Towards a Low-Cost Photogrammetric Face Scanner for Medical Purposes

Photogrammetry is very promising for the cost reduction of biometric systems but it still suffers of a high amount of human intervention. After having conducted several tests to verify the validity of the photogrammetric method, the present experimental study has been realized using a scanning system involving a dummy face in order to eliminate all the errors caused by un-intentional movements of the subject. The system is composed of three 10 megapixel CMOS sensors of commercial cameras and one coded flash projector synchronized by the software with the cameras. To increase the target visibility on the surface of interest, the acquisition has been realized using only the light of the projector. The preliminary automatic orientation of the images is performed exploiting a specifically designed retro-illuminated pattern. Experimental results point out that the system is able to 3D digitize the subject but enhancements are needed to increase the contrast of the targets on the human skin.