Using the Fourier slice theorem for representation of object views and models with application to face recognition

A novel method unifying viewer and model centered approaches for representing structurally complex 3-D objects like human faces is presented. The unified 3-D frequency-domain representation (called volumetric/iconic spectral signatures-V/ISS) encapsulates both the spatial structure of the object and a continuum of the projection slice theorem is used to directly extract the frequency-domain image of an object as viewed from any direction. Each such Fourier-transformed view is a planar slice of the volumetric frequency representation. The V/ISS representation is employed for pose-invariant recognition of complex objects such as faces. The recognition and pose estimation is based on an efficient matching algorithm in a four dimensional Fourier space. Experimental examples of pose estimation and recognition of faces are presented.