A systolic multi-layer and multi-line stereo vision system for 3D visual inspection

Abstract

This paper describes a new stereo vision system for 3D visual inspection. 2D visual inspection is a typical method to assess a structure visually for corrosion and cracks, as well as other irregularities. However, if we use 3D shape information in addition to the 2D pattern, we can locate defects more clearly and exactly. Stereo vision is a process of recreating 3D spatial information from a pair of 2D images and is one of the most difficult tasks in computer vision due to the ill-posed nature of the problem. We present a new practical stereo vision system, which incorporates a multi-line multi-layer algorithm with a method based on geometrical states in 3D space. In this manner, this system is robust to miscalibration, noise, and variable lighting conditions. In our experiment, the system was attached to an inspection robot and was used to search for weld defects on a metal plate. It showed good results from a pair of input images captured by CCD cameras.