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Mozhaeva A, Cree MJ, Durrant RJ, Vlasuyk I, Potashnikov A, Mazin V, Streeter L. A contrast sensitivity model of the human visual system in modern conditions for presenting video content. PLoS One 2024; 19:e0303987. [PMID: 38814909 PMCID: PMC11139320 DOI: 10.1371/journal.pone.0303987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 05/04/2024] [Indexed: 06/01/2024] Open
Abstract
Digital video incurs many distortions during processing, compression, storage, and transmission, which can reduce perceived video quality. Developing adaptive video transmission methods that provide increased bandwidth and reduced storage space while preserving visual quality requires quality metrics that accurately describe how people perceive distortion. A severe problem for developing new video quality metrics is the limited data on how the early human visual system simultaneously processes spatial and temporal information. The problem is exacerbated by the fact that the few data collected in the middle of the last century do not consider current display equipment and are subject to medical intervention during collection, which does not guarantee a proper description of the conditions under which media content is currently consumed. In this paper, the 27840 thresholds of the visibility of spatio-temporal sinusoidal variations necessary to determine the artefacts that a human perceives were measured by a new method using different spatial sizes and temporal modulation rates. A multidimensional model of human contrast sensitivity in modern conditions of video content presentation is proposed based on new large-scale data obtained during the experiment. We demonstrate that the presented visibility model has a distinct advantage in predicting subjective video quality by testing with video quality metrics and including our and other visibility models against three publicly available video datasets.
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Affiliation(s)
| | - Michael J. Cree
- School of Engineering, The University of Waikato, Hamilton, New Zealand
| | - Robert J. Durrant
- School of Engineering, The University of Waikato, Hamilton, New Zealand
| | - Igor Vlasuyk
- Department of Television and Sound Broadcasting, Moscow Technical University of Communications and Informatics, Moscow, Russian Federation
| | - Aleksei Potashnikov
- Department of Television and Sound Broadcasting, Moscow Technical University of Communications and Informatics, Moscow, Russian Federation
| | - Vladimir Mazin
- Department of Television and Sound Broadcasting, Moscow Technical University of Communications and Informatics, Moscow, Russian Federation
| | - Lee Streeter
- School of Engineering, The University of Waikato, Hamilton, New Zealand
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Huchzermeyer C, Kremers J. Perifoveal L- and M-cone-driven temporal contrast sensitivities at different retinal illuminances. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2016; 33:1989-1998. [PMID: 27828102 DOI: 10.1364/josaa.33.001989] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We established a protocol using a well-established LED stimulator to measure temporal contrast sensitivities driven by sine-wave modulation of L- and M-cones in the perifovea using triple silent substitution. The stimulus was presented in an annular field (2° inner diameter, 13° outer diameter). We validated this technique by studying the contrast sensitivity of three color normal observers at 10 different temporal frequencies (between 1 and 28 Hz) over a large range of retinal illuminances (between 0.07 and 587 phot Td), spanning the complete mesopic range. In one subject, sensitivities to counterphase modulation of L- and M-cones and in-phase modulation of L, M, and S-cones were additionally measured, which putatively reflected the parvo- and magnocellular retinogeniculate pathways, respectively. Furthermore, we performed measurements of temporal contrast sensitivities as a function of frequency at 294 phot Td in two protanopes, in two deuteranopes, and in one subject with S-cone monochromacy. Quality of isolation was satisfactory and we were able to reproduce known physiological patterns of temporal vision, such as the typical temporal contrast sensitivity functions of the L- and M-cone, the parvo- and magnocellular retinogeniculate pathways, as well as the light adaptation curves. These results will help determine optimal stimulus conditions in future studies. Results from the dichromats and the S-cone monochromat also support the quality of isolation of our protocol and underpin its potential clinical value.
