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Journal of the Optical Society of America. A, Optics, Image Science, and Vision

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https://www.readbyqxmd.com/read/28375340/high-performance-analysis-of-layered-nanolithography-masks-by-a-surface-impedance-generating-operator
#1
Alireza Gholipour, Reza Faraji-Dana, Guy A E Vandenbosch
A fast computational algorithm is presented for the analysis of multilayered nanolithography masks. The technique used is an exact field-theoretical approach which can model the diffraction effects in subwavelength propagation regimes. The field scattered by the mask pattern is obtained in two steps. First, a surface impedance generating operator (SIGO) that relates the tangential electric field on the boundary of each etched area to its equivalent surface electric current is computed. Second, the exterior problem is formulated based on the equivalence theorem in electromagnetics and is combined with the SIGO model...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375339/fractal-and-spinodal-decomposed-turbidities-of-nanoporous-glass-fluctuation-picture-in-turbid-and-transparent-vycor
#2
Shigeo Ogawa, Jiro Nakamura
The light propagation and scattering in monolithic transparent nanoporous materials such as Vycor glasses exhibit two optical turbidities, both of which are slightly deviated from the λ<sup>-4</sup> Rayleigh wavelength dependence in the visible region: one is a transient white turbidity τ<sub>f</sub>, characterized by the convex-upward dependence on the inverse fourth power of wavelength, and the other is turbidity τ<sub>sp</sub> inherent to the structural inhomogeneity, characterized by the convex-downward dependence...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375338/fresnel-diffraction-from-a-step-in-the-general-case
#3
Hamid Salvdari, M Taghi Tavassoly, S R Hosseini
Recently, Fresnel diffraction from phase steps with parallel plates has been studied in detail, and the subject has led to many interesting metrological applications. In this report we formulate Fresnel diffraction from a physical step with arbitrarily oriented plates in reflection mode. We simulate the diffraction patterns for different orientations of the plates and develop the required procedure for determining the involved angles by analysis of the diffraction pattern. In the experimental part of the report we arrange a setup to form diffraction patterns in different orientations of the step plates and test the derived formulations...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375337/correction-of-geometrically-distorted-underwater-images-using-shift-map-analysis
#4
Kalyan Kumar Halder, Manoranjan Paul, Murat Tahtali, Sreenatha G Anavatti, Manzur Murshed
In underwater imaging, water waves cause severe geometric distortions and blurring of the acquired short-exposure images. Corrections for these distortions have been tackled reasonably well by previous efforts but still need improvement in the estimation of pixel shift maps to increase restoration accuracy. This paper presents a new algorithm that efficiently estimates the shift maps from geometrically distorted video sequences and uses those maps to restore the sequences. A nonrigid image registration method is employed to estimate the shift maps of the distorted frames against a reference frame...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375336/design-of-angularly-tolerant-zero-contrast-grating-filters-for-pixelated-filtering-in-the-mid-ir-range
#5
Léopold Macé, Olivier Gauthier-Lafaye, Antoine Monmayrant, Henri Camon
Zero-contrast gratings (ZCG) can be used to implement narrow bandpass transmission filters. However, they suffer from poor angular tolerance, which hinders their use in pixelated applications. Combining ZCG with double-corrugation grating, we increase the resonance width and angular tolerance of the filter by more than 1 order of magnitude. Filters tunable around 4.6 μm with more than 90% transmission and compatibility with 140 μm pixel size are demonstrated.
