Structured light scanning

Subject of this research project is a synthesis of state-of-the-art as well as the development of novel algorithms, in order to implement a 3D scanning system consisting of one consumer digital camera (DSLR) and a video projector. This Structured Light system relies on the pro­jection of different light patterns, by means of a video projector, on 3D object surfaces, which are recorded by the digital camera. Automatic pattern identification on images allows re­con­structing the shape of recorded 3D objects via triangulation of the optical rays corresponding to projector and camera pixels. Models draped with realistic photo-texture may be thus also generated, reproducing both geometry and appearance of the 3D world. 


The system is calibrated in one step by projecting a coloured chess-board pattern on top of a targeted planar surface. The planar calibration board is rotated in space producing different perspectives captured by the camera. Both the targets and corners of the projected pattern are automatically identified on the images with sub-pixel accuracy, allowing precise simulta­neous estimation of internal and external system parameters in a bundle adjustment. The scanning process is performed through projection of binary Gray coded pattern (horizontal and vertical stripes) onto the unknown 3D surface. In this way, matching of homologue pro­jector and camera pixels can be performed without redundancy. Sub-pixel correspondences are also established to increase precision and smoothness of the final 3D reconstruction, which is obtained through standard photogrammetric space intersection.


2011 A structured-light approach for the reconstruction of complex objects. I. Kalisperakis, L. Gram­matikopoulos, E. Petsa, G. Karras, XXIII CIPA International Symposium, Prague, 12-16 September

2011 Δημιουργία Οπτικού-Φωτογραμμετρικού Σαρωτή για την Αυτόματη 3D Ανακατασκευή Μικρών Αντικειμένων. Ε. Πέτσα, Η. Καλησπεράκης, Λ.Γραμματικόπουλος, Γ. Καρράς, Τεχνική Έκ­θεση ερευνητικού προγράμματος, Τμήμα Τοπογραφίας, ΤΕΙ Αθήνας.