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1

Is colour vision impairment associated with cognitive impairment in solvent exposed workers?  

PubMed Central

Methods: A sample of 82 painters and 38 other subjects were studied. Alcohol, drug, and smoking histories were obtained. Colour vision was tested using the Lanthony D-15-d colour vision test. Cognitive impairment was measured using the Benton visual retention test, Trail making A, and Trail making B tests. Pre-morbid IQ was estimated using the National Adult Reading Test. Solvent exposure in all subjects was estimated using a previously validated, structured subjective assessment methodology. Results: After exclusion of subjects with competing causes of colour vision impairment the final group of men numbered 78. There was a significant association on multiple linear regression between the mean colour confusion index (CCI) and three measures of cognitive impairment, the Benton visual retention test, Trail making A, and Trail making B tests after adjusting for the effects of age (or IQ as appropriate), alcohol, and smoking. Conclusion: Acquired colour vision loss is associated with cognitive impairment in solvent exposed workers. However, given the prevalence of acquired colour vision losses in the adult population, colour vision testing is unlikely to be of value as a screening test.

Dick, F; Semple, S; Soutar, A; Osborne, A; Cherrie, J; Seaton, A

2004-01-01

2

Colour Vision and Colour Vision Theories  

Microsoft Academic Search

IN a recent letter to NATURE (September 29, p. 473) Dr. Edridge-Green has condemned the colour theory of Young and Helmholtz by the sweeping statement: ``There is no fact that directly supports the trichromatic theory.'' It is scarcely credible that such men of science as Young, Helmholtz, Maxwell, and Abney could have deliberately adopted a theory of colour vision with

Frank Allen

1923-01-01

3

Colour Vision and Colour Vision Theories  

Microsoft Academic Search

IN the first of my two recent letters on this subject I selected five of the cases in which Dr. Edridge-Green asserts that the trichromatic theory cannot explain certain phenomena of colour vision; and I indicated, in each case, the source of his error. In more than one case I gave the full proof. In his reply he took no

W. Peddie

1923-01-01

4

All Vision Impairment  

MedlinePLUS

Home » Resources » Statistics and Data » Vision Impairment All Vision Impairment Vision Impairment Defined Vision impairment is defined as the best-corrected visual acuity less than 6/12 (‹20/40) in the ...

5

Colour Vision and Colour Vision Theories  

Microsoft Academic Search

PROF. PEDDIE, in NATURE of August 4, p. 163, has dealt with some of my strictures of the trichromatic theory. Whilst nothing can be said against his mathematical presentation of the theory, it can easily be shown that, when a case of colour blindness is fully and carefully examined, the mathematical presentation will not account for the facts. All the

F. W. Edridge-Green

1923-01-01

6

Factorial Analysis of Colour Vision  

Microsoft Academic Search

HOUSTOUN1 has pointed out that a three-colour theory, such as that of Young and Helmholtz, inevitably leads to mathematical contradictions. It is well known in addition that a theory in which there are only three primary sensitivities, such as red, green and blue, becomes unsatisfactory when the many different forms of defective colour vision are studied in detail. Piéron2 has

R. W. Pickford

1946-01-01

7

A Colour Vision Experiment.  

ERIC Educational Resources Information Center

The model for color vision put forward by Edwin Land is explained. The aspects of the theory that can be demonstrated within the classroom are described. A random arrangement of straight-edged colored areas mounted on a screen, called a Mondrian, projectors, and a computer are used to calculate reflectance. (KR)

Lovett, David; Hore, Kevin

1991-01-01

8

Acquired colour vision deficiency in patients receiving digoxin maintenance therapy  

PubMed Central

Background/aims: Disturbances of colour vision are a frequently reported sign of digoxin toxicity. The aim of this study was to investigate the incidence of acquired colour vision deficiency in elderly hospitalised patients receiving maintenance digoxin therapy. Methods: 30 patients (mean age 81.3 (SD 6.1) years) receiving digoxin were tested using a battery of colour vision tests (Ishihara, AO Hardy Rand Rittler plates, City tritan test, Lanthony tritan album, and the Farnsworth D15). These were compared to an age matched control group. Serum digoxin concentrations were determined from venous blood samples. Results: Slight to moderate red-green impairment was found in approximately 20–30% of patients taking digitalis, and approximately 20% showed a severe tritan deficiency. There was no correlation between colour vision impairment and serum digoxin level. Conclusions: Formal colour vision testing of elderly patients taking digitalis showed a high incidence of colour deficiency, suggesting that impairment of retinal function can occur even at therapeutic drug levels. As a result, colour vision testing in this population would have limited value for the detection of drug toxicity.

Lawrenson, J G; Kelly, C; Lawrenson, A L; Birch, J

2002-01-01

9

A STANDARDIZED LANTERN FOR TESTING COLOUR VISION  

PubMed Central

A Lantern for lesting Colour-Vision is arranged to show test colours in pairs as in the Board of Trade Lantern. It is adapted to use electric light, and is standardized by stringent testing. The paper discusses the experiments and considerations which led to the formulation of the allowable tolerances in the transmission and colour co-ordinate specifications of the filters, the colour temperature of the lamps and so on. The results of tests on normal and colour-defective subjects are described.

Martin, L. C.

1939-01-01

10

The Physics of Colour Vision.  

ERIC Educational Resources Information Center

An elementary physical model of cone receptor cells is explained and applied to complexities of human color vision. One-, two-, and three-receptor systems are considered, with the later shown to be the best model for the human eye. Color blindness is also discussed. (DH)

Goldman, Martin

1985-01-01

11

Colour Phenomena in Ultra-Violet Vision  

Microsoft Academic Search

THE note by N. I. Pinegin1 suggests a more detailed discussion of the relation between the threshold intensities for scotopic and photopic vision in the ultra-violet. The threshold ratio Tp\\/Ts is a measure of the intensity range, often misleadingly called `photochromatic interval', in which the visual impression is free from the specific colour sensation. This intensity range is a marked

E. E. Schneider

1945-01-01

12

Impairments to Vision  

MedlinePLUS

... to Vision Normal Vision Diabetic Retinopathy Age-related Macular Degeneration In this and all subsequent pictures, fixate on ... vision where the leaking occurred. In age-related macular degeneration, the center part of the eye and retina ...

13

Mechanisms, functions and ecology of colour vision in the honeybee.  

PubMed

Research in the honeybee has laid the foundations for our understanding of insect colour vision. The trichromatic colour vision of honeybees shares fundamental properties with primate and human colour perception, such as colour constancy, colour opponency, segregation of colour and brightness coding. Laborious efforts to reconstruct the colour vision pathway in the honeybee have provided detailed descriptions of neural connectivity and the properties of photoreceptors and interneurons in the optic lobes of the bee brain. The modelling of colour perception advanced with the establishment of colour discrimination models that were based on experimental data, the Colour-Opponent Coding and Receptor Noise-Limited models, which are important tools for the quantitative assessment of bee colour vision and colour-guided behaviours. Major insights into the visual ecology of bees have been gained combining behavioural experiments and quantitative modelling, and asking how bee vision has influenced the evolution of flower colours and patterns. Recently research has focussed on the discrimination and categorisation of coloured patterns, colourful scenes and various other groupings of coloured stimuli, highlighting the bees' behavioural flexibility. The identification of perceptual mechanisms remains of fundamental importance for the interpretation of their learning strategies and performance in diverse experimental tasks. PMID:24828676

Hempel de Ibarra, N; Vorobyev, M; Menzel, R

2014-06-01

14

Preretinopic changes in the colour vision of juvenile diabetics  

PubMed Central

AIMS—To examine the colour vision of juvenile patients suffering from diabetes mellitus without retinopathy in relation to metabolic and ophthalmic state.?METHODS—Metameric matches, both Rayleigh (red/green) and Moreland (blue/green) were used to test the colour vision yearly of 10 juvenile patients. The patients were monitored over 4 years, and during the final year, their blood glucose level was determined directly after testing colour vision. An ophthalmic examination was performed on the day of colour vision testing and blood and urine were analysed regularly throughout the 4 years. Their results are compared with an aged matched control group of 20 subjects, seven of whom were retested after 9-16 months.?RESULTS—After 4 years, the colour vision results show an enlarged matching range for the Moreland match, as well as a smaller increase in the matching range for the Rayleigh match. No significant correlation was found between blood glucose at the time of testing and any of the variables measured.?CONCLUSION—The pattern of colour vision deficits in metameric matching shown by juvenile diabetics is consistent with post-receptoral alterations of the inner retina, at this preretinopic stage of disease. Duration of diabetes is correlated with both colour vision changes and morphological alteration of the retina.?? Keywords: anomaloscope; blood glucose; colour vision; diabetes

Kurtenbach, A.; Schiefer, U.; Neu, A.; Zrenner, E.

1999-01-01

15

Adaptive plasticity during the development of colour vision  

Microsoft Academic Search

Colour vision greatly enhances the discriminatory and cognitive capabilities of visual systems and is found in a great majority of vertebrates and many invertebrates. However, colour coding visual systems are confronted with the fact that the external stimuli are ambiguous because they are subject to constant variations of luminance and spectral composition. Furthermore, the transmittance of the ocular media, the

Hans-Joachim Wagner; Ronald H. H. Kröger

2005-01-01

16

Occupational styrene exposure, colour vision and contrast sensitivity: a cohort study with repeated measurements  

Microsoft Academic Search

Objective  Associations between occupational styrene exposures and impairment of visual functions were investigated with a view to answering\\u000a three questions: (1) are the published findings for colour vision deficiencies and impaired contrast sensitivity to reproduce\\u000a in a new study approach, (2) if such effects exist, are they related to current or chronic exposures and (3) if effects exist,\\u000a are there reductions

Andreas Seeber; Thomas Bruckner; Gerhard Triebig

2009-01-01

17

Behavioural evidence of colour vision in free flying stingless bees.  

PubMed

Colour vision was first demonstrated with behavioural experiments in honeybees 100 years ago. Since that time a wealth of quality physiological data has shown a highly conserved set of trichromatic colour receptors in most bee species. Despite the subsequent wealth of behavioural research on honeybees and bumblebees, there currently is a relative dearth of data on stingless bees, which are the largest tribe of the eusocial bees comprising of more than 600 species. In our first experiment we tested Trigona cf. fuscipennis, a stingless bee species from Costa Rica in a field setting using the von Frisch method and show functional colour vision. In a second experiment with these bees, we use a simultaneous colour discrimination test designed for honeybees to enable a comparative analysis of relative colour discrimination. In a third experiment, we test in laboratory conditions Tetragonula carbonaria, an Australian stingless bee species using a similar simultaneous colour discrimination test. Both stingless bee species show relatively poorer colour discrimination compared to honeybees and bumblebees; and we discuss the value of being able to use these behavioural methods to efficiently extend our current knowledge of colour vision and discrimination in different bee species. PMID:24519371

Spaethe, J; Streinzer, M; Eckert, J; May, S; Dyer, A G

2014-06-01

18

Dark Adaptation of Colour Vision in Diabetic Subjects  

NASA Astrophysics Data System (ADS)

Eye disease, a late complication of diabetes mellitus (DM) occurs even under a careful glicemic control. It includes optic nerve, retina, vitreous humor, crystalline lens and pupillary affection. The physiopathological process could be independent of blood glucose levels or start at initial stages of the disease. Photoreceptors have specific physiological functions. The functional substrate of day light or colour vision in superior primates, the cones have different spectral sensitivity, 455, 530 and 560 nm. The rods, maximal sensitivity at 505 nm, are much more sensitive to light than are cones. Dark adaptation was tested to evaluate functional impairment differences in photoreceptors of diabetic subjects. 14 DM2 (type 2 DM), and 5 DM1 (type 1 DM) patients, as well as 9 healthy subjects were studied. Retinal affected individuals, were excluded. Dark adaptation curves seemed to be different between DM, and healthy subjects. Cones, specially those sensitive to 560 nm type, seems to be more labile to DM, as demonstrated by the lack of sensitivity to low, and medium intensity stimuli. Medical Physics and elementary Biomedical Engineering exhibited to be useful to discern malfunction between different types of photorreceptors. The inexpensive method used could be applied for early color vision alteration detection.

Márquez-Gamiño, S.; Cortés-Peñaloza, J. L.; Pérez-Hernández, J. U.; Cruz-Rodríguez, E.; Caudillo, C.

2004-09-01

19

Visual ecology of flies with particular reference to colour vision and colour preferences.  

PubMed

The visual ecology of flies is outstanding among insects due to a combination of specific attributes. Flies' compound eyes possess an open rhabdom and thus separate rhabdomeres in each ommatidium assigned to two visual pathways. The highly sensitive, monovariant neural superposition system is based on the excitation of the peripheral rhabdomeres of the retinula cells R1-6 and controls optomotor reactions. The two forms of central rhabdomeres of R7/8 retinula cells in each ommatidium build up a system with four photoreceptors sensitive in different wavelength ranges and thought to account for colour vision. Evidence from wavelength discrimination tests suggests that all colour stimuli are assigned to one of just four colour categories, but cooperation of the two pathways is also evident. Flies use colour cues for various behavioural reactions such as flower visitation, proboscis extension, host finding, and egg deposition. Direct evidence for colour vision, the ability to discriminate colours according to spectral shape but independent of intensity, has been demonstrated for few fly species only. Indirect evidence for colour vision provided from electrophysiological recordings of the spectral sensitivity of photoreceptors and opsin genes indicates similar requisites in various flies; the flies' responses to coloured targets, however, are much more diverse. PMID:24664124

Lunau, Klaus

2014-06-01

20

Are colour vision standards justified for the transport industry?  

PubMed

Colour vision standards are imposed in the road, rail, maritime and aviation industries and are often subject to vigorous opposition by those excluded by the standard. With greater emphasis in recent years on equality of opportunity, it is important that standards of personal fitness, such as colour vision standards, be subject to critical scrutiny. Such appraisal should be able to demonstrate that the community benefit arising from the application of the standard is sufficient to justify the personal and other costs of retaining the standard. This paper reviews the evidence relating to colour vision standards in the transport industries and concludes that a strong case can be made for their retention in public transport. PMID:3269506

Vingrys, A J; Cole, B L

1988-01-01

21

Scrap Metal Sorting with Colour Vision and Inductive Sensor Array  

Microsoft Academic Search

This paper presents a novel automatic scrap metal sorting system which employs a colour vision based optical sensing system and an inductive sensor array. The operation of the system is verified in a real metal recycling plant. The long period test results indicate that 80 % purity can be achieved when the feeding conveyor speed is limited below 1,5 m\\/s.

Matti Kutila; Jouko Viitanen; Antero Vattulainen

2005-01-01

22

Impaired colour discrimination among workers exposed to styrene: relevance of a urinary metabolite.  

PubMed Central

OBJECTIVES--To survey the loss of colour vision among Japanese workers who have been exposed to styrene concentrations currently considered low (about 20 ppm). Also to assess the effects of styrene by examination of the nature of the relation between disorder of colour vision and age, alcohol consumption, and other variables. METHODS--Colour discrimination was examined in 64 male workers exposed to styrene (mean age; 38.0, mean exposed years; 7.0) and in 69 controls (mean age; 38.0). A standardised questionnaire was adopted to collect work history, occupational or non-occupational solvent exposure, alcohol consumption, and drug use. Colour vision was evaluated by the Lanthony desaturated panel D-15 test. The results of the test were expressed as the colour confusion index (CCI). RESULTS--The mean atmospheric styrene concentration was about 20 ppm. The mean urinary concentration of mandelic acid was 0.22 g/l. There was a significant difference in CCI between exposed workers and age matched controls. Colour vision of workers whose concentration of urinary mandelic acid was > or = 0.42 g/l was significantly impaired when compared with workers whose concentration was < 0.42 g/l. Multiple linear regression analysis that controlled confounding variables such as age, alcohol consumption, smoking, and educational attainment showed that the CCI was significantly related to the concentration of urinary mandelic acid. In both exposed workers and controls, the types of defects were mostly blue-yellow loss, although a few subjects showed complex loss. No one showed only red-green loss. CONCLUSIONS--These findings suggest that exposure to moderate styrene concentrations can lead to impairment of colour vision, and that there is a significant correlation with the urinary metabolite of styrene.

Eguchi, T; Kishi, R; Harabuchi, I; Yuasa, J; Arata, Y; Katakura, Y; Miyake, H

1995-01-01

23

A Standalone Vision Impairments Simulator for Java Swing Applications  

NASA Astrophysics Data System (ADS)

A lot of work has been done lately in an attempt to assess accessibility. For the case of web rich-client applications several tools exist that simulate how a vision impaired or colour-blind person would perceive this content. In this work we propose a simulation tool for non-web JavaTM Swing applications. Developers and designers face a real challenge when creating software that has to cope with a lot of interaction situations, as well as specific directives for ensuring an accessible interaction. The proposed standalone tool will assist them to explore user-centered design and important accessibility issues for their JavaTM Swing implementations.

Oikonomou, Theofanis; Votis, Konstantinos; Korn, Peter; Tzovaras, Dimitrios; Likothanasis, Spriridon

24

Orientation tuning in human colour vision at detection threshold  

PubMed Central

We measure the orientation tuning of red-green colour and luminance vision at low (0.375?c/deg) and mid (1.5?c/deg) spatial frequencies using the low-contrast psychophysical method of subthreshold summation. Orientation bandwidths of the underlying neural detectors are found using a model involving Minkowski summation of the rectified outputs of a bank of oriented filters. At 1.5?c/deg, we find orientation-tuned detectors with similar bandwidths for chromatic and achromatic contrast. At 0.375?c/deg, orientation tuning is preserved with no change in bandwidth for achromatic stimuli, however, for chromatic stimuli orientation tuning becomes extremely broad, compatible with detection by non-oriented colour detectors. A non-oriented colour detector, previously reported in single cells in primate V1 but not psychophysically in humans, can transmit crucial information about the color of larger areas or surfaces whereas orientation-tuned detectors are required to detect the colour or luminance edges that delineate an object's shape.

Gheiratmand, Mina; Mullen, Kathy T.

2014-01-01

25

Psychological Adjustment in Adolescents with Vision Impairment  

ERIC Educational Resources Information Center

The present study compared psychological adjustment of 158 adolescents with vision impairment and 158 sighted adolescents with a matched-pair design using the Strengths and Difficulties Questionnaire. Adolescent self-reports and teacher reports on emotional problems, peer problems, and total difficulties showed higher scores in students with…

Pinquart, Martin; Pfeiffer, Jens P.

2012-01-01

26

Low Vision Aids for Visually Impaired Children  

ERIC Educational Resources Information Center

It is a widely accepted belief in clinical practice that children with a visual impairment can profit from the use of a low vision aid (LVA). However, we found a considerable gap in our scientific understanding of LVA use, particularly in young children. This is the reason for the analysis presented in this paper. A selected overview of LVA use in…

Schurink, J.; Cox, R. F. A.; Cillessen, A. H. N.; van Rens, G. H. M. B.; Boonstra, F. N.

2011-01-01

27

Screening for Vision Problems in Children with Hearing Impairments.  

ERIC Educational Resources Information Center

Vision problems occur at higher rates in the deaf and hearing impaired population than in the general population. When an individual has a hearing impairment, vision becomes more significant in the instructional and learning process, as well as in social and communicative exchanges. Regular comprehensive visual screening of hearing impaired

Demchak, MaryAnn; Elquist, Marty

28

Colour Vision in Migraine: Selective Deficits for SCone Discriminations  

Microsoft Academic Search

Three studies are reported that explore colour perception in migraine. In each, sensitivity for colours detected selectively by the S-cones and the L- and M-cones was assessed separately. The first study assessed the discrimination of small colour differences using the Farnsworth-Munsell 100-hue test. The second assessed threshold detection for purple, yellow, red and green targets on five equiluminant background colours.

AJ Shepherd

2005-01-01

29

Theory and Practice of Colour Vision Testing: A Review. Part 1.  

National Technical Information Service (NTIS)

It is the concern of this paper to examine not only the effectiveness of tests for detecting colour confusion but also their usefulness in assessing colour vision generally. In part 1, problems of administration and age and the question of the basic eleme...

R. Lakowski

1968-01-01

30

Recognition of traffic signs based on their colour and shape features extracted using human vision models  

Microsoft Academic Search

Colour and shape are basic characteristics of traffic signs which are used both by the driver and to develop artificial traffic sign recognition systems. However, these sign features have not been represented robustly in the earlier developed recognition systems, especially in disturbed viewing conditions. In this study, this information is represented by using a human vision colour appearance model and

X. W. Gao; L. Podladchikova; D. Shaposhnikov; K. Hong; N. Shevtsova

2006-01-01

31

Research the mobile phone operation interfaces for vision-impairment.  

PubMed

Due to the vision-impaired users commonly having difficulty with mobile-phone function operations and adaption any manufacturer's user interface design, the goals for this research are established for evaluating how to improve for them the function operation convenience and user interfaces of either mobile phones or electronic appliances in the market currently. After applying collecting back 30 effective questionnaires from 30 vision-impairment, the comments have been concluded from this research include: (1) All mobile phone manufactures commonly ignorant of the vision-impairment difficulty with operating mobile phone user interfaces; (2) The vision-impairment preferential with audio alert signals; (3) The vision-impairment incapable of mobile-phone procurement independently unless with assistance from others; (4) Preferential with adding touch-usage interface design by the vision-impairment; in contrast with the least requirement for such functions as braille, enlarging keystroke size and diversifying-function control panel. With exploring the vision-impairment's necessary improvements and obstacles for mobile phone interface operation, this research is established with goals for offering reference possibly applied in electronic appliance design and . Hopefully, the analysis results of this research could be used as data references for designing electronic and high-tech products and promoting more usage convenience for those vision-impaired. PMID:22317456

Yao, Yen-Ting; Leung, Cherng-Yee

2012-01-01

32

The nature of sound and vision in relation to colour  

NASA Astrophysics Data System (ADS)

The increasing role of sound within the visual arts context and the trend in postmodernism towards interdisciplinary artworks has demanded a heightened awareness of the audio-visual. This paper explores some of the fundamental physical properties of both sound and colour, their similarities and differences and how the audio and visual senses are related. Ways in which soundscapes have been combined with paintings in exhibitions by the author will be used to illustrate how the two media can be combined to enhance the overall artistic experience.

Greated, Marianne

2011-03-01

33

Beyond W3C: TruVision--Enhanced Online Learning for People Blind or Vision Impaired.  

ERIC Educational Resources Information Center

This paper describes the design and development of TruVision, an online learning environment designed to enable blind and vision impaired students to develop skills and expertise in elementary and advanced information processing strategies to enable them to seek full-time employment within industry in such positions as administrative assistants,…

Bate, Frank; Oliver, Ron

34

Global cost of correcting vision impairment from uncorrected refractive error  

PubMed Central

Abstract Objective To estimate the global cost of establishing and operating the educational and refractive care facilities required to provide care to all individuals who currently have vision impairment resulting from uncorrected refractive error (URE). Methods The global cost of correcting URE was estimated using data on the population, the prevalence of URE and the number of existing refractive care practitioners in individual countries, the cost of establishing and operating educational programmes for practitioners and the cost of establishing and operating refractive care facilities. The assumptions made ensured that costs were not underestimated and an upper limit to the costs was derived using the most expensive extreme for each assumption. Findings There were an estimated 158 million cases of distance vision impairment and 544 million cases of near vision impairment caused by URE worldwide in 2007. Approximately 47?000 additional full-time functional clinical refractionists and 18?000 ophthalmic dispensers would be required to provide refractive care services for these individuals. The global cost of educating the additional personnel and of establishing, maintaining and operating the refractive care facilities needed was estimated to be around 20?000 million United States dollars (US$) and the upper-limit cost was US$ 28?000 million. The estimated loss in global gross domestic product due to distance vision impairment caused by URE was US$ 202?000 million annually. Conclusion The cost of establishing and operating the educational and refractive care facilities required to deal with vision impairment resulting from URE was a small proportion of the global loss in productivity associated with that vision impairment.

Fricke, TR; Wilson, DA; Schlenther, G; Naidoo, KS; Resnikoff, S; Frick, KD

2012-01-01

35

Vision with equiluminant colour contrast: 2. A large-scale technique and observations.  

