Prácticas de Óptica Visual I. Miopía, parte 1 (curso 2011-2012)

Guión de prácticas 3 de laboratorio: miopía, parte 1

Retos ergonómicos-visuales actuales y futuros de la HMI en la conducción

Se exponen un balance de los retos actuales y futuros para gestionar de forma eficiente la distracción visual en conductores ante la avalancha tecnológica de pantallas de navegación, ya sea por su tecnología, como por el diseño e interacción con la información visual, e incluso con otros sentidos (táctil, etc.).II Jornadas de Seguridad Visual: http://catedra-vectalia-movilidad.ua.es/es/jornadas/ii-jornadas-de-seguridad-vial-el-reto-de-la-conservacion-y-la-seguridad-vial.htm

Ciencia del color multi-espectral en Biología

Seminario impartido en el programa de doctorado UA "Biología experimental y aplicada" sobre las aplicaciones potenciales de la ciencia del color multi-espectral en Biología

Spectral responsivity vs. action spectrum in digital photography

We propose an experimental and theoretical methodology based on spectroradiometric procedures to determine the spectral sensitivity of digital still cameras (DSC). The opto-electronic conversion spectral functions (OECSF's) are obtained from normalized digital level (NDL) vs. spectral exposure data, fitted by a typical sigmoidal transition curve. At this stage, we define spectral responsivity r(λ, H) and action spectrum a(λ, NDL), which are conceptual derivations of the general concept of spectral sensitivity of any image sensor. Then, the real spectral responsivity and action spectrum are represented as 3-dimensional functions, where r(λ, H = constant) and a(λ, NDL = constant) profiles are scaled relatively to determine the valid linear output range of the digital image capture device. This range would serve to design the colorimetric profile of the camera with CIE-1931 XYZ standard observer, which is considered as a linear color image sensor.This research was supported by the Comisión Interministerial de Ciencia y Tecnología (CICYT) (Spain) under grants TAP96-0887 and TAP99-0856

Design of online practical lessons in colorimetry

Applied colorimetry is an important module in the program of the elective subject "Colour Science: industrial applications”. This course is taught in the Optics and Optometry Degree and it has been used as a testing for the application of new teaching and assessment techniques consistent with the new European Higher Education Area. In particular, the main objective was to reduce the attendance to lessons and encourage the individual and collective work of students. The reason for this approach is based on the idea that students are able to work at their own learning pace. Within this dynamic work, we propose online lab practice based on Excel templates that our research group has developed ad-hoc for different aspects of colorimetry, such as conversion to different colour spaces, calculation of perceptual descriptors (hue, saturation, lightness), calculation of colour differences, colour matching dyes, etc. The practice presented in this paper is focused on the learning of colour differences. The session is based on a specific Excel template to compute the colour differences and to plot different graphs with these colour differences defined at different colour spaces: CIE ΔE, CIE ΔE94 and the CIELAB colour space. This template is implemented on a website what works by addressing the student work at a proper and organized way. The aim was to unify all the student work from a website, therefore the student is able to learn in an autonomous and sequential way and in his own pace. To achieve this purpose, all the tools, links and documents are collected for each different proposed activity to achieve guided specific objectives. In the context of educational innovation, this type of website is normally called WebQuest. The design of a WebQuest is established according to the criteria of usability and simplicity. There are great advantages of using WebQuests versus the toolbox “Campus Virtual” available in the University of Alicante. The Campus Virtual is an unfriendly environment for this specific purpose as the activities are organized in different sectors depending on whether the activity is a discussion, an activity, a self-assessment or the download of materials. With this separation, it is more difficult that the student follows an organized sequence. However, our WebQuest provides a more intuitive graphical environment, and besides, all the tasks and resources needed to complete them are grouped and organized according to a linear sequence. In this way, the student guided learning is optimized. Furthermore, with this simplification, the student focuses on learning and not to waste resources. Finally, this tool has a wide set of potential applications: online courses of colorimetry applied for postgraduate students, Open Course Ware, etc

Guías y materiales docentes en Moodle para el programa de postgrado en tecnología de color

Actualmente la medida y gestión de la calidad de color de materiales gonio-aparentes es compleja, pero altamente demandada desde varios sectores industriales, como en automoción. En particular, en los últimos años, ha habido una gran demanda de titulados con una buena formación en Tecnología de Color. Por tal motivo, para satisfacer las competencias demandas por la industria, desde el Grupo de Visión y Color de la Universidad de Alicante, se está trabajando en la articulación de un programa de postgrado que oferte a estudiantes, titulados y no titulados, de una amplia y completa formación en Tecnología de Color. Por tanto, el objetivo principal de este trabajo es la elaboración del diseño curricular y materiales docentes para el programa de postgrado propuesto. En una primera fase, el trabajo se centra en la elaboración de la guía docente de cada una de las asignaturas. La segunda fase se centra en la gestión de los materiales docentes mediante la plataforma Moodle que permitirá el seguimiento por parte del alumno a distancia (b-learning). De esta forma, mediante este programa de postgrado se pretende aportar mayores vías de empleabilidad laboral a unos postgraduados en un sector industrial de gran importancia socio-económica a nivel mundial

Diseño curricular y elaboración de materiales para el programa de postgrado en tecnología de color utilizando la plataforma Moodle

