3D scanning method for fast motion using single grid pattern with coarse-to-fine technique

An active 3D scanning method that can capture a fast motion is strongly required in wide areas. Since most commercial products using a laser projector basically reconstruct the shape with a point or a line for each scan, a fast motion cannot be captured in principle. In addition, an extended method using a structured light can drastically reduce the number of projecting patterns, however, they still require several patterns and a fast motion cannot be captured. One solution for the purpose is to use a single pattern (one shot scan). Although, one shot scanning methods have been intensively studied, they often have stability problems and their result tend to have low resolution. In this paper, we develop a new system which achieves dense and robust 3D measurement from a single grid pattern. A 3D reconstruction can be achieved by identifying grid patterns using coplanarity constraints. We also propose a coarse-to-fine method to increase the density of the shape with a single pattern.