Pattern Recognition using Moiré Fringe Topography and Rasterstereography

Moiré fringe topography and rasterstereography are 3-D optical imaging techniques, which provide height and curvature maps of the subject or the object under study. These are non-contact and non-invasive techniques, which project moiré and raster grids on the body. The distorted grids contain height and curvature information, which may be recovered using image-processing algorithms. These techniques are being applied to face recognition. The information may be stored in the database and not easily accessi-ble to ordinary citizen. Hence, the chances of fake pictures or fabricated patterns are mini-mized. Techniques are developed to project, simultaneously, moiré and raster grids and analyze height and curvature information, separately, using selective optical filtering, which could be used to record height and curvature patterns during a certain action, e. g., uttering a standard word. Edge-based algorithms, combined with moiré contours and raster patterns, allow study of face move-ments through changing height and curvature maps. A multiple-level screening of suspects using these technologies is proposed. Keywords–Face recognition, stereophotography, image processing