Numerical reconstruction and twin-image suppression using an off-axis Fresnel digital hologram

2008 ◽  
Vol 90 (3-4) ◽  
pp. 527-532 ◽  
Author(s):  
G.L. Chen ◽  
C.Y. Lin ◽  
M.K. Kuo ◽  
C.C. Chang
Keyword(s):  
Digital Hologram ◽  
Numerical Reconstruction

Development of a Parallel Fast Fourier Transform-Based Algorithm for Digital Hologram Reconstruction

2014 ◽  
Vol 1040 ◽  
pp. 949-953 ◽  
Author(s):  
T.R. Vuyets ◽  
Vladislav A. Ovchinnikov
Keyword(s):  
Digital Holography ◽  
Graphics Processing Unit ◽  
Processing Unit ◽  
Time Analysis ◽  
Digital Hologram ◽  
Central Processing ◽  
Numerical Reconstruction ◽  
Real Time Analysis ◽  
Observation Method ◽  
Graphics Processing

Digital holography is a comparatively new observation method for micron-sized particles. It is based on numerical reconstruction of recorded interference fringe. Calculation processes for reconstruction are both time- and memory-intensive. The aim of this study was to develop a faster, more efficient algorithm for digital hologram reconstruction. To this purpose Central Processing Unit (CPU) and Graphics Processing Unit (GPU) programming were implemented. For the problem solving the algorithms’ run-time for both configurations was measured. The results showed that the algorithm using a GPU board is faster and more suitable for reconstruction processes. Thus, it makes possible the accomplishment of real-time analysis.

Electron holography in materials science

1991 ◽  
Vol 49 ◽  
pp. 670-671
Author(s):  
Hannes Lichte ◽  
Edgar Voelkl
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Materials Science ◽  
Fourier Spectrum ◽  
Object Wave ◽  
Electron Holography ◽  
Reconstruction Procedure ◽  
Numerical Reconstruction ◽  
Transmission Electron ◽  
Unique Interpretation

The object wave o(x,y) = a(x,y)exp(iφ(x,y)) at the exit face of the specimen is described by two real functions, i.e. amplitude a(x,y) and phase φ(x,y). In stead of o(x,y), however, in conventional transmission electron microscopy one records only the real intensity I(x,y) of the image wave b(x,y) loosing the image phase. In addition, referred to the object wave, b(x,y) is heavily distorted by the aberrations of the microscope giving rise to loss of resolution. Dealing with strong objects, a unique interpretation of the micrograph in terms of amplitude and phase of the object is not possible. According to Gabor, holography helps in that it records the image wave completely by both amplitude and phase. Subsequently, by means of a numerical reconstruction procedure, b(x,y) is deconvoluted from aberrations to retrieve o(x,y). Likewise, the Fourier spectrum of the object wave is at hand. Without the restrictions sketched above, the investigation of the object can be performed by different reconstruction procedures on one hologram. The holograms were taken by means of a Philips EM420-FEG with an electron biprism at 100 kV.

A numerical reconstruction method in inverse elastic scattering

2017 ◽  
Vol 25 (11) ◽  
pp. 1577-1600 ◽  
Author(s):  
F. S. V. Bazán ◽  
J. B. Francisco ◽  
K. H. Leem ◽  
G. Pelekanos ◽  
V. Sevroglou
Keyword(s):  
Elastic Scattering ◽  
Reconstruction Method ◽  
Numerical Reconstruction

scholarly journals Periods of Excess Energy in Extreme Weather Events

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Igor G. Zurbenko ◽  
Amy L. Potrzeba-Macrina
Keyword(s):  
Atmospheric Pressure ◽  
Original Data ◽  
Extreme Weather Events ◽  
Noise Levels ◽  
Tidal Waves ◽  
Numerical Reconstruction ◽  
Weather Events ◽  
Periodic Signals ◽  
High Level ◽  
The Waves

The reconstruction of periodic signals that are embedded in noise is a very important task in many applications. This already difficult task is even more complex when some observations are missed or some are presented irregularly in time. Kolmogorov-Zurbenko (KZ) filtration, a well-developed method, offers a solution to this problem. One section of this paper provides examples of very precise reconstructions of multiple periodic signals covered with high level noise, noise levels that make those signals invisible within the original data. The ability to reconstruct signals from noisy data is applied to the numerical reconstruction of tidal waves in atmospheric pressure. The existence of such waves was proved by well-known naturalist Chapman, but due to the high synoptic fluctuation in atmospheric pressure he was unable to numerically reproduce the waves. Reconstruction of the atmospheric tidal waves reveals a potential intensification on wind speed during hurricanes, which could increase the danger imposed by hurricanes. Due to the periodic structure of the atmospheric tidal wave, it is predictable in time and space, which is important information for the prediction of excess force in developing hurricanes.

Direct full compensation of the aberrations in quantitative phase microscopy of thin objects by a single digital hologram

2007 ◽  
Vol 90 (4) ◽  
pp. 041104 ◽  
Author(s):  
L. Miccio ◽  
D. Alfieri ◽  
S. Grilli ◽  
P. Ferraro ◽  
A. Finizio ◽  
...  
Keyword(s):  
Quantitative Phase ◽  
Digital Hologram ◽  
Phase Microscopy ◽  
Quantitative Phase Microscopy ◽  
Full Compensation
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