Results 31 to 40 of about 9,643,688 (148)

Mesopic radial frequency contrast sensitivity function for young and older adults

Brazilian Journal of Medical and Biological Research, 2006
The objective of the present study was to determine contrast sensitivity curves of concentric circular patterns with radial frequencies of 0.25, 0.5, 1.0, 2.0, and 4.0 cycles per degree in young and older adult volunteers.
N.A. Santos, A.B. Oliveira, R.M.T.B.L. Nogueira, M.L.B. Simas   +3 more
doaj   +1 more source

Peeling Plaids Apart: Context Counteracts Cross-Orientation Contrast Masking [PDF]

, 2009
Background: Contrast discrimination for an image is usually harder if another image is superimposed on top. We asked whether such contrast masking may be enhanced or relieved depending on cues promoting integration of both images as a single pattern ...
Verghese, P., Preeti Verghese, Freeman, E, Verghese, P, Freeman, E. D., Elliot Freeman   +5 more
core   +2 more sources

Image quality optimization, via application of contextual contrast sensitivity and discrimination functions [PDF]

, 2015
What is the best luminance contrast weighting-function for image quality optimization? Traditionally measured contrast sensitivity functions (CSFs), have been often used as weighting-functions in image quality and difference metrics. Such weightings have
Fry, E., Edward Fry, Gupta, G., Triantaphillidou, S., Sophie Triantaphillidou, John Jarvis, Gaurav Gupta, Jarvis, J.   +7 more
core   +1 more source

Modified human contrast sensitivity function based phase mask for susceptibility-weighted imaging

NeuroImage: Clinical, 2014
The aim of the work is to increase the visual information in magnetic resonance imaging based susceptibility weighted images. Our approach is to amplify spatial frequency information of the phase mask used to increase susceptibility weighting using a ...
Wei-Hsin Wang, David C. Reutens, Zhengyi Yang, Giang Nguyen, Viktor Vegh   +4 more
doaj   +1 more source

Consequences of Monocular Diplopia for the Contrast Sensitivity Function [PDF]

, 1996
Though the human eye generally creates a single image on the retina, the literature contains many examples showing perceptual monocular diplopia. Previously, monocular diplopia resulting from astigmatic defocus has been demonstrated to cause a notch ...
ATCHISON, DAVID A., WOODS, RUSSELL L., BRADLEY, ARTHUR   +2 more
core   +1 more source

Binocular contrast vision at and above threshold [PDF]

, 2006
A fundamental problem for any visual system with binocular overlap is the combination of information from the two eyes. Electrophysiology shows that binocular integration of luminance contrast occurs early in visual cortex, but a specific systems ...
Georgeson, Mark A., Meese, Tim S., Meese, Timothy S., D. H. Baker, T. S. Meese, M. A. Georgeson, Baker, Daniel H.   +6 more
core   +1 more source

Effects of COVID-19 on the contrast sensitivity [PDF]

Brazilian Journal of Medical and Biological Research
There are significant gaps in understanding the extent of the damage caused by COVID-19, with few publications examining its link to contrast sensitivity function (CSF).
G.M. Silva, J.J.S Souto, T. Fernandes, G.S. Souza, M.J.O. de Andrade, N.A. dos Santos   +5 more
doaj   +1 more source

Defining human contrast sensitivity and discrimination from complex imagery

, 2013
Shape, form and detail define image structure in our visual world. These attributes are dictated primarily by local variations in luminance contrast.
Gupta, G., Rana, H., S. Triantaphillidou, Triantaphillidou, S., H. Rana, J. Jarvis, G. Gupta, Jarvis, J.   +7 more
core   +1 more source

On the calculation of optical performance factors from vertebrate spatial contrast sensitivity [PDF]

, 2007
A novel technique for calculating the visual optical modulation transfer function (OMTF) is described. The technique involves application of the Rovamo–Barten model of spatial vision to measured contrast sensitivity data.
Jarvis, John R., Wathes, Christopher M., Wathes, C M, Jarvis, J R, Wathes, C.M., Jarvis, J.   +5 more
core   +1 more source

Laboratory implementation of edge illumination X-ray phase-contrast imaging with energy-resolved detectors [PDF]

, 2015
Edge illumination (EI) X-ray phase-contrast imaging (XPCI) has potential for applications in different fields of research, including materials science, non-destructive industrial testing, small-animal imaging, and medical imaging.
A. Olivo, De Ruvo, L, Endrizzi, M., Kallon, G, SPANDRE, GLORIA, G. Spandre, Vincenzi, A, Kallon, G., A. Brez, Hagen, C. K., Olivo, A, L. De Ruvo, Basta, D, P. C. Diemoz, F. A. Vittoria, Hagen, CK, Olivo, A., C. K. Hagen, Spandre, G, Brez, A., M. Marenzana, Brez, A, DELOGU, PASQUALE, Vittoria, F. A., Marenzana, M., Bellazzini, R, Diemoz, P. C., Vincenzi, A., BELLAZZINI, RONALDO, A. Vincenzi, D. Basta, M. Endrizzi, G. Kallon, R. Bellazzini, Diemoz, PC, Vittoria, FA, Delogu, P, Endrizzi, M, Marenzana, M, De Ruvo, L., Basta, D., P. Delogu   +41 more
core   +1 more source