Person: Canabal Boutureira, Héctor Alfonso
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First Name
Héctor Alfonso
Last Name
Canabal Boutureira
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Óptica
Area
Optica
Identifiers
12 results
Search Results
Now showing 1 - 10 of 12
Item Automatic processing in Moiré deflectometry by local fringe direction calculation(Applied Optics, 1998) Canabal Boutureira, Héctor Alfonso; Quiroga Mellado, Juan Antonio; Bernabéu Martínez, EusebioAn algorithm for accurately extracting the local fringe direction is presented. The algorithm estimates, in the neighborhood of n × n points, the direction of the gradient that points normal to the local fringe direction. The performance of four different derivative kernels is also compared. Since this method is sensitive to noise and variations in background and amplitude, a preprocessing step is used to limit these error sources. The method has been applied to the moiré deflectogram of a spherical and a progressive addition ophthalmic lens, resulting in a map of the refractive power of these lenses. The results are compared with the data obtained with a commercial focimeter. This technique is useful for analyzing the fringe patterns where the fringe direction is variable and must be obtained locally.- Project number: 54
Item Desarrollo de material docente audiovisual online de apoyo para la asignatura: dispositivos de instrumentación óptica(2023) Vargas Balbuena, Javier; Diez Garrote, Francisco; Quiroga Mellado, Juan Antonio; Canabal Boutureira, Héctor Alfonso; Boiso Calero, AntonioEn este proyecto de innovación docente se han desarrollado una serie de videos cortos para fijar visualmente conceptos clave sobre instrumentación óptica. Estos videos están enfocados en la mejora de la compresión y análisis de los estudiantes de la asignatura Dispositivos de Instrumentación Óptica de cuarto curso del Grado en Físicas. Es decir, nuestro objetivo es proporcionar a los estudiantes con experiencias virtuales de laboratorio que les permitan entender de forma sencilla y rápida conceptos esenciales de la asignatura. También estos videos serán utilizados en el aula por los profesores como material docente de apoyo. Item Enhancement of surface inspection by Moiré interferometry using flexible reference gratings(Optics Express, 2001) Quiroga Mellado, Juan Antonio; Martínez Antón, Juan Carlos; Canabal Boutureira, Héctor Alfonso; Bernabéu Martínez, Eusebio; Álvaro Labajo, M.; Cortés Testillano, V.We have extended the use of shadow Moiré technique to be implemented in simple curved surfaces by using a flexible grating. Dynamic visual inspection of surface micro-damages is significantly favored by the use of well adapted pliable gratings compared to the use of flat reference gratings. The experimental set-up consists of a plastic foil with a printed Ronchi grating stretched between three points which adapts to any cylindrical or conical convex surface independently of the relative orientation grating/surface. Static quantification of defects profiles is also possible with an attached CCD camera. Visual detection of defects in the range of ~30 μm in depth is obtainable.Item Energy optimization of a light projection system for buildings that virtually restores artworks(Digital Applications in Archaeology and Cultural Heritage, 2019) Vázquez Molini, Daniel; Álvarez Fernández-Balbuena, Antonio; Canabal Boutureira, Héctor Alfonso; Muro, Carmen; Durmus, D.; Davis, W.; Benítez Iglesias, Antonio Jesús; Mayorga Pinilla, SantiagoThe need to achieve energy efficiency standards in the lighting systems of buildings makes it necessary to optimize all aspects of them. Here, the development of a light projection system that achieves this goal by studying and modifying the spectral output, compared to conventional illumination, is described. A lighting system that estimates the reflectance characteristics of artwork and emits optimized lighting can reduce light absorption. A damage-minimizing point-by-point light projection system is developed using an optimization algorithm, to improve the appearance of the surfaces of artworks whose color has faded. In this case, a simulation of an aged oil painting was made by manipulating the original photograph, which was printed and to which the proposed system was applied. The results show that, when the aged printed image is illuminated with the optimized light source, it appears indistinguishable from the non-aged oil painting.Item Detection of microbumps in aeronautic surfaces by means of an elastical Moire system(Optical Measurement Systems for Industrial Inspection II: Application in Industrial Design, 2001) Quiroga Mellado, Juan Antonio; Martínez Antón, Juan Carlos; Canabal Boutureira, Héctor Alfonso; Bernabéu Martínez, Eusebio; Álvaro Labajo, M.; Cortés Testillano, V.We provide a simple solution for the particular problem of the in-service inspection of aeronautic surfaces in order to detect bumps that otherwise it is made visually and usually less reliably. Bumps and other surface defects can be a symptom of a more serious internal damage. We have extended the use of the well know shadow Moire technique to be implemented in convex curved surfaces. The use of flexible Ronchi grating allows its adaptation to a convex general surface. The effect is the contrast enhancement of only the small defects sweeping-off other misleading height profile fringes. The result obtained are quite satisfactory compared to the use of flat reference gratings. The