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Contrast sensitivity in relapsing-remitting multiple sclerosis assessed by sine-wave gratings and angular frequency stimuli. Vis Neurosci 2014; 31:381-6. [PMID: 24834838 DOI: 10.1017/s0952523814000182] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Previous studies have shown that multiple sclerosis (MS) affects the visual system, mainly by reducing contrast sensitivity (CS), a function that can be assessed by measuring contrast sensitivity function (CSF). To this end, we measured both the CSF for sine-wave gratings and angular frequency stimuli with 20 participants aged between 21 and 44 years, of both genders, with normal or corrected to normal visual acuity. Of these 20 participants, there were 10 volunteers with clinically defined MS of the relapsing-remitting clinical form, with no history of optic neuritis (ON), as well as 10 healthy volunteers who served as the control group (CG). We used a forced-choice detection paradigm. The results showed reduced CS to both classes of stimuli. Differences were found for sine-wave gratings at spatial frequencies of 0.5, 1.25, and 2.5 cycles per degree (cpd) (P < 0.002) and for angular frequency stimuli of 4, 24, and 48 cycles/360° (P < 0.05). On the one hand, comparing the maxima of the respective CSFs, the CS to angular frequency stimuli (24 cycles/360°) was 1.61-fold higher than that of the CS to vertical sine-wave gratings (4.0 cpd) in the CG; for the MS group, these values were 1.55-fold higher. On the other hand, CS in the MS group attained only 75% for 24 cycles/360° and 78% for 4.0 cpd of the 100% CS estimates found for the CG at the peak frequencies. These findings suggest that MS affects the visual system, mostly at its maximum contrast sensitivities. Also, since angular frequencies and sine-wave gratings operate at distinct levels of contrast in the visual system, MS seems to affect CS at both high and low levels of contrast.
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Abstract
Acute optic neuritis is the most common optic neuropathy affecting young adults. Exciting developments have occurred over the past decade in understanding of optic neuritis pathophysiology, and these developments have been translated into treatment trials. In its typical form, optic neuritis presents as an inflammatory demyelinating disorder of the optic nerve, which can be associated with multiple sclerosis. Atypical forms of optic neuritis can occur, either in association with other inflammatory disorders or in isolation. Differential diagnosis includes various optic nerve and retinal disorders. Diagnostic investigations include MRI, visual evoked potentials, and CSF examination. Optical coherence tomography can show retinal axonal loss, which correlates with measures of persistent visual dysfunction. Treatment of typical forms with high-dose corticosteroids shortens the period of acute visual dysfunction but does not affect the final visual outcome. Atypical forms can necessitate prolonged immunosuppressive regimens. Optical coherence tomography and visual evoked potential measures are suitable for detection of neuroaxonal loss and myelin repair after optic neuritis. Clinical trials are underway to identify potential neuroprotective or remyelinating treatments for acutely symptomatic inflammatory demyelinating CNS lesions.
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Affiliation(s)
- Ahmed T Toosy
- Queen Square Multiple Sclerosis Centre, UCL Institute of Neurology, University College London, London, UK; Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, University College London, London, UK.
| | - Deborah F Mason
- Department of Neurology, Christchurch Hospital, Christchurch, New Zealand
| | - David H Miller
- Queen Square Multiple Sclerosis Centre, UCL Institute of Neurology, University College London, London, UK; Department of Neuroinflammation, UCL Institute of Neurology, University College London, London, UK; New Zealand Brain Research Institute, University of Otago, Christchurch, New Zealand
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Cao D, Zele AJ, Pokorny J, Lee DY, Messner LV, Diehl C, Ksiazek S. Functional loss in the magnocellular and parvocellular pathways in patients with optic neuritis. Invest Ophthalmol Vis Sci 2011; 52:8900-7. [PMID: 22016061 DOI: 10.1167/iovs.11-7644] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To evaluate contrast threshold and contrast gain in patients with optic neuritis under conditions designed to favor mediation by either the inferred magnocellular (MC) or parvocellular (PC) pathway. METHODS Achromatic and chromatic contrast discrimination was measured in 11 patients with unilateral or bilateral optic neuritis and in 18 age-matched controls with normal vision, using achromatic steady- and pulsed-pedestal paradigms to bias performance toward the MC or PC pathway, respectively. In addition, L-M chromatic discrimination at equiluminance was evaluated using the steady-pedestal paradigm. A physiologically plausible model could describe the data with parameters accounting for contrast gain and contrast sensitivity in the inferred MC or PC pathway. The fitted parameters from the eye affected by optic neuritis were compared with those from the normal eye using generalized estimation equation (GEE) models that can account for within-subject correlations. RESULTS Compared with normal eyes, the affected eyes had significantly higher saturation parameters when measured with both the achromatic pulsed-pedestal paradigm (GEE: β [SE] = 0.35 [0.06]; P < 0.001) and the chromatic discrimination paradigm (β [SE] = 0.18 [0.08]; P = 0.015), suggesting that contrast gain in the inferred PC pathway is reduced; the affected eyes also had reduced absolute sensitivity in the inferred MC pathway measured with the achromatic steady-pedestal paradigm (β [SE] = 0.12 [0.04]; P = 0.005). CONCLUSIONS Optic neuritis produced large sensitivity losses mediated by the MC pathway and contrast gain losses in the inferred PC pathway. A clinical framework is presented for interpreting contrast sensitivity and gain loss to chromatic and achromatic stimuli in terms of retinal and postretinogeniculate loci contributions to detection and discrimination.