PubMed

A simple technique is described for producing large-scale, tritanopic displays. The technique reproduces the various phenomena of vision with equiluminous-colour contrast that have previously been reported with red/green stimuli. It is, however, much less demanding technically, robust against artifacts, and can be used on large-scale scenes. One advantage of the technique is that a piece of blue filter can be used individually by each observer to compare quickly tritanopic and luminance conditions. PMID:1513671

Cavanagh, P; Adelson, E H; Heard, P

1992-01-01

36

The Evolution of the Multicoloured Face of Mandrills: Insights from the Perceptual Space of Colour Vision  

PubMed Central

Multicomponent signals consist of several traits that are perceived as a whole. Although many animals rely on multicomponent signals to communicate, the selective pressures shaping these signals are still poorly understood. Previous work has mainly investigated the evolution of multicomponent signals by studying each trait individually, which may not accurately reflect the selective pressures exerted by the holistic perception of signal receivers. Here, we study the design of the multicoloured face of an Old World primate, the mandrill (Mandrillus sphinx), in relation to two aspects of signalling that are expected to be selected by receivers: conspicuousness and information. Using reflectance data on the blue and red colours of the faces of 34 males and a new method of hue vectorisation in a perceptual space of colour vision, we show that the blue hue maximises contrasts to both the red hue and the foliage background colouration, thereby increasing the conspicuousness of the whole display. We further show that although blue saturation, red saturation and the contrast between blue and red colours are all correlated with dominance, dominance is most accurately indicated by the blue-red contrast. Taken together our results suggest that the evolution of blue and red facial colours in male mandrills are not independent and are likely driven by the holistic perception of conspecifics. In this view, we propose that the multicoloured face of mandrills acts as a multicomponent signal. Last, we show that information accuracy increases with the conspicuousness of the whole display, indicating that both aspects of signalling can evolve in concert.

Renoult, Julien P.; Schaefer, H. Martin; Salle, Bettina; Charpentier, Marie J. E.

2011-01-01

37

Register of Children with Impaired Vision and Hearing.  

ERIC Educational Resources Information Center

The register of children (under 20 years of age) with impaired vision and hearing provides the number of children in deaf blind programs, other educational programs, at home, and in institutions for the mentally handicapped for the academic year 1968-9. Additional information on the 777 handicapped children registered by the American Foundation…

Wagner, Elizabeth

38

Developmental Growth Curves of Preschool Children with Vision Impairments.  

ERIC Educational Resources Information Center

Used growth curve analysis to describe the development of 186 preschoolers with vision impairments. Found that mental retardation and developmental delay were associated with lower developmental ages and slower growth rates. Visual function of 20/800 or worse was associated with lower developmental ages and slower growth rates in personal-social…

Hatton, Deborah D.; Bailey, Donald B., Jr.; Burchinal, Margaret R.; Ferrell, Kay Alicyn

1997-01-01

39

Resource Guide for Persons with Vision Impairments.  

ERIC Educational Resources Information Center

The resource guide identifies products which assist visually impaired individuals in accessing IBM (International Business Machine) Personal Computers or the IBM Personal System/2 family of products. An introduction provides a general overview of ways computers can help persons with visual handicaps. The document then provides descriptions of…

IBM, Atlanta, GA. National Support Center for Persons with Disabilities.

40

Prevalence of Adult Vision Impairment and Age-Related Eye Diseases in America  

MedlinePLUS

... Eye Diseases in America Prevalence of Adult Vision Impairment and Age-Related Eye Diseases in America (Based ... Total Population ? 40 142,648,393 All Vision Impairment 4,195,966 Blindness 1,288,275 Low ...

41

Spotting fruit versus picking fruit as the selective advantage of human colour vision  

PubMed Central

The spatiochromatic properties of the red–green dimension of human colour vision appear to be optimized for picking fruit in leaves at about arms' reach. However, other evidence suggests that the task of spotting fruit from a distance might be more important. This discrepancy may arise because the task a system (e.g. human trichromacy) is best at is not necessarily the same task where the largest advantage occurs over the evolutionary alternatives (dichromacy or anomalous trichromacy). We tested human dichromats, anomalous trichromats and “normal” trichromats in a naturalistic visual search task in which they had to find fruit pieces in a bush at 1, 4, 8 or 12 m viewing distance. We found that the largest advantage (in terms of either performance ratio or performance difference) of normal trichromacy over both types of colour deficiency was for the largest viewing distance. We infer that in the evolution of human colour vision, spotting fruit from a distance was a more important selective advantage than picking fruit at arms' reach.

Bompas, Aline; Kendall, Grace; Sumner, Petroc

2013-01-01

42

The flicker fusion frequency of the blue-sensitive mechanism of colour vision  

PubMed Central

1. The flicker fusion frequency for blue stimuli on zero background increases steadily with increasing luminance up to 50 c/s, but if a strong yellow background is added it increases steadily only to about 18 c/s, and then remains nearly independent of luminance over a range of a factor of 20. 2. It is argued that the maximum flicker fusion frequency is about three times lower for the blue-sensitive mechanism of colour vision than for the red- or green-sensitive.

Brindley, G. S.; Du Croz, J. J.; Rushton, W. A. H.

1966-01-01

43

The Reliability of the CVI Range: A Functional Vision Assessment for Children with Cortical Visual Impairment  

ERIC Educational Resources Information Center

Children who are identified as visually impaired frequently have a functional vision assessment as one way to determine how their visual impairment affects their educational performance. The CVI Range is a functional vision assessment for children with cortical visual impairment. The purpose of the study presented here was to examine the…

Newcomb, Sandra

2010-01-01

44

Computer vision-based analysis of foods: a non-destructive colour measurement tool to monitor quality and safety.  

PubMed

Computer vision-based image analysis has been widely used in food industry to monitor food quality. It allows low-cost and non-contact measurements of colour to be performed. In this paper, two computer vision-based image analysis approaches are discussed to extract mean colour or featured colour information from the digital images of foods. These types of information may be of particular importance as colour indicates certain chemical changes or physical properties in foods. As exemplified here, the mean CIE a* value or browning ratio determined by means of computer vision-based image analysis algorithms can be correlated with acrylamide content of potato chips or cookies. Or, porosity index as an important physical property of breadcrumb can be calculated easily. In this respect, computer vision-based image analysis provides a useful tool for automatic inspection of food products in a manufacturing line, and it can be actively involved in the decision-making process where rapid quality/safety evaluation is needed. PMID:24288215

Mogol, Burçe Ataç; Gökmen, Vural

2014-05-01

45

The Impact of Residual Vision in Spatial Skills of Individuals with Visual Impairments  

ERIC Educational Resources Information Center

Loss of vision is believed to have a great impact on the acquisition of spatial knowledge. The aims of the present study are to examine the performance of individuals with visual impairments on spatial tasks and the impact of residual vision on processing these tasks. In all, 28 individuals with visual impairments--blindness or low…

Papadopoulos, Konstantinos; Koustriava, Eleni; Kartasidou, Lefkothea

2011-01-01

46

Mutations in S-cone pigment genes and the absence of colour vision in two species of nocturnal primate.  

PubMed

Most primates have short-wavelength sensitive (S) cones and one or more types of cone maximally sensitive in the middle to long wavelengths (M/L cones). These multiple cone types provide the basis for colour vision. Earlier experiments established that two species of noctural primate, the owl monkey (Aotus trivirgatus) and the bushbaby (Otolemur crassicaudatus), lack a viable population of S cones. Because the retinas of these species have only a single type of M/L cone, they lack colour vision. Both of these species have an S-cone pigment gene that is highly homologous to the human S-cone pigment gene. Examination of the nucleotide sequences of the S-cone pigment genes reveals that each species has deleterious mutational changes: in comparison to the sequence for the corresponding region of the human gene, exon 4 of the bushbaby S-cone pigment gene has a two nucleotide deletion and a single nucleotide insertion that produces a frame shift and results in the introduction of a stop codon. Exon 1 of the owl monkey S-cone pigment gene likewise contains deletions and insertions that produce a stop codon. The absence of colour vision in both of these nocturnal primates can thus be traced to defects in their S-cone pigment genes. PMID:8763792

Jacobs, G H; Neitz, M; Neitz, J

1996-06-22

47

Physical Activity and Occasional Drinking Found to Be Associated with Decrease in Vision Impairment Risk  

MedlinePLUS

Physical Activity and Occasional Drinking Found to be Associated with Decrease in Vision Impairment Risk 03/19/2014 ... the study. "Lifestyle behaviors like smoking, drinking and physical activity, however, can be altered. So, it's promising, in ...

48

Education of Children with Vision Impairments in the Sultanate of Oman.  

ERIC Educational Resources Information Center

Describes the prevalence and patterns of vision impairment in the Sultanate of Oman. Reviews the types of special education and rehabilitation services offered and future priorities. Concludes that, although at present, few visually impaired children are receiving services, a special education system is evolving into a community-based approach to…

Hadidi, Muna S. Z.

1998-01-01

49

The Effect of Gender and Level of Vision on the Physical Activity Level of Children and Adolescents with Visual Impairment  

ERIC Educational Resources Information Center

This study was planned in order to determine physical activity levels of visually impaired children and adolescents and to investigate the effect of gender and level of vision on physical activity level in visually impaired children and adolescents. A total of 30 visually impaired children and adolescents (16 low vision and 14 blind) aged between…

Aslan, Ummuhan Bas; Calik, Bilge Basakci; Kitis, Ali

2012-01-01

50

High complexity of aquatic irradiance may have driven the evolution of four-dimensional colour vision in shallow-water fish.  

PubMed

Humans use three cone photoreceptor classes for colour vision, yet many birds, reptiles and shallow-water fish are tetrachromatic and use four cone classes. Screening pigments, which narrow the spectrum of photoreceptors in birds and diurnal reptiles, render visual systems with four cone classes more efficient. To date, however, the question of tetrachromacy in shallow-water fish that, like humans, lack screening pigments, is still unsolved. We raise the possibility that tetrachromacy in fish has evolved in response to higher spectral complexity of underwater light. We compared the dimensionality of colour vision in humans and fish by examining the spectral complexity of the colour signal reflected from objects into their eyes. We show that fish require four to six cone classes to reconstruct the colour signal of aquatic objects at the accuracy level achieved by humans viewing terrestrial objects. This is because environmental light, which alters the colour signals, is more complex and contains more spectral fluctuations underwater than on land. We further show that fish cones are better suited than human cones to detect these spectral fluctuations, suggesting that the capability of fish cones to detect high-frequency fluctuations in the colour signal confers an advantage. Taken together, we propose that tetrachromacy in fish has evolved to enhance the reconstruction of complex colour signals in shallow aquatic environments. Of course, shallow-water fish might possess fewer than four cone classes; however, this would come with the inevitable loss in accuracy of signal reconstruction. PMID:23393278

Sabbah, Shai; Troje, Nikolaus F; Gray, Suzanne M; Hawryshyn, Craig W

2013-05-01

51

14 CFR 382.53 - What information must carriers give individuals with a vision or hearing impairment at airports?  

Code of Federal Regulations, 2010 CFR

...with a vision or hearing impairment at airports? 382.53 Section 382.53 Aeronautics...DISABILITY IN AIR TRAVEL Accessibility of Airport Facilities § 382.53 What information...with a vision or hearing impairment at airports? (a)(1) As a U.S....

2010-01-01

52

14 CFR 382.119 - What information must carriers give individuals with vision or hearing impairment on aircraft?  

Code of Federal Regulations, 2011 CFR

...individuals with vision or hearing impairment on aircraft? 382.119 Section 382.119 Aeronautics...DISABILITY IN AIR TRAVEL Services on Aircraft § 382.119 What information must...individuals with vision or hearing impairment on aircraft? (a) As a carrier, you...

2014-01-01

53

Colour Perception in ADHD  

ERIC Educational Resources Information Center

Attention-deficit/hyperactivity disorder (ADHD) is associated with unexplained impairments on speeded naming of coloured stimuli. These deficits may reflect hypofunctioning retinal dopaminergic mechanisms impairing particularly blue-yellow colour discrimination. Colour perception and rapid colour naming ability were investigated in 14 children…

Banaschewski, Tobias; Ruppert, Sinje; Tannock, Rosemary; Albrecht, Bjorn; Becker, Andreas; Uebel, Henrik; Sergeant, Joseph A.; Rothenberger, Aribert

2006-01-01

54

Audio from Orbit: The Future of Libraries for Individuals Who Are Blind or Vision Impaired  

ERIC Educational Resources Information Center

Free library service is a component of the foundations of democracy, citizenship, economic and social development, scholarship and education, in progressive societies. The evolution of libraries for people who are blind or vision impaired is briefly discussed and an innovative project, a talking book and daily newspaper delivery system that…

Steer, Michael; Cheetham, Leonie

2005-01-01

55

Students with Low Vision Describe Their Visual Impairments and Visual Functioning  

ERIC Educational Resources Information Center

In the study reported here, the responses to a survey that was designed to determine the knowledge of their visual impairment of 51 students with low vision were analyzed. Although the students described their visual weaknesses and strengths, they had limited knowledge of, and difficulty communicating about, the medical aspects of their…

Guerette, Amy R.; Lewis, Sandra; Mattingly, Cameron

2011-01-01

56

Benign Visual Hallucinations, or "Phantom Vision" in Visually Impaired and Blind Persons.  

ERIC Educational Resources Information Center

Benign visual hallucinations ("phantom vision") were examined in 2 studies, involving a total of 443 adventitiously blinded and sight-impaired veterans. In one study, unusual visual events were reported by 38.7 percent, with 30.6 percent reporting complex hallucinations. Causes of the hallucinations and their treatment are discussed. (Author/JDD)

Needham, W. E.; Taylor, R. E.

1992-01-01

57

A novel speech controller for radio amateurs with a vision impairment.  

PubMed

This paper describes a portable speech controller system for persons with a vision impairment to adjust the channel frequency of a radio set via speech commands. The speech commands are recognized on a general-purpose digital signal processor using a hidden Markov model (HMM), and are used to remotely control radio channel changes. PMID:10779112

Lin, C L; Bai, B R; Du, L C; Hu, C T; Young, S T; Kuo, T S

2000-03-01

58

Test Anxiety Research: Students with Vision Impairments and Students with Mild Intellectual Disabilities  

ERIC Educational Resources Information Center

There is an absence of research on test anxiety in students with disabilities although such testing is taken for granted among students without disabilities. This study investigated the test anxiety of the students in each of the two disability groups, those with vision impairments and those with intellectual disabilities who are placed in…

Datta, Poulomee

2014-01-01

59

Space Vision: Making Astronomy Accessible to Visually Impaired Students  

NASA Astrophysics Data System (ADS)

Astronomy, with good reason, is thought of as a visual science. Spectacular images of deep space objects or other worlds of our solar system inspire public interest in Astronomy. People encounter news about the universe during their daily life. Developing concepts about celestial objects presents an extra challenge of abstraction for people with visual impairments. The Texas Space Grant Consortium with educators at the Texas School for the Blind and Visually Impaired have developed a 2 day workshop to be held in April 2004 to help students with visual impairments understand these concepts. Hands-on activities and experiments will emphasize non-visual senses. For example, students will learn about: - Constellations as historical ways of finding one's way across the sky. - The size and structure of the Solar System by building a scale model on a running track. They will also: - Plan a planetary exploration mission. - Explore wave phenomenon using heat and sound waves. In preparation for the workshop we worked with teens involved in the countywide 4-H Teens Leading with Character (TLC) program to create the tactile materials necessary for the activities. The teens attended solar system education training so they would have the skills necessary to make the tactile displays to be used during the workshop. The results and evaluation of the workshop will be presented at the meeting. Touch the Universe: A NASA Braille Book of Astronomy inspired this workshop, and it is supported by HST Grant HST-ED-90255.01-A.

Ries, J. G.; Baguio, M. R.; Jurgens, T. D.; Pruett, K. M.

2004-05-01

60

Sensory impairments in community health care: a descriptive study of hearing and vision among elderly Norwegians living at home  

PubMed Central

Background Hearing and vision impairments increase with age and are common risk factors for functional decline reduced social participation and withdrawal. Objective Describe the hearing and vision of home care patients older than 80 years. Methods Ninety-three older adults (80+ years) receiving home care were screened for hearing and vision in their homes. Data were collected using a HEINE Mini 3000® Otoscope to examine the eardrum and presence of earwax, an Entomed SA201-IV portable pure-tone audiometer to measure the pure-tone average (PTAV), a logarithm of the minimum angle of resolution chart to measure visual acuity (VA), and the Combined Serious Sensory Impairment interview guide. Results Slight and moderate hearing impairments were found in 41% and 47% of the population, respectively (mean PTAV =40.4 dB for the better ear), and 40% and 56% had impaired and slightly impaired vision, respectively (mean VA =0.45 for the better eye). The participants’ self-assessments of hearing and vision were only weakly correlated with PTAV and VA values. The visual function was significantly worse in men than in women (P=0.033). Difficulty in performing instrumental activities of daily living because of hearing and vision impairments was experienced by 17% of the participants, whereas 76% experienced no difficulties. When many people were present, 72% of the participants found it difficult to understand speech. Nearly 30% found it tiring to read, and 41% could not read very small print. Conclusion The patients’ self-assessments of their hearing and vision did not correlate strongly with their VA and PTAV scores. Asking the elderly about their overall hearing and vision ability is not sufficient for detecting sensory impairment, and asking more specific questions about what they could not hear and see was not an adequate indicator of the patients’ hearing and vision problems. To detect hearing and vision impairments among elderly home care patients, standardized measurements of their hearing and vision are necessary.

Haanes, Gro Gade; Kirkevold, Marit; Horgen, Gunnar; Hofoss, Dag; Eilertsen, Grethe

2014-01-01

61

Colour Vision and Colour Vision Theories  

Microsoft Academic Search

PROF. PEDDIE states in his letter in NATURE of September 8, p. 362, that the facts that I have given as totally opposed to the trichromatic theory can be explained by it. If he will show how this can be done I can then deal with his explanations. Directly the trichromatic theory is put in a definite form its failure

F. W. Edridge-Green

1923-01-01

62

Colour Vision and Colour Vision Theories  

Microsoft Academic Search

IN reply to Sir Oliver Lodge (NATURE, January 12, p. 50), I have made numerous experiments extending over years on the simple and compound yellow. The results are given in a paper on the simple character of the yellow sensation, Journal of Physiology, 1915, page 265. The identity of the compound yellow made with spectral red and green with the

F. W. Edridge-Green

1924-01-01

63

Colour Vision and Colour Vision Theories  

Microsoft Academic Search

IN his letter published in NATURE of August 25, Dr. Edridge-Green seems to admit the accuracy of the deductions from the trichromatic theory which I made in the issue of August 4. But, in making these, I used no other postulate than that of the fact of normal trichromasy. In the sense in which the word is used, trichromasy is

W. Peddie

1923-01-01

64

Colour Vision and Colour Vision Theories  

Microsoft Academic Search

SURELY it might have been better had Dr. Edridge-Green omitted the remark in his letter (NATURE, December 22) regarding the attitude of certain physicists towards physiology. But that is a small matter. I should be quite prepared, if it stood in need of defence by a physicist, which I am quite certain it does not, to defend physiology against Dr.

W. Peddie

1924-01-01

65

Colour Vision and Colour Vision Theory  

Microsoft Academic Search

IN his letter on this subject which appeared in NATURE of September 29, p. 473, Dr. Edridge-Green apparently promised to deal with my explanations when these were given. In reply I selected two in which the full reasoning had been given, and I invited him to implement his undertaking. In his letter in NATURE of November 10, p. 687, he

W. Peddie

1923-01-01

66

Colour Vision and Colour Vision Theories  

Microsoft Academic Search

WITHOUT interfering in any current controversy, an experiment suggests itself, from the concluding sentence of Dr. Edridge-Green in NATURE of December 22, p. 900, which if carefully tried might be instructive.

Oliver Lodge

1924-01-01

67

Colour Vision and Colour Vision Theories  

Microsoft Academic Search

PROF. PEDDIE seems to suggest that no one understands the trichromatic theory but himself. I resent his remarks in this connexion, and for this reason, unless some one else joins in the discussion, this is my final letter.

F. W. Edridge-Green

1923-01-01

68

Colour Vision and Colour Vision Theories  

Microsoft Academic Search

WHETHER Prof. Peddie's explanations are adequate is a matter for the reader to decide. Let us take one of a fact which is conclusive evidence against the trichromatic theory. If the terminal portion of the red end of the spectrum be isolated in my spectrometer it will appear as a faint red upon a black background. If the eye be

F. W. Edridge-Green

1923-01-01

69

Mobility restriction and comorbidity in vision-impaired individuals living in the community.  

PubMed

A review of data presented in a national study of perceptions and experiences of mobility with an age-stratified sample of 564 Irish adults with vision impairment found that mobility was a significant issue. Comorbidity is a factor with 97 (29.5%) of the under-65 age group and 135 (59%) of the older age group reporting additional health challenges. Adapting to vision loss and ageing has psychological, functional, social and health implications and help-seeking is a complex process. This may explain the limited use of mobility aids and guide dogs in the total sample (5%), with a notable absence of use in the older age group. A broad view of the Person-Environment-Occupation Model was proposed for primary and community care services, in collaboration with specialist vision impairment agencies to enhance mobility, maintain functional capacity, influence positive and healthy adaptation to vision impairment, social inclusion and quality of life in a population expected to increase by more than 170% over the next 25 years. PMID:24335794

Mac Cobb, Siobhan

2013-12-01

70

Effectiveness of screening older people for impaired vision in community setting: systematic review of evidence from randomised controlled trials  

PubMed Central

Objective: To assess whether population screening for impaired vision among older people in the community leads to improvements in vision. Design: Systematic review of randomised controlled trials of population screening in the community that included any assessment of vision or visual function with at least 6 months’ follow up. Subjects: Adults aged 65 or over. Main outcome measure: Proportions with visual impairment in intervention and control groups with any method of assessing visual impairment. Results: There were no trials that primarily assessed visual screening. Outcome data on vision were available for 3494 people in five trials of multiphasic assessment. All the trials used self reported measures for vision impairment, both as screening tools and as outcome measures. The inclusion of a visual screening component in the assessments did not result in improvements in self reported visual problems (pooled odds ratio 1.04: 95% confidence interval 0.89 to 1.22). A small reduction (11%) in the number of older people with self reported visual problems cannot be excluded. Conclusions: Screening of asymptomatic older people in the community is not justified on present evidence. Visual impairment in this age group can usually be reduced with treatment. It is unclear why no benefit was seen. Further work is needed to clarify what interventions are appropriate for older people with unreported impairment of vision. Key messages Impaired vision is common among older people and has a variety of adverse associations General practitioners are currently obliged to offer an annual assessment of vision as part of the 75 and over programme Evidence for effectiveness of visual screening is lacking, but a small beneficial effect cannot be excluded The continued inclusion of screening for impaired vision in screening programmes for older people is not supported by the evidence Further work is needed to clarify appropriate interventions for older people with unreported visual impairment

Smeeth, Liam; Iliffe, Steve

1998-01-01

71

The Influence of Manifest Strabismus and Stereoscopic Vision on Non-Verbal Abilities of Visually Impaired Children  

ERIC Educational Resources Information Center

This research was conducted in order to examine the influence of manifest strabismus and stereoscopic vision on non-verbal abilities of visually impaired children aged between 7 and 15. The sample included 55 visually impaired children from the 1st to the 6th grade of elementary schools for visually impaired children in Belgrade. RANDOT stereotest…

Gligorovic, Milica; Vucinic, Vesna; Eskirovic, Branka; Jablan, Branka

2011-01-01

72

The importance of friendship and family support in adaptation to chronic vision impairment.  

PubMed

The importance of friendship and family support in adaptation for 241 elders experiencing age-related vision loss was examined. Adaptation was operationalized with two global measures of psychological well-being (life satisfaction, depressive symptoms) and a domain-specific measure, adaptation to vision loss. Hierarchical regression analyses tested the effects of sociodemographic, vision, health, and functional disability variables in the first step, family support quality in the second step, and friendship support quality in the third step. Variables entered at each step contributed significant portions of explained variance in outcome variables. Thus, the importance of friendship support, independent of family support, in adaptation to chronic impairment was demonstrated. The effect of relationship type and gender on multiple support components was also assessed. Scores for family support were higher than those for friend support on almost all components. Close relationships were perceived as providing greater attachment in females and greater instrumental assistance and social integration in males. PMID:8809003

Reinhardt, J P

1996-09-01

73

Development of a quantitative method to measure vision in children with chronic cortical visual impairment.  

