IMPLEMENTATION OF A LOW COST STRUCTURED LIGHT SCANNER
Keywords: Cultural Heritage, 3D Reconstruction, Stereo Vision, Coded structured light, Stereo Matching, System Calibration, Essential matrix, Line shift processing
Abstract. In this paper, a practical 3D scanner based on coded structured light principle is reported. The system integrates the technology of close range photogrammetry and Gray code structured light together with multi-line shift processing methodology. This 3D acquisition device allows bulding highly dense and accurate models of real world in a cost- and time-effective manner. The configuration consists of a digital multimedia projector and two digital cameras. One advantage of this configuration is, that the projection device can, but is not required to be stable over time nor it does have to be calibrated. Given a point on left image, the correspondent point on right image is the intersection of coded light stripes with the same code and epipolar line. Then, the depth is estimated by triangulation. The experimental restults have showen that, the proposed solution for essential matrix derivation and applying it to find correspondent points throughout Grey coded multi-line data sets yields high accuracy and density surface reconstruction with the lowest percentage of mismatch or blunder even for semi-complex objects. Some other advantages of this system lie in its design simplicity, low cost and the potential for fast and robust implementation.