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Affiliation(s)
- Dingcai Cao
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1905 W.Taylor Street, Room 149, Chicago, IL 60615, USA.
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Human vision with a lesion of the parvocellular pathway: an optic neuritis model for selective contrast sensitivity deficits with severe loss of midget ganglion cell function. Exp Brain Res 2011; 215:293-305. [DOI: 10.1007/s00221-011-2896-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Accepted: 09/28/2011] [Indexed: 10/16/2022]
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Gregori B, Papazachariadis O, Farruggia A, Accornero N. A differential color flicker test for detecting acquired color vision impairment in multiple sclerosis and diabetic retinopathy. J Neurol Sci 2011; 300:130-4. [DOI: 10.1016/j.jns.2010.09.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Revised: 08/10/2010] [Accepted: 09/01/2010] [Indexed: 11/15/2022]
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Abstract
PURPOSE We simulate how subjects with losses in chromatic and achromatic contrast sensitivity perceive colored images by using the spatiochromatic corresponding pair algorithm. METHODS This is a generalized version of the algorithm by Capilla et al. (J Opt Soc Am (A) 2004;21:176-186) for simulating color perception of color deviant subjects, which incorporates a simple spatial vision model, consisting of a linear filtering stage, with a band-pass achromatic filter and two low-pass chromatic ones, for the red-green and blue-yellow mechanisms. These filters, except for the global scaling, are the subject's contrast sensitivity functions measured along the cardinal directions of the color space. In its present form, the algorithm would serve to simulate alterations both in the spectral sensitivities and in the contrast sensitivities of the visual mechanisms. RESULTS After a preliminary theoretical study on the effect of frequency selective and overall reductions in the contrast sensitivity function of a single mechanism, we present cases of real subjects with glaucoma and diabetes, suffering alterations of different magnitude in the three mechanisms. CONCLUSIONS The simulations allow us to learn about the different types of distortions that can be experienced by a subject with impaired contrast sensitivities (blur, haloes, color shifts, local or global contrast, brightness and colorfulness reductions, etc.) and highlight the difficulties arising when trying to predict the quality of the final image from the losses in the individual mechanisms.
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Chromatic discrimination losses in multiple sclerosis patients with and without optic neuritis using the Cambridge Colour Test. Vis Neurosci 2008; 25:463-8. [DOI: 10.1017/s0952523808080437] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We assessed chromatic discrimination in multiple sclerosis (MS) patients both with (ON) and without (no ON) a history of optic neuritis using the Cambridge color test (CCT). Our goal was to determine the magnitude and chromatic axes of any color vision losses in both patient groups, and to evaluate age-related changes in chromatic discrimination in both patient groups compared to normals. Using the CCT, we measured chromatic discrimination along the protan, deutan and tritan axes in 35 patients with MS (17 ON eyes) and 74 age matched controls. Color thresholds for both patient groups were significantly higher than controls' along the protan and tritan axes (p < 0.001). In addition, the ON and no-ON groups differed significantly along all three-color axes (p < 0.001). MS patients presented a progressive color discrimination impairment with age (along the deutan and tritan axes) that was almost two times faster than controls, even in the absence of ON. These findings suggest that demyelinating diseases reduce sensitivity to color vision in both red-green and blue-yellow axes, implying impairment in both parvocellular and koniocellular visual pathways. The CCT is a useful tool to help characterize vision losses in MS, and the relationship between these losses and degree of optic nerve involvement.
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Reliability of Visual Temporal Thresholds. Can J Neurol Sci 2007; 34:433-7. [DOI: 10.1017/s0317167100007319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Background:Visual processing deficits involving temporal characteristics are typically not captured by the widely used outcome measures (i.e., Expanded Disability Status Scale, Multiple Sclerosis Functional Composite) in multiple sclerosis (MS). Visual temporal thresholds (i.e., measurements of the temporal aspects in visual processing) are typically significantly higher (i.e., prolonged) in MS patients when compared to controls. The test-retest reliability of these thresholds was examined in patients with MS.Methods:Visual temporal thresholds were measured in 21 stable MS patients during two separate test sessions. Test-retest reliability and the standard error of measurement were calculated. The threshold of change in visual temporal thresholds in MS patients that would correspond to real change beyond measurement error with 95% certainty was also calculated. For comparisons, a control group (n = 10) was included.Results:The test-retest reliability of this measure of visual temporal thresholds was 0.97. The threshold indicating change beyond chance or measurement error with 95% certainty was 11 ms. Higher thresholds were significantly correlated with longer durations of disease.Conclusions:This measure of visual temporal thresholds has excellent test-retest reliability and a change of greater than 11 ms is highly likely to represent real change in MS patients. The findings indicate that these measurements may provide useful clinical information about functional changes regarding the temporal aspects of the visual system, which is currently not captured by the Extended Disability Status Scale.
