Three-dimensional object recognition using joint fractional Fourier transform correlators with the help of digital Fresnel holography

Digital holography (DH) helps record true three-dimensional (3D) perspective of a 3D object. The technique of DH can be used for various applications, including 3D object recognition, which can be implemented optically. In this paper, 3D object recognition with joint fractional Fourier transform (JFRT) correlators is proposed in which the technique of digital Fresnel holography is used. Digital Fresnel hologram of a 3D object is synthesized and reconstructed digitally. After removal of the dc and twin image terms from the reconstructed image, two different target objects have been compared using linear and nonlinear JFRT correlators. The results are also verified using an optically recorded digital Fresnel hologram. The performance measure parameters, such as, discrimination ratio, peak-to-correlation energy, and peak-to-sidelobe ratio have been computed to compare the two proposed correlation schemes.