Results 51 to 60 of about 1,461 (175)
IET Image Processing, Volume 20, Issue 1, January/December 2026.This paper presents a robust reversible watermarking algorithm based on Chebyshev moments, employing a two‐stage embedding mechanism. The proposed method leverages image block partitioning to embed the copyright watermark and the reversible watermark into non‐overlapping regions located inside and outside the inscribed circle of the image, respectively.
Wenjing Sun, Ling Zhang, Hongjun Zhang
wiley +1 more source
An FPGA Architecture for Extracting Real-Time Zernike Coefficients from Measured Phase Gradients
Measurement Science Review, 2015 Zernike modes are commonly used in adaptive optics systems to represent optical wavefronts. However, real-time calculation of Zernike modes is time consuming due to two factors: the large factorial components in the radial polynomials used to define them
Moser Steven +2 more
doaj +1 more source
Zernike expansion of derivatives and Laplacians of the Zernike circle polynomials [PDF]
Journal of the Optical Society of America A, 2014 The partial derivatives and Laplacians of the Zernike circle polynomials occur in various places in the literature on computational optics. In a number of cases, the expansion of these derivatives and Laplacians in the circle polynomials are required. For the first-order partial derivatives, analytic results are scattered in the literature, starting as
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Performance Analysis of the LDPC‐Coded Hybrid LQAM‐MPPM for UWOC Systems
IET Optoelectronics, Volume 20, Issue 1, January/December 2026.The effectiveness of LDPC codes in improving the performance of hybrid modulations is discussed, with coded 128‐QAM‐(12, 2) MPPM offering ~6.5 and 5.8 dB code gains at a BER of in strong and moderate turbulence, respectively. These results demonstrate the promise of hybrid modulation with LDPC as a robust and efficient modulation scheme for UWOC ...
Hongyan Jiang +6 more
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Journal of Ophthalmology, Volume 2026, Issue 1, 2026.Purpose This study evaluated the impact of clear corneal incision (CCI) morphology on corneal endothelial cell density (ECD), astigmatism, and higher‐order aberrations (HOAs) following implantable collamer lens (ICL) implantation. Design Prospective study. Methods Sixty‐five patients (65 eyes) undergoing ICL implantation were included.
I-Chun Lin +10 more
wiley +1 more source
Acta Ophthalmologica, Volume 103, Issue 8, Page 966-973, December 2025.Abstract Objective To evaluate the effects of customized corneal collagen cross‐linking (CXL) on higher‐order aberrations (HOAs) in keratoconus (KC): vertical coma (VC), horizontal coma (HC), spherical aberration (SA), trefoil (TF) and astigmatism, compared with the same effects in healthy eyes undergoing CXL for low‐grade myopia.
Jad Hayek +4 more
wiley +1 more source
Assessment about Luneberg integrals and application to digital in-line holography
Journal of the European Optical Society-Rapid Publications, 2021 In this publication, the Luneberg integrals are revisited and the conditions of the using of such integrals have been recalled. Additivity law of Luneberg’s integrals and the link with the Frenel kernel for the propagation are discussed.
S. Coëtmellec +3 more
doaj +1 more source
Compact Spectral Imaging: A Review of Miniaturized and Integrated Systems
Laser &Photonics Reviews, Volume 19, Issue 21, November 6, 2025.This review explores the rapid shift toward compact spectral imaging systems by examining four key design paradigms: Do‐It‐Yourself (DIY) platforms, freeform optics, filter‐on‐chip integration, and multifunctional metasurfaces. The discussion highlights critical applications in medicine, agriculture, and environmental monitoring, providing comparative ...
Sani Mukhtar, Amir Arbabi, Jaime Viegas
wiley +1 more source
Automated alignment of XFEL nanofocusing mirrors via wavefront optimization
Journal of Synchrotron Radiation, Volume 32, Issue 6, Page 1534-1538, November 2025.An automated alignment system for nanofocusing Kirkpatrick–Baez mirrors has been developed at SACLA. A wavefront optimization technique routinely provides nanofocused XFEL beams.An automated alignment procedure, based on wavefront measurement with a single‐grating interferometer, has been developed for precise tuning of Kirkpatrick–Baez nanofocusing ...
Jumpei Yamada +5 more
wiley +1 more source
Zernike polynomials for photometric characterization of LEDs [PDF]
Journal of Optics, 2016 Kuala Lumpur, Malaysia, 23-26 April ...
Velázquez, J.L. +4 more
openaire +3 more sources