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Newman Wright B, Wilkins AJ, Zoukos Y. Spectral filters can improve reading and visual search in patients with multiple sclerosis. J Neurol 2007; 254:1729-35. [DOI: 10.1007/s00415-007-0648-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2006] [Revised: 04/16/2007] [Accepted: 05/03/2007] [Indexed: 11/30/2022]
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Moro SI, Rodriguez-Carmona ML, Frost EC, Plant GT, Barbur JL. Recovery of vision and pupil responses in optic neuritis and multiple sclerosis. Ophthalmic Physiol Opt 2007; 27:451-60. [PMID: 17718884 DOI: 10.1111/j.1475-1313.2007.00501.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The recovery of visual performance and pupil responses were investigated in patients with demyelinating optic neuritis (ON) and multiple sclerosis (MS). The pupil constriction amplitude and the time delay (latency) of the pupil response were measured in 14 patients with a history of unilateral ON in response to either achromatic (luminance) or chromatic (isoluminant) stimulus modulation. Five of these subjects were diagnosed later with MS. In addition, we measured detection thresholds for achromatic stimuli using standard visual field perimetry and chromatic thresholds using a new colour assessment and diagnosis (CAD) test that isolates the use of colour signals. The results show that, despite significant improvements in visual function following the acute phase (as assessed using visual acuity and fields), significant pupil response deficits remain. The findings also demonstrate that accurate measurements of pupil responses and chromatic thresholds can reveal deficits that remain undetected with more conventional techniques. These preliminary findings suggest that the techniques described here can provide useful information about remitting and relapsing demyelinative phases, often observed during MS and ON.
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Affiliation(s)
- S I Moro
- Applied Vision Research Centre, The Henry Wellcome Laboratories for Vision Sciences, City University, London, UK.
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Rucker JC, Sheliga BM, FitzGibbon EJ, Miles FA, Leigh RJ. Contrast sensitivity, first-order motion and Initial ocular following in demyelinating optic neuropathy. J Neurol 2006; 253:1203-9. [PMID: 16649097 PMCID: PMC2408647 DOI: 10.1007/s00415-006-0200-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2005] [Accepted: 12/13/2005] [Indexed: 10/24/2022]
Abstract
The ocular following response (OFR) is a measure of motion vision elicited at ultra-short latencies by sudden movement of a large visual stimulus. We compared the OFR to vertical sinusoidal gratings (spatial frequency 0.153 cycles/ degrees or 0.458 cycles/ degrees) of each eye in a subject with evidence of left optic nerve demyelination due to multiple sclerosis (MS). The subject showed substantial differences in vision measured with stationary low-contrast Sloan letters (20/63 OD and 20/200 OS at 2.5% contrast) and the Lanthony Desaturated 15-hue color test (Color Confusion Index 1.11 OD and 2.14 OS). Compared with controls, all of the subject's OFR to increasing contrast showed a higher threshold. The OFR of each of the subject's eyes were similar for the 0.153 cycles/ degrees stimulus, and psychophysical measurements of his ability to detect these moving gratings were also similar for each eye. However, with the 0.458 cycles/ degrees stimulus, the subject's OFR was asymmetric and the affected eye showed decreased responses (smaller slope constant as estimated by the Naka-Rushton equation). These results suggest that, in this case, optic neuritis caused a selective deficit that affected parvocellular pathways mediating higher spatial frequencies, lower-contrast, and color vision, but spared the field-holding mechanism underlying the OFR to lower spatial frequencies. The OFR may provide a useful method to study motion vision in individuals with disorders affecting anterior visual pathways.
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Affiliation(s)
- Janet C. Rucker
- Veterans Affairs Medical Center, Cleveland, Ohio
- University Hospitals Case Western Reserve University, Cleveland, Ohio
| | - Boris M. Sheliga
- Laboratory of Sensorimotor Research, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Edmond J. FitzGibbon
- Laboratory of Sensorimotor Research, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Frederick A. Miles
- Laboratory of Sensorimotor Research, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - R. John Leigh
- Veterans Affairs Medical Center, Cleveland, Ohio
- University Hospitals Case Western Reserve University, Cleveland, Ohio
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