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Aproximadamente 23 registro(s) hasta el momento: (journal)

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Recurso libre

Computation and visualization of the MacAdam limits for any lightness, hue angle, and light source
Martínez Verdú, Francisco Miguel - Perales Romero, Esther - Chorro Calderón, Elísabet - Fez Saiz, Dolores de - Viqueira Pérez, Valentín - Gilabert Pérez, Eduardo

Formato:	info:eu-repo/semantics/article
Enlaces:	We present a systematic algorithm capable of searching for optimal colors for any lightness L* (between 0 and 100), any illuminant (D65, F2, F7, F11, etc.), and any light source reported by CIE. Color solids are graphed in some color…
Fecha:	2007-07-11
Recurso:	RUA Docencia

Recurso libre

Colorimetric and spectral evaluation of the optical anisotropy of metallic and pearlescent samples
Chorro Calderón, Elísabet - Perales Romero, Esther - Martínez Verdú, Francisco Miguel - Campos Acosta, Joaquín - Pons Aglio, Alicia

Formato:	info:eu-repo/semantics/article
Enlaces:	The visual and optical anisotropies of metallic and pearlescent samples have been evaluated using a multi-gonio-spectrophotometer and by adapting a gonio-template over the instrument aperture for measuring the relative spectral reflectance factor when the sample is rotated around an axis…
Fecha:	2010-02-04
Recurso:	RUA Docencia

Recurso libre

Angular responses of the first diffracted order in over-modulated volume diffraction gratings
Neipp López, Cristian - Álvarez López, Mariela Lázara - Gallego Rico, Sergi - Ortuño Sánchez, Manuel - Sheridan, John T. - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	Kogelnik's coupled-wave (CW) theory has been used for decades to predict the diffraction efficiency of volume diffraction gratings. Although this theory has been applied with success to volume diffraction gratings recorded under a great variety of experimental conditions, its predictions…
Fecha:	2009-02-03
Recurso:	RUA Docencia

Recurso libre

Corneal primary aberrations compensation by oblique light incidence
Espinosa Tomás, Julián - Mas Candela, David - Kasprzak, Henryk T.

Formato:	info:eu-repo/semantics/article
Enlaces:	The eye is not a centered system. The line of sight connects the fovea with the center of the pupil and is usually tilted in the temporal direction. Thus, off-axis optical aberrations, mainly coma and oblique astigmatism, are introduced at…
Fecha:	2009-09-04
Recurso:	RUA Docencia

Recurso libre

Refractive analysis of the human cornea through propagated fields
Illueca Contri, Carlos - Mas Candela, David - Pérez Rodríguez, Jorge - Pons Moreno, Álvaro Máximo - Artigas Verde, José María

Formato:	info:eu-repo/semantics/article
Enlaces:	A new technique for analysing the optical quality of the human cornea is presented. Corneal maps are obtained through keratographies and then converted into phase maps. The propagated fields generated from this surface are plotted and studied. It is shown…
Fecha:	2007-10-16
Recurso:	RUA Docencia

Recurso libre

Fresnel diffraction in a theoretical eye: a fractional Fourier transform approach
Pons Moreno, Álvaro Máximo - Lorente Velázquez, Amalia - Illueca Contri, Carlos - Mas Candela, David - Artigas Verde, José María

Formato:	info:eu-repo/semantics/article
Enlaces:	In this work, we have applied the fractional Fourier transform to obtain the Fresnel diffraction patterns in a theoretical eye. The FRT approach to Fresnel diffraction is easily implemented in a Gullstrand-Emsley theoretical eye, and it allows us to obtain…
Fecha:	2007-10-16
Recurso:	RUA Docencia

Recurso libre

Optical surface reconstruction technique through combination of zonal and modal fitting
Espinosa Tomás, Julián - Mas Candela, David - Pérez Rodríguez, Jorge - Illueca Contri, Carlos

Formato:	info:eu-repo/semantics/article
Enlaces:	Videokeratometers and Scheimpflug cameras permit accurate estimation of corneal surfaces. From height data it is possible to adjust analytical surfaces that will be later used for aberration calculation. Zernike polynomials are often used as adjusting polynomials, but they have shown…
Fecha:	2010-05-03
Recurso:	RUA Docencia

Recurso libre

Scale corrections for faster evaluation of convergent Fresnel patterns
Mas Candela, David - Espinosa Tomás, Julián - Pérez Rodríguez, Jorge - Illueca Contri, Carlos

