Purpose: Amblyopia is a developmental disorder of spatial vision for which there is no positive diagnostic test. The present study evaluates the recently developed “Pelli-Levi Dual Acuity Chart” as a positive diagnostic test for amblyopia (Pelli, Levi & Chung, 2004). This chart consists of letters, as usual, on one side and letters in noise on the other. This exploits the finding that, for lett...

Pinhole imaging of large (mm scale) carbon-deuterium (CD) plasmas by proton self-emission has been used for the first time to study the microphysics of shock formation, which is of astrophysical relevance. The 3 MeV deuterium-deuterium (DD) fusion proton self-emission from these plasmas is imaged using a novel pinhole imaging system, with up to five different 1 mm diameter pinholes positioned 2...

This paper presents an application of “shape from polarization” method in the far Infrared range with applications for three-dimensional reconstruction of transparent objects. Shape from polarization is a recent application of more general polarization imaging technique having the aim to digitize the shape of the observed object. The principle is to evaluate the normal on each observed point fo...

In this work, we developed and validated two novel imaging geometries of benchtop multi-pinhole X-ray fluorescence computed tomography (XFCT) systems with Geant4 Toolkit. One the Monte Carlo (MC) models utilized a fan beam source to illuminate single slice object, detector collimator image each slice’s (XRF). The other model consisted cone-beam (designed as 5 mm wide reduce simulation time) sca...

SPEAR3 has two diagnostic beam lines: an x-ray pinhole camera and a visible/UV beam line. The pinhole camera images ~8 keV dipole synchrotron radiation (SR) incident on a phosphor screen. The visible beam line delivers conventional optical radiation to an array of cameras and diagnostic elements on a 1x3m optical bench. This paper briefly reviews the pinhole camera system while concentrating mo...

A new pinhole camera system has been installed on Spear 2 to measure its vertical emittance. The hard X-rays from a bending magnet source point are imaged on a phosphor screen through a 30 um x 25 um pinhole aperture. The resolution of the system for 8 keV photons is limited to 31.2 um by Fraunhoffer diffraction and is much smaller than the 340 um FWHM vertical beam size corresponding to 0.9% v...

Camera tracking for uncalibrated image sequences has now reached a level of maturity where 3D point structure and cameras can be recovered automatically for a significant class of scene types and camera motions. However, problems still occur, and their solution requires a combination of theoretical analysis and good engineering. We describe several such problems including missing data, degenera...

Calibration of the pinhole camera model has a well–established theory, especially in the presence of a known calibration object. Unfortunately, in wide-base multi–camera setups, it is hard to create a calibration object, which is visible by all the cameras simultaneously. This results in the fact that conventional calibration methods do not scale well. Using well-known algorithms, we developed ...

____________________________________________________________________________ Abstract The present ISR describes the encircled energy(EE) analysis of pinhole images made on the M10 WFC3 1R-MUX at the Goddard Space Flight Center (GSFC) Detector Characterization Lab (DCL) on 29 May 2001. Analysis shows that the pinhole image’s centroid is stable within a 1-pixel area and the 80% of the encircled e...