experimental set- up consists of a plastic foil with a printed Ronchi grating stretched between three points which adapts to nay cylindrical or conical convex surface independently of the relative grating-surface orientation. Static quantification of defects profiles is also possible by means of with an attached CCD camera. Visual detectability of local surface structures lye in the range of approximately 30 micrometers in depth.Item A generalization of Prentice's law for lenses with arbitrary refracting surfaces(Ophthalmic & Physiological Optics (OPO), 1998) Canabal Boutureira, Héctor Alfonso; Gómez Pedrero, José Antonio; Alonso Fernández, José; Bernabéu Martínez, EusebioA generalization of the Prentice's law is presented in this paper. The idea consists of removing some (but not all) of the approximations that comprise the paraxial approach. In that way, we obtain a new formulation that permits us to compute the prismatic power of a lens made up of arbitrary refracting surfaces, and to improve the precision obtained by Prentice's law when applied to monofocal lenses. The resulting formalism is simple and manageable and its derivation leads us to a precise definition of the local dioptric power matrix, introduced in a previous paper, as well as a better understanding of the same.- Project number: 49
Item Ampliación y actualización de las prácticas del laboratorio de Instrumentación Biomédica buscando un aprendizaje y evaluación centrados en el estudiante(2020) Chevalier Del Río, Margarita; Alieva Krasheninnikova, Tatiana; Martínez Matos, Óscar; Rodrigo Martín Romo, José Augusto; Canabal Boutureira, Héctor Alfonso; Comas Renfigo, María Dolores; Soto Rueda, Juan Manuel; Angulo Curto, Mercedes; Castillo García, MaríaEl objetivo del proyecto es el diseño de las prácticas de laboratorio para la asignatura Instrumentación Biomédica del Master de Física Biomédica. Se pretende mejorar el aprendizaje potenciando la participación activa y autonomía de los estudiantes. La falta de financiación económica se ha traducido en obtener como resultado del proyecto la redacción de guiones de prácticas que posibiliten el trabajo individual del alumno fuera del laboratorio dado el alto número de alumnos por puesto para llevar a cabo las prácticas. Estos guiones se han complementado con scripts en MatLab para analizar y procesar los datos obtenidos en el laboratorio así como datos obtenidos en diversas bases. Esta propuesta dió información sobre el progreso de los estudiantes en el aprendizaje cuando se utilizó el sistema de rúbricas tambien resultado de este proyecto. Item Improved Phase-Shifting Method for Automatic Processing of Moiré Deflectograms(Applied Optics, 1998) Canabal Boutureira, Héctor Alfonso; Quiroga Mellado, Juan Antonio; Bernabéu Martínez, EusebioAn improved moiré deflectometry phase-shifting technique is presented. A squared grating is used to multiplex the information of the deflections in two orthogonal directions in one image. This procedure avoids the need to rotate the gratings to obtain complete deflection information. However, the use of these gratings makes impossible the application of standard phase-shifting algorithms. Specifically, the problems associated with the nonsinusoidal profile of the moiré fringes and the low-modulation areas produced by the square gratings are solved. A modified moiré deflectometry phase-shifting method is designed to deal with these problems. In addition, a method to obtain the zero order of the prismatic effect is developed. The technique configures a complete and automatic method of mapping ray deflections. From them the refractive power maps can be derived. Experimental results obtained with a progressive-addition lens are shown.- Project number: 136
Item Estrategias de iniciación a la experimentación en laboratorios de las enseñanzas en Óptica(2015) Martínez Matos, Óscar; Alieva Krasheninnikova, Tatiana; Canabal Boutureira, Héctor Alfonso; Navarrete Fernández, María de la Cruz; Gonzalo Fonrodona, Isabel; Herrera Fernández, José María; Irigoyen Irigoyen, Maite; Luis Aina, Alfredo; Piquero Sanz, Gemma María; Rodrigo Martín Romo, José Augusto; Sánchez Brea, Luis Miguel; Sánchez Martín, José Antonio; Serna Galán, Julio; Tercero Gómez, José Luis; Torcal Milla, Francisco José; Vilas Prieto, José Luis; Weigand Talavera, Rosa MaríaSe propone un cambio en la metodología docente de la asignatura Laboratorio de Física III del Grado en Física, para hacerla más dinámica y potenciar la participación e iniciativas de los estudiantes, adecuándola al espíritu de Bolonia Item In-line detection and evaluation of surface defects on thin metallic wires(Optical Measurement Systems for Industrial Inspection II: Applications in Production Engineering, 2001) Martínez Antón, Juan Carlos; Siegmann, Philip; Sánchez Brea, Luis Miguel; Gómez Pedrero, José Antonio; Canabal Boutureira, Héctor Alfonso; Bernabéu Martínez, Eusebio; Hoefling, Roland; Jueptner, Werner P. O.; Kujawinska, MalgorzataWe have developed a prototype for in-line detection of surface defects in metallic wires, specially for scratches. A simple geometrical relationship between surface topography and conical reflection, permits to correlate the defects with intensity patterns in a simple way. The presented apparatus consists basically in a grating-divided laser beam incident on angular equidistant points. A CCD and an associated optics capture the information of the whole wire perimeter at once. Analytic rudiments are provided in agreement with the experimental results.