Formato:	info:eu-repo/semantics/article
Enlaces:	Numerical calculation of Fresnel patterns through fast Fourier transforms usually requires an extremely large number of samples in order to fulfil the Nyquist sampling condition. In many applications, the cut-off frequency of the system is much below the limit fixed…
Fecha:	2007-10-02
Recurso:	RUA Docencia

Recurso libre

Near-field light distributions propagated from human corneas: determination of relevant patterns
Mas Candela, David - Pérez Rodríguez, Jorge - Vázquez Ferri, Carmen - Hernández Poveda, Consuelo - Illueca Contri, Carlos

Formato:	info:eu-repo/semantics/article
Enlaces:	A procedure to determine the best image range of distances that can be obtained from an aphakic eye is presented. Corneal surfaces are calculated from videokeratographic data. Light distributions at different distances inside the eye are calculated with a near-field…
Fecha:	2007-10-16
Recurso:	RUA Docencia

Recurso libre

10.

Influence of the gaze-stabilizing eye movements on the quality of the retinal image of the human eye
Pons Moreno, Álvaro Máximo - Lorente Velázquez, Amalia - Illueca Contri, Carlos - Artigas Verde, José María - Felipe Marcet, Adelina

Formato:	info:eu-repo/semantics/article
Enlaces:	In this work we have studied the influence of the gaze stabilizing movements of the eye on the quality of the retinal image of the human eye obtained by double pass methods. The results obtained agree with the expected differences…
Fecha:	2007-10-16
Recurso:	RUA Docencia

Recurso libre

11.

Complete algorithm for the calculation light patterns inside the ocular media
Pérez Rodríguez, Jorge - Mas Candela, David - Illueca Contri, Carlos - Miret Marí, Juan José - Vázquez Ferri, Carmen - Hernández Poveda, Consuelo

Formato:	info:eu-repo/semantics/article
Enlaces:	Realistic mathematical models are of great importance for studying the optical performance of the human eye. Light propagation algorithms provide robust methods to calculate field distributions inside a homogeneous medium, and thus they can be applied to the study of…
Fecha:	2007-10-08
Recurso:	RUA Docencia

Recurso libre

12.

Calculation of the color matching functions of digital cameras from their complete spectral sensitivities
Martínez Verdú, Francisco Miguel - Pujol Ramo, Jaume - Capilla Perea, Pascual

Formato:	info:eu-repo/semantics/article
Enlaces:	We propose a new algorithm to obtain the color matching functions of any digital camera, with correct weights and white balance, from the relative scaling of their complete (3-D) spectral sensitivities obtained from real spectroradiometric data. Thanks to this algorithm,…
Fecha:	2007-09-11
Recurso:	RUA Docencia

Recurso libre

13.

Color visualization system for near-infrared multispectral images
Vilaseca Ricart, Meritxell - Pujol Ramo, Jaume - Arjona Carbonell, Montserrat - Martínez Verdú, Francisco Miguel

Formato:	info:eu-repo/semantics/article
Enlaces:	The aim of this study is to develop a color visualization system for multispectral images in the near-infrared region (NIR, 800–1000 nm). Samples with the same color or appearance in the visible region, which are therefore indistinguishable to the human
Fecha:	2007-09-11
Recurso:	RUA Docencia

Recurso libre

14.

Characterization of a digital camera as an absolute tristimulus colorimeter
Martínez Verdú, Francisco Miguel - Pujol Ramo, Jaume - Capilla Perea, Pascual

Formato:	info:eu-repo/semantics/article
Enlaces:	An algorithm is proposed for the spectral and colorimetric characterization of digital still cameras (DSC) which allows them to be used as tele-colorimeters with CIE–XYZ color output, in cd/m2. The spectral characterization consists in the calculation of the color-matching functions…
Fecha:	2007-09-11
Recurso:	RUA Docencia

Recurso libre

15.

Custom designed dynamic videokeratometer
Mas Candela, David - Kowalska, Malgorzata A. - Espinosa Tomás, Julián - Kasprzak, Henryk T.

Formato:	info:eu-repo/semantics/article
Enlaces:	The human eye is a complex dynamic system that undergoes fine rotations and deformations. Usually information about the eye globe deformation and micromovements are averaged and lost when using commercial measuring devices, although they provide important information about the eye’s…
Fecha:	2010-02-25
Recurso:	RUA Docencia

Recurso libre

16.

Birefringence of cellotape: Jones representation and experimental analysis
Beléndez Vázquez, Augusto - Fernández Varó, Elena - Francés Monllor, Jorge - Neipp López, Cristian

Formato:	info:eu-repo/semantics/article
Enlaces:	In this paper we analyze a simple experiment to study the effects of polarized light. A simple optical system composed of a polarizer, a retarder (cellotape) and an analyzer is used to study the effect on the polarization state of…
Fecha:	2010-03-22
Recurso:	RUA Docencia

Recurso libre

17.