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375335/cross-scale-cost-aggregation-integrating-intrascale-smoothness-constraint-with-weighted-least-squares-in-stereo-matching
#6
Hao Ma, Shunyi Zheng, Chang Li, Yingsong Li, Li Gui, Rongyong Huang
Cross-scale cost aggregation (CSCA) allows pixel-wise multiscale interaction in the aggregated cost computation. This kind of multiscale constraint strengthens the consistency of interscale cost volume and behaves well in a textureless region, compared with single-scale cost aggregation. However, the relationship between neighbors' cost is ignored. Based on the prior knowledge that costs should vary smoothly, except at object boundaries, the smoothness constraint on cost in a neighborhood system is integrated into the CSCA model with weighted least squares for reliable matching in this paper...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375334/evaluation-of-whiteness-formulas-for-fwa-and-non-fwa-whites
#7
Minchen Wei, Shining Ma, Yuzhao Wang, Ming Ronnier Luo
Whiteness is an important colorimetric characteristic for surface colors. Currently, the CIE whiteness formula is widely used to characterize the whiteness of a surface in industry, whose limitations have been well documented. In this study, the whiteness appearance of 55 textile samples [43 non-fluorescent whitening agents (FWAs) and 12 FWA samples] were evaluated under six lighting conditions, comprising three levels of correlated color temperature (CCT) (i.e., 3000, 4000, and 6500 K) and two levels of UV radiation (i...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375333/camera-calibration-based-on-the-principal-rays-model-of-imaging-optical-systems
#8
Toshiaki Matsuzawa
The parametric camera model is newly presented in order to calibrate rotationally nonsymmetric and noncentral cameras. This model assumes cameras designed rotationally symmetric and containing manufacturing errors. For this purpose, the general expression of the principal rays, which are equivalent to the backprojection lines corresponding to the image coordinates, on the object side of imaging optical systems is derived based on aberration theory, which includes all components of distortion and pupil aberration...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375332/probability-density-cloud-as-a-geometrical-tool-to-describe-statistics-of-scattered-light
#9
Natalia Yaitskova
First-order statistics of scattered light is described using the representation of the probability density cloud, which visualizes a two-dimensional distribution for complex amplitude. The geometric parameters of the cloud are studied in detail and are connected to the statistical properties of phase. The moment-generating function for intensity is obtained in a closed form through these parameters. An example of exponentially modified normal distribution is provided to illustrate the functioning of this geometrical approach...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375331/evaluation-of-the-influence-of-arbitrary-masks-on-the-output-field-of-optical-systems-using-abcd-matrices
#10
Malchiel Haskel, Adrian Stern
We propose a method to express the complex field amplitude (CFA) at the output of any optical system with arbitrary masks. The method provides a general equation for any first-order optical system with given parameters and arbitrary masks. The method is based on the ABCD matrices of the system components, ignoring the masks. The obtained output CFA is formulated in a way that helps recognize the influence of each mask on the output CFA by projecting its influence on the output with the aid of ABCD matrices...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375330/parameterization-of-the-deterministic-mueller-matrix-application-to-a-uniform-medium
#11
Colin J R Sheppard
The extraction of the elementary polarization properties of a uniform medium from a deterministic Mueller matrix has been considered by several researchers. The relationship between a parameterization of the deterministic Mueller matrix that we described recently and the elementary polarization properties for a uniform medium is investigated. The elementary polarization properties can be calculated exactly from the Mueller matrix parameters. Simplified forms for the Mueller matrix parameters in terms of the elementary polarization properties are presented...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375329/study-of-a-weak-scattering-model-in-aero-optic-simulations-and-its-computation
#12
Lingfei Xu, Zhichao Zhou, Tianrong Ren
Atmosphere optic statistical modeling cannot be used to analyze aerodynamic flow laser beam propagation characteristics without accounting for the density spectrum of the refractive index. However, numerical simulations support the analysis of these characteristics through ray tracing, random-phase-screen diffraction modeling, and Maxwell-equation-based scattering modeling. We analyzed the laser-beam propagation in aero-optics using the Maxwell-equation-based scattering model. Three approaches offer solutions to Maxwell's equations in statistically inhomogeneous media: high-order numerical differentiations with paraxial approximation and Runge-Kutta methods, Born-approximated scattering potential integral equations, and Rytov-approximated scattering potential integral equations...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375328/simulating-visibility-under-reduced-acuity-and-contrast-sensitivity
#13
William B Thompson, Gordon E Legge, Daniel J Kersten, Robert A Shakespeare, Quan Lei
Architects and lighting designers have difficulty designing spaces that are accessible to those with low vision, since the complex nature of most architectural spaces requires a site-specific analysis of the visibility of mobility hazards and key landmarks needed for navigation. We describe a method that can be utilized in the architectural design process for simulating the effects of reduced acuity and contrast on visibility. The key contribution is the development of a way to parameterize the simulation using standard clinical measures of acuity and contrast sensitivity...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375327/s-shaped-non-paraxial-corrections-to-general-astigmatic-beams
