 to 0.5 mm in thickness. As a result of the experiments, it was found that many elements affect width measurement. However, crack width measurement is dependent on the measured pixel values. To accurately measure width, the measured pixel values must be in decimal units, but that is theoretically impossible. According to the results, in the case of 0.3 mm wide or wider cracks, a working distance of 1 m was secured when the focal length was 50 mm, and working distances of 3 m and 4 m were secured when the focal length was 100 mm and 135 mm, respectively. However, for cracks not wider than 0.1 mm, focal lengths of 100 mm and 135 mm showed measurability within 1 m, but a focal length of 50 mm was judged to hardly enable measurement except for certain working positions. Field measurement tests were conducted to verify measurement parameters identified by the results of the indoor experiment. The widths of actual cracks were measured through visual inspection and used for the analysis. From the evaluation, it was confirmed that the number of pixels corresponding to the working distance had a great influence on crack width measurement accuracy when using image processing. Therefore, the optimal distance and measurement guidelines required for the measurement of the size of certain objects was presented for the imaging equipment and optical equipment applied in this study.

scholarly journals CRACK WIDTH MEASUREMENT FOR NON-PLANAR SURFACES BY TRIANGLE MESH ANALYSIS IN CIVIL ENGINEERING MATERIAL TESTING

2019 ◽  
Vol XLII-2/W18 ◽  
pp. 107-113 ◽  
Author(s):  
F. Liebold ◽  
H.-G. Maas ◽  
A. A. Heravi
Keyword(s):  
Crack Width ◽  
High Speed ◽  
Impact Load ◽  
Image Sequences ◽  
Stereo Image ◽  
Triangle Mesh ◽  
Engineering Material ◽  
Planar Surfaces ◽  
Width Measurement ◽  
Mesh Analysis

Abstract. This publication concentrates on the photogrammetric crack width measurement of crack patterns of concrete probes under impact loading in high-speed stereo image sequences. The presented algorithm works for non-planar specimens with deformations that only appear tangential to the surface and the method is based on triangle mesh analysis. Experiments were conducted with cylindrical specimens with an impact load affecting parallel to the main axis of the cylinder.

Pavement Crack Width Measurement Based on Laplace's Equation for Continuity and Unambiguity

2017 ◽  
Vol 33 (2) ◽  
pp. 110-123 ◽  
Author(s):  
Wenjuan Wang ◽  
Allen Zhang ◽  
Kelvin C. P. Wang ◽  
Andrew F. Braham ◽  
Shi Qiu
Keyword(s):  
Crack Width ◽  
Laplace’S Equation ◽  
Laplace's Equation ◽  
Width Measurement
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