Results 161 to 170 of about 2,554 (206)

Autofocusing in digital holography using eigenvalues

Applied Optics, 2021
A new autofocusing algorithm for digital holography is proposed based on the eigenvalues of the images reconstructed at different distances in the measurement volume. An image quality metric evaluated based on the distribution of its eigenvalues is compared in function of the reconstruction distance to identify the location of the focal plane.
Anik, Ghosh, Rishikesh, Kulkarni, Pranab Kumar, Mondal   +2 more
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Separation of antibiotics by autofocusing

ELECTROPHORESIS, 1990
AbstractThe autofocusing separation of nine antibiotics was investigated: tetracycline and chloramphenicol in large‐scale batches, and seven others in gram preparation amounts. All except one were found to be hetergeneous in autofocusing, and 2‐4 well‐characterized fractions emerged. These heterogeneities are described and the industrial utilization of
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Autofocusing in digital holography

SPIE Proceedings, 2013
Digital holography allows the acquisition of 3D profiles of objects. Digitally captured holograms are reconstructed at the respective distances of the objects to reveal the phase and the intensity profiles. However, computing an object’s 3D profile with only a single reconstruction requires prior knowledge of the distance of the object from the ...
Hazar A. İlhan, Mert Doğar, Meric Özcan   +2 more
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Circular Mathieu and Weber autofocusing beams

Optics Letters, 2022
In this Letter, the new classes of non-paraxial autofocusing beams are introduced for the first time, to the best of our knowledge. We investigate both numerically and experimentally non-paraxial circular Mathieu and Weber autofocusing beams based on the solutions of the Helmholtz equation in elliptical and parabolic coordinates, respectively.
Yong Zhang, Zhenwu Mo, Danling Xu, Shangling He, Yiping Ding, Qiaobing Huang, Zhili Lu, Dongmei Deng   +7 more
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Abruptly autofocusing circular swallowtail beams

Optics Letters, 2021
In this Letter, to the best of our knowledge, we report the first experimental demonstration of a new family of autofocusing beams, circular swallowtail beams (CSBs), based on the high-order swallowtail catastrophe, which were determined by potential functions depending on the state and control parameters.
Houan, Teng, Yixian, Qian, Yanping, Lan, Yiming, Cai   +3 more
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Multi-Subaperture PGA for SAR Autofocusing

IEEE Transactions on Aerospace and Electronic Systems, 2013
For spotlight mode synthetic aperture radar (SAR) autofocusing, the traditional full-aperture phase gradient autofocus (PGA) algorithm might suffer from performance degradation in the presence of significant high-order phase error and residual range cell migration (RCM), which tend to occur when the coherent processing interval (CPI) is long. Meanwhile,
Daiyin Zhu, Rui Jiang, Xinhua Mao, Zhaoda Zhu   +3 more
openaire   +1 more source

The autofocusing system of the IMAT neutron camera

Review of Scientific Instruments, 2013
In this paper, we present the autofocusing system of the imaging instrument to be used on IMAT, a new neutron-imaging facility under construction at the ISIS (UK) target station 2. We have compared 16 different autofocus algorithms to select the one with the best performance. The algorithms have been evaluated by using both a qualitative analysis and a
V Finocchiaro, F Aliotta, D Tresoldi, RC Ponterio, C S Vasi, G Salvato   +5 more
openaire   +4 more sources

Adaptive autofocusing: a closed-loop perspective

Journal of the Optical Society of America A, 2005
We present an adaptive autofocusing scheme. In this scheme, the focus measure is updated with focus tuning. To achieve this, we construct the focus measure by using image moments and develop an adaptive focus-tuning strategy to estimate the measure in closed loop.
Ying, Zhang, Changyun, Wen, Yeng Chai, Soh, Aik Meng, Fong   +3 more
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Autofocusing optical-resolution photoacoustic endoscopy

Optics Letters, 2018
Photoacoustic (PA) endoscopy has the potential to diagnose early diseases in the gastrointestinal tract. For the first time, to our knowledge, we developed an autofocusing PA endoscope (AF-PAE) for the usually irregular gastrointestinal tract imaging to solve the deterioration of transverse resolution caused by the defocus scanning of the probe.
Kedi, Xiong, Sihua, Yang, Xiaowan, Li, Da, Xing   +3 more
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Autofocusing accelerator beams

A novel tuning approach, Model Coupled Accelerator Tuning (MCAT), has been applied to the separated function DTL at TRIUMF's Isotope Separator and Accelerator (ISAC). A digital twin of the rare-isotope postaccelerator is used for transverse and longitudinal tune optimizations, which are then loaded directly into the control system.
Katrusiak,Alexander, Shelbaya,Olivier, Baartman,Rick, Kester,Oliver, Ruiz,Chris   +4 more
openaire   +2 more sources