Measuring Three-Dimensional Shapes of a Human Face Using Photometric Stereo Method with Two Light Sources and Slit Patterns

In this paper, a new method for measuring 3D (three-dimensional) facial shapes is introduced. First, the normal vectors at the points on a face are computed by the photometric stereo method with two light sources. Next, multiple light stripes are projected onto the face with the slit pattern projector. The 3D coordinates of the points on the stripes are measured using the stereo vision algorithm. The normal vectors are then integrated within 2D finite intervals centered at the measured points on the stripes. The 3D curved segment within each finite interval is computed by the integration. Finally, all the curved segments are blended into the complete facial shape using a family of exponential functions. This method enables accurate 3D measurement of the complicated shapes of a human face in a short time.