Weighted Zernike polynomial fitting in steep corneas sampled in Cartesian grid
Espinosa Tomás, Julián - Pérez Rodríguez, Jorge - Mas Candela, David - Illueca Contri, Carlos

Formato:	info:eu-repo/semantics/article
Enlaces:	Surfaces with radial structure do not fit well to squared detectors or sampling matrices. Cartesian grid sampling provides a different density of nodes in sectors. Zernike polynomials are a complete set of orthogonal polynomials defined on a unit disk often…
Fecha:	2011-02-21
Recurso:	RUA Docencia

Recurso libre

18.

Corneal aberrometric and refractive performance of 2 intrastromal corneal ring segment models in early and moderate ectatic disease
Piñero Llorens, David Pablo - Alió y Sanz, Jorge L. - El Kady, Bassam - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	Purpose: To evaluate and compare visual, refractive, and corneal aberrometric outcomes after implantation of 2 types of intrastromal corneal ring segments (ICRS) in eyes with early to moderate ectatic disease. Settings: Vissum Corporation-Instituto Oftalmológico de Alicante, Alicante, Spain. Methods: This…
Fecha:	2010-02-15
Recurso:	RUA Docencia

Recurso libre

19.

Number of discernible colors for color-deficient observers estimated from the MacAdam limits
Perales Romero, Esther - Martínez Verdú, Francisco Miguel - Maciel Linhares, João Manuel - Cardoso Nascimento, Sérgio Miguel

Formato:	info:eu-repo/semantics/article
Enlaces:	We estimated the number of colors perceived by color normal and color-deficient observers when looking at the theoretic limits of object-color stimuli. These limits, the optimal color stimuli, were computed for a color normal observer and CIE standard illuminant D65,…
Fecha:	2011-09-20
Recurso:	RUA Docencia

Recurso libre

20.

Blinking kinematics description through non-invasive measurement
Pérez Rodríguez, Jorge - Espinosa Tomás, Julián - Doménech Amigot, Begoña - Mas Candela, David - Illueca Contri, Carlos

Formato:	info:eu-repo/semantics/article
Enlaces:	Spontaneous eye blinking is a complex process, which implies the joint actions of the eyelid muscles and the eye globe. These actions provoke the eyelid closure and simultaneous eye retraction into the orbit. Recently, the authors presented a non-invasive technique…
Fecha:	2011-02-16
Recurso:	RUA Docencia

Recurso libre

21.

New method for comparing colour gamuts among printing technologies
Perales Romero, Esther - Chorro Calderón, Elísabet - Viqueira Pérez, Valentín - Martínez Verdú, Francisco Miguel - Otero Belmar, Susana - Gracia Bonache, Vicente de

Formato:	info:eu-repo/semantics/article
Enlaces:	The authors have developed a simple method to compare the colour gamuts of different industries (printing, textiles, plastics, etc.) based on representing the reproduced colours in constant lightness L* and hue hab* planes. This method allows the analysis of those
Fecha:	2008-10-31
Recurso:	RUA Docencia

Recurso libre

22.

Optical analysis of PresbyLASIK treatment by a light propagation algorithm
Ortiz Márquez, Dolores - Alió y Sanz, Jorge L. - Illueca Contri, Carlos - Mas Candela, David - Sala Pomares, Esperanza - Pérez Rodríguez, Jorge - Espinosa Tomás, Julián

Formato:	info:eu-repo/semantics/article
Enlaces:	PURPOSE: To evaluate the changes in the optical quality of corneas of hyperopic patients operated using central multifocal presbyLASIK treatment through the study of light patterns around the retinal plane. METHODS: This study included eight hyperopic eyes that underwent central…
Fecha:	2008-02-17
Recurso:	RUA Docencia

Recurso libre

23.

Hybrid ternary modulation applied to multiplexing holograms in photopolymers for data page storage
Fernández Varó, Elena - Márquez Ruiz, Andrés - Gallego Rico, Sergi - Fuentes Rosillo, Rosa - García Llopis, Celia - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	Holographic data storage is a new optical technology, which allows an important number of bits to be stored in a recording material. In this paper, holographic data pages were stored in a polyvinyl alcohol/acrylamide (AA) photopolymer layer, using a peristrophic…
Fecha:	2011-07-18
Recurso:	RUA Docencia