A Method for Extracting the Center of Ring-Structured-Light Stripe

Extracting stripe center accurately is very important in 3D measurement with structured light. A new method for extracting the center of ring-structured-light stripe has been proposed, which combines morphological thinning with improved barycenter method. Convert the original gray-scale image to a binary one, in which stripe stroke at pixel-level can be obtained by morphological thinning. Then the center of ring faculae is gained by curve fitting using the least squares method. Consider the directions pointing from the ring faculae center to every stroke point as normal directions of stripe center locus at its corresponding points. Along each normal direction, barycenter method is applied to the preprocessed gray-scale image. Compared to other stripe center extracting algorithms, the proposed method benefits from its simple intensity segmentation and no curve fitting for the curvature. Experiments show that it can meet industrial real-time applications for its rapidity as well as its sub-pixel level accuracy.