En los últimos años, la investigación realizada por el grupo de Visión y Color nos ha permitido conocer la demanda existente en el mercado laboral de expertos en tecnología y reproducción del color, especialmente relacionado con los materiales gonio-aparentes, materiales que ofrecen atractivos atributos para el sector del automóvil, entre otros. Por esta razón, miembros del Grupo de Visión y Color de la Universidad de Alicante nos hemos involucrado en esta red cuyo objetivo principal es ofrecer un programa de postgrado para titulados y no titulados, con una amplia y completa formación en Tecnología de Color. En particular, esta red se ha centrado en el diseño curricular y la elaboración de materiales docentes para este programa de postgrado. En primer lugar, se han desarrollado las guías docentes de cada una de las asignaturas propuestas con el fin de planificar cada una de ellas y poder desarrollar los materiales docentes adecuados. Dado las características de este programa de postgrado, todos los materiales se han elaborado en la plataforma Moodle ya que permite el seguimiento por parte del alumno a distancia (b-learning)

Visual and instrumental correlation of sparkle by the magnitude estimation method

Most real surfaces and objects show variations in appearance with viewing and illumination directions. Besides angular dependency, they also show spatial variation in color, i.e., they exhibit some sort of texture. Of the surfaces we see, surfaces colored by special-effect pigments produce several complex visual effects, like change in color and lightness with viewing and illumination angles, and effects like sparkle and gloss on other textures. In the last two decades, different commercial devices have appeared to help ensure the proper characterization of materials with special-effect pigments. However, the instrumental characterization of sparkle is currently available only by a commercial device integrated into a multi-angle spectrophotometer. As it is difficult to find complete open original studies about the sparkle effect for designing and calibrating this commercial instrument, the main objective of this work was to check whether a good visual and instrumental correlation exists between the sparkle that the observer perceives and the sparkle value provided by the device using some subsets of goniochromatic samples with different types of special-effect pigments and colors. Visual assessments were made by a conventional magnitude estimation method in a directional lighting booth, which belonged to the same company owner of the sparkle instrument, in different geometries and at distinct illuminance levels. The results revealed that there was a good visual correlation of the sparkle grade value. By separately analyzing the factors used in its instrument algorithm, such as sparkle intensity and sparkle area values, it was clearly shown that the correlation was not good or simply did not exist. Consequently, and perhaps in regards to the choice of new special-effect pigments, such as synthetic mica and other future ones, we generated herein even more questions about current mathematical algorithms, and only recognized calculating this texture effect at the industrial level.The authors are grateful to the EMRP for funding the project “Multidimensional Reflectometry for Industry”. The EMRP is jointly funded by EMRP participating countries within EURAMET and the European Union. We thank the Spanish Ministry of Economy and Competitiveness for the coordinated project DPI2011-30090-C02 and project DPI-2015-68514 and University of Alicante for project GRE13-28. Omar Gómez Lozano would also like to thank the above-cited ministry for his pre-doctoral fellowship (FPI BES-2012-053080)

Texture Evaluation of Automotive Coatings by Means of a Gonio-Hyperspectral Imaging System Based on Light-Emitting Diodes

Sparkle and graininess are textural effects that appear as intrinsic spatial features of coatings containing goniochromatic pigments, whereas others such as mottling are undesired outcomes. In this study, we present new methods for the evaluation of sparkle, graininess and mottling of automotive coatings through images acquired with a novel gonio-hyperspectral imaging system based on light-emitting diodes with extended spectral sensitivity beyond the visible range (368–1309 nm). A novel analysis of sparkle that considered the amount of sparkling spots was used. Graininess was quantified through a novel statistical descriptor based on the energy descriptor computed from the histogram. A new index was proposed for an enhanced detection of mottling based on the analysis of striping, which was better observed and quantified in the infrared range. Spectral assessments showed a strong relationship with color and spectral reflectance for graininess and mottling. In conclusion, the results showed that these new spatial and spectral methods are a suitable, alternative and potential approach for the assessment of these textural features.Ministerio de Ciencia e Innovación (MICINN, DPI2011-30090-C02-01) and Ministerio de Economía y Competitividad (MINECO, DPI2014-56850-R); and the European Union

Aplicación de la colorimetría triestímulo al estudio del fenómeno de copigmentación en vinos tintos: Influencia del factor varietal

Se ha demostrado la utilidad de la Colorimetría Triestímulo, específicamente el espacio de color CIELAB, en la evaluación de las implicaciones colorimétricas asociadas al fenómeno de copigmentación de antocianos en vinos tintos jóvenes. En general, la magnitud de copigmentación calculada por colorimetría osciló entre el 11% y el 44%. En todos los vinos, la contribución de la copigmentación al color del vino superó el umbral de discriminación visual, teniendo un mayor peso la modificación de la claridad y favoreciendo que el color del vino fuese más oscuro, vivo y de tonalidad más azulada. Se confirmó la influencia, tanto cuantitativa como cualitativa, de la variedad de uva en la capacidad de copigmentación y la estabilidad del color de vinos tintos jóvenes.Consejería de Innovación, Ciencia y Empresa de la Junta de Andalucía: proyecto de excelencia P07-AGR-0289