#14
X Liu, K Cassou, K Dupraz, P Favier, W H Huang, A Martens, C F N'Diaye, C X Tang, T Williams, L X Yan, F Zomer
Non-paraxial perturbation wave equations are solved for general astigmatic Gaussian beams for the first time, to the best of our knowledge, in the angular spectrum representation by taking into account generic boundary conditions. Expressions for second-order corrections are derived and exemplified with an optical cavity made of two cylindrical mirrors. Non-paraxial corrections can lead, depending on the choice of boundary conditions, to a transverse S-shaped beam mode, which has been qualitatively been observed in a highly divergent non-planar four-mirror cavity...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375326/monstar-disclinations-in-the-polarization-of-singular-optical-beams
#15
Enrique J Galvez, Behzad Khajavi
The control of spatial and polarization modes of optical beams enables the production of topological singularities encoded on the polarization of the light. This allows the study of topological disclinations not easily found in the natural setting. In this article we report on the observation of new features in disclinations realized with singular optical beams. They were prepared using three spatial modes bearing optical vortices in non-separable superpositions with circular polarization states. The disclinations involve asymmetric rotational dislocations, whose optical counterparts in the optical far field are known as C-points, and which are classified as monstars...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375325/wave-amplitude-synthesis-applied-to-gaussian-beam-scattering-by-an-off-axis-sphere
#16
Dimitrios P Chrissoulidis, Elodie Richalot
Electromagnetic scattering of a Gaussian beam by an off-axis dielectric sphere is treated by the sum-of-waves formulation, which is inherent in Lorenz-Mie theory. Each "wave" is a spherical eigenvector, defined in the natural frame of the scatterer, and the coefficient of that wave is the "wave amplitude." Decomposition of the beam into homogeneous plane waves lays the ground for a synthesis of the wave amplitudes, which is done by an integration over the polar angle that defines the direction of propagation of the plane-wave constituents of the beam...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375324/optical-performance-characterization-of-light-logging-actigraphy-dosimeters
#17
Luke L A Price, Andrey Lyachev, Marina Khazova
There are several wearable products specially developed or marketed for studying sleep, circadian rhythms, and light levels. However, new recommendations relating to human physiological responses to light have changed what measurements researchers may demand. The performances of 11 light-logging dosimeters from eight manufacturers were compared. The directional and spectral sensitivities, linearity, dynamic range, and resolution were tested for seven models, and compared along with other published data. The sample mainly comprised light-logging actigraphy dosimeters wearable as badges, in accordance with measurement protocols for larger-scale field studies...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375323/robust-object-tracking-based-on-local-discriminative-sparse-representation
#18
Xin Wang, Siqiu Shen, Chen Ning, Yuzhen Zhang, Guofang Lv
Despite much success in the application of sparse representation to object tracking, most of the existing sparse-representation-based tracking methods are still not robust enough for challenges such as pose variations, illumination changes, occlusions, and background distractions. In this paper, we propose a robust object-tracking algorithm via local discriminative sparse representation. The key idea in our method is to develop what we believe is a novel local discriminative sparse representation method for object appearance modeling, which can be helpful to overcome issues such as appearance variations and occlusions...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375322/transformation-of-a-high-dimensional-color-space-for-material-classification
#19
Huajian Liu, Sang-Heon Lee, Javaan Singh Chahl
Images in red-green-blue (RGB) color space need to be transformed to other color spaces for image processing or analysis. For example, the well-known hue-saturation-intensity (HSI) color space, which separates hue from saturation and intensity and is similar to the color perception of humans, can aid many computer vision applications. For high-dimensional images, such as multispectral or hyperspectral images, transformation images to a color space that can separate hue from saturation and intensity would be useful; however, the related works are limited...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375321/great-a-gradient-based-color-sampling-scheme-for-retinex
#20
Michela Lecca, Alessandro Rizzi, Raul Paolo Serapioni
Modeling the local color spatial distribution is a crucial step for the algorithms of the Milano Retinex family. Here we present GREAT, a novel, noise-free Milano Retinex implementation based on an image-aware spatial color sampling. For each channel of a color input image, GREAT computes a 2D set of edges whose magnitude exceeds a pre-defined threshold. Then GREAT re-scales the channel intensity of each image pixel, called target, by the average of the intensities of the selected edges weighted by a function of their positions, gradient magnitudes, and intensities relative to the target...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
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