Browsing by Subject "Real time"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Publication
    Open Access
    GPU-based processing of Hartmann-Shack images for accurate and high-speed ocular wavefront sensing
    (Elsevier, 2019-02) Mompeán, J.; Aragón, J.L.; Prieto, P.; Artal, P.; Ingeniería y Tecnología de Computadores
    Hartmann–Shack aberrometry is a widely used technique in the field of visual optics but, high-speed and accurate processing of Hartmann–Shack images can be a computationally expensive/resource intensive task. While some advancements have been made in achieving high-performance processing units, they have not been specifically designed for processing Hartmann–Shack images of the human eye with Graphics Processing Units. In this work, we present the first full-Graphics Processing Unit implementation of a Hartmann–Shacksensor algorithm aimed at accurately measuring ocular aberrations at a high speed from high-resolution spot pattern images. The proposed algorithm, called PaPyCS (Parallel Pyramidal Centroid Search), is inherently parallel and performs a very robust centroid search to avoid image noise and other artifacts. This is a field where the use of Graphics Processing Units have not been exploited despite the fact that they can boost Adaptive Optics systems and related closed-loop approaches. Our proposed implementation achieves processing speeds of 380 frames per second for high resolution (1280x1280 pixels) images, in addition to showing a high resilience to system and image artifacts that appear in Hartmann–Shack images from human eyes: more than 98% of the Hartmann–Shack images, with aberrations of up to 4m Root Mean Square for a 5.12mm pupil diameter, were measured with less than 0.05m Root Mean Square Error, which is basically negligible for ocular aberrations.
  • Thumbnail Image
    Publication
    Open Access
    Portable device for presbyopia correction with optoelectronic lenses driven by pupil response
    (Springer Nature, 2020-11-20) Mompeán, J.; Aragón, J.L.; Artal, P.; Aragón, J.L.; Artal, P.; Ingeniería y Tecnología de Computadores
    A novel portable device has been developed and built to dynamically, and automatically, correct presbyopia by means of a couple of opto-electronics lenses driven by pupil tracking. The system is completely portable providing with a high range of defocus correction up to 10 D. The glasses are controlled and powered by a smartphone. To achieve a truly real-time response, image processing algorithms have been implemented in OpenCL and ran on the GPU of the smartphone. To validate the system, different visual experiments were carried out in presbyopic subjects. Visual acuity was maintained nearly constant for a range of distances from 5 m to 20 cm.
  • Thumbnail Image
    Publication
    Open Access
    Reseña: Mateo García, M. V., y García Marcos, F. (2022). "Evaluación sociolingüística, la dimensión del tiempo real". Granada: Editorial Comares.
    (Instituto de Lingüística Materialista, 2023) Zapata Barrero, Belén
    Basándose en la sociolingüística variacionista de Labov, Mateo García y García Marcos (2022) abordan el fenómeno de la generación de actitudes hacia el aprendizaje de las lenguas extranjeras en la comunidad de habla de Almería mediante la implementación de una metodología de tiempo real. Los resultados obtenidos a través de esta perspectiva cronológica ofrecen conclusiones relevantes respecto a la programación lingüística, la normativización, la normalización del repertorio lingüístico y la mortandad lingüística. En base a esto, los autores predicen la conformación de un panorama sociolingüístico global multilingüe, que se torna necesario para poder operar de forma efectiva en una sociedad cada vez más globalizada.