Pitkäaho, Tomi and Naughton, Thomas J. (2014) Speckle Noise Reduction in Michelson Digital Holography Using Known or Unknown Reference Linear Phases and Image Processing. In: Fringe 2013. Springer, pp. 649-652. ISBN 9783642363580
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Abstract
Speckle is caused by the illumination of an optically rough surface by coherent
light [1] which can cause problems in digital holography. Speckle in a reconstruction
reduces visibility of details and may impede important measurements of an
object. Speckle can be reduced by capturing multiple holograms and summing the
reconstructed intensities [2-4]. Digital signal processing methods, which are applied
after capture, have also been proposed [5–8].
With respect to three-dimensional (3D) objects, we solve this problem by outof-
plane rotating the reference mirror in discrete steps, capturing a hologram each
time, and introducing image processing to rectify the resulting shifted diffraction
fields. Each rotation amount need not be known and so can be generated by a very
fast unstable device. This reference beam rotation is different from [4], where the
object beam is rotated at different angles. Changing the angle of incidence of the
reference beam changes the phase implicitly captured in the hologram, and results in a different speckle pattern in each reconstructed object. The positions of the
object and the camera remain the same so there is no change in perspective between
holograms, allowing integration of an arbitrary number of them using the
full rotation range allowed by the space-bandwidth product of the camera. The
intensities of numerical reconstructions are averaged after image processing registration
steps, which produces speckle-reduced reconstructions that closely match
theoretical predictions for statistically independent speckle fields.
Item Type: | Book Section |
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Additional Information: | This is the postprint version of the published chapter, which is available at DOI: 10.1007/978-3-642-36359-7_120 |
Keywords: | Speckle Noise Reduction; Michelson Digital Holography; Reference Linear Phases; Image Processing; |
Academic Unit: | Faculty of Science and Engineering > Computer Science |
Item ID: | 6533 |
Identification Number: | 10.1007/978-3-642-36359-7_120 |
Depositing User: | Thomas Naughton |
Date Deposited: | 04 Nov 2015 16:59 |
Publisher: | Springer |
Refereed: | Yes |
Related URLs: | |
URI: | https://mural.maynoothuniversity.ie/id/eprint/6533 |
Use Licence: | This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here |
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