PubMed Central

PURPOSE: Cortical visual impairment (CVI) is the most common cause of bilateral vision impairment in children in Western countries. Better quantitative tools for measuring vision are needed to assess these children, to allow measurement of their visual deficit, and to monitor their response to treatment and rehabilitation. The author performed a series of experiments to assess the use of the sweep visual evoked potential (VEP) as a quantitative tool for measuring vision in CVI. METHODS: The first experiment was a reliability measure (test/retest) of VEP grating acuity thresholds of 23 children with CVI. To validate the VEP procedure, VEP grating acuity was compared to a clinical measure of vision, the Huo scale, and to a psychophysical measure of vision, the Teller Acuity Card procedure. Finally, the sweep VEP was tested as a tool for defining optimal luminance conditions for grating acuity in 13 children with CVI, by measuring grating thresholds under 2 different luminance conditions: 50 and 100 candela per square meter (cd/m2). RESULTS: Retest thresholds were similar to original thresholds (r2 = 0.662; P = .003, 1-tailed t test). Grating VEP measures correlate significantly with the clinical index (r2 = 0.63; P = .00004). Teller acuity measurements are also similar to VEP measures in children (r2 = 0.64; P = .0005) but show lower acuities compared to the VEP for children with particularly low vision. Finally, 3 of 13 children tested under 2 background luminance conditions showed paradoxical improvement in grating threshold with dimmer luminance. CONCLUSIONS: The sweep VEP tool is a reliable and valid means for measuring grating acuity in children with CVI. The tool also shows promise as a means of determining the optimal visual environment for children with CVI.

Good, W V

2001-01-01

74

Genetics of Castes and Tribes of India: A Review of Population Differences in Red and Green Colour Vision Deficiency in India  

Microsoft Academic Search

KEYWORDS Colour vision defect; X-linked trait; population differences; relaxed natural selection ABSTRACT The discipline of Biological Anthropology (or Human Biology) incorporates study of biology and environmental factors, as well as the forces of micro-evolution leading to macro-evolution, which ultimately influences the structure of human populations. In the present paper and attempt has been made to study the distribution differences in

M. K. Bhasin

75

Colour Model for Outdoor Machine Vision for Tropical Regions and its Comparison with the CIE Model  

NASA Astrophysics Data System (ADS)

Accurate modeling of daylight and surface reflectance are very useful for most outdoor machine vision applications specifically those which are based on color recognition. Existing daylight CIE model has drawbacks that limit its ability to predict the color of incident light. These limitations include lack of considering ambient light, effects of light reflected off the ground, and context specific information. Previously developed color model is only tested for a few geographical places in North America and its accountability is under question for other places in the world. Besides, existing surface reflectance models are not easily applied to outdoor images. A reflectance model with combined diffuse and specular reflection in normalized HSV color space could be used to predict color. In this paper, a new daylight color model showing the color of daylight for a broad range of sky conditions is developed which will suit weather conditions of tropical places such as Malaysia. A comparison of this daylight color model and daylight CIE model will be discussed. The colors of matte and specular surfaces have been estimated by use of the developed color model and surface reflection function in this paper. The results are shown to be highly reliable.

Sahragard, Nasrolah; Ramli, Abdul Rahman B.; Hamiruce Marhaban, Mohammad; Mansor, Shattri B.

2011-02-01

76

The Use of a Tactile-Vision Sensory Substitution System as an Augmentative Tool for Individuals with Visual Impairments  

ERIC Educational Resources Information Center

The promise of novel technological strategies and solutions to assist persons with visual impairments (that is, those who are blind or have low vision) is frequently discussed and held to be widely beneficial in countless applications and daily activities. One such approach involving a tactile-vision sensory substitution modality as a mechanism to…

Williams, Michael D.; Ray, Christopher T.; Griffith, Jennifer; De l'Aune, William

2011-01-01

77

Vision Impairment  

MedlinePLUS

... Women's Checkup Pregnancy Checkup Baby Checkup Mens Checkup Stephen J. Schueler, M.D. About Stephen J. Schueler, MD How it Works Testimonials FAQ ... should you do to care for yourself? About Stephen J. Schueler, M.D News Advertising How It ...

78

Comparison on testability of visual acuity, stereo acuity and colour vision tests between children with learning disabilities and children without learning disabilities in government primary schools  

PubMed Central

Context: Children with learning disabilities might have difficulties to communicate effectively and give reliable responses as required in various visual function testing procedures. Aims: The purpose of this study was to compare the testability of visual acuity using the modified Early Treatment Diabetic Retinopathy Study (ETDRS) and Cambridge Crowding Cards, stereo acuity using Lang Stereo test II and Butterfly stereo tests and colour perception using Colour Vision Test Made Easy (CVTME) and Ishihara's Test for Colour Deficiency (Ishihara Test) between children in mainstream classes and children with learning disabilities in special education classes in government primary schools. Materials and Methods: A total of 100 primary school children (50 children from mainstream classes and 50 children from special education classes) matched in age were recruited in this cross-sectional comparative study. The testability was determined by the percentage of children who were able to give reliable respond as required by the respective tests. ‘Unable to test’ was defined as inappropriate response or uncooperative despite best efforts of the screener. Results: The testability of the modified ETDRS, Butterfly stereo test and Ishihara test for respective visual function tests were found lower among children in special education classes (P < 0.001) but not in Cambridge Crowding Cards, Lang Stereo test II and CVTME. Conclusion: Non verbal or “matching” approaches were found to be more superior in testing visual functions in children with learning disabilities. Modifications of vision testing procedures are essential for children with learning disabilities.

Abu Bakar, Nurul Farhana; Chen, Ai-Hong

2014-01-01

79

Early Chronic Low-Level Methylmercury Poisoning in Monkeys Impairs Spatial Vision  

NASA Astrophysics Data System (ADS)

Five monkeys were treated from birth with oral doses of mercury as methylmercury (50 micrograms per kilogram of body weight per day); concentrations in the blood peaked at 1.2 to 1.4 parts per million; and declined after weaning from infant formula to a steady level of 0.6 to 0.9 part per million. There were no overt signs of toxicity. When tested between 3 and 4 years of age under conditions of both high and low luminance, treated monkeys exhibited spatial vision that was impaired compared with that of control monkeys.

Rice, Deborah C.; Gilbert, Steven G.

1982-05-01

80

Eye Diseases and Impaired Vision as Possible Risk Factors for Recurrent Falls in the Aged: A Systematic Review  

PubMed Central

Background. Recurrent falls are common among the aged. Vision is needed in maintaining balance, and impaired vision may be an intrinsic risk factor of recurrent falls. The aim was to perform a systematic review about the relationships between eye diseases or impaired vision and the risk of recurrent falls in the aged. Material and Methods. MEDLINE and CINAHL databases were searched in order to find longitudinal epidemiological studies about the associations between eye diseases or impaired vision and the risk of recurrent falls. Altogether 19 studies were found. A qualitative systematic analysis of these studies was performed. Results and Conclusions. The evidence about poor depth perception/stereoacuity and poor low-contrast visual acuity as risk factors of recurrent falls is quite convincing. Discrepant vision, a decrease in visual acuity, and loss of visual field may be risk factors, but more studies are needed. The results concerning the relationships between poor visual acuity and poor contrast sensitivity and the risk of recurrent falls are controversial. More studies about the relationships between different measures of vision and the risk of recurrent falls are needed before final conclusions about poor vision as a risk factor for recurrent falling can be done.

Salonen, Liisa; Kivela, Sirkka-Liisa

2012-01-01

81

The Hong Kong vision study: a pilot assessment of visual impairment in adults.  

PubMed Central

PURPOSE: The Hong Kong Adult Vision Pilot Study is a population based study of the distribution and determinants of eye disease in a random sample of the Chinese population age 40 and over. The present pilot study identifies the extent and causes of visual loss using methods developed in the United States and Australia. The pilot study uses the prevalence data to estimate the sample size necessary to predict the size of an effect a larger study may detect and the confidence with which that effect may be considered and the standard deviation of the Hong Kong population. The smallest detectable odds ratios were calculated based on known risk factor prevalence rates of the pilot study. METHODS: Hong Kong Chinese residents aged 40 and over in 2 random cluster sites were identified by private household census. The examinations were performed at one location and included, health history and habits, presenting and best corrected LogMar vision, Humphrey visual field and IOP measurement, dilated slit lamp, fundus examination, fundus photography and echography. RESULTS: In the two test sites, 355 people were examined of the 441 eligible residents (81% response). 76.6% of the population reported a change in vision in the last 10 years; 45% had not sought examination. 4.54% had vision less than 20/60. This was caused by: myopic choroidal degeneration (31%), cataract (19%), cataract + ARM (19%), ARMD (19%), glaucoma (6%), and corneal disease (6%). Vision loss increased significantly with age. Vision loss was more common in older women than in older men. The prevalence rates calculated from the pilot study data were used, requiring a relative precision of 95% and +/- 20% confidence interval of the prevalence rates, indicate that a sample size of 2500 would be a good number for a larger study. CONCLUSIONS: The methods developed in the United States and Australia for completing eye disease prevalence studies are applicable in Hong Kong. Vision loss is increasingly common in older people and the percent of visual impairment in Hong Kong is higher than studies in the US and Australia. As the population ages demands on the health care systems will increase. The results from this pilot warrant continuation of the study. Efforts must be directed toward prevention of visual loss.

Van Newkirk, M R

1997-01-01

82

The effect of gender and level of vision on the physical activity level of children and adolescents with visual impairment.  

PubMed

This study was planned in order to determine physical activity levels of visually impaired children and adolescents and to investigate the effect of gender and level of vision on physical activity level in visually impaired children and adolescents. A total of 30 visually impaired children and adolescents (16 low vision and 14 blind) aged between 8 and 16 years participated in the study. The physical activity level of cases was evaluated with a physical activity diary (PAD) and one-mile run/walk test (OMR-WT). No difference was found between the PAD and the OMR-WT results of low vision and blind children and adolescents. The visually impaired children and adolescents were detected not to participate in vigorous physical activity. A difference was found in favor of low vision boys in terms of mild, moderate activities and OMR-WT durations. However, no difference was found between physical activity levels of blind girls and boys. The results of our study suggested that the physical activity level of visually impaired children and adolescents was low, and gender affected physical activity in low vision children and adolescents. PMID:22699253

Aslan, Ummuhan Bas; Calik, Bilge Basakc?; Kiti?, Ali

2012-01-01

83

Impact of low vision care on reading performance in children with multiple disabilities and visual impairment  

PubMed Central

Background: Lack of evidence in literature to show low vision care enhances the reading performance in children with Multiple Disabilities and Visual Impairment (MDVI). Aim: To evaluate the effectiveness of Low Vision Care intervention on the reading performance of children with MDVI. Materials and Methods: Three subjects who were diagnosed to have cerebral palsy and visual impairment, studying in a special school were recruited for the study. All of them underwent detailed eye examination and low vision care evaluation at a tertiary eye care hospital. A single subject multiple baseline (study) design was adopted and the study period was 16 weeks. The reading performance (reading speed, reading accuracy, reading fluency) was evaluated during the baseline phase and the intervention phase. The median of all the reading parameters for each week was noted. The trend of the reading performance was graphically represented in both the phases. Results: Reading speed increased by 37 Word per minute, 37 Letters per minute and 5 letters per minute for the subject 1, 2 and 3 respectively after the intervention. Reading accuracy was 84%, 91% and 86.4% at the end of the baseline period and 98.7%, 98.4% and 99% at the end of 16 weeks for subject 1, 2 and 3 respectively. Average reading fluency score was 8.3, 7.1 and 5.5 in the baseline period and 10.2, 10.2 and 8.7 in the intervention period. Conclusion: This study shows evidence of noticeable improvement in reading performance of children with MDVI using a novel study design.

Ramani, Krishna Kumar; Police, Shailaja Reddy; Jacob, Namita

2014-01-01

84

Causes of childhood visual impairment and unmet low-vision care in blind school students in Ghana  

Microsoft Academic Search

The purpose of this study was to determine the causes of childhood visual impairment and blindness in students of a school\\u000a for blind children, to determine how many students had some residual vision, and to evaluate any unmet low-vision care. A\\u000a survey of students in the blind school was conducted in two parts in May–June and then October 2003. The

C. T. Ntim-Amponsah; W. M. K. Amoaku

2008-01-01

85

Crowded visual search in children with normal vision and children with visual impairment.  

PubMed

This study investigates the influence of oculomotor control, crowding, and attentional factors on visual search in children with normal vision ([NV], n=11), children with visual impairment without nystagmus ([VI-nys], n=11), and children with VI with accompanying nystagmus ([VI+nys], n=26). Exclusion criteria for children with VI were: multiple impairments and visual acuity poorer than 20/400 or better than 20/50. Three search conditions were presented: a row with homogeneous distractors, a matrix with homogeneous distractors, and a matrix with heterogeneous distractors. Element spacing was manipulated in 5 steps from 2 to 32 minutes of arc. Symbols were sized 2 times the threshold acuity to guarantee visibility for the VI groups. During simple row and matrix search with homogeneous distractors children in the VI+nys group were less accurate than children with NV at smaller spacings. Group differences were even more pronounced during matrix search with heterogeneous distractors. Search times were longer in children with VI compared to children with NV. The more extended impairments during serial search reveal greater dependence on oculomotor control during serial compared to parallel search. PMID:24456806

Huurneman, Bianca; Cox, Ralf F A; Vlaskamp, Björn N S; Boonstra, F Nienke

2014-03-01

86

Comparison of accessibility among Vision-impaired patients visiting mobile and stationary hospitals in rural Bangladesh.  

PubMed

The aim of this study is to compare accessibility of vision-impaired (VI) patients to other eyecare centres before attending the mobile and stationary hospitals. Under a cross-sectional study design, VI patients were consecutively enrolled if they visited one of the three Impact Foundation Hospitals--one mobile and two stationary hospitals. The cost and service output of all hospitals were also reviewed; 27.7% of patients at the mobile and 36.8% at the two stationary hospitals had sought eyecare at other health facilities in the past. Mobile hospital patients lived closer to the hospital but spent more time in travelling, bore less direct cost, needed less extra support, and had a higher level of satisfaction on the service. They also identified more barriers to access eyecare in the past. The mobile hospital had a higher percentage of patients with accessibility problems and should continue to help the remote population in overcoming these problems. PMID:23930341

Alam, Md Ferdaws; Chongsuvivatwong, Virasakdi; Mahmud, Hasib; Gupta, Pradip Sen

2013-06-01

87

Book4All: A Tool to Make an e-Book More Accessible to Students with Vision/Visual-Impairments  

NASA Astrophysics Data System (ADS)

Empowering people who are blind or otherwise visually impaired includes ensuring that products and electronic materials incorporate a broad range of accessibility features and work well with screen readers and other assistive technology devices. This is particularly important for students with vision impairments. Unfortunately, authors and publishers often do not include specific criteria when preparing the contents. Consequently, e-books can be inadequate for blind and low vision users, especially for students. In this paper we describe a semi-automatic tool developed to support operators who adapt e-documents for visually impaired students. The proposed tool can be used to convert a PDF e-book into a more suitable accessible and usable format readable on desktop computer or on mobile devices.

Calabrò, Antonello; Contini, Elia; Leporini, Barbara

88

Object knowledge modulates colour appearance  

PubMed Central

We investigated the memory colour effect for colour diagnostic artificial objects. Since knowledge about these objects and their colours has been learned in everyday life, these stimuli allow the investigation of the influence of acquired object knowledge on colour appearance. These investigations are relevant for questions about how object and colour information in high-level vision interact as well as for research about the influence of learning and experience on perception in general. In order to identify suitable artificial objects, we developed a reaction time paradigm that measures (subjective) colour diagnosticity. In the main experiment, participants adjusted sixteen such objects to their typical colour as well as to grey. If the achromatic object appears in its typical colour, then participants should adjust it to the opponent colour in order to subjectively perceive it as grey. We found that knowledge about the typical colour influences the colour appearance of artificial objects. This effect was particularly strong along the daylight axis.

Witzel, Christoph; Valkova, Hanna; Hansen, Thorsten; Gegenfurtner, Karl R

2011-01-01

89

The relative contributions of colour and luminance signals towards the visuomotor localisation of targets in human peripheral vision.  

PubMed

We sought to determine the extent to which colour (and luminance) signals contribute towards the visuomotor localization of targets. To do so we exploited the movement-related illusory displacement a small stationary window undergoes when it has a continuously moving carrier grating behind it. We used drifting (1.0-4.2 Hz) red/green-modulated isoluminant gratings or yellow/black luminance-modulated gratings as carriers, each curtailed in space by a stationary, two-dimensional window. After each trial, the perceived location of the window was recorded with reference to an on-screen ruler (perceptual task) or the on-screen touch of a ballistic pointing movement made without visual feedback (visuomotor task). Our results showed that the perceptual displacement measures were similar for each stimulus type and weakly dependent on stimulus drift rate. However, while the visuomotor displacement measures were similar for each stimulus type at low drift rates (<4 Hz), they were significantly larger for luminance than colour stimuli at high drift rates (>4 Hz). We show that the latter cannot be attributed to differences in perceived speed between stimulus types. We assume, therefore, that our visuomotor localization judgements were more susceptible to the (carrier) motion of luminance patterns than colour patterns. We suggest that, far from being detrimental, this susceptibility may indicate the operation of mechanisms designed to counter the temporal asynchrony between perceptual experiences and the physical changes in the environment that give rise to them. We propose that perceptual localisation is equally supported by both colour and luminance signals but that visuomotor localisation is predominantly supported by luminance signals. We discuss the neural pathways that may be involved with visuomotor localization. PMID:17643232

Ashida, Hiroshi; Yamagishi, Noriko; Anderson, Stephen J

2007-12-01

90

The "voice" has it: screen reader adoption and switching behavior among vision impaired persons in India  

PubMed Central

We present results from a mixed methods study of screen reader use and switching behavior among people with vision impairments in India. We examine loyalty and experimentation with screen readers and find that the main drivers of adoption for early users differ significantly from the factors that drive continued use by advanced users. We discuss the factor that emerges as one of the strongest stated drivers of early adoption, TTS “voice” quality, particularly a “human-sounding voice” as one of the key features differentiating free/open source (FOSS) products from more expensive proprietary products. While the initial preferences are driven by voice quality, application support becomes more important over time as users speed up their sound settings and become more comfortable with the resultant non-human-sounding speech. We discuss these findings from two theoretical perspectives – first, through the application of the economics of behavior switching, and second, vis-à-vis novice and expert approaches toward new product adoption. We argue that these findings further our understanding of initial user comfort related to assistive technology adoption, and the impact of early technology choices on long-term technology switching behavior.

Pal, Joyojeet; Cutrell, Edward

2013-01-01

91

Candidate genes for colour and vision exhibit signals of selection across the pied flycatcher (Ficedula hypoleuca) breeding range.  

PubMed

The role of natural selection in shaping adaptive trait differentiation in natural populations has long been recognized. Determining its molecular basis, however, remains a challenge. Here, we search for signals of selection in candidate genes for colour and its perception in a passerine bird. Pied flycatcher plumage varies geographically in both its structural and pigment-based properties. Both characteristics appear to be shaped by selection. A single-locus outlier test revealed 2 of 14 loci to show significantly elevated signals of divergence. The first of these, the follistatin gene, is expressed in the developing feather bud and is found in pathways with genes that determine the structure of feathers and may thus be important in generating variation in structural colouration. The second is a gene potentially underlying the ability to detect this variation: SWS1 opsin. These two loci were most differentiated in two Spanish pied flycatcher populations, which are also among the populations that have the highest UV reflectance. The follistatin and SWS1 opsin genes thus provide strong candidates for future investigations on the molecular basis of adaptively significant traits and their co-evolution. PMID:22027894

Lehtonen, P K; Laaksonen, T; Artemyev, A V; Belskii, E; Berg, P R; Both, C; Buggiotti, L; Bureš, S; Burgess, M D; Bushuev, A V; Krams, I; Moreno, J; Mägi, M; Nord, A; Potti, J; Ravussin, P-A; Sirkiä, P M; Sætre, G-P; Winkel, W; Primmer, C R

2012-04-01

92

The Effect of Visual Impairment on Vision-Related Quality of Life in American Indian/Alaska Natives  

PubMed Central

Purpose To determine if National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) scores decrease with worsening visual acuity (VA) in American Indian/Alaska Natives (AI/AN), as well as determine the other associated explanatory factors for vision-related quality of life Methods The study included 414 randomly selected AI/AN tribal members aged 40 years or older from the Pacific Northwest. We excluded candidates who were deceased, seriously ill, had dementia, or otherwise were unable to perform subjective testing such as visual field testing. The participants completed the NEI-VFQ-25, as well as a detailed eye examination. We defined visual impairment as presenting distance VA 20/40 or worse in the better-seeing eye. The main outcome measures were NEI-VFQ-25 composite and subscale scores. We compared median NEI-VFQ-25 composite and subscale scores in those with visual impairment to those without visual impairment. Results Visual impairment occurred in 53 (12.8%, CI: 9.6–16.0) participants. The NEI-VFQ-25 median composite score was significantly lower in those with visual impairment as compared to those without visual impairment (77.5 vs. 90.1, p=.001). A univariate analysis showed VA to be significantly (p ? .05) associated with all subscales except ocular pain. When controlling for age, gender, income level, education, percent AIAN heritage, and marital status, a multivariate proportional odds model analysis showed VA to be the best predictor of NEI-VFQ 25 composite scores. Conclusion Visual impairment is common in Northwest AI/AN. The NEI-VFQ-25 was sensitive to differences in VA, suggesting it is a valid measure of vision-related quality of life in AI/AN.

McClure, Tina M.; Choi, Dongseok; Becker, Thomas; Cioffi, George A.; Mansberger, Steven L.

2013-01-01

93

Colour constancy in insects.  

PubMed

Colour constancy is the perceptual phenomenon that the colour of an object appears largely unchanged, even if the spectral composition of the illuminating light changes. Colour constancy has been found in all insect species so far tested. Especially the pollinating insects offer a remarkable opportunity to study the ecological significance of colour constancy since they spend much of their adult lives identifying and choosing between colour targets (flowers) under continuously changing ambient lighting conditions. In bees, whose colour vision is best studied among the insects, the compensation provided by colour constancy is only partial and its efficiency depends on the area of colour space. There is no evidence for complete 'discounting' of the illuminant in bees, and the spectral composition of the light can itself be used as adaptive information. In patchy illumination, bees adjust their spatial foraging to minimise transitions between variously illuminated zones. Modelling allows the quantification of the adaptive benefits of various colour constancy mechanisms in the economy of nature. We also discuss the neural mechanisms and cognitive operations that might underpin colour constancy in insects. PMID:24647930

Chittka, Lars; Faruq, Samia; Skorupski, Peter; Werner, Annette

2014-06-01

94

Design for Simulator Performance Evaluations of Driving with Vision Impairments and Visual Aids  

Microsoft Academic Search

Driving simulator technology provides a safe method for evaluating the impact of vision loss on different components of the driving task and the potential efficacy of visual aids intended to compensate for a particular type of vision loss. Most previous investigations have used general driving scenarios. It is proposed here that scenarios with different task require- ments be designed specifically

E. Peli; A. R. Bowers; A. J. Mandel; K. Higgins; R. B. Goldstein; L. Bobrow

2005-01-01

95

The assessment of colour perception, naming and knowledge: a new test device with a case study.  

PubMed

Besides ocular diseases, also cerebral damage may cause colour vision deficits; cerebral lesions may be associated with a variety of clinical conditions that impair colour processing. This study presents procedures and normative data for a rapid, comprehensive seven-test battery aimed at assessing colour perception, colour naming and object colour knowledge. The norms, obtained from 96 healthy Italian participants, allow normality/pathology judgements on the basis of one-sided tolerance limits, after adjusting the score of each test for the demographic variables of the proband subjects. We also report, as an example, use of the battery in a stroke patient; this patient was chosen because her lesion affected the left temporal-occipital cortex, an area sometimes associated with a deficit of colour processing. The patient resulted normal on colour perception and colour name retrieval, but defective on object colour knowledge probed using the stimulus name. For the sound definition of the functional locus of cognitive impairment at the single case level, a multi-faceted set of tasks is necessary. PMID:22076482

Pagani, Rossella; Bosco, Giovanna; Dalla Valle, Elisabetta; Capitani, Erminio; Laiacona, Marcella

2012-08-01

96

Television, computer and portable display device use by people with central vision impairment  

PubMed Central

Purpose To survey the viewing experience (e.g. hours watched, difficulty) and viewing metrics (e.g. distance viewed, display size) for television (TV), computers and portable visual display devices for normally-sighted (NS) and visually impaired participants. This information may guide visual rehabilitation. Methods Survey was administered either in person or in a telephone interview on 223 participants of whom 104 had low vision (LV, worse than 6/18, age 22 to 90y, 54 males), and 94 were NS (visual acuity 6/9 or better, age 20 to 86y, 50 males). Depending on their situation, NS participants answered up to 38 questions and LV participants answered up to a further 10 questions. Results Many LV participants reported at least “some” difficulty watching TV (71/103), reported at least “often” having difficulty with computer displays (40/76) and extreme difficulty watching videos on handheld devices (11/16). The average daily TV viewing was slightly, but not significantly, higher for the LV participants (3.6h) than the NS (3.0h). Only 18% of LV participants used visual aids (all optical) to watch TV. Most LV participants obtained effective magnification from a reduced viewing distance for both TV and computer display. Younger LV participants also used a larger display when compared to older LV participants to obtain increased magnification. About half of the TV viewing time occurred in the absence of a companion for both the LV and the NS participants. The mean number of TVs at home reported by LV participants (2.2) was slightly but not significantly (p=0.09) higher than NS participants (2.0). LV participants were equally likely to have a computer but were significantly (p=0.004) less likely to access the internet (73/104) compared to NS participants (82/94). Most LV participants expressed an interest in image enhancing technology for TV viewing (67/104) and for computer use (50/74), if they used a computer. Conclusion In this study, both NS and LV participants had comparable video viewing habits. Most LV participants in our sample reported difficulty watching TV, and indicated an interest in assistive technology, such as image enhancement. As our participants reported that at least half their video viewing hours are spent alone and that there is usually more than one TV per household, this suggests that there are opportunities to use image enhancement on the TVs of LV viewers without interfering with the viewing experience of NS viewers.

