Edge enhancement in digital holo-microscopy

A simple edge enhancement technique in the digital holo-microscopy is presented here. In Digital Holo-microscopy (DHM) the intensity distribution of the CCD is produced by the interference of a plane reference wave and that scattered by the object. The reconstruction is accomplished by multiplication of the digitally stored hologram with a digital model of the reference wave and subsequent numerical determination of the diffracted field of the object in a defined image plane. Hence, a focused and a defocused version of the object may be reconstructed from only one recorded hologram by varying the reconstruction distance during numerical reconstruction. The edge enhancement of the object is possible by simply subtracting this numerically reconstructed defocused real image from the focused real image. It is interesting to note that using this technique edge enhancement technique is possible for amplitude and phase objects. The simulation and experimental results presented validate our theoretical expectations.