Three-dimensional Crack-Change Detection Based on Monocular Vision
The depth information of two-dimensional(2D)images cannot be captured via monocular-vision measurement technology,consequently,the three-dimensional(3D)coordinates in the 2D image cannot be measured rapidly and directly.Hence,this paper proposes a 3D crack-change detection method based on monocular vision.Using an equivalent crack-change model,a special target was designed,feature points were used to solve the Epnp(efficient perspective-n-point),the relative pose of the camera during repeated photograph capturing was obtained,the depth information was restored using the least-squares method,and the actual 3D displacement change was obtained using the iterative closest point algorithm for coordinate-system conversion.The absolute-error accuracy was within 0.5 mm,which satisfies the requirements of cracks specified in engineering.
monocular visioniterative closest point algorithmthree-dimensional reconstructioncrack measurement