Woods, Russell L; Satgunam, PremNandhini

2011-01-01

97

Trichromacy, Opponent Colours Coding and Optimum Colour Information Transmission in the Retina  

Microsoft Academic Search

This paper presents a systematic analysis of the role of opponent type processing in colour vision and the relation between opponent type colour transformations and the initial three colour mechanisms. It is shown that efficient information transmission is achieved by a transformation of the initial three colour mechanisms into an achromatic and two opponent chromatic channels. The derivation of the

G. Buchsbaum; A. Gottschalk

1983-01-01

98

Exercise and Drinking May Play a Role in Vision Impairment Risk  

MedlinePLUS

... Reduced Vision Tearing See all Symptoms > Glasses, Contacts & LASIK Contact Lenses Colored Contact Lenses Eyeglasses IOLs Refractive Surgery & LASIK Sunglasses Living EyeSmart About Ophthalmologists Adults Under 40 ...

99

Changes in quality of life in visually impaired patients after low-vision rehabilitation.  

PubMed

The objective of the study was to assess the impact of low-vision aids on quality of life. Interviews included a modified version of the National Eye Institute Visual Functioning Questionnaire (Modified German NEI VFQ-25), the Hospital Anxiety and Depression Scale, the Mini-Mental State Examination Blind, and Indicators of the Rehabilitation Status. These were conducted before and 5 months after low-vision rehabilitation that involved recommendation of devices and instructing patients on how to use them. Of a total of 88 patients interviewed before low-vision rehabilitation, 50 patients could be reached for the follow-up interview. A huge proportion of the sample reported clinically significant depression (30%) or anxiety (30%). There were no differences between participants or dropouts. After fitting of low-vision devices, patients reported a significant improvement in perceived near tasks (P<0.01), social functioning (P<0.01), and reading ability (P<0.001). The magnitude of change was moderate. No significant changes were found in Hospital Anxiety and Depression Scale, Mini-Mental State Examination Blind, and Indicators of the Rehabilitation Status. Low-vision rehabilitation appears to have a broader effect than simply improving visual performance, as it may positively influence social functioning. Even though this study had no control group, the influence of low-vision aids on social functioning has not been reported before and should encourage their use. PMID:22890293

Renieri, Giulia; Pitz, Susanne; Pfeiffer, Norbert; Beutel, Manfred E; Zwerenz, Rüdiger

2013-03-01

100

Changes in Quality of Life in Visually Impaired Patients after Low-Vision Rehabilitation  

ERIC Educational Resources Information Center

The objective of the study was to assess the impact of low-vision aids on quality of life. Interviews included a modified version of the National Eye Institute Visual Functioning Questionnaire (Modified German NEI VFQ-25), the Hospital Anxiety and Depression Scale, the Mini-Mental State Examination Blind, and Indicators of the Rehabilitation…

Renieri, Giulia; Pitz, Susanne; Pfeiffer, Norbert; Beutel, Manfred E.; Zwerenz, Rudiger

2013-01-01

101

Fuzzy-based human vision properties in stereo sonification system for the visually impaired  

NASA Astrophysics Data System (ADS)

This paper presents incorporation of certain human vision properties in the image processing methodologies, applied in the vision substitutive system for human blind. The prototype of the system has digital video camera fixed in a headgear, stereo earphone and a laptop computer, interconnected. The processing of the captured image is designed as human vision. It involves lateral inhibition, which is developed using Feed Forward Neural Network (FFNN) and domination of the object properties with suppression of background by means of Fuzzy based Image Processing System (FLIPS). The processed image is mapped to stereo acoustic signals to the earphone. The sound is generated using non-linear frequency incremental sine wave. The sequence of the scanning to construct the acoustic signal is designed to produce stereo signals, which aids to locate the object in horizontal axis. Frequency variation implies the location of object in the vertical axis. The system is tested with blind volunteer and his suggestion in formatting, pleasantness and discrimination of sound pattern were also considered.

Nagarajan, Ramachandran; Yaacob, Sazali; Sainarayanan, G.

2001-10-01

102

The Psychological Challenge of Late-Life Vision Impairment: Concepts, Findings, and Practical Implications  

PubMed Central

The intention is to summarize the body of evidence speaking to the psychological challenges faced by visually impaired older adults, as well as their coping efforts. This evidence is substantiated by a rich set of concepts, theories, and empirical findings that have accumulated under the umbrella of age-related psychoophthalmology (APO). I introduce the field of APO and continue with a discussion of important concepts and theories for a better understanding of adaptational processes in visually impaired older adults. I then summarize the most relevant and most recent data from four areas: (1) everyday competence, (2) cognitive functioning, (3) social functioning, and (4) subjective well-being-related outcomes, depression, and adaptational processes. Thereafter, major insights related to the current state-of-the art psychosocial interventions with visuallyimpaired older adults are reviewed. I close with the need that the public health community should become more aware of and address the psychosocial needs of visually impaired older adults.

Wahl, Hans-Werner

2013-01-01

103

Visualizing without Vision at the Microscale: Students with Visual Impairments Explore Cells with Touch  

ERIC Educational Resources Information Center

Science instruction is typically highly dependent on visual representations of scientific concepts that are communicated through textbooks, teacher presentations, and computer-based multimedia materials. Little is known about how students with visual impairments access and interpret these types of visually-dependent instructional materials. This…

Jones, M. Gail; Minogue, James; Oppewal, Tom; Cook, Michelle P.; Broadwell, Bethany

2006-01-01

104

Magnitude and Causes of Low Vision Disability (Moderate and Severe Visual Impairment) among Students of Al-Noor Institute for the Blind in Al-Hassa, Saudi Arabia  

PubMed Central

Objectives: This study aimed to estimate the magnitude and causes of low vision disability (severe visual impairment [SVI] and moderate visual impairment [MVI]) among students at Al-Noor Institute for the Blind (NIB) in Al-Hassa, Saudi Arabia in 2006. Methods: An optometrist conducted refraction of 122 eyes of the 61 students (27 boys and 34 girls) with MVI (vision <6/18 to 6/60) and SVI (vision <6/60 to 3/60). Ophthalmologists examined the anterior and posterior segments, and analysed the outcomes of additional investigations to finalise the diagnosis. The results were categorised as ‘preventable’, ‘treatable’ and ‘not amenable to treatment’. The low vision care was also reviewed. Results: In 12 (9.8%) eyes, visual acuity was ?6/18 and in 28 (23%) eyes, it was <3/60. MVI and SVI were found in 82 eyes (67.2%). Hereditary retinal disorders were found in 68 (55.7%) eyes. Although refractive errors were found in 112 (91.8%) eyes, isolated refractive error was found in only 9 students. Congenital glaucoma and cataract were responsible for visual impairment in 16 (13.1%) and 9 (7.4%) eyes. These students were prescribed optical and non-optical low vision aids. Conclusion: Retinal disease was the main cause of SVI and MVI in our series. Some students at Al-Noor Institute for the Blind have curable low vision conditions. Rehabilitation of low vision disability should be different from that offered to the absolutely blind.

Al-Wadani, Fahad; Khandekar, Rajiv; Al-Hussain, Muneera A.; Alkhawaja, Ahmed A.; Khan, Mohammed Sarfaraz; Alsulaiman, Ramzy A

2012-01-01

105

Auditory localization and precedence effect: An exploratory study in infants and toddlers with visual impairment and normal vision.  

PubMed

The precedence effect is a spatial hearing phenomenon implicated in sound localization on reverberant environments. It occurs when a pair of sounds, with a brief delay between them, is presented from different directions; listeners give greater perceptual weight to localization cues coming from the first-arriving sound, called lead, and suppress localization cues from the later-arriving reflection, called lag. Developmental studies with sighted infants show that the first responses to precedence effect stimuli are observed at 4-5 months of life. In this exploratory study, we use the minimum audible angle (MAA) paradigm in conjunction with the observer-based psychophysical procedure to test the ability of infants and toddlers, with visual impairment and normal vision, to discriminate changes in the azimuthal position of sounds configured under precedence effect conditions. The results indicated that similar and, in some conditions, higher performances were obtained by blind toddlers when compared to sighted children of similar age, and revealed that the observer-based psychophysical procedure is a valuable method to measure auditory localization acuity in infants and toddlers with visual impairment. The video records showed auditory orienting behaviors specific of the blind children group. PMID:24864055

Hüg, Mercedes X; Arias, Claudia; Tommasini, Fabián C; Ramos, Oscar A

2014-09-01

106

Cav1.4 IT mouse as model for vision impairment in human congenital stationary night blindness type 2  

PubMed Central

Mutations in the CACNA1F gene encoding the Cav1.4 Ca2+ channel are associated with X-linked congenital stationary night blindness type 2 (CSNB2). Despite the increasing knowledge about the functional behavior of mutated channels in heterologous systems, the pathophysiological mechanisms that result in vision impairment remain to be elucidated. This work provides a thorough functional characterization of the novel IT mouse line that harbors the gain-of-function mutation I745T reported in a New Zealand CSNB2 family.1 Electroretinographic recordings in IT mice permitted a direct comparison with human data. Our data supported the hypothesis that a hyperpolarizing shift in the voltage-dependence of channel activation—as seen in the IT gain-of-function mutant2—may reduce the dynamic range of photoreceptor activity. Morphologically, the retinal outer nuclear layer in adult IT mutants was reduced in size and cone outer segments appeared shorter. The organization of the outer plexiform layer was disrupted, and synaptic structures of photoreceptors had a variable, partly immature, appearance. The associated visual deficiency was substantiated in behavioral paradigms. The IT mouse line serves as a specific model for the functional phenotype of human CSNB2 patients with gain-of-function mutations and may help to further understand the dysfunction in CSNB.

Knoflach, Dagmar; Kerov, Vasily; Sartori, Simone B; Obermair, Gerald J; Schmuckermair, Claudia; Liu, Xiaoni; Sothilingam, Vithiyanjali; Garrido, Marina Garcia; Baker, Sheila A; Glosmann, Martin; Schicker, Klaus; Seeliger, Mathias; Lee, Amy; Koschak, Alexandra

2013-01-01

107

Monitor, a vibrotactile aid for environmental perception: a field evaluation by four people with severe hearing and vision impairment.  

PubMed

Monitor is a portable vibrotactile aid to improve the ability of people with severe hearing impairment or deafblindness to detect, identify, and recognize the direction of sound-producing events. It transforms and adapts sounds to the frequency sensitivity range of the skin. The aid was evaluated in the field. Four females (44-54 years) with Usher Syndrome I (three with tunnel vision and one with only light perception) tested the aid at home and in traffic in three different field studies: without Monitor, with Monitor with an omnidirectional microphone, and with Monitor with a directional microphone. The tests were video-documented, and the two field studies with Monitor were initiated after five weeks of training. The detection scores with omnidirectional and directional microphones were 100% for three participants and above 57% for one, both in their home and traffic environments. In the home environment the identification scores with the omnidirectional microphone were 70%-97% and 58%-95% with the directional microphone. The corresponding values in traffic were 29%-100% and 65%-100%, respectively. Their direction perception was improved to some extent by both microphones. Monitor improved the ability of people with deafblindness to detect, identify, and recognize the direction of events producing sounds. PMID:23861651

Ranjbar, Parivash; Stenström, Ingeborg

2013-01-01

108

Low vision due to cerebral visual impairment: differentiating between acquired and genetic causes  

PubMed Central

Background To gain more insight into genetic causes of cerebral visual impairment (CVI) in children and to compare ophthalmological findings between genetic and acquired forms of CVI. Methods The clinical data of 309 individuals (mainly children) with CVI, and a visual acuity ?0.3 were analyzed for etiology and ocular variables. A differentiation was made between acquired and genetic causes. However, in persons with West syndrome or hydrocephalus, it might be impossible to unravel whether CVI is caused by the seizure disorder or increased intracranial pressure or by the underlying disorder (that in itself can be acquired or genetic). In two subgroups, individuals with ‘purely’ acquired CVI and with ‘purely’ genetic CVI, the ocular variables (such as strabismus, pale optic disc and visual field defects) were compared. Results It was possible to identify a putative cause for CVI in 60% (184/309) of the cohort. In the remaining 40% the etiology could not be determined. A ‘purely’ acquired cause was identified in 80 of the patients (26%). West syndrome and/or hydrocephalus was identified in 21 patients (7%), and in 17 patients (6%) both an acquired cause and West and/or hydrocephalus was present. In 66 patients (21%) a genetic diagnosis was obtained, of which 38 (12%) had other possible risk factor (acquired, preterm birth, West syndrome or hydrocephalus), making differentiation between acquired and genetic not possible. In the remaining 28 patients (9%) a ‘purely’ genetic cause was identified. CVI was identified for the first time in several genetic syndromes, such as ATR-X, Mowat-Wilson, and Pitt Hopkins syndrome. In the subgroup with ‘purely’ acquired causes (N?=?80) strabismus (88% versus 64%), pale optic discs (65% versus 27%) and visual field defects (72% versus 30%) could be observed more frequent than in the subgroup with ‘purely’ genetic disorders (N?=?28). Conclusions We conclude that CVI can be part of a genetic syndrome and that abnormal ocular findings are present more frequently in acquired forms of CVI.

2014-01-01

109

Colour detection thresholds in faces and colour patches.  

PubMed

Human facial skin colour reflects individuals' underlying health (Stephen et al 2011 Evolution & Human Behavior 32 216-227); and enhanced facial skin CIELab b* (yellowness), a* (redness), and L* (lightness) are perceived as healthy (also Stephen et al 2009a International Journal of Primatology 30 845-857). Here, we examine Malaysian Chinese participants' detection thresholds for CIELab L* (lightness), a* (redness), and b* (yellowness) colour changes in Asian, African, and Caucasian faces and skin coloured patches. Twelve face photos and three skin coloured patches were transformed to produce four pairs of images of each individual face and colour patch with different amounts of red, yellow, or lightness, from very subtle (deltaE = 1.2) to quite large differences (deltaE = 9.6). Participants were asked to decide which of sequentially displayed, paired same-face images or colour patches were lighter, redder, or yellower. Changes in facial redness, followed by changes in yellowness, were more easily discriminated than changes in luminance. However, visual sensitivity was not greater for redness and yellowness in nonface stimuli, suggesting red facial skin colour special salience. Participants were also significantly better at recognizing colour differences in own-race (Asian) and Caucasian faces than in African faces, suggesting the existence of cross-race effect in discriminating facial colours. Humans' colour vision may have been selected for skin colour signalling (Changizi et al 2006 Biology Letters 2 217-221), enabling individuals to perceive subtle changes in skin colour, reflecting health and emotional status. PMID:24344549

Tan, Kok Wei; Stephen, Ian D

2013-01-01

110

Vision Changes in Space  

NASA Video Gallery

This Human Research Program 'Research to Outreach' video featuring NASA Clinical Translational Scientist Jennifer Fogarty explains the risk of vision impairment both during and after spaceflight, i...

111

Applying colour science in colour design  

NASA Astrophysics Data System (ADS)

Although colour science has been widely used in a variety of industries over the years, it has not been fully explored in the field of product design. This paper will initially introduce the three main application fields of colour science: colour specification, colour-difference evaluation and colour appearance modelling. By integrating these advanced colour technologies together with modern colour imaging devices such as display, camera, scanner and printer, some computer systems have been recently developed to assist designers for designing colour palettes through colour selection by means of a number of widely used colour order systems, for creating harmonised colour schemes via a categorical colour system, for generating emotion colours using various colour emotional scales and for facilitating colour naming via a colour-name library. All systems are also capable of providing accurate colour representation on displays and output to different imaging devices such as printers.

Luo, Ming Ronnier

2006-06-01

112

Kids' Quest: Vision Impairment  

MedlinePLUS

... page: About CDC.gov . Kids' Quest National Center Homepage Share Compartir What is it like to not ... 888) 232-6348 Contact CDC-INFO Kids' Quest Homepage ADHD Quest Autism Spectrum Disorders Quest Fetal Alcohol ...

113

Colour-space distortion in women who are heterozygous for colour deficiency.  

PubMed

We examined colour perception among a group of women heterozygous for colour vision deficiency. Judgements of colour dissimilarity were collected by presenting colour stimuli in groups of three for odd-one-out decisions. The judgements were summarised as one consensus colour space for the heterozygotes and another for age-matched controls. Individual differences MDS was also applied, resulting in a single colour space which can be adjusted to fit each subject's responses individually by compressing it along its axes. Heterozygous women showed a trend towards colour-space compression in a red-green dimension, or reduced salience of that dimension compared to controls, though less extreme than found in overt colour deficiency. PMID:19167418

Bimler, David; Kirkland, John

2009-03-01

114

Faerg-och Symbolupptattning vid Foerhoejd +Gz-Belastning (Colour Identification, Symbol Identification, and Colour Discrimination during Moderately Elevated G2-Load).  

National Technical Information Service (NTIS)

Colour is used today in displays in modern fighter aircraft. As the knowledge of elevated +Gz-load on foveal colour vision is insufficient, further studies are needed. Foveal colour and symbol identification and colour discrimination were studied in two e...

P. Andersson G. Derefeldt L. Eriksson O. Eiken R. Koelegard P. Andersson B. Lindborg H. Oemhagen

2000-01-01

115

The set-up of a vision pyrometer  

Microsoft Academic Search

The paper presents a new radiation pyrometer, a vision pyrometric device based on a commercial digital colour camera and SUNPRO software, which converts the calibrated commercial digital colour camera into a scientific instrument for temperature measurement. We introduce the calibration experiments and the principle of this vision pyrometer, and the application of the vision pyrometer is illustrated in the specific

Tairan Fu; Xiaofang Cheng; Congling Shi; Maohua Zhong; Tiemin Liu; Xiaobing Zheng

2006-01-01

116

Colour Sensation  

Microsoft Academic Search

IN NATURE of July 15 there is given an abstract of a paper by Dr. F. W. Edridge-Green in which he gives reasons for supposing that the sensation produced by spectral yellow is a simple sensation, and not a compound of red and green, as supposed by the Young-Helmholtz theory. In 1872 I read a paper on colour sensation before

John Aitken

1915-01-01

117

Low Vision Training in Sweden.  

ERIC Educational Resources Information Center

The article describes the team work approach used in Sweden to provide services to the four main categories of visual impairment: central scotoma, nystagmus, loss of peripheral vision while retaining central vision, and amblyopia. (Author/PHR)

Inde, Krister

1978-01-01

118

X-linked cone dystrophy and colour vision deficiency arising from a missense mutation in a hybrid L/M cone opsin gene.  

PubMed

In this report, we describe a male subject who presents with a complex phenotype of myopia associated with cone dysfunction and a protan vision deficiency. Retinal imaging demonstrates extensive cone disruption, including the presence of non-waveguiding cones, an overall thinning of the retina, and an irregular mottled appearance of the hyper-reflective band associated with the inner segment ellipsoid portion of the photoreceptor. Mutation screening revealed a novel p.Glu41Lys missense mutation in a hybrid L/M opsin gene. Spectral analysis shows that the mutant opsin fails to form a pigment in vitro and fails to be trafficked to the cell membrane in transfected Neuro2a cells. Extensive sequence and quantitative PCR analysis identifies this mutant gene as the only gene present in the affected subject's L/M opsin gene array, yet the presence of protanopia indicates that the mutant opsin must retain some activity in vivo. To account for this apparent contradiction, we propose that a limited amount of functional pigment is formed within the normal cellular environment of the intact photoreceptor, and that this requires the presence of chaperone proteins that promote stability and normal folding of the mutant protein. PMID:23337435

McClements, Michelle; Davies, Wayne I L; Michaelides, Michel; Carroll, Joseph; Rha, Jungtae; Mollon, John D; Neitz, Maureen; MacLaren, Robert E; Moore, Anthony T; Hunt, David M

2013-03-22

119

X-linked cone dystrophy and colour vision deficiency arising from a missense mutation in a hybrid L/M cone opsin gene  

PubMed Central

In this report, we describe a male subject who presents with a complex phenotype of myopia associated with cone dysfunction and a protan vision deficiency. Retinal imaging demonstrates extensive cone disruption, including the presence of non-waveguiding cones, an overall thinning of the retina, and an irregular mottled appearance of the hyper reflective band associated with the inner segment ellipsoid portion of the photoreceptor. Mutation screening revealed a novel p.Glu41Lys missense mutation in a hybrid L/M opsin gene. Spectral analysis shows that the mutant opsin fails to form a pigment in vitro and fails to be trafficked to the cell membrane in transfected Neuro2a cells. Extensive sequence and quantitative PCR analysis identifies this mutant gene as the only gene present in the affected subject’s L/M opsin gene array, yet the presence of protanopia indicates that the mutant opsin must retain some activity in vivo. To account for this apparent contradiction, we propose that a limited amount of functional pigment is formed within the normal cellular environment of the intact photoreceptor, and that this requires the presence of chaperone proteins that promote stability and normal folding of the mutant protein.

McClements, Michelle; Davies, Wayne I L; Michaelides, Michel; Carroll, Joseph; Rha, Jungate; Mollon, John D; Neitz, Maureen; MacLaren, Robert E; Moore, Anthony T; Hunt, David M

2013-01-01

120

Localization of the gene (or genes) for a syndrome with X-linked mental retardation, ataxia, weakness, hearing impairment, loss of vision and a fatal course in early childhood  

Microsoft Academic Search

Linkage analysis is described in a family with X-linked mental retardation, ataxia, weakness, floppiness, delayed motor development,\\u000a absence of deep tendon reflexes, hearing impairment and loss of vision (MIM no. 301835). The disease has a fatal course due\\u000a to the susceptibility of the patients to infections, especially of the respiratory tract. Clinical signs indicate impairment\\u000a of the posterior columns, peripheral

H. Kremer; B. C. J. Hamel; B. van den Helm; W. F. M. Arts; I. J. de Wijs; E. A. Sistermans; H.-H. Ropers; E. C. M. Mariman

1996-01-01

121

In the Palm of Your Hand: A Vision of the Future of Technology for People with Visual Impairments.  

ERIC Educational Resources Information Center

This article discusses future directions for wireless cell phones, including personal computer capabilities, multiple input and output modalities, and open source platforms, and the benefits for people with visual impairments. The use of cell phones for increased accessibility of the Internet and for electronic books is also discussed. (Contains…

Fruchterman, James R.

2003-01-01

122

Degas: Vision and Perception.  

