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Related papers: 3-Dimensional Mapping of Corneal Topography and Th…

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Precise 3D measurements of rigid surfaces are desired in many fields of application like quality control or surgery. Often, views from all around the object have to be acquired for a full 3D description of the object surface. We present a…

Optics · Physics 2014-01-10 Oliver Arold , Svenja Ettl , Florian Willomitzer , Gerd Häusler

We have investigated the effects of resonant scattering of emission lines on the image morphology and intensity from coronal loop structures. It has previously been shown that line of sight effects in optically thin line emission can yield…

Astrophysics · Physics 2009-10-31 Kenneth Wood , John Raymond

Structured-light three-dimensional (3D) imaging can achieve 3D shape of a stationary object via one or more pixelated array cameras with phase-shifting illumination. In order to extend 3D imaging to moving scenarios, we propose a 3D imaging…

Image and Video Processing · Electrical Eng. & Systems 2019-05-01 Wen-Kai Yu

Understanding corneal stiffness is valuable for improving refractive surgery, detecting corneal abnormalities, and assessing intraocular pressure. However, accurately measuring the elastic properties, particularly the tensile and shear…

Medical Physics · Physics 2023-08-11 Guo-Yang Li , Xu Feng , Seok-Hyun Yun

When the cornea becomes hydrated above its physiologic level it begins to significantly scatter light, loosing transparency and thus impairing eyesight. This condition, known as corneal edema, can be associated with different causes, such…

The propagation of a light ray in thin layer (film) within geometrical optics is considered. It is assumed that the ray is captured inside the layer due to reflecting walls or total internal reflection (in the case of a dielectric layer).…

Optics · Physics 2018-12-12 Tomasz Radozycki

High-precision laser interferometric instruments require optical surfaces with a close to perfect contour, as well as low scattering and absorption. Especially point absorbers are problematic because they heat up at high optical intensities…

Optics · Physics 2023-12-20 Leif Albers , Malte Hagemann , Roman Schnabel

Optical coherence tomography offers astounding opportunities to image the complex structure of living tissue, but lacks functional information. We present dynamic full-field optical coherence tomography to image living human induced…

Formation of a bright-field microscopic image of a transparent phase object is described in terms of elementary geometrical optics. Our approach is based on the premise that image replicates the intensity distribution (real or virtual) at…

Optics · Physics 2018-02-14 A. K. Khitrin , M. A. Model

Phase is a fundamental resource for optical imaging but cannot be directly observed with intensity measurements. The existing methods to quantify a phase distribution rely on complex devices and structures. Here we experimentally…

Optics · Physics 2020-03-25 Tengfeng Zhu , Junyi Huang , Zhichao Ruan

In the beginning stage, face verification is done using easy method of geometric algorithm models, but the verification route has now developed into a scientific progress of complicated geometric representation and matching process. In…

Computer Vision and Pattern Recognition · Computer Science 2014-02-03 V. Karthikeyan , Manjupriya , C. K. Chithra , M. Divya

Coupling to longitudinal modes of thin spherical shells, under Gaussian-beam illumination, was explored with a theoretical method based on Fourier-optics analysis and vector spherical harmonics. The illumination frequency band was fixed…

Retinal fundus images are widely used for the clinical screening and diagnosis of eye diseases. However, fundus images captured by operators with various levels of experience have a large variation in quality. Low-quality fundus images…

Image and Video Processing · Electrical Eng. & Systems 2020-12-10 Ziyi Shen , Huazhu Fu , Jianbing Shen , Ling Shao

An onion-peeling technique is developed for inferring the emissivity profile of a stellarator plasma from a two-dimensional image acquired through a CCD or CMOS camera. Each pixel in the image is treated as an integral of emission along a…

Plasma Physics · Physics 2016-08-17 K. C. Hammond , R. Diaz-Pacheco , Y. Kornbluth , F. A. Volpe , Y. Wei

This paper demonstrates a method of interpreting the mechanism of aberration of optical systems based on non-Fourier transform optical transfer function (OTF). According to the parameters of object plane cosine fringe, we obtain the…

Optics · Physics 2018-12-27 Yu Bai , Jiaqi Chen , Fangjie Li , Zhenming Zhao

The optical matrix formalism is applied to find parameters such as focal distance, back and front focal points, principal planes, and the equation relating object and image distances for a thick spherical lens immerse in air. Then, the…

Optics · Physics 2021-08-20 Fulvio Andres Callegari

Conventional optical components shape the wavefront of propagating light by adjusting the optical path length, which requires the use of rather thick lenses, especially for the adjustment of terahertz (THz) radiation due to its long…

When the thickness of the layer is smaller than the electrons mean free path, the morphology affects the conductivity directly based on the layer thickness. This issue provides basis in order to estimate the thickness of the layer by…

Mesoscale and Nanoscale Physics · Physics 2015-06-16 M. Jannesar , G. R. Jafari , S. Vasheghani Farahani , S. Moradi

Diffraction microtomography in coherent light is foreseen as a promising technique to image transparent living samples in three dimensions without staining. Contrary to conventional microscopy with incoherent light, which gives…

Optics · Physics 2009-11-13 Stanislas Vertu , Jean-Jacques Delaunay , Olivier Haeberle

Various methods have been introduced to measure the orbital angular momentum (OAM) of light, from fork holograms to Dove prism interferometers, from tilted lenses to triangular apertures - each with their own benefits and limitations. Here…