Depth Detection of Target Object Using Parallax Information Produced by Digital Holography

Digital holography can record the amplitude and phase of the optical wavefront of an object using a CCD camera and reproduce the 3D object information by the numerical reconstruction process. Since object information is recorded on the whole hologram, even a portion of the hologram can reconstruct the object information though it only includes the information observed from its recording position. In this study, we propose a depth detection method that uses the parallax information synthesized from subholograms obtained by dividing a single digital hologram. We can obtain the optimum in-focus distance of a part of the object as well as the whole object using the proposed method. Two efficient focusing algorithms have been proposed and demonstrated experimentally using the digital Fresnel hologram.