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Journals and Conferences
Signal detection psychophysical experiments were conducted to investigate the visual path of children with autism. Computer generated images with Gaussian noise were used. Simple signals, still and in motion were embedded in the background noise. The computer monitor was linearized to properly display the contrast changes. To our knowledge, this is the… (More)
A fully automatic computerized method for segmenting contours of corneal endothelial cells is proposed. As part of the method, scale-space filtering (i.e. Gaussian filtering) is used to achieve tasks different from noise removal. This type of filtering is applied making use of the separability property of Gaussian kernels, avoiding the erosion of images. A… (More)
We present two contour-based techniques, for computerized object recognition that avoid the difficulties due to translations, rotations and scaling. Our techniques do not require any shape representation. The first technique uses the scale-space filtered coordinate functions of contours and their "largest diameters". The second, uses the Hotelling transform… (More)
OBJECTIVE To describe a simple and quick procedure for modeling samples of tissue with Voronoi diagrams. STUDY DESIGN Instead of calculating the centers of the so-called Dirichlet domains (i.e., the polygonal areas occupied by individual cells), the centroid of such areas is used to generate Voronoi diagrams. The coordinates of the centroids are… (More)
The fabrication and testing of glass microlenses with rod and spherical shapes are described. The sizes of the lenses range from tens of micrometers to several millimeters. The surfaces of the lenses were fabricated by the melting method. These surfaces have been studied by several methods. The theoretical behavior of the lenses was investigated by ray… (More)
Plateau's experiment, in which the bisection method was introduced, is recognized as the first psychophysical experiment ever done. That experiment was replicated and extended using modem imaging devices. First, participants with professional training in visual arts painted grayscales with no control on illumination. Then, the trained participants and the… (More)
To study the radiation emitted by the human skin, the emissivity of its surface must be known. We present a new approach to measure the emissivity of the human skin in vivo. Our method is based on the calculation of the difference of two infrared images: one acquired before projecting a CO(2) laser beam on the surface of the skin and the other after such… (More)
Here we propose a new optical method, to our knowledge, to measure the pressure in liquids or gases by means of a flexible lens. Images of an object given by the dynamical lens are analyzed, and through the visibility of those images pressure is inferred.
Here we propose optofluidic spherical microlenses that can change their focal distance by varying the refractive index of the liquid that composes them. These lenses are fabricated in the bulk of a polymeric mixture. Results of a characterization study of the profile of the lenses, the image forming capability, and the behavior of the focal distance as a… (More)
We present a new kind of compact, simple, and low cost optical pressure sensor. The physical principle on which the sensor is based, components, layout of the system, and characterization are described. The range of pressures in which the sensor works is from about 0.5 to 3 psi (1 psi=6.895 kPa).