ERIC Educational Resources Information Center

The art of Edgar Degas is discussed in relation to his impaired vision, including amblyopia, later blindness in one eye, corneal scarring, and photophobia. Examined are ways in which Degas compensated for vision problems, and dominant themes of his art such as the process of perception and spots of brilliant light. (Author/JDD)

Kendall, Richard

1988-01-01

123

Quaternion Colour Texture  

Microsoft Academic Search

The quaternion representation of colour is shown to be effective in the context of colour texture region segmentation in digital colour images. The advantage of using quaternion arithmetic is that a colour can be represented and analyzed as a single entity. A basis for the colour textures occurring in a given image is derived via quaternion principal component analysis of

Lilong Shi; Brian Funt

124

Certification for vision impairment: researching perceptions, processes and practicalities in health and social care professionals and patients  

PubMed Central

Objectives To explore the patient experience, and the role of ophthalmologists and other health and social care professionals in the certification and registration processes and examine the main barriers to the timely certification of patients. Design Qualitative study. Setting Telephone interviews with health and social care professionals and patients in three areas in England. Participants 43 health and social care professionals who are part of the certification or registration process. 46 patients certified as severely sight impaired (blind) or sight impaired (partially sighted) within the previous 12?months. Results Certification and registration are life changing for patients and the help they receive can substantially improve their lives. Despite this, ophthalmologists often found it difficult to ascertain when it is appropriate to certify patients, particularly for people with long-term conditions. Ophthalmologists varied in their comprehension of the certification process and many regarded certification as the ‘final stage’ in treatment. Administrative procedures meant the process of certification and registration could vary from a few weeks to many months. The avoidable delays in completing certification can be helped by Eye Clinic Liaison Officers (ECLO). Conclusions A better understanding of the certification and registration processes can help improve standards of support and service provision for people who are severely sighted impaired or sight impaired. Better education and support are required for ophthalmologists in recognising the importance of timely referral for rehabilitative support through certification and registration. ECLOs can improve the process of certification and registration. Finally, better education is needed for patients on the benefits of certification and registration.

Boyce, T; Leamon, Shaun; Slade, J; Simkiss, P; Rughani, S; Ghanchi, Faruque

2014-01-01

125

Shadow And Highlight Invariant Colour Segmentation Algorithm For Traffic Signs  

Microsoft Academic Search

Shadows and highlights represent a challenge to the computer vision researchers due to a variance in the brightness on the surfaces of the objects under consideration. This paper presents a new colour detection and segmentation algorithm for road signs in which the effect of shadows and highlights are neglected to get better colour segmentation results. Images are taken by a

Hasan Fleyeh

2006-01-01

126

Colour Lovers  

NSDL National Science Digital Library

The endless hues and shades of colors fascinate many persons, including interior-designers, fashionistas, and those who study the workings of the human eye. This particular site is "a place to view, rate and review some lovely colours & palettes." The site contains a number of user forums where people may gather around the electronic glow of the screen to discuss and debate the merits of different colors, along with a place for users to submit their own fanciful and innovative colors. On the right-hand side of the home page, visitors can browse through the top-rated colors, newly added colors, and new palettes. Many of the colors have rather curious names, such as "wegobysundawn" and "victory or ignorance." Of course, there is space provided for visitors to give their own opinions on each color or palette. Overall, a compelling site, and one that will delight those with a penchant for the uses of color.

127

Prevalence of colour blindness in young Jordanians.  

PubMed

Colour blindness is one of the common genetic disorders observed in all human populations. It is a sex-linked recessive trait. The genes are located on the X chromosome within the Xq28 band. 1,418 university students (1,200 female and 218 male) from Zarka Private University and the Hashemite University were randomly selected and tested for congenital red/green colour blindness, by using Ishihara pseudo-isochromatic colour plates. A total of 23 individuals were found to be colour blind. In females, 4 students (0.33%) were colour blind: 1 of them showed protanomalia, 1 protanopia and 2 deuteranomalia. In males, 19 students (8.72%) were colour blind: 4 showed protanomalia, 3 protanopia, 8 deuteranomalia and 4 deuteranopia. The allelic frequencies of the colour vision gene were found to be 0.087 in males, 0.003 in females and 0.016 in the total population. Studies on colour blindness in Jordan are very few; this population-based investigation is meant to fill a gap in this field. PMID:11125268

Al-Aqtum, M T; Al-Qawasmeh, M H

2001-01-01

128

Topographic Mapping of Residual Vision by Computer  

ERIC Educational Resources Information Center

Many persons with low vision have diseases that damage the retina only in selected areas, which can lead to scotomas (blind spots) in perception. The most frequent of these diseases is age-related macular degeneration (AMD), in which foveal vision is often impaired by a central scotoma that impairs vision of fine detail and causes problems with…

MacKeben, Manfred

2008-01-01

129

Colour constancy in the swallowtail butterfly Papilio xuthus.  

PubMed

We have recently shown that the Japanese yellow swallowtail butterfly Papilio xuthus uses colour vision when searching for food. In the field, these butterflies feed on nectar provided by flowers of various colours not only in direct sunlight but also in shaded places and on cloudy days, suggesting that they have colour constancy. Here, we tested this hypothesis. We trained newly emerged Papilio xuthus to feed on sucrose solution on a paper patch of a certain colour under white illumination. The butterflies were then tested under both white and coloured illumination. Under white illumination, yellow- and red-trained butterflies selected the correctly coloured patch from a four-colour pattern and from a colour Mondrian collage. Under four different colours of illumination, we obtained results that were fundamentally similar to those under white illumination. Moreover, we performed critical tests using sets of two similar colours, which were also correctly discriminated by trained butterflies under coloured illumination. Taken together, we conclude that the butterfly Papilio xuthus exhibits some degree of colour constancy when searching for food. PMID:11060214

Kinoshita, M; Arikawa, K

2000-12-01

130

Doctors and the assessment of blood glucose testing sticks: does colour blindness matter?  

PubMed Central

A group of doctors with congenital colour vision deficiency (CCVD) were compared with a group of controls in their assessment of colour blocks in the colour range of a widely available blood glucose testing stick. The majority of doctors with CCVD agreed with controls on colour matching. However, subjects with severe CCVD tended to match test blocks to a wider range of options than either those with a less severe defect or controls. This paper discusses the implications of these findings.

Campbell, J L; Spalding, J A; Mir, F A; Birch, J

2000-01-01

131

Color vision: Introduction by the feature editors.  

PubMed

This feature issue of the Journal of the Optical Society of America A (JOSA A) stems from the 22nd Biennial Symposium of the International Colour Vision Society (ICVS) and reflects the basic and applied research interests of members of the color vision community. A profile is included of the 2013 Verriest Medal recipient. PMID:24695210

Buck, Steven L; Baraas, Rigmor; Bonnardel, Valérie; Lee, Barry B; Lindsey, Delwin T; Webster, Michael A; Werner, John S

2014-04-01

132

(Computer) Vision without Sight.  

PubMed

Computer vision holds great promise for helping persons with blindness or visual impairments (VI) to interpret and explore the visual world. To this end, it is worthwhile to assess the situation critically by understanding the actual needs of the VI population and which of these needs might be addressed by computer vision. This article reviews the types of assistive technology application areas that have already been developed for VI, and the possible roles that computer vision can play in facilitating these applications. We discuss how appropriate user interfaces are designed to translate the output of computer vision algorithms into information that the user can quickly and safely act upon, and how system-level characteristics affect the overall usability of an assistive technology. Finally, we conclude by highlighting a few novel and intriguing areas of application of computer vision to assistive technology. PMID:22815563

Manduchi, Roberto; Coughlan, James

2012-01-01

133

Vision and Driving  

PubMed Central

Driving is the primary means of personal travel in many countries and is relies heavily on vision for its successful execution. Research over the past few decades has addressed the role of vision in driver safety (motor vehicle collision involvement) and in driver performance (both on-road and using interactive simulators in the laboratory). Here we critically review what is currently known about the role of various aspects of visual function in driving. We also discuss translational research issues on vision screening for licensure and re-licensure and rehabilitation of visually impaired persons who want to drive.

Owsley, Cynthia; McGwin, Gerald

2010-01-01

134

Advanced colour matching theory  

Microsoft Academic Search

Traditionally, computer colour matching systems have employed the Kubelka-Munk algorithms. This approach makes many assumptions which do not hold true when colour matching in non-hiding applications such as printing inks, plastics and woodstains. A many flux mathematical model has been proven to give accurate colour matches across all regions of optical density. The GretagMacbeth ProPalette™ colour matching software employs this

Colin Wakeford

1998-01-01

135

Cognition factors in colour identification of colour blind people  

Microsoft Academic Search

Cognition of colour blind people differs significantly from colour normal observers especially in their colour identification and discrimination. Dichromats lacking one of the three cone photoreceptor types identify less colours and have a general confusion determining colour terms. Our research was aimed to reveal several aspects of their colour cognition with newly developed methodologies and diagnostic equipment. Among other features

Gyorgy Abraham; Balazs V. Nagy

2011-01-01

136

Colour, Theories of  

Microsoft Academic Search

The world as perceived by human beings is full of colour. The world as described by physical scientists is composed of colourless particles and fields. Philosophical theories of colour since the scientific revolution have been primarily driven by a desire to harmonize these two apparently conflicting pictures of the world. Any adequate theory of colour has to be consistent with

David R. Hilbert

137

One blue colour channel or two?  

PubMed

Contrary to the general belief that the yellow-blue mechanism has lower spatial resolution than the red-green mechanism, it has been recently claimed that both mechanisms have similar spatial sensitivity (McKeefry et al, 2001 Vision Research 41 245-255). Studying high-spatial-frequency tritanopia (a colour illusion based on spatio-chromatic interactions in human vision), we found strong evidence for the existence of two blue mechanisms-with low and high spatial-frequency resolution. If confirmed, this may resolve the apparent paradox concerning spatial resolution of the yellow-blue mechanism. PMID:16178144

Logvinenko, Alexander D; Hutchinson, Sara J

2005-01-01

138

Colour contribution to children's wayfinding in school environments  

NASA Astrophysics Data System (ADS)

The purpose of this study was to explore the contribution of colour to children's wayfinding ability in school environments and to examine the differences between colours in terms of their remembrance and usability in route learning process. The experiment was conducted with three different sample groups for each of three experiment sets differentiated by their colour arrangement. The participants totalled 100 primary school children aged seven and eight years old. The study was conducted in four phases. In the first phase, the participants were tested for familiarity with the experiment site and also for colour vision deficiencies by using Ishihara's tests for colour-blindness. In the second phase, they were escorted on the experiment route by the tester one by one, from one starting point to one end point and were asked to lead the tester to the end point by the same route. In the third phase, they were asked to describe verbally the route. In the final phase, they were asked to remember the specific colours at their correct locations. It was found that colour has a significant effect on children's wayfinding performances in school environments. However, there were no differences between different colours in terms of their remembrances in route finding tasks. In addition, the correct identifications of specific colours and landmarks were dependent on their specific locations. Contrary to the literature, gender differences were not found to be significant in the accuracy of route learning performances.

Helvac?o?lu, Elif; Olguntürk, Nilgün

2011-03-01

139

Colour constancy as counterfactual  

Microsoft Academic Search

There is nothing in this World constant but Inconstancy.[Swift 1711: 258]In this paper I argue that two standard characterizations of colour constancy are inadequate to the phenomenon. This inadequacy matters, since, I contend, philosophical appeals to colour constancy as a way of motivating illumination-independent conceptions of colour turn crucially on the shortcomings of these characterizations. After critically reviewing the standard

Jonathan Cohen

2008-01-01

140

Colour displays for categorical images  

Microsoft Academic Search

We propose a method for identifying a set of colours for displaying 2D and 3D categorical images when the categories are unordered labels. The principle is to find maximally distinct sets of colours. We either generate colours sequentially, to maximize the dissimilarity or distance between a new colour and the set of colours already chosen, or use a simulated annealing

Chris Glasbey; Heijden van der G. W. A. M; V. F. K. Toh; Alision Gray

2007-01-01

141

Colour knowledge: the role of the right hemisphere in colour processing and object colour knowledge.  

PubMed

The lateralisation of colour processing is not well understood, although there is a reasonable amount of evidence indicating a right hemisphere bias for colour processing. Tasks that require colour naming are associated with a left hemisphere bias and it is likely that asymmetry of colour processing is influenced by task demands. It is not known whether object colour knowledge is lateralised. In the current study colour and achromatic Mondrian-like objects were presented to either the left or right hemisphere to assess the lateralisation of colour processing. Participants were required to judge whether the objects were colour or achromatic. To assess colour knowledge, congruently and incongruently coloured familiar objects were presented to either the left or right hemisphere and participants were required to judge whether the objects were correctly or incorrectly coloured. The data show that both colour processing and colour knowledge are associated with a right hemisphere bias. PMID:18608853

Barnett, Kylie J

2008-09-01

142

Seeing into the future. Vision and aging.  

PubMed Central

The leading causes of visual impairment in North Americans are age-related, but appropriate care can preserve useful vision for most older adults. Cataract surgery is highly successful. Early detection and treatment of glaucoma can prevent vision loss. Laser treatment is remarkably effective against diabetic retinopathy. Vision loss due to macular degeneration cannot be delayed in all patients, but low-vision rehabilitation can maximize the usefulness of remaining sight.

Kalina, R E

1997-01-01

143

Do Hermann's tortoises (Testudo hermanni) discriminate colours? An experiment with natural and artificial stimuli  

Microsoft Academic Search

Many animals use chemical and visual cues to obtain reliable information about potential food resources. Most reptiles have evolved highly specialized chemosensory and visual capacities, in particular colour vision, to accomplish this task. By presenting animals with flowers and coloured cardboard discs in two-choice experiments, we examined whether both male and female Hermann's tortoises (Testudo hermanni) were able to distinguish

D. Pellitteri-Rosa; R. Sacchi; P. Galeotti; M. Marchesi; M. Fasola

2010-01-01

144

Nocturnal hunting of a brightly coloured sit-and-wait predator  

Microsoft Academic Search

Many studies have shown that colour signals are important in spidereinsect interactions. The bright body coloration of certain orb-weaving spiders seems to serve as a visual lure to diurnal prey. However, no studies have examined whether this coloration affects spiders' nocturnal hunting. Some nocturnal lepi- dopteran pollinators use colour vision to locate their food resources, so orb-weaving spiders' bright color-

I.-Min Tso; Jen-Pan Huang; Chen-Pan Liao

2007-01-01

145

Computer Vision.  

National Technical Information Service (NTIS)

The field of computer vision is surveyed and assessed, key research issues are identified, and possibilities for a future vision system are discussed. The problems of descriptions of two and three dimensional worlds are discussed. The representation of su...

D. Gennery R. Cunningham E. Saund J. High C. Ruoff

1981-01-01

146

Application of Vision Models to Traffic Sign Recognition  

Microsoft Academic Search

A system for traffic sign recognition has been developed. Both colour and shape information from signs are utilised for extraction\\u000a of features. Colour appearance model CIECAM97 has been applied to extract colour information and to segment and classify traffic\\u000a signs. Whilst shape features are extracted using FOSTS model, the extension of Behaviour Model of Visions (BMV). Recoganition\\u000a rate is very

X. W. Gao; L. Podladchikova; D. Shaposhnikov

2003-01-01

147

Effects of memory colour on colour constancy for unknown coloured objects  

PubMed Central

The perception of an object's colour remains constant despite large variations in the chromaticity of the illumination—colour constancy. Hering suggested that memory colours, the typical colours of objects, could help in estimating the illuminant's colour and therefore be an important factor in establishing colour constancy. Here we test whether the presence of objects with diagnostical colours (fruits, vegetables, etc) within a scene influence colour constancy for unknown coloured objects in the scene. Subjects matched one of four Munsell papers placed in a scene illuminated under either a reddish or a greenish lamp with the Munsell book of colour illuminated by a neutral lamp. The Munsell papers were embedded in four different scenes—one scene containing diagnostically coloured objects, one scene containing incongruent coloured objects, a third scene with geometrical objects of the same colour as the diagnostically coloured objects, and one scene containing non-diagnostically coloured objects (eg, a yellow coffee mug). All objects were placed against a black background. Colour constancy was on average significantly higher for the scene containing the diagnostically coloured objects compared with the other scenes tested. We conclude that the colours of familiar objects help in obtaining colour constancy for unknown objects.

Granzier, Jeroen J M; Gegenfurtner, Karl R

2012-01-01

148

21 CFR 886.5910 - Image intensification vision aid.  

Code of Federal Regulations, 2010 CFR

...SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5910 Image intensification vision aid...limited dark adaptation or impaired vision to amplify ambient light. (b) Classification. Class I (general...

2010-04-01

149

21 CFR 886.5910 - Image intensification vision aid.  

Code of Federal Regulations, 2010 CFR

...SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5910 Image intensification vision aid...limited dark adaptation or impaired vision to amplify ambient light. (b) Classification. Class I (general...

2009-04-01

150

The connotations of colour terms: colour based X-phemisms  

Microsoft Academic Search

This paper investigates the connotations of colour terms with particular attention to figurative uses of black, white, grey, brown, yellow, red, green, blue and a few miscellaneous colours. The connotations are judged on the basis of whether the phrases in which the colour terms occur are typically orthophemistic, euphemistic, or dysphemistic. All the colours surveyed have some, often many, orthophemistic

Keith Allan

151

Television and vision: reading captions when vision is blurred.  

PubMed

Closed captions for television have become an important means of communication for hearing-impaired people. Yet, previous studies show that hearing-impaired people are very likely to have visual problems that may interfere with caption reading. In this study, the effect of reduced vision on caption reading is examined. Six hearing-impaired and 14 hearing subjects viewed segments of captioned movies on a 19-inch television screen at a distance of three meters. All of the subjects had normal vision. Their vision was blurred with plus lenses of five different strengths. The data show that caption reading is affected by relatively small amounts of blur. If a person has even a slight visual problem, the caption letters under normal television viewing conditions are too small for maximum reading performance. PMID:2735309

Thorn, S; Thorn, F

1989-03-01

152

The Brightness of Colour  

Microsoft Academic Search

BackgroundThe perception of brightness depends on spatial context: the same stimulus can appear light or dark depending on what surrounds it. A less well-known but equally important contextual phenomenon is that the colour of a stimulus can also alter its brightness. Specifically, stimuli that are more saturated (i.e. purer in colour) appear brighter than stimuli that are less saturated at

David Corney; John-Dylan Haynes; Geraint Rees; R. Beau Lotto; Olaf Sporns

2009-01-01

153

Colour Mixing Based on Daylight  

ERIC Educational Resources Information Center

Colour science is based on the sensation of monochromatic light. In contrast to that, surface colours are caused by reflection of wide sections of the daylight spectrum. Non-spectral colours like magenta and purple appear homologous to colours with spectral hue, if the approach of mixing monochromatic light is abandoned. It is shown that a large…

Meyn, Jan-Peter

2008-01-01

154

Tetrachromatic colour space  

NASA Astrophysics Data System (ADS)

We derive colour spaces of the hue-colourfulness-luminance type, on the basis of a four-dimensional hypercube I4 (I = [0, 1]). The hypercube corresponds to a tetrachromatic colour system, analogous to the three-dimensional RGB cube. In the first derived space the colourfulness is chromatic saturation while in the second one, colourfulness refers to the vividness of the colour, even if it is achromatic. The hue is defined on the basis of an icositetrahedron of 24 triangles that is embedded in the boundary of the hypercube. The boundary of the hypercube is the polytope {4 3 3} (in Sclafli notation) that is a topological 3-sphere. Out of the 24 square faces in the boundary of the hypercube, 6 meet the black vertex and 6 meet the white vertex; the remaining 12 faces form a dodecahedron which is a topological 2-sphere. This equatorial or chromatic dodecahedron is used to define a hue for each point in the hypercube that is not on the achromatic segment; the icositetrahedron results from a division of each of the square faces of the dodecahedron into two triangles. In addition, a hexdecahedron of 16 square faces with the topology of a torus that is also embedded in the boundary of the hypercube, is used to define an alternate two-dimensional hue space.

Restrepo, Alfredo

2012-02-01

155

Gene therapy for red-green colour blindness in adult primates.  

PubMed

Red-green colour blindness, which results from the absence of either the long- (L) or the middle- (M) wavelength-sensitive visual photopigments, is the most common single locus genetic disorder. Here we explore the possibility of curing colour blindness using gene therapy in experiments on adult monkeys that had been colour blind since birth. A third type of cone pigment was added to dichromatic retinas, providing the receptoral basis for trichromatic colour vision. This opened a new avenue to explore the requirements for establishing the neural circuits for a new dimension of colour sensation. Classic visual deprivation experiments have led to the expectation that neural connections established during development would not appropriately process an input that was not present from birth. Therefore, it was believed that the treatment of congenital vision disorders would be ineffective unless administered to the very young. However, here we show that the addition of a third opsin in adult red-green colour-deficient primates was sufficient to produce trichromatic colour vision behaviour. Thus, trichromacy can arise from a single addition of a third cone class and it does not require an early developmental process. This provides a positive outlook for the potential of gene therapy to cure adult vision disorders. PMID:19759534

Mancuso, Katherine; Hauswirth, William W; Li, Qiuhong; Connor, Thomas B; Kuchenbecker, James A; Mauck, Matthew C; Neitz, Jay; Neitz, Maureen

2009-10-01

156

Gene therapy for red-green colour blindness in adult primates  

PubMed Central

Red-green colour blindness, which results from the absence of either the long- (L) or middle- (M) wavelength-sensitive visual photopigments, is the most common single locus genetic disorder. Here, the possibility of curing colour blindness using gene therapy was explored in experiments on adult monkeys that had been colour blind since birth. A third type of cone pigment was added to dichromatic retinas, providing the receptoral basis for trichromatic colour vision. This opened a new avenue to explore the requirements for establishing the neural circuits for a new dimension of colour sensation. Classic visual deprivation experiments1 have led to the expectation that neural connections established during development would not appropriately process an input that was not present from birth. Therefore, it was believed that treatment of congenital vision disorders would be ineffective unless administered to the very young. Here, however, addition of a third opsin in adult red-green colour-deficient primates was sufficient to produce trichromatic colour vision behaviour. Thus, trichromacy can arise from a single addition of a third cone class and it does not require an early developmental process. This provides a positive outlook for the potential of gene therapy to cure adult vision disorders.

Mancuso, Katherine; Hauswirth, William W.; Li, Qiuhong; Connor, Thomas B.; Kuchenbecker, James A.; Mauck, Matthew C.; Neitz, Jay; Neitz, Maureen

2009-01-01

157

Immediate colour constancy.  

PubMed

Colour constancy is traditionally interpreted as the stable appearance of the colour of a surface despite changes in the spectral composition of the illumination. When colour constancy has been assessed quantitatively, however, by observers making matches between surfaces illuminated by different sources, its completeness has been found to be poor. An alternative operational approach to colour constancy may be taken which concentrates instead on detecting the underlying chromatic relationship between the parts of a surface under changes in the illuminant. Experimentally the observer's task was to determine whether a change in the appearance of a surface was due to a change in its reflecting properties or to a change in the incident light. Observers viewed computer simulations of a row of three Mondrian patterns of Munsell chips. The centre pattern was a reference pattern illuminated by a simulated, spatially uniform daylight; one of the outer patterns was identical but illuminated by a different daylight; and the other outer pattern was equivalent but not obtainable from the centre pattern by such a change in illuminant. Different patterns and different shifts in daylight were generated in each experimental trial. The task of the observer was to identify which of the outer patterns was the result of an illuminant change. Observers made reliable discriminations of the patterns with displays of durations from several seconds to less than 200 ms, and, for one observer, with displays of 1 ms. By these measures, human observers appear capable of colour constancy that is extremely rapid, and probably preattentive in origin. PMID:1408163

Foster, D H; Craven, B J; Sale, E R

1992-04-01

158

Cadmium colours: composition and properties  

NASA Astrophysics Data System (ADS)

The composition and the properties of cadmium aquarelle colours are discussed. The examined colours were 24 different aquarelle cadmium colours from six different manufacturers. The colours ranged from light, bright yellows to dark, deep-red tones. The aim of this research was to find out if the pigments contain cadmium salts: sulphides and/or selenides. This information will help in choosing watercolours in conservation processes. Today, aquarelle colours not containing cadmium pigments are being sold as cadmium colours; thus their properties might be different from actual cadmium colours. The aim of the research was to verify that the colour samples contained cadmium pigments and to estimate their compositions and ageing properties. Element analyses were performed from colour samples using micro-chemical tests and X-ray fluorescence measurements. Thin-layer chromatography was used for analysing gum Arabic as a possible binding medium in the chosen colour samples. Through ageing tests, the resistance of the colour samples to the exposure to light, heat and humidity was studied. Visible-light spectroscopy was used in determining the hues and hue changes of the aquarelle colour samples. The spectrophotometer used the CIE L*a*b* tone colour measuring system. From the colour measurements the changes in the lightness/darkness, the redness, the yellowness and the saturation of the samples were examined.

Paulus, J.; Knuutinen, U.

