A fringe pattern correlator (FPC) is developed for human face recognition. Because of the object tracking property of the FPC to 3D translation, the FPC can recognize individual face regardless of a slight motion of human face. A server authentication type recognition system and experimental results are presented.
The fringe pattern correlator (FPC) can recognize 3D objects using a height transformed complex amplitude as 3D information. The height transformed complex amplitude is a two-dimensional (2D) complex amplitude whose phase factor includes actual height information of 3D objects. The FPC can perform effective 3D correlation using 2D correlation with the height transformed complex amplitude. In this study, we describe the effect of the amplitude factor of the height transformed complex amplitude in the FPC. The amplitude factor represents contrast information of the projected grating on the object, which corresponds to the reflectance property depending on 3D shape. We classify the amplitude factor by the 3D shape (flat surface, slope, edge, large step) and other factor (illumination condition, shadow, random pattern). We present the recognition characteristics with respect to the amplitude factor.
A fringe pattern correlator (FPC) for three-dimensional (3D) object recognition is developed using a spatial frequency multiplex color grating (SFMCG) to avoid phase ambiguity problem. The SFMCG consists of multiple color gratings with different carrier frequency. When the SFMCG is projected onto a 3D object, a color deformed grating pattern modulated by 3D shapes is obtained. Using color decomposition techniques, multiple monochromatic deformed grating patterns can be extracted from the color deformed grating pattern. Because the FPC in different sensitivity is easily executed using these monochromatic deformed grating patterns, exact 3D object recognition can be performed.