Robust laser stripe extraction for 3D measurement of complex objects

Laser stripe center extraction is a critical step for a structured-light system, which plays an important role in industrial fields. However, existing center extraction methods are mainly for simple objects, where the stripe contours are relatively clear and no fake stripe areas caused by surface texture or surface reflection disturb the extraction of the real stripe area. To develop center extraction methods for complex objects, this paper proposed a new laser stripe extraction method based on the features of the laser stripe. After extracting seed points of the laser stripe using an extreme value method and connected component analysis, we can determine the stripe directions from the seed points and iteratively grow the centerline of the laser stripe. Finally, a gray-gravity method is used to extract the accurate center points of the laser stripe based on the obtained centerline. Experiments on 2D image laser stripe extraction and real 3D reconstruction application verified the robustness and accuracy of the proposed method.