159

A 14-year-old girl who regained normal vision after bilateral visual impairment following hot water injury to the eyes  

Microsoft Academic Search

A 14-year-old girl presented with bilateral visual impairment following hot water injury to the eyes. The patient was admitted for a week and managed with guttae tropicamide 0.5% 8h, diclofenac sodium 0.1% 4h, and fluoroquinolone 0.3% 6h and ointment chloramphenicol 8h. Also, the patient was managed with capsule doxycycline 100mg 12h for 10days, tablet cataflam 50mg 12h for 7days and

Kehinde F. Monsudi; Abdulkabir A. Ayanniyi

2011-01-01

160

Shape and colour measurement of colourful objects by fringe projection  

NASA Astrophysics Data System (ADS)

In this paper, we present a novel method to measure shape and colour information of a colourful object by projecting separate red, green and blue colour fringe patterns onto the object surface. With regard to the object surface's colour, the modulation at each pixel position in the three colour channels has different values. For example, when projecting blue fringe patterns onto a red point, the corresponding pixel has too low a fringe modulation to accurately calculate the phase (shape) information; but with red fringe patterns a high fringe modulation is obtained. Therefore, phase information of the red point can be calculated by projecting red fringe patterns. For each object point, by comparing the modulation values from the three colour channels, it is possible to choose the channel having maximum modulation, and hence phase information can be reliably obtained by the phase-shifting algorithm. The fringe order information is obtained by using the optimum three-frequency selection method, so there is a maximum reliability in determining the fringe order and the 3-D shape of an object with step or large slopes on the surface. Since three colour channels are used, colour information of the object surface can be extracted with high dynamic range from the same fringe patterns. Chromatic aberration between colour channels is unavoidable and can be eliminated by a software-based method. Using the recently developed colour fringe projection system, separate colour fringe patterns are projected onto a mug having different colour patterns, a colourful box and plate, and a colour checker card to test the proposed method. The results show the range of colours that can be measured and that shape and colour information of colourful objects can be reliably obtained.

Zhang, Zonghua; Towers, Catherine E.; Towers, David P.

2008-08-01

161

2-Colour photolithography.  

PubMed

Photolithography is a crucial technology for both research and industry. The desire to be able to create ever finer features has fuelled a push towards lithographic methods that use electromagnetic radiation or charged particles with the shortest possible wavelength. At the same time, the physics and chemistry involved in employing light or particles with short wavelengths present great challenges. A new class of approaches to photolithography on the nanoscale involves the use of photoresists that can be activated with one colour of visible or near-ultraviolet light and deactivated with a second colour. Such methods hold the promise of attaining lithographic resolution that rivals or even exceeds that currently sought by industry, while at the same time using wavelengths of light that are inexpensive to produce and can be manipulated readily. The physical chemistry of 2-colour photolithography is a rich area of science that is only now beginning to be explored. PMID:24705478

Fourkas, John T; Petersen, John S

2014-05-21

162

Machine Vision  

NSDL National Science Digital Library

An overview of a generic image-based machine vision system is provided on this Web site (1). The tutorial describes the main components of such a system, how its accuracy is measured, and what scientific and industrial applications benefit from machine vision. A more technical perspective of machine vision technology is given in an online publication of the Automated Imaging Association (2). Monthly feature articles discuss breaking issues related to machine vision, and several technical papers can be downloaded, which are sorted into categories such as three dimensional imaging and nanotechnology. Researchers from the MIT's Artificial Intelligence Laboratory (3) are investigating how to enable a computer to interpret visual and audio signals from its human user. By using machine perception systems to track the user's gaze, for example, the computer could ascertain the focus of the user's attention, thereby facilitating interaction between the human and the computer. The project's homepage includes numerous research papers, as well as video demonstrations of some of its systems. Machine vision is also finding its way into vehicles. A March 2003 news article (4) highlights a field test in Michigan of a collision avoidance system that uses, among other things, machine vision to warn drivers that they are approaching a slower or stopped object too quickly. The 3D Computer Vision Group at Carnegie Mellon University (5) is involved in several projects, including three dimensional object recognition and humanoid robot vision. Many of the group's recent publications are available for download. NASA's Mars Exploration Rovers, the second of which was launched in July 2003, have vision systems that will let them safely navigate rough terrain. These systems are described in this conference paper (6), including specifics of the stereo vision algorithm and insights into future missions. A new implementation of machine vision comes from a former researcher from Cambridge University. His shape recognition system, which is detailed in this news article (7), is reportedly much more related to human visual processes than existing techniques. For additional developments related to this evolving technology, Machine Vision News (8) has information about worldwide research and new applications of machine vision systems.

Leske, Cavin.

163

Why birds eat colourful grit: colour preferences revealed by the colour of gizzard stones.  

PubMed

Colour preferences from sexual or social contexts are assumed to have arisen owing to preferences for specific kinds of food, representing a sensory bias, but once colour preferences have evolved in a sexual context, they may also be expressed during foraging. We tested whether preferences for specific body colours (i.e. plumage and soft parts) were related to colour preferences for grit ingested by birds. Birds eat grit to facilitate break down of food by the gizzard, and this function is independent of the colour of grit, but depends on the physical properties of stones. Bird species were significantly consistent in colour of grit, and grit of different colours varied in prevalence among species, even when analyses were restricted to a sample from a single locality. There were positive correlations between presence of lilac and red grit in the gizzard and presence of sexually dichromatic lilac and red colour on the body. There was a positive correlation between red grit colour and red sexually monochromatic body colour. Bird species with many different sexual colours, but not sexually monochromatic colours on their body had many different colours of grit. Males had more lilac and red grit than females, with this effect differing among species, whereas that was not the case for grit of other colours. These findings are consistent with the sensory bias hypothesis that birds express preferences for grit of specific colours and a high diversity of colours related to sexual colouration of the body, even when the colour of such grit is only visible to the individual at the moment of ingestion. PMID:20050966

Møller, A P; Erritzøe, J

2010-03-01

164

A Low Vision Reading Comprehension Test.  

ERIC Educational Resources Information Center

Fifty adults (ages 28-86) with macular degeneration were given the Low Vision Reading Comprehension Assessment (LVRCA) to test its reliability and validity in evaluating the reading comprehension of those with vision impairments. The LVRCA was found to take only nine minutes to administer and was a valid and reliable tool. (CR)

Watson, G. R.; And Others

1996-01-01

165

Color Vision Deficits and Literacy Acquisition.  

ERIC Educational Resources Information Center

Shows that color blindness, whether partial or total, inhibits literacy acquisition. Offers a case study of a third grader with impaired color vision. Presents a review of literature on the topic. Notes that people with color vision deficits are often unaware of the handicap. (RS)

Hurley, Sandra Rollins

1994-01-01

166

Television and Vision: Reading Captions when Vision Is Blurred.  

ERIC Educational Resources Information Center

Six hearing-impaired and 14 hearing adults, all with normal vision, viewed segments of captioned movies on television under 5 conditions of blur. The study found that, if a person has even a slight visual problem, the caption letters under normal television viewing conditions are too small for maximum reading performance. (Author/JDD)

Thorn, Sondra; Thorn, Frank

1989-01-01

167

Mimicry, colour forms and spectral sensitivity of the bluestriped fangblenny, Plagiotremus rhinorhynchos  

PubMed Central

Animals change their body coloration for a variety of purposes including communication, thermoregulation and crypsis. The cues that trigger adaptive colour change are often unclear, and the role of colour vision remains largely untested. Here, we investigated the bluestriped fangblenny (Plagiotremus rhinorhynchos), an aggressive mimic that changes its body coloration to impersonate a variety of coral reef fishes. In this field, we determined the fish species that the fangblenny associated with and measured the spectral reflectance of mimics and their models. We measured the spectral absorbance characteristics of the retinal photoreceptor visual pigments in the bluestriped fangblenny using microspectrophotometry and found it to have rod photoreceptors (?max 498?nm), single cones (449?nm) and double cones (561?nm principal member; 520?nm accessory member). Using theoretical vision models, fangblennies could discriminate between the colours they adopted and the colours of the fish they associated with. Potential signal receivers (Abudefduf abdominalis and Ctenochaetus strigosus) perceived colours of most mimics to closely resemble fishes they associated with. However, fishes with ultraviolet-sensitive visual pigments were better at discriminating between mimics and models. Therefore, colour vision could be used by fangblennies when initiating colour change enabling them to accurately resemble fishes they associate with and to avoid detection by signal receivers.

Cheney, Karen L.; Skogh, Charlotta; Hart, Nathan S.; Marshall, N. Justin

2009-01-01

168

The colours of cloaks  

Microsoft Academic Search

We present a survey of results from various research groups under the unifying viewpoint of transformational physics, which has been recently introduced for the design of metamaterials in optics and acoustics. We illustrate the versatility of underlying geometric transforms in order to bridge wave phenomena (the different 'colours' of waves) ranging from transverse electric waves, to linear surface water waves

Sébastien Guenneau; Ross C. McPhedran; Stefan Enoch; Alexander B. Movchan; Mohamed Farhat; Nicolae-Alexandru P. Nicorovici

2011-01-01

169

Computer vision  

NASA Technical Reports Server (NTRS)

The field of computer vision is surveyed and assessed, key research issues are identified, and possibilities for a future vision system are discussed. The problems of descriptions of two and three dimensional worlds are discussed. The representation of such features as texture, edges, curves, and corners are detailed. Recognition methods are described in which cross correlation coefficients are maximized or numerical values for a set of features are measured. Object tracking is discussed in terms of the robust matching algorithms that must be devised. Stereo vision, camera control and calibration, and the hardware and systems architecture are discussed.

Gennery, D.; Cunningham, R.; Saund, E.; High, J.; Ruoff, C.

1981-01-01

170

Multi-camera colour tracking  

Microsoft Academic Search

We propose a colour tracker for use in visual surveillance. The tracker is part of a framework designed to monitor a dynamic scene with more than one camera. Colour tracking complements spatial tracking: it can also be used over large temporal intervals, and between spatially uncalibrated cameras. The colour distributions from objects are modelled, and measures of difference between them

J. Orwell; P. Remagnino; G. A. Jones

1999-01-01

171

Improving Vision  

NASA Technical Reports Server (NTRS)

Many people are familiar with the popular science fiction series Star Trek: The Next Generation, a show featuring a blind character named Geordi La Forge, whose visor-like glasses enable him to see. What many people do not know is that a product very similar to Geordi's glasses is available to assist people with vision conditions, and a NASA engineer's expertise contributed to its development. The JORDY(trademark) (Joint Optical Reflective Display) device, designed and manufactured by a privately-held medical device company known as Enhanced Vision, enables people with low vision to read, write, and watch television. Low vision, which includes macular degeneration, diabetic retinopathy, and glaucoma, describes eyesight that is 20/70 or worse, and cannot be fully corrected with conventional glasses.

2003-01-01

172

Vision Underwater.  

ERIC Educational Resources Information Center

Provides information regarding underwater vision. Includes a discussion of optically important interfaces, increased eye size of organisms at greater depths, visual peculiarities regarding the habitat of the coastal environment, and various pigment visual systems. (CS)

Levine, Joseph S.

1980-01-01

173

Age-Related Psychophysical Changes and Low Vision  

PubMed Central

When considering the burden of visual impairment on aging individuals and society at large, it is important to bear in mind that vision changes are a natural aspect of aging. In this article, we consider vision changes that are part of normal aging, the prevalence of abnormal vision changes caused by disorders of the visual system, and the anticipated incidence and impact of visual impairment as the US population ages. We then discuss the services available to reduce the impact of vision loss, and the extent to which those services can and should be improved, not only to be better prepared for the anticipated increase in low vision over the coming decades, but also to increase the awareness of interactions between visual impairment and comorbidities that are common among the elderly. Finally, we consider how to promote improved quality, availability, and acceptance of low vision care to lessen the impact of visual impairment on individuals, and its burden on society.

Dagnelie, Gislin

2013-01-01

174

Minimalist surface-colour matching.  

PubMed

Some theories of surface-colour perception assume that observers estimate the illuminant on a scene so that its effects can be discounted. A critical test of this interpretation of colour constancy is whether surface-colour matching is worse when the number of surfaces in a scene is so small that any illuminant estimate is unreliable. In the experiment reported here, observers made asymmetric colour matches between pairs of simultaneously presented Mondrian-like patterns under different daylights. The patterns had either 49 surfaces or a minimal 2 surfaces. No significant effect of number was found, suggesting that illuminant estimates are unnecessary for surface-colour matching. PMID:16178156

Amano, Kinjiro; Foster, David H; Nascimento, Sérgio M C

2005-01-01

175

Minimalist surface-colour matching  

PubMed Central

Some theories of surface-colour perception assume that observers estimate the illuminant on a scene so that its effects can be discounted. A critical test of this interpretation of colour constancy is whether surface-colour matching is worse when the number of surfaces in a scene is so small that any illuminant estimate is unreliable. In the experiment reported here, observers made asymmetric colour matches between pairs of simultaneously presented Mondrian-like patterns under different daylights. The patterns had either 49 surfaces or a minimal 2 surfaces. No significant effect of number was found, suggesting that illuminant estimates are unnecessary for surface-colour matching.

Amano, Kinjiro; Foster, David H.; Nascimento, Sergio M C

2007-01-01

176

Chiral colour and axigluons  

SciTech Connect

The authors studies the phenomenological implications of the Chiral Colour model which allow him to derive experimental bounds on the axigluon mass or to predict deviations from the Standard Model. After a short introduction to the theory, the author examines the way it modifies the standard decay of quarkonium. Comparison with the observed lifetime of the upsilon allows him to exclude the existence of axigluons lighter than 9 GeV. (Others have since extended the work and were able to increase this limit to 25 GeV.) He then studies the Chiral Colour contribution to the hadronic cross-section in the electron-positron scattering and derive a conservative lower bound of 50 GeV for the axigluon mass. Finally, he predicts observable enhancements of the lifetime and rare decay channels of the Z{sup O} in the presence of light axigluons.

Cuypers, F.

1989-01-01

177

Coloured Petri Nets  

Microsoft Academic Search

This paper describes a Petri net model, called Coloured Petri nets (CP-nets), where information is attached to each token.\\u000a The information can be inspected and modified when a transition fires. For most applications, this generalization of ordinary\\u000a Petri nets allows the user to make more manageable descriptions, due to the fact that equal subnets can be folded into each\\u000a other,

Kurt Jensen

1986-01-01

178

Vision channels, contrast sensitivity, and functional vision  

Microsoft Academic Search

The neurophysiology and psychophysics of vision provide the basis for vision channels. Vision channels are the foundation of understanding spatial vision. This understanding has led to the development of a general model of visual perception and tests of functional vision. The channel model is shown to predict the Gestalt of many objects and perceptual distortions in a wide variety of

Arthur P. Ginsburg

2004-01-01

179

Temporal analysis of the chromatic flash VEP—separate colour and luminance contrast components  

Microsoft Academic Search

Temporal analysis of the chromatic flash visual evoked potential (VEP) was studied in human subjects with normal and anomalous colour vision using a deterministic pseudo-random binary stimulus (VERIS). Five experiments were carried out on four normal subjects investigating heterochromatic red–green exchange and single colour\\/achromatic (either red\\/grey or green\\/grey) exchange over a wide range of luminance ratios for the two stimuli,

A Klistorner; D. P Crewther; S. G Crewther

1998-01-01

180

The Improvement of Vision by Vision Stimulation and Training: A Review of the Literature.  

ERIC Educational Resources Information Center

This article reviews the theoretical and research literature on vision stimulation and vision training of children with severe irreversible visual impairments. It recommends early stimulation to prevent visual deprivation, use of operant conditioning, and the presentation of highly contrasting stimuli to stimulate visual awareness in children with…

Tavernier, G. G. F.

1993-01-01

181

Distinctive convergence in Australian floral colours seen through the eyes of Australian birds.  

PubMed

We used a colour-space model of avian vision to assess whether a distinctive bird pollination syndrome exists for floral colour among Australian angiosperms. We also used a novel phylogenetically based method to assess whether such a syndrome represents a significant degree of convergent evolution. About half of the 80 species in our sample that attract nectarivorous birds had floral colours in a small, isolated region of colour space characterized by an emphasis on long-wavelength reflection. The distinctiveness of this 'red arm' region was much greater when colours were modelled for violet-sensitive (VS) avian vision than for the ultraviolet-sensitive visual system. Honeyeaters (Meliphagidae) are the dominant avian nectarivores in Australia and have VS vision. Ancestral state reconstructions suggest that 31 lineages evolved into the red arm region, whereas simulations indicate that an average of five or six lineages and a maximum of 22 are likely to have entered in the absence of selection. Thus, significant evolutionary convergence on a distinctive floral colour syndrome for bird pollination has occurred in Australia, although only a subset of bird-pollinated taxa belongs to this syndrome. The visual system of honeyeaters has been the apparent driver of this convergence. PMID:24573847

Burd, Martin; Stayton, C Tristan; Shrestha, Mani; Dyer, Adrian G

2014-04-22

182

Distinctive convergence in Australian floral colours seen through the eyes of Australian birds  

PubMed Central

We used a colour-space model of avian vision to assess whether a distinctive bird pollination syndrome exists for floral colour among Australian angiosperms. We also used a novel phylogenetically based method to assess whether such a syndrome represents a significant degree of convergent evolution. About half of the 80 species in our sample that attract nectarivorous birds had floral colours in a small, isolated region of colour space characterized by an emphasis on long-wavelength reflection. The distinctiveness of this ‘red arm’ region was much greater when colours were modelled for violet-sensitive (VS) avian vision than for the ultraviolet-sensitive visual system. Honeyeaters (Meliphagidae) are the dominant avian nectarivores in Australia and have VS vision. Ancestral state reconstructions suggest that 31 lineages evolved into the red arm region, whereas simulations indicate that an average of five or six lineages and a maximum of 22 are likely to have entered in the absence of selection. Thus, significant evolutionary convergence on a distinctive floral colour syndrome for bird pollination has occurred in Australia, although only a subset of bird-pollinated taxa belongs to this syndrome. The visual system of honeyeaters has been the apparent driver of this convergence.

Burd, Martin; Stayton, C. Tristan; Shrestha, Mani; Dyer, Adrian G.

2014-01-01

183

The Role of Organizations in Reaching Older Adults about Vision Loss  

ERIC Educational Resources Information Center

Vision impairment affects approximately 17% of Americans age 45 and older. Yet, 94% of adults with self-reported vision loss did not receive any type of vision rehabilitation services to help them retain independence. These findings underscore the need for promoting awareness about what can be done when vision fails. A national dissemination…

Sussman-Skalka, Carol J.; Cimarolli, Verena R.; Stuen, Cynthia

2006-01-01

184

Home vision tests  

MedlinePLUS

... done at home: Amsler grid, distance vision, and near vision testing. AMSLER GRID TEST This test helps ... you read correctly. Repeat with the other eye. NEAR VISION This is similar to the distance vision ...

185

Colour misbinding during motion rivalry  

PubMed Central

When two dissimilar colours are displayed to the two eyes at overlapping retinal locations, binocular rivalry typically results: a fluctuating struggle for perceptual dominance of each eye's stimulus. We found instead that isoluminant counter-rotating patterns consisting of coloured and achromatic portions can promote an illusory colour ‘misbinding’, where the colours from both eyes were perceived within a single rotating pattern. The achromatic portion of one rotating pattern thus appeared to take on the colour of the other, oppositely rotating pattern. The results suggest that the neural mechanisms of colour binding can operate even while representations of the same patterns' motions are undergoing rivalry, and support the idea that rivalry can occur in isolation within the motion system.

Maloney, Ryan T.; Lam, Sarah K.; Clifford, Colin W. G.

2013-01-01

186

ROAD SIGN RECOGNITION BY MEANS OF THE BEHAVIORAL MODEL OF VISION  

Microsoft Academic Search

Algorithms and procedures to solve the task of road sign detection and recognition invariant of viewing conditions and results of testing during computer simulation with British and Russian signs are presented. After preliminary colour segmentation of initial real world images and classification according to road sign colours and external forms, biologically plausible Behavoiral Model of Vision (BMV) (1,2) which was

X. W. GAO; A. V. GOLOVAN; K. HONG; L. N. PODLADCHIKOVA; D. G. SHAPOSHNIKOV; N. A. SHEVTSOVA

187

Class Separation Improvements in Pixel Classification Using Colour Injection  

PubMed Central

This paper presents an improvement in the colour image segmentation in the Hue Saturation (HS) sub-space. The authors propose to inject (add) a colour vector in the Red Green Blue (RGB) space to increase the class separation in the HS plane. The goal of the work is the development of an algorithm to obtain the optimal colour vector for injection that maximizes the separation between the classes in the HS plane. The chromatic Chrominace-1 Chrominance-2 sub-space (of the Luminance Chrominace-1 Chrominance-2 (YC1C2) space) is used to obtain the optimal vector to add. The proposal is applied on each frame of a colour image sequence in real-time. It has been tested in applications with reduced contrast between the colours of the background and the object, and particularly when the size of the object is very small in comparison with the size of the captured scene. Numerous tests have confirmed that this proposal improves the segmentation process, considerably reducing the effects of the variation of the light intensity of the scene. Several tests have been made in skin segmentation in applications for sign language recognition via computer vision, where an accurate segmentation of hands and face is required.

Blanco, Edward; Mazo, Manuel; Bergasa, Luis; Palazuelos, Sira; Rodriguez, Jose; Losada, Cristina; Martin, Jose

2010-01-01

188

ASIC vision  

Microsoft Academic Search

Advances in VLSI vision sensor design that enable high-quality, analog images to be formed through devices fabricated using standard 5 V CMOS ASIC processes are reported. The potential for integrating mixed sensor-processor systems, using an integrated VLSI camera system as an example, is reported. The feasibility of the techniques is confirmed by results obtained from working prototype CMOS sensor arrays.

D. Renshaw; P. B. Denyer; G. Wang; M. Lu

1990-01-01

189

Presidential Visions.  

ERIC Educational Resources Information Center

This journal issue is devoted to the theme of university presidents and their visions of the future. It presents the inaugural addresses and speeches of 16 Catholic college and university presidents focusing on their goals, ambitions, and reasons for choosing to become higher education leaders at this particular time in the history of education in…

Gallin, Alice, Ed.

1992-01-01

190

Active vision  

Microsoft Academic Search

We investigate several basic problems in vision under the assumption that the observer is active. An observer is called active when engaged in some kind of activity whose purpose is to control the geometric parameters of the sensory apparatus. The purpose of the activity is to manipulate the constraints underlying the observed phenomena in order to improve the quality of

John Aloimonos; Isaac Weiss; Amit Bandyopadhyay

1988-01-01

191

Giovanni Schiaparelli: Visions of a colour blind astronomer  

NASA Astrophysics Data System (ADS)

The greatest observer of Mars of the nineteenth century was the Italian astronomer Giovanni Virginio Schiaparelli. In his classic compilation of Martian observations, La Planete Mars, published in 1892, Camille Flammarion readily conceded that Schiaparelli's was 'the greatest work which has been carried out with regard to Mars,'1 while another eminent Martian, Percival Lowell, referred to the Italian astronomer alone as his Martian master ('cher maitre Martien').

Sheehan, W.

1997-02-01

192

Across light: through colour  

NASA Astrophysics Data System (ADS)

The speed at which our world is changing is reflected in the shifting way artistic images are created and produced. Holography can be used as a medium to express the perception of space with light and colour and to make the material and the immaterial experiments with optical and digital holography. This paper intends to be a reflection on the final product of that process surrounding a debate of ideas for new experimental methodologies applied to holographic images. Holography is a time-based medium and the irretrievable linear flow of time is responsible for a drama, unique to traditional cinematography. If the viewers move to left or right, they see glimpses of the next scene or the previous one perceived a second ago. This interaction of synthetic space arises questions such as: can we see, in "reality", two forms in the same space? Trying to answer this question, a series of works has been created. These concepts are embryonic to a series of digital art holograms and lenticulars technique's titled "Across Light: Through Colour". They required some technical research and comparison between effects from different camera types, using Canon IS3 and Sony HDR CX105.

Azevedo, Isabel; Richardson, Martin; Bernardo, Luis Miguel

2012-02-01

193

The colours of cloaks  

NASA Astrophysics Data System (ADS)

We present a survey of results from various research groups under the unifying viewpoint of transformational physics, which has been recently introduced for the design of metamaterials in optics and acoustics. We illustrate the versatility of underlying geometric transforms in order to bridge wave phenomena (the different 'colours' of waves) ranging from transverse electric waves, to linear surface water waves at an air-fluid interface, to pressure waves in fluids and out-of-plane shear waves in elastic media: these waves are all governed by a second order scalar partial differential equation (PDE) invariant under geometric transform. Moreover, flexural waves propagating in thin plates represent a very peculiar situation whereby the displacement field satisfies a fourth order scalar PDE which also retains its form under geometric transform (unlike for the Navier equation in elastodynamics). Control of flexural wave trajectories is illustrated with a multilayered cloak and a carpet. Interestingly, the colours of waves can be revealed through an analysis of the band spectra of invisibility cloaks. In the context of acoustics, this suggests one can hear the shape of a drum. Alternative avenues towards cloaking based upon anomalous resonances of a negatively refracting coating (which can be seen as the result of folding the space back onto itself), and even plasmonic shells reducing the scattering cross-section of nano-objects are also addressed.

