David Carmona, Juan Manuel Trujillo, Sergio Bonaque, Ángela Hernández, José M Rodríguez-Ramos
Tensor display is an option in glasses-free three-dimensional (3-D) display technology. An initial solution has to be set to decompose the light-field information to be represented by the system. We have analyzed the impact of the initial guess on the multiplicative update rules in terms of peak signal-to-noise ratio, and proposed a method based on depth map estimation from an input light field.
Óscar Gómez, José G. Marichal, Juan Manuel Trujillo, David Carmona, José Manuel Rodríguez-Ramos
The discrete Radon transform, DRT, calculates, with linearithmic complexity, the sum of pixels through a set of discrete lines covering all possible slopes and intercepts in an image. In 2006, a method was proposed to compute the inverse DRT that remains exact and fast, in spite of being iterative. In this work the DRT pair is used to propose a Ridgelet and a Curvelet transform that perform focus measurement of an image.
Sergio Bonaque, J.J. Fernández-Valdivia, Juan Manuel Trujillo, Oscar Gomez
In this work we propose the use of a new full definition wave front sensing technique for aberration measurement in optical elements. The technique apparatus doesn’t need additional optics elements and wave front map resolution is only limited by the resolution of the imaging sensor being used. We outline some of the analitical details and the advantages of this method compared with classic wave front sensors.
J.J. Fernández, Juan Trujillo, Oscar Casanova, R. L. López, S. Velasco, C. Colodro, M. Puga, A. Oscoz, R. Rebolo, C. Mackay, A. Pérez, L.F. Rodríguez, D. King, L. Labadie, B. Muthusubramanian, G. Rodríguez-Coira, José M Rodríguez-Ramos
This paper presents a method to recover the wavefront phase at the telescope pupil, distorted because of the atmosphere action, and its use to command a deformable mirror…
Juan Manuel Trujillo, Vladimir Katkovnik, Bahram Javidi, José Manuel Rodríguez-Ramos
This paper contains an original development of the compressed sensing technique for restoring integral images from a number of observed 2D images. The proposed data acquisition uses a conventional camera equipped with a horizontal 1D mask placed in the pupil plane of the lens. The compressed sensing style algorithm developed is based on a sparsity hypothesis imposed on 2D cross sections of the light field.
Juan Manuel Trujillo, Juan J. Fernández, Luis F. Rodríguez, Óscar G. Cárdenes, José G. Marichal, Bahram Javidi, José Manuel Rodríguez-Ramos
In this paper, we use information from the light field to obtain a distribution map of the wavefront phase. This distribution is associated with changes in refractive index which are relevant in the propagation of light through a heterogeneous or turbulent medium. Through the measurement of the wavefront phase from a single shot, it is possible to make the deconvolution of blurred images affected by the turbulence.
Juan Manuel Trujillo, J. J. Fernández-Valdivia, J. G. Marichal-Hernández, José Manuel Rodríguez-Ramos, L. F. Rodríguez-Ramos, I. Mantilla
The deconvolution applied to plenoptic sensors has only been studied in the area of light intensity, including no treatment for the possible path changes that optical rays suffer due to the refraction index changes in the medium.
Juan Manuel Trujillo, L. F. Rodríguez-Ramos, I. Montilla, José Manuel Rodríguez-Ramos
Plenoptic imaging systems are becoming more common since they provide capabilities unattainable in conventional imaging systems, but one of their main limitations is the poor bidimensional resolution. Combining the wavefront phase measurement and the plenoptic image deconvolution, we propose a system capable of improving the resolution when a wavefront aberration is present and the image is blurred.
Juan Manuel Trujillo, L. F. Rodríguez-Ramos, Juan J. Fernández-Valdivia, José G. Marichal, José Manuel Rodríguez-Ramos
Modern astronomic telescopes take advantage of multi-conjugate adaptive optics, in which wavefront sensors play a key role. A single sensor capable of measuring wavefront phases at any angle of observation would be helpful when improving atmospheric tomographic reconstruction.
Luis F. Rodríguez-Ramos, Icíar Montilla, Juan Manuel Trujillo, José Manuel Rodríguez-Ramos
The use of the plenoptic camera as a wavefront sensor has been proposed and demonstrated in the past by our group, as especially adequate for extended objects, within the context of the design of the European Solar Telescope (EST), and also may be used with point sources and even with elongated objects like laser guide stars.