Quantitative Evaluation of Reconstructed Images of Parallel Phase-Shifting Digital Holographies.
ABSTRACT Parallel phase-shifting digital holography is a technique capable of instantaneous three-dimensional measurement and can simultaneously obtain the holograms required for phase-shifting digital holography. The number of phase shifts of the reference wave in holography is inversely proportional to the number of pixels per each hologram in the technique. The authors quantitatively evaluated the quality of the images reconstructed by the three kinds of the technique in terms of the number of phase shifts. The techniques were numerically simulated and mean square errors between the object image and the reconstructed images were calculated. It was found that higher quality image is attained by smaller number of phase shifts of reference wave in the technique. This is because the smaller the number of phase shifts is, the shorter the sampling interval of spatial frequency per each hologram is, and the more detailed information of object can be reconstructed.
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ABSTRACT: We present an optoelectronic method to analyze three-dimensional (3D) scenes that is able to detect the presence, and also the position and orientation, of a reference 3D object. The data-acquisition procedure is based on digital holography. A phase-shifting interferometer records a single digital Fresnel hologram of the 3D scene with an intensity-recording device. Holographic information of the 3D reference object is also obtained with the same method. Correlation techniques are then applied to recognize the presence and position of the 3D reference object in the 3D scene. The technique also allows us to detect the 3D reference with a small out-of-plane rotation. Preliminary experimental results are presented that demonstrate the theory.Applied Optics 09/2001; 40(23):3877-86. DOI:10.1364/AO.40.003877 · 1.78 Impact Factor
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ABSTRACT: Digital in-line holography with numerical reconstruction has been developed into a new tool, specifically for biological applications, that routinely achieves both lateral and depth resolution, at least at the micron level, in three-dimensional imaging. The experimental and numerical procedures have been incorporated into a program package with a very fast reconstruction algorithm that is now capable of real-time reconstruction. This capability is demonstrated for diverse objects, such as suspension of microspheres and biological samples (diatom, the head of Drosophila melanogaster), and the advantages are discussed by comparing holographic reconstructions with images taken by using conventional compound light microscopy.Digital Holography for MEMS and Microsystem Metrology, 07/2011: pages 109 - 138; , ISBN: 9781119997290
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ABSTRACT: A three-dimensional (3-D) optical image-recognition technique is proposed and studied. The proposed technique is based on two-pupil optical heterodyne scanning and is capable of performing 3-D image recognition. A hologram of the 3-D reference object is first created and then is used to modulate spatially one of the pupils of the optical system; the other pupil is a point source. A 3-D target object to be recognized is then scanned in two dimensions by optical beams modulated by the two pupils. The result of the two-dimensional scan pattern effectively displays the correlation of the holographic information of the 3-D reference object and that of the 3-D target object. A strong correlation peak results if the two pieces of the holographic information are matched. We analyze the proposed technique and thereby lay a theoretical foundation for optical implementations of the idea. Finally, computer simulations are performed to verify the proposed idea.Applied Optics 02/1999; 38(2):370-81. DOI:10.1364/AO.38.000370 · 1.78 Impact Factor