Guenneau, Sébastien; McPhedran, Ross C.; Enoch, Stefan; Movchan, Alexander B.; Farhat, Mohamed; Nicorovici, Nicolae-Alexandru P.

2011-02-01

194

Exploring consumers' product-specific colour meanings  

Microsoft Academic Search

Purpose – The impact of colour is acknowledged, yet empirical studies on colours with marketing implications are rare. The paper seeks to advance our understanding of the role of package colours in consumers' product experiences by studying the relationship between colour meanings and product. It also aims at offering insights into the meanings associated with colours in a product context.

Hannele Kauppinen-Räisänen; Harri T. Luomala

2010-01-01

195

Digital colour management system for colour parameters reconstruction  

NASA Astrophysics Data System (ADS)

Digital Colour Management System (DCMS) and its application to new adaptive camouflage system are presented in this paper. The DCMS is a digital colour rendering method which would allow for transformation of a real image into a set of colour pixels displayed on a computer monitor. Consequently, it can analyse pixels' colour which comprise images of the environment such as desert, semi-desert, jungle, farmland or rocky mountain in order to prepare an adaptive camouflage pattern most suited for the terrain. This system is described in present work as well as the use the subtractive colours mixing method to construct the real time colour changing electrochromic window/pixel (ECD) for camouflage purpose. The ECD with glass/ITO/Prussian Blue(PB)/electrolyte/CeO2-TiO2/ITO/glass configuration was assembled and characterized. The ECD switched between green and yellow after +/-1.5 V application and the colours have been controlled by Digital Colour Management System and described by CIE LAB parameters.

Grudzinski, Karol; Lasmanowicz, Piotr; Assis, Lucas M. N.; Pawlicka, Agnieszka; Januszko, Adam

2013-10-01

196

The Physical Environment and the Visually Impaired.  

ERIC Educational Resources Information Center

Reported are results of a project carried out at the Swedish Institute for the Handicapped to determine needs of the visually impaired in the planning and adaptation of buildings and other forms of physical environment. Chapter 1 considers implications of impaired vision and includes definitions, statistics, and problems of the visually impaired

Braf, Per-Gunnar

197

Optoelectronic vision  

NASA Astrophysics Data System (ADS)

Scientists have searched every discipline to find effective methods of treating blindness, such as using aids based on conversion of the optical image, to auditory or tactile stimuli. However, the limited performance of such equipment and difficulties in training patients have seriously hampered practical applications. A great edification has been given by the discovery of Foerster (1929) and Krause & Schum (1931), who found that the electrical stimulation of the visual cortex evokes the perception of a small spot of light called `phosphene' in both blind and sighted subjects. According to this principle, it is possible to invite artificial vision by using stimulation with electrodes placed on the vision neural system, thereby developing a prosthesis for the blind that might be of value in reading and mobility. In fact, a number of investigators have already exploited this phenomena to produce a functional visual prosthesis, bringing about great advances in this area.

Ren, Chunye; Parel, Jean-Marie A.

1993-06-01

198

Complementary Colours for a Physicist  

ERIC Educational Resources Information Center

This paper reports on a simple experiment which enables splitting incident light into two different modes, each having a colour exactly complementary to the other. A brief historical development of colour theories and differences in a physicist's point of view with respect to an artist's one is discussed. An experimental system for producing…

Babic, Vitomir; Cepic, Mojca

2009-01-01

199

CIE Colorimetry and Colour Displays  

Microsoft Academic Search

CIE colorimetry was standardised 65 years ago to describe colorimetric properties of signal lights. The first real application of CIE colorimetry occurred, however, in the textile and coating industries to describe colour matches between sample and reference. Thus also the experiments conducted to achieve a uniform colour scale diagram were performed by using material samples usually illuminated by a daylight

J Schanda

1996-01-01

200

The Gradual Transformation of Historical Situations: Understanding "Change and Continuity" through Colours and Timelines  

ERIC Educational Resources Information Center

The small-scale research that Yosanne Vella reports in this article was driven by concern to help pupils develop "big picture" visions of the past and to engage effectively with the idea of change as a process rather than an event. The strategy that she adopts--asking groups of students to colour in a timeline recording their judgement in response…

Vella, Yosanne

2011-01-01

201

Neuronal morphology of biological vision: a basis for machine vision (Proceedings Only)  

NASA Astrophysics Data System (ADS)

In this paper, we are concerned with the study of the biological vision system and the emulation of some of its mathematical functions, in both the retinal and visual cortex, for the development of a robust computer vision system. This field of research is not only intriguing, but offers a great challenge to systems scientists in the development of functional algorithms. These functional algorithms can be generalized for further studies for fields such as signal processing, control systems and image processing. Our studies are heavily dependent on the use of neuronal layers and the generalized receptive fields. Building blocks of such neuronal layers and receptive fields may lead to the design of better sensors and better computer vision systems. It is hoped that these studies will lead to the development of better artificial vision systems with applications to vision prosthesis for visually impaired persons, robotic vision, medical imaging, medical sensors, industrial automation, remote sensing, space stations and ocean exploration.

Gupta, Madan M.

1992-03-01

202

Optimal colour quality of LED clusters based on memory colours.  

PubMed

The spectral power distributions of tri- and tetrachromatic clusters of Light-Emitting-Diodes, composed of simulated and commercially available LEDs, were optimized with a genetic algorithm to maximize the luminous efficacy of radiation and the colour quality as assessed by the memory colour quality metric developed by the authors. The trade-off of the colour quality as assessed by the memory colour metric and the luminous efficacy of radiation was investigated by calculating the Pareto optimal front using the NSGA-II genetic algorithm. Optimal peak wavelengths and spectral widths of the LEDs were derived, and over half of them were found to be close to Thornton's prime colours. The Pareto optimal fronts of real LED clusters were always found to be smaller than those of the simulated clusters. The effect of binning on designing a real LED cluster was investigated and was found to be quite large. Finally, a real LED cluster of commercially available AlGaInP, InGaN and phosphor white LEDs was optimized to obtain a higher score on memory colour quality scale than its corresponding CIE reference illuminant. PMID:21451716

Smet, Kevin; Ryckaert, Wouter R; Pointer, Michael R; Deconinck, Geert; Hanselaer, Peter

2011-03-28

203

Colour Graphics for Hydrocode Simulations.  

National Technical Information Service (NTIS)

This report describes the production of colour graphical output for the two dimensional finite difference reactive hydrocodes currently used by Weapons Systems Division. The programs use the NCAR graphics package and show how the careful choice appropriat...

A. Doyle D. A. Jones G. Kemister

1996-01-01

204

What Colour Is a Shadow?  

ERIC Educational Resources Information Center

What colour is a shadow? Black, grey, or some other colour? This article describes how to use a digital camera to test the hypothesis that a shadow under a clear blue sky has a blue tint. A white sheet of A4 paper was photographed in full sunlight and in shadow under a clear blue sky. The images were analysed using a shareware program called…

Hughes, S. W.

2009-01-01

205

COLOUR RENDERING: AN OBJECT BASED APPROACH  

Microsoft Academic Search

Light sources with limited spectral content cannot render colours correctly. Typical spectra of phosphor white and RGB LEDs often result in a low colour rendering index, in spite of a high appreciation of LED lighting in visual experiments. The standard approach to colour rendering evaluation has always been based on a relative assessment: the colour coordinates of a set of

Kevin Smet; W. R. Ryckaert; G. Deconinck; Peter Hanselaer; Gebroeders Desmetstraat

206

Colour as visual rhetoric in financial reporting  

Microsoft Academic Search

Visual rhetoric within communication seeks to persuade through the use of picturing and encompasses words and colour. Visual rhetoric is present within annual reports. The specific role of colour in financial reporting is a neglected field of enquiry. A survey of 100 Hong Kong annual reports related colour usage to profitability change and found companies used more colour when profitability

John K. Courtis

2004-01-01

207

Sexual colouration and sperm traits in guppies  

Microsoft Academic Search

The relationships among the area, hue, saturation and brightness of orange colouration and sperm traits in the guppy Poecilia reticulata were investigated. Males with greater areas of orange colouration had significantly larger sperm loads, more motile sperm and longer sperm relative to males with relatively little orange colouration. Males with greater areas of orange colouration did not possess more viable

T. E. Pitcher; F. H. Rodd; L. Rowe

2007-01-01

208

Colour preferences of flower-naive honeybees  

Microsoft Academic Search

Flower-naive honeybees Apis mellifera L. flying in an enclosure were tested for their colour preferences. Bees were rewarded once on an achromatic (grey, aluminium or hardboard), or on a chromatic (ultraviolet) disk. Since naive bees never alighted on colour stimuli alone, a scent was given in combination with colour. Their landings on twelve colour stimuli were recorded. Results after one

M. Giurfa; J. Núñez; L. Chittka; R. Menzel

1995-01-01

209

Bullying in German Adolescents: Attending Special School for Students with Visual Impairment  

ERIC Educational Resources Information Center

The present study analysed bullying in German adolescents with and without visual impairment. Ninety-eight adolescents with vision loss from schools for students with visual impairment, of whom 31 were blind and 67 had low vision, were compared with 98 sighted peers using a matched-pair design. Students with low vision reported higher levels of…

Pinquart, Martin; Pfeiffer, Jens P.

2011-01-01

210

Prentice medal lecture 2013: visual accessibility: a challenge for low-vision research.  

PubMed

Low vision may be defined as any chronic form of vision impairment, not correctable by glasses or contact lenses, that adversely affects everyday function. Visual accessibility refers to factors that make an environment, device, or display usable by vision. In this article, I discuss the concept of visual accessibility with special reference to low vision. What role can vision science play in enhancing visual accessibility for people with low vision? I propose that greater efforts to embed low-vision research in real-world contexts and collaboration with other disciplines will accelerate progress. I describe examples from my current research projects on architectural accessibility and reading accessibility. PMID:24978657

Legge, Gordon E

2014-07-01

211

Robot Vision  

NASA Technical Reports Server (NTRS)

The operation of a system is described that is built both to model the vision of primate animals, including man, and serve as a pre-prototype of possible object recognition system. It was employed in a series of experiments to determine the practicability of matching left and right images of a scene to determine the range and form of objects. The experiments started with computer generated random-dot stereograms as inputs and progressed through random square stereograms to a real scene. The major problems were the elimination of spurious matches, between the left and right views, and the interpretation of ambiguous regions, on the left side of an object that can be viewed only by the left camera, and on the right side of an object that can be viewed only by the right camera.

Sutro, L. L.; Lerman, J. B.

1973-01-01

212

Binocular Vision  

PubMed Central

This essay reviews major developments –empirical and theoretical –in the field of binocular vision during the last 25 years. We limit our survey primarily to work on human stereopsis, binocular rivalry and binocular contrast summation, with discussion where relevant of single-unit neurophysiology and human brain imaging. We identify several key controversies that have stimulated important work on these problems. In the case of stereopsis those controversies include position versus phase encoding of disparity, dependence of disparity limits on spatial scale, role of occlusion in binocular depth and surface perception, and motion in 3D. In the case of binocular rivalry, controversies include eye versus stimulus rivalry, role of “top-down” influences on rivalry dynamics, and the interaction of binocular rivalry and stereopsis. Concerning binocular contrast summation, the essay focuses on two representative models that highlight the evolving complexity in this field of study.

Blake, Randolph; Wilson, Hugh

2010-01-01

213

Vision Screening  

NASA Technical Reports Server (NTRS)

The Visi Screen OSS-C, marketed by Vision Research Corporation, incorporates image processing technology originally developed by Marshall Space Flight Center. Its advantage in eye screening is speed. Because it requires no response from a subject, it can be used to detect eye problems in very young children. An electronic flash from a 35 millimeter camera sends light into a child's eyes, which is reflected back to the camera lens. The photorefractor then analyzes the retinal reflexes generated and produces an image of the child's eyes, which enables a trained observer to identify any defects. The device is used by pediatricians, day care centers and civic organizations that concentrate on children with special needs.

1993-01-01

214

Animat Vision: Active Vision in Artificial Animals  

Microsoft Academic Search

We propose and demonstrate a new paradigm for active vision r e- search that draws upon recent advances in the fields of artific ial life and computer graphics. A software alternative to the pr evailing hardware vision mindset, animat vision prescribes artifici al animals, or animats, situated in physics-based virtual worlds as aut onomous virtual robots possessing active perception systems.

Demetri Terzopoulos; Tamer F. Rabie

1995-01-01

215

Test and field spectral sensitivities of colour mechanisms obtained on small white backgrounds: action of unitary opponent-colour processes?  

PubMed

It has been shown that for human foveal vision the test spectral sensitivity curve obtained in the presence of a large white background exhibits peaks at about 440, 530 and 610 nm and a small dip or notch at about 580 nm. Additionally, field spectral sensitivity curves for the medium- and long-wavelength sensitive colour mechanisms when derived in the presence of a small monochromatic background (auxiliary field) spatially coincident with the test field are sharper than the corresponding Stiles's II mechanisms and peak at about 530 and 605 nm. The short-wavelength sensitive colour mechanism shows no such effect, the peak remaining at about 440 nm. The test spectral sensitivity curve obtained on a large white background and the sharpened field spectral sensitivity curves obtained on a spatially coincident, monochromatic auxiliary field have each been interpreted in terms of an opponent-process theory of colour vision: the response of the non-opponent luminance system is considered to be reduced by selective achromatic adaptation (with the large white background) or by selective contour masking (with the spatially coincident auxiliary field). The present study combined the two techniques of achromatic and spatial adaptation: a small white auxiliary field spatially coincident with the test field was used in measurements of both test and field spectral sensitivities. Under these conditions, it was found that the test spectral sensitivity curve showed more clearly defined peaks and a deeper notch at about 580 nm than when obtained on the large white background and that the test curve was well fitted by the upper envelope of the short-wavelength and sharpened medium- and long-wavelength field spectral sensitivity curves, suggesting the possibility that three unitary opponent-colour mechanisms may underlie test and field spectral sensitivities. A test of this hypothesis is proposed concerning the effect of auxiliary-field chromaticity on the position of the notch at about 580 nm in the test spectral sensitivity curve. PMID:6623938

Foster, D H; Snelgar, R S

1983-01-01

216

Vision and Hearing Screening in Jefferson County Public Schools.  

ERIC Educational Resources Information Center

The document contains materials from the Jefferson County (Alabama) vision and hearing screening program to identify students with sensory impairments, to monitor "at risk" students, and to provide appropriate educational intervention. The package contains the following: instructions for the principle on vision screening; procedures for…

O'Brien, Esther; Sanspree, Mary Jean

217

Adolescents with Low Vision: Perceptions of Driving and Nondriving  

ERIC Educational Resources Information Center

Two studies examined how adolescents with low vision perceive their ability to drive. The results of both studies indicated similarities in the participants' responses with respect to knowledge of visual impairment, information about options for driving with low vision, frustrations and obstacles imposed by not being able to drive, and independent…

Sacks, Sharon Zell; Rosenblum, L. Penny

2006-01-01

218

"Colour constancy" in Mondrian patterns: a partial cancellation of physical chromaticity shifts by simultaneous contrast.  

PubMed

Edwin Land's Mondrian demonstrations (Land 1977, 1983, 1986a) are striking examples that the perceived colours of objects are largely independent of the chromaticity of the light incident upon them. Attempts to implement this independence in artificial vision systems have renewed interest in colour constancy and contrast, and the explanation of these phenomena in the Retinex theory. We use colour matches to demonstrate that departures from "colour constancy" are large and that it is possible to obtain the same colour shifts when the complex Mondrian pattern is replaced by a homogeneous grey field surrounding a test patch. A given patch has the same colour when surrounded by the Mondrian as when set in a grey background, provided that the grey represents the spatially weighted average of the Mondrian. Neither the colour shifts nor the equivalence of this neutral surround are correctly predicted by the Retinex theory. The phenomenon of partial cancellation of physical chromaticity shifts with changes of illuminant thus reduces to one of simultaneous contrast and adaptation where a spatio-chromatic and luminance average over a Mondrian pattern is the same as for a grey surround. Experiments with simultaneous contrast demonstrate that spatial weighting factors need to be applied in computations of the effect of the separate areas of a complex Mondrian pattern. PMID:2336796

Valberg, A; Lange-Malecki, B

1990-01-01

219

XXXIV. On sensory energy, with special reference to vision and colour-vision  

Microsoft Academic Search

Transformations of the energy of a primary sensory stimulus to that of molecules of the material of a sense-organ lead to the concept of receptor energy, in the form of damped vibrations causing the ejection of electrons. It is shown that this energy, the proximal stimulus of sensory action currents, is the quantity S in the Weber-Fechner Law S=K log

John H. Shaxby

1943-01-01

220

All about Low Vision  

MedlinePLUS

... About Low Vision & Blindness > All About Low Vision All About Low Vision Due to an increase in the number of aging baby boomers and the growing ... sensitivity, a significantly obstructed field of vision -- or all three. Watch simulations of some of the most ...

221

Ultraviolet Light: Some Considerations for Vision Stimulation.  

ERIC Educational Resources Information Center

The article examines evidence of visual impairment caused by excessive amounts of ultraviolet (UV) light. Among considerations when using a source of UV light for vision stimulation are the position of the child and teacher, use of window glass filters or protective glasses, and careful recordkeeping of all UV stimulation. (Author/JW)[

Knowlton, Marie

1986-01-01

222

Personal and Family Stress in Individuals with Diabetes and Vision Loss.  

ERIC Educational Resources Information Center

Assessed intrapersonal distress and impact of diabetes and vision impairment on marital functioning. Found significant degrees of intrapersonal distress and compromised family functioning. Of 18 subjects in committed relationship at onset of vision impairment, 9 later separated. Totally blind subjects were at greater risk for separation than were…

Bernbaum, Marla; And Others

1993-01-01

223

Colour Glass Condensate: An Introduction.  

National Technical Information Service (NTIS)

In these lectures, the authors develop the theory of the Colour Glass Condensate. This is the matter made of gluons in the high density environment characteristic of deep inelastic scattering or hadron-hadron collisions at very high energy. The lectures a...

E. Iancu A. Leonidov L. McLerran

2002-01-01

224

True three-colour photoceramic  

Microsoft Academic Search

This paper presents the true three-colour photoceramic, introduced by the authors since 1992, which allows wide new possibilities in the field of the ceramic decoration, for reproduction on ceramic (majolica, porcelain, earthenware, etc.) surfaces of images either photographic or painted images or even directly coming from computer-made image files. The correspondent technological process used to produce this kind of decoration

A. Krajewski; L. Paci

2001-01-01

225

Colour of Red Blood Corpuscles  

Microsoft Academic Search

IN a recent communication1, Dr. J. R. Baker has asked why a single red blood corpuscle looks yellow instead of pink. Whether a thinned-out red colour is pink or yellow depends on the extent of its absorption in the blue end of the spectrum. Let us for simplicity regard white light as composed of equal parts of red, green and

E. J. Bowen

1943-01-01

226

Interference colours of soap bubbles  

Microsoft Academic Search

In this article, we present a new versatile method for calculating the interference colour of any configuration of thin, optically isotropic, dielectric films. This method is free from common weakness of previous methods, namely the poor accuracy for large angles of incidence of light. This method gives full control over the accuracy and speed of computations, and allows for adjustments

Dariusz Jaszkowski; Janusz Rzeszut

2003-01-01

227

7—AN INTRODUCTION TO COLOUR THEORY AND ITS APPLICATION TO COLOUR SPECIFICATIONS  

Microsoft Academic Search

This paper is designed to provide a knowledge of the elements of colour theory and an up-to-date survey of methods of specifying colour tolerances. It is intended to fill the gap between textbooks on colour and publications that deal mainly with applications of colour theory to specific problems.

D. Leverington

1967-01-01

228

The connotations of English colour terms: Colour-based X-phemisms  

Microsoft Academic Search

This paper investigates the connotations of English colour terms with particular attention to figurative uses of black, white, grey, brown, yellow, red, green, blue and a few miscellaneous colours. The connotations are judged on the basis of whether the phrases in which the colour terms occur are typically orthophemistic, euphemistic, or dysphemistic. All the colours surveyed have some, often many,

Keith Allan

2009-01-01

229

Biological Components of Colour Preference in Infancy  

ERIC Educational Resources Information Center

Adult colour preference has been summarized quantitatively in terms of weights on the two fundamental neural processes that underlie early colour encoding: the S-(L+M) ("blue-yellow") and L-M ("red-green") cone-opponent contrast channels ( Ling, Hurlbert & Robinson, 2006; Hurlbert & Ling, 2007). Here, we investigate whether colour preference in…

Franklin, Anna; Bevis, Laura; Ling, Yazhu; Hurlbert, Anya

2010-01-01

230

Traffic sign recognition using colour information  

Microsoft Academic Search

In this paper, we present a novel approach for the detection and recognition of traffic signs. Colour images are acquired by a camera mounted in a car. In the first step, these images are colour segmented with a pixel classifier. Colour combinations which are characteristic for traffic signs generate hypotheses. These hypotheses are verified using a pictogram classifier.Our system has

W. Ritter; F. Stein; R. Janssen

1995-01-01

231

How feather colour reflects its melanin content  

Microsoft Academic Search

Summary 1. Melanin coloration is the most common type of colour in animals. Many species use melanin-based black, brown, grey or earth-toned colours as intraspecific signals of quality. 2. Melanin comes in two main forms in vertebrates - eumelanin and phaeomelanin - and these are said to create different colours, with eumelanin giving a darker black, brown or grey appearance

K. J. McGRAW; R. J. SAFRAN; K. WAKAMATSU

2005-01-01

232

Innate colour preferences of flower visitors  

Microsoft Academic Search

Freshly emerged flower visitors exhibit colour preferences prior to individual experience with flowers. The understanding of innate colour preferences in flower visitors requires a detailed analysis, as, on the one hand, colour is a multiple-signal stimulus, and, on the other hand, flower visits include a sequence of behavioural reactions each of which can be driven by a preferential behaviour. Behavioural

K. Lunau; E. J. Maier

1995-01-01

233

Nine Tools for Generating Harmonious Colour Schemes  

Microsoft Academic Search

We survey a number of tools that have been developed for generating sets of colours according to commonly accepted rules for colour harmony. Informal manual techniques for generating harmonious sets of colo urs have been known and used for at least a century. Although superficially simple, they have not been precise techniques, as pigment-based and dye-based colouring techniques are not

Paul Lyons; Giovanni Moretti

2004-01-01

234

Memory for colours: a reaction time experiment  

Microsoft Academic Search

We used simultaneous and delayed match to sample tasks to investigate memory for 5 colour tests (green, yellow, purple, pink and orange) in men and women. Stimuli were emulated Munsell colour samples displayed on a CRT monitor. Colour tests were presented with distracters that could vary either in hue or in saturation. Our results indicate that: 1) over the five

V. Bonnardel; J. Herrero

235

Colour space models for soil science  

Microsoft Academic Search

Soil colour is an important soil property. It is frequently used by soil scientists for the identification and classification of soil. It is also used as an indicator of field soil physical, chemical and biological properties as well as of the occurrence of soil processes. Measurements of soil colour are commonly made using the Munsell soil colour charts. A number

R. A. Viscarra Rossel; B. Minasny; P. Roudier; A. B. McBratney

2006-01-01

236

Colour annealing - a toy model of colour reconnections  

SciTech Connect

We present a simple toy model for colour reconnections at the nonperturbative level. The model resembles an annealing-type algorithm and is applicable to any collider and process type, though we argue for a possible enhancement of the effect in hadron-hadron collisions. We present a simple application and study of the consequences for semileptonic t{bar t} events at the Tevatron.

Sandhoff, Marisa; /Wuppertal U.; Skands, Peter; /Fermilab

2005-12-01

237

Low vision care--two case reports.  

PubMed

Two patients are discussed and their similarities and differences are noted. Both lost an eye as a result of military service. One had low vision in the remaining eye because of a retinal problem with generally clear media. The other had an essentially normally functioning retina but light transmission was compromised because of a developing cataract. It was demonstrated that visually impaired or legally blind persons can be helped and they do not always need sophisticated devices to achieve useful vision. I described the devices prescribed and the advice given. PMID:7325206

Crinigan, R P

1981-12-01

238

The effects of noise on vision efficiency.  

PubMed

The aim of this study was to determine the relationship between intensity, noise duration and non-auditory effect represented by changes both in visual acuity and the near point of accommodation. Changes in vision efficiency determined by a black and white chess board were monitored during and after 1 h exposure to 4 levels of noise: 90 dB-A, 93 dB-A, 96 dB-A or 99 dB-A and 2 h exposure to 96 dB-A. Results indicated that vision impairment can be attributed to a complex relationship between the intensity and the duration of exposure to noise. PMID:2130868

Harazin, B; Grzesik, J; Pawlas, K; Kozak, A

1990-01-01

239

Raven's Coloured Progressive Matrices as a Measure of Cognitive Functioning in Cerebral Palsy  

ERIC Educational Resources Information Center

Background: Cognitive dysfunction is frequent in Cerebral Palsy (CP). CP motor impairment and associated speech deficits often hinder cognitive assessment, with the result being that not all CP studies consider cognitive dysfunction. Raven's Coloured Progressive Matrices is a simple, rapid test which can be used in persons with severe motor…

Pueyo, R.; Junque, C.; Vendrell, P.; Narberhaus, A.; Segarra, D.

2008-01-01

240

Robot Vision Library  

NASA Technical Reports Server (NTRS)

The JPL Robot Vision Library (JPLV) provides real-time robot vision algorithms for developers who are not vision specialists. The package includes algorithms for stereo ranging, visual odometry and unsurveyed camera calibration, and has unique support for very wideangle lenses

Howard, Andrew B.; Ansar, Adnan I.; Litwin, Todd E.; Goldberg, Steven B.

2009-01-01

241

Printing colour at the optical diffraction limit.  

PubMed

The highest possible resolution for printed colour images is determined by the diffraction limit of visible light. To achieve this limit, individual colour elements (or pixels) with a pitch of 250 nm are required, translating into printed images at a resolution of ?100,000 dots per inch (d.p.i.). However, methods for dispensing multiple colourants or fabricating structural colour through plasmonic structures have insufficient resolution and limited scalability. Here, we present a non-colourant method that achieves bright-field colour prints with resolutions up to the optical diffraction limit. Colour information is encoded in the dimensional parameters of metal nanostructures, so that tuning their plasmon resonance determines the colours of the individual pixels. Our colour-mapping strategy produces images with both sharp colour changes and fine tonal variations, is amenable to large-volume colour printing via nanoimprint lithography, and could be useful in making microimages for security, steganography, nanoscale optical filters and high-density spectrally encoded optical data storage. PMID:22886173

Kumar, Karthik; Duan, Huigao; Hegde, Ravi S; Koh, Samuel C W; Wei, Jennifer N; Yang, Joel K W

2012-09-01

242

Printing colour at the optical diffraction limit  

NASA Astrophysics Data System (ADS)

The highest possible resolution for printed colour images is determined by the diffraction limit of visible light. To achieve this limit, individual colour elements (or pixels) with a pitch of 250 nm are required, translating into printed images at a resolution of ~100,000 dots per inch (d.p.i.). However, methods for dispensing multiple colourants or fabricating structural colour through plasmonic structures have insufficient resolution and limited scalability. Here, we present a non-colourant method that achieves bright-field colour prints with resolutions up to the optical diffraction limit. Colour information is encoded in the dimensional parameters of metal nanostructures, so that tuning their plasmon resonance determines the colours of the individual pixels. Our colour-mapping strategy produces images with both sharp colour changes and fine tonal variations, is amenable to large-volume colour printing via nanoimprint lithography, and could be useful in making microimages for security, steganography, nanoscale optical filters and high-density spectrally encoded optical data storage.

Kumar, Karthik; Duan, Huigao; Hegde, Ravi S.; Koh, Samuel C. W.; Wei, Jennifer N.; Yang, Joel K. W.

2012-09-01

243

Characteristics of Visually Impaired Persons, United States, July 1963-June 1964.  

National Technical Information Service (NTIS)

Statistics are provided on vision impairments for persons 6 years and older by degree of impairment, activity limitation, receipt of aid, restriction of social activities, employment status, sex, age, education, and income. The study is based on data coll...

R. W. Wilson

1968-01-01

244

Microwave vision for robots  

NASA Technical Reports Server (NTRS)

Microwave Vision (MV), a concept originally developed in 1985, could play a significant role in the solution to robotic vision problems. Originally our Microwave Vision concept was based on a pattern matching approach employing computer based stored replica correlation processing. Artificial Neural Network (ANN) processor technology offers an attractive alternative to the correlation processing approach, namely the ability to learn and to adapt to changing environments. This paper describes the Microwave Vision concept, some initial ANN-MV experiments, and the design of an ANN-MV system that has led to a second patent disclosure in the robotic vision field.

Lewandowski, Leon; Struckman, Keith

1994-01-01

245

Colour and surface fluorescence development and their relationship with Maillard reaction markers as influenced by structural changes during cornflakes production.  

PubMed

The aim of this work was to study colour and surface fluorescence development in relation to the chemical markers for the Maillard reaction at the cooking, flaking and toasting stages of cornflake production process. Colour was measured by a calibrated computer vision system. Surface fluorescence was measured on compressed samples. Aqueous extracted Maillard reaction markers (hydroxymethylfurfural, carboxymethyl-lysine, absorbance at 420nm and total fluorescence) were measured on protease hydrolyzed samples. Sample microstructure was observed by scanning electron microscopy. During cooking the colour coordinates L(?) and b(?) decreased and a(?) increased. After flaking, the samples appeared lighter, while the pigment concentration, fluorescence and hydroxymethylfurfural did not change. Toasting generated bubbles in the matrix and L(?) apparently increased, although brown pigment concentration increased. Pigment concentration did not correlate with surface colour due to the destruction or generation of interfaces. Surface and microstructure effects can be avoided by milling and compressing the samples. PMID:22953910

Farroni, Abel; Buera, María Del Pilar

2012-12-01

246

The original colours of fossil beetles  

PubMed Central

Structural colours, the most intense, reflective and pure colours in nature, are generated when light is scattered by complex nanostructures. Metallic structural colours are widespread among modern insects and can be preserved in their fossil counterparts, but it is unclear whether the colours have been altered during fossilization, and whether the absence of colours is always real. To resolve these issues, we investigated fossil beetles from five Cenozoic biotas. Metallic colours in these specimens are generated by an epicuticular multi-layer reflector; the fidelity of its preservation correlates with that of other key cuticular ultrastructures. Where these other ultrastructures are well preserved in non-metallic fossil specimens, we can infer that the original cuticle lacked a multi-layer reflector; its absence in the fossil is not a preservational artefact. Reconstructions of the original colours of the fossils based on the structure of the multi-layer reflector show that the preserved colours are offset systematically to longer wavelengths; this probably reflects alteration of the refractive index of the epicuticle during fossilization. These findings will allow the former presence, and original hue, of metallic structural colours to be identified in diverse fossil insects, thus providing critical evidence of the evolution of structural colour in this group.

McNamara, Maria E.; Briggs, Derek E. G.; Orr, Patrick J.; Noh, Heeso; Cao, Hui

2012-01-01

247

True and false memory for colour names versus actual colours: support for the visual distinctiveness heuristic in memory for colour information.  

PubMed

In a colour variation of the Deese-Roediger-McDermott (DRM) false memory paradigm, participants studied lists of words critically related to a nonstudied colour name (e.g., "blood, cherry, scarlet, rouge ... "); they later showed false memory for the critical colour name (e.g., "red"). Two additional experiments suggest that participants generate colour imagery in response to such colour-related DRM lists. First, participants claim to experience colour imagery more often following colour-related than standard non-colour-related DRM lists; they also rate their colour imagery as more vivid following colour-related lists. Second, participants exhibit facilitative priming for critical colours in a dot selection task that follows words in the colour-related DRM list, suggesting that colour-related DRM lists prime participants for the actual critical colours themselves. Despite these findings, false memory for critical colour names does not extend to the actual colours themselves (font colours). Rather than leading to source confusion about which colours were self-generated and which were studied, presenting the study lists in varied font colours actually worked to reduce false memory overall. Results are interpreted within the framework of the visual distinctiveness hypothesis. PMID:19941197

Eslick, Andrea N; Kostic, Bogdan; Cleary, Anne M

2010-06-01

248

The multiple disguises of spiders: web colour and decorations, body colour and movement  

PubMed Central

Diverse functions have been assigned to the visual appearance of webs, spiders and web decorations, including prey attraction, predator deterrence and camouflage. Here, we review the pertinent literature, focusing on potential camouflage and mimicry. Webs are often difficult to detect in a heterogeneous visual environment. Static and dynamic web distortions are used to escape visual detection by prey, although particular silk may also attract prey. Recent work using physiological models of vision taking into account visual environments rarely supports the hypothesis of spider camouflage by decorations, but most often the prey attraction and predator confusion hypotheses. Similarly, visual modelling shows that spider coloration is effective in attracting prey but not in conveying camouflage. Camouflage through colour change might be used by particular crab spiders to hide from predator or prey on flowers of different coloration. However, results obtained on a non-cryptic crab spider suggest that an alternative function of pigmentation may be to avoid UV photodamage through the transparent cuticle. Numerous species are clearly efficient locomotory mimics of ants, particularly in the eyes of their predators. We close our paper by highlighting gaps in our knowledge.

Thery, Marc; Casas, Jerome

2008-01-01

249

Cognitive Impairments  

Microsoft Academic Search

Cognitive impairments, including learning disability, traumatic brain injury, and minimal brain dysfunction, have characteristics that include impulsiveness, communication skill deficits, difficulties with reasoning and problem solving, and impaired self-concept. Without professional intervention, these problems are likely to lead to marginal social acceptance, low levels of intimacy, and impaired sexuality development. This paper describes selected cognitive and behavioral implications of cognitive

Gary Sigler; Romel W. Mackelprang

1993-01-01

250

Visual Impairment and Risk of Hip Fracture  

Microsoft Academic Search

As part of a case-control study, the Auckland Hip Fracture Study (1991-1994), the authors examined associations between impaired vision and risk of hip fracture. Subjects (911 cases and 910 controls aged 60 years or older) completed a questionnaire and had vision measurements taken, including measurements of visual acuity and stereopsis (depth perception). Binocular visual acuity worse than 20\\/60 was statistically

Rebecca Q. Ivers; Robyn Norton; Robert G. Cumming; Meg Butler; A. John Campbell

251

Representing object colour in language comprehension.  

PubMed

Embodied theories of cognition hold that mentally representing something red engages the neural subsystems that respond to environmental perception of that colour. This paper examines whether implicit perceptual information on object colour is represented during sentence comprehension even though doing so does not necessarily facilitate task performance. After reading a sentence that implied a particular colour for a given object, participants were presented with a picture of the object that either matched or mismatched the implied colour. When asked if the pictured object was mentioned in the preceding sentence, people's responses were faster when the colours mismatched than when they matched, suggesting that object colour is represented differently to other object properties such as shape and orientation. A distinction between stable and unstable embodied representations is proposed to allow embodied theories to account for these findings. PMID:16616075

Connell, Louise

2007-03-01

252

Colour Consideration for Waiting areas in hospitals  

NASA Astrophysics Data System (ADS)

Colour is one the most important factors in the nature that can have some affects on human behaviour. Many years ago, it was proven that using colour in public place can have some affect on the users. Depend of the darkness and lightness; it can be vary from positive to negative. The research will mainly focus on the colour and psychological influences and physical factors. The statement of problem in this research is what is impact of colour usually applied to waiting area? The overall aim of the study is to explore the visual environment of hospitals and to manage the colour psychological effect of the hospital users in the waiting area by creating a comfortable, pleasant and cozy environment for users while spend their time in waiting areas. The analysisconcentrate on satisfaction and their interesting regarding applied colour in two private hospital waiting area in Malaysia.

Zraati, Parisa

2012-08-01

253

Colour-independent partition functions in coloured vertex models  

NASA Astrophysics Data System (ADS)

We study lattice configurations related to Sn, the scalar product of an off-shell state and an on-shell state in rational An integrable vertex models, n?{1,2}. The lattice lines are colourless and oriented. The state variables are n conserved colours that flow along the line orientations, but do not necessarily cover every bond in the lattice. Choosing boundary conditions such that the positions where the colours flow into the lattice are fixed, and where they flow out are summed over, we show that the partition functions of these configurations, with these boundary conditions, are n-independent. Our results extend to trigonometric An models, and to all n. This n-independence explains, in vertex-model terms, results from recent studies of S2 (Caetano and Vieira, 2012, [1], Wheeler, arXiv:1204.2089, [2]). Namely, 1.S2, which depends on two sets of Bethe roots, {b1} and {b2}, and cannot (as far as we know) be expressed in single determinant form, degenerates in the limit {b1}??, and/or {b2}??, into a product of determinants, 2. Each of the latter determinants is an A1 vertex-model partition function.

Foda, O.; Wheeler, M.

2013-06-01

254

Composition of a vision screen for servicemembers with traumatic brain injury: consensus using a modified nominal group technique.  

PubMed

Vision impairment is common in the first year after traumatic brain injury (TBI), including among service members whose brain injuries occurred during deployment in Iraq and Afghanistan. Occupational therapy practitioners provide routine vision screening to inform treatment planning and referral to vision specialists, but existing methods are lacking because many tests were developed for children and do not screen for vision dysfunction typical of TBI. An expert panel was charged with specifying the composition of a vision screening protocol for servicemembers with TBI. A modified nominal group technique fostered discussion and objective determinations of consensus. After considering 29 vision tests, the panel recommended a nine-test vision screening that examines functional performance, self-reported problems, far-near acuity, reading, accommodation, convergence, eye alignment and binocular vision, saccades, pursuits, and visual fields. Research is needed to develop reliable, valid, and clinically feasible vision screening protocols to identify TBI-related vision disorders in adults. PMID:25005505

Radomski, Mary Vining; Finkelstein, Marsha; Llanos, Imelda; Scheiman, Mitchell; Wagener, Sharon Gowdy

2014-01-01

255

Colour Gradients in Clusters of Galaxies  

NASA Astrophysics Data System (ADS)

We investigate the environmental effects (interactions/mergers, ram preasure stripping) in clusters of galaxies by means of colour gradients. These effects affect the photometrical properties of clusters, enhancing the fraction of blue galaxies (Butcher-Oemler effect). In this paper we determine the colour gradients frac{d(B-V)}{dR} in 13 clusters of galaxies, with redshifts 0.198 < = z < = 0.81, and investigate their cosmological dependence. The problem of colour evolution of galaxies in clusters, the connexion between the colour gradients and the Butcher-Oemler effect are also discussed.

Suran, M. D.; Popescu, N. A.

256

How temporal cues can aid colour constancy  

PubMed Central

Colour constancy assessed by asymmetric simultaneous colour matching usually reveals limited levels of performance in the unadapted eye. Yet observers can readily discriminate illuminant changes on a scene from changes in the spectral reflectances of the surfaces making up the scene. This ability is probably based on judgements of relational colour constancy, in turn based on the physical stability of spatial ratios of cone excitations under illuminant changes. Evidence is presented suggesting that the ability to detect violations in relational colour constancy depends on temporal transient cues. Because colour constancy and relational colour constancy are closely connected, it should be possible to improve estimates of colour constancy by introducing similar transient cues into the matching task. To test this hypothesis, an experiment was performed in which observers made surface-colour matches between patterns presented in the same position in an alternating sequence with period 2 s or, as a control, presented simultaneously, side-by-side. The degree of constancy was significantly higher for sequential presentation, reaching 87% for matches averaged over 20 observers. Temporal cues may offer a useful source of information for making colour-constancy judgements.

Foster, David H.; Amano, Kinjiro; Nascimento, Sergio M. C.

2007-01-01

257

FPGA Vision Data Architecture  

NASA Technical Reports Server (NTRS)

JPL has produced a series of FPGA (field programmable gate array) vision algorithms that were written with custom interfaces to get data in and out of each vision module. Each module has unique requirements on the data interface, and further vision modules are continually being developed, each with their own custom interfaces. Each memory module had also been designed for direct access to memory or to another memory module.

Morfopoulos, Arin C.; Pham, Thang D.

2013-01-01

258

Macular degeneration: do conventional measurements of impaired visual function equate with visual disability?  

Microsoft Academic Search

AIMSTo examine the relation between measures of vision and ability to perform daily living tasks in those visually impaired with macular degeneration.METHODSA visual functioning index (daily living tasks dependent on vision: DLTV) was used to evaluate patients' perception of their ability to perform vision dependent tasks. Distance visual acuity, near visual acuity, reading speed, and contrast sensitivity were measured in

M E McClure; P M Hart; A J Jackson; M R Stevenson; U Chakravarthy

2000-01-01

259

The global burden of trachomatous visual impairment: II. assessing burden  

Microsoft Academic Search

This paper builds on results of a previous paper on the prevalence of trachomatous visual impairment as the foundation for assessing the global burden of trachomatous blindness and low vision: approximately 2.9 million cases of trachomatous blindness and 3.8 million low visioned corresponding to a global prevalence of trachomatous visual impairment equal to 1.3\\/1,000 in 1990 was estimated. For each

Timothy G. Evans; M. Kent Ranson

1995-01-01

260

On the colour contribution to effective weak vertex in broken colour gauge theories  

Microsoft Academic Search

Treating the breaking of colour symmetry via the mixing between the colour gluons and weak bosons (a la Rajasekaran and Roy)\\u000a it is observed that the colour contribution to the effective weak vertex of a quark at zero momentum transfer is zero uptoO(?).

R Ramachandran

1979-01-01

261

Presbyopia Laser Vision Correction Surgery  

MedlinePLUS

... FAQ I’m happy with my glasses and contacts. Should I have laser vision correction? Most surgeons ... have laser vision correction if I play extreme contact sports? Presbyopia laser vision correction is a type ...

262

Near Vision Test for Adults  

MedlinePLUS

Near vision test for adults This test will check your close-up vision in each eye. Before ... printers: ? This test requires you to print the Near Vision Chart. The appearance of your printed chart ...

263

Colour mathematics: with graphs and numbers  

NASA Astrophysics Data System (ADS)

The different combinations involved in additive and subtractive colour mixing can often be difficult for students to remember. Using transmission graphs for filters of the primary colours and a numerical scheme to write out the relationships are good exercises in analytical thinking that can help students recall the combinations rather than just attempting to memorize them.

Lo Presto, Michael C.

2009-07-01

264

Representing Object Colour in Language Comprehension  

ERIC Educational Resources Information Center

Embodied theories of cognition hold that mentally representing something "red" engages the neural subsystems that respond to environmental perception of that colour. This paper examines whether implicit perceptual information on object colour is represented during sentence comprehension even though doing so does not necessarily facilitate task…

Connell, Louise

2007-01-01

265

Colour Mathematics: With Graphs and Numbers  

ERIC Educational Resources Information Center

The different combinations involved in additive and subtractive colour mixing can often be difficult for students to remember. Using transmission graphs for filters of the primary colours and a numerical scheme to write out the relationships are good exercises in analytical thinking that can help students recall the combinations rather than just…

LoPresto, Michael C.

2009-01-01

266

Colour changes in bruised apple fruit tissue  

Microsoft Academic Search

A study of changes with time in aspects of bruise colour in ‘Granny Smith’ apples (Malus domestica) was undertaken in an attempt to identify the optimum time for assessment of bruise severity in experiments on apples. Bruised cortical tissue became darker (decreased lightness), browner (decreased hue angle), and increased in colour intensity (increased chroma) in the first few hours following

Waiss Samim; Nigel H. Banks

1993-01-01

267

Modelling Ambient Systems with Coloured Petri Nets.  

National Technical Information Service (NTIS)

This paper is concerned with the formal modelling of Ambient Systems, focussing on the issues that emerge in their modelling using coloured Petri nets. A new class of coloured Petri nets, called Ambient Petri Nets (APNs), is introduced. Furthermore, a rel...

A. Konios M. Pietkiewicz-Koutny

2013-01-01

268

Skin colour and bilirubin in neonates  

Microsoft Academic Search

The correlation between the yellow colour of the skin and serum bilirubin concentration, reserve albumin concentration, and pH was investigated in 76 icteric neonates. Significant linear correlation existed between yellow colour of the skin and serum bilirubin concentration, reciprocal of the reserve albumin concentration, and the squared hydrogen ion concentration. Furthermore, the basic yellowness of the skin at birth correlated

A Knudsen; R Brodersen

1989-01-01

269

Clear Underwater Vision  

Microsoft Academic Search

Underwater imaging is important for scientific research and technology, as well as for popular activities. We present a computer vision approach which easily removes degradation effects in underwater vision. We analyze the physical effects of visibility degradation. We show that the main degradation effects can be associated with partial polarization of light. We therefore present an algorithm which inverts the

Yoav Y. Schechner; Nir Karpel

2004-01-01

270

Progress in computer vision.  

NASA Astrophysics Data System (ADS)

Computer vision has emerged as a challenging and important area of research, both as an engineering and a scientific discipline. The growing importance of computer vision is evident from the fact that it was identified as one of the "Grand Challenges" and also from its prominent role in the National Information Infrastructure. While the design of a general-purpose vision system continues to be elusive machine vision systems are being used successfully in specific application elusive, machine vision systems are being used successfully in specific application domains. Building a practical vision system requires a careful selection of appropriate sensors, extraction and integration of information from available cues in the sensed data, and evaluation of system robustness and performance. The authors discuss and demonstrate advantages of (1) multi-sensor fusion, (2) combination of features and classifiers, (3) integration of visual modules, and (IV) admissibility and goal-directed evaluation of vision algorithms. The requirements of several prominent real world applications such as biometry, document image analysis, image and video database retrieval, and automatic object model construction offer exciting problems and new opportunities to design and evaluate vision algorithms.

Jain, A. K.; Dorai, C.

271

What Is Low Vision?  

MedlinePLUS Videos and Cool Tools

... up in there with your forehead. Good. The diseases that cause low vision-- the most common one we see here is macular degeneration. We ... lot of albinism. Diabetic retinopathy is another very common cause of vision ... degeneration. It's a retinal disease so that means it affects the very back ...

272

Computer Vision on Mars  

Microsoft Academic Search

Increasing the level of spacecraft autonomy is essential for broadening the reach of solar system exploration. Computer vision has and will continue to play an important role in increasing autonomy of both spacecraft and Earth- based robotic vehicles. This article addresses progress on computer vision for planetary rovers and landers and has four main parts. First, we review major milestones

Larry Matthies; Mark W. Maimone; Andrew Edie Johnson; Yang Cheng; Reg G. Willson; Carlos Villalpando; Steve B. Goldberg; Andres Huertas; Andrew Stein; Anelia Angelova

2007-01-01

273

INSIGHT: Vision & Leadership, 2002.  

ERIC Educational Resources Information Center

This publication focuses on promising new and emerging technologies and what they might mean to the future of K-12 schools. Half of the volume contains articles devoted in some way to "Vision," and articles in the other half are under the heading of "Leadership." Contents in the "Vision" section include: "The Future of Reading and Learning To…

McGraw, Tammy, Ed.

2002-01-01

274

New Term, New Vision?  

ERIC Educational Resources Information Center

During the affluent noughties it was sometimes said of government that it had "more visions than Mystic Meg and more pilots than British Airways". In 2011, the pilots, the pathfinders, the new initiatives are largely gone--implementation is the name of the game--but the visions remain. The latest one, as it affects adult learners, is in the…

Ravenhall, Mark

2011-01-01

275

Color vision deficiencies  

NASA Astrophysics Data System (ADS)

Congenital and acquired color vision defects are described in the context of physiological data. Light sources, photometry, color systems and test methods are described. A list of medicines is also presented. The practical social consequences of color vision deficiencies are discussed.

Vannorren, D.

1982-04-01

276

Skin colour and bilirubin in neonates.  

PubMed Central

The correlation between the yellow colour of the skin and serum bilirubin concentration, reserve albumin concentration, and pH was investigated in 76 icteric neonates. Significant linear correlation existed between yellow colour of the skin and serum bilirubin concentration, reciprocal of the reserve albumin concentration, and the squared hydrogen ion concentration. Furthermore, the basic yellowness of the skin at birth correlated linearily with the yellow colour of the skin measured when the child became jaundiced. The results support the proposed hypothesis that bilirubin is transferred from plasma to skin through two different mechanisms: (a) leakage of bilirubin-albumin complexes into extravascular spaces and (b) precipitation of bilirubin acid in phospholipid membranes. The latter mechanism suggests that measurement of the yellow colour of the skin may be a better predictor of brain damage than the serum bilirubin concentration and thus be of clinical utility. Measurement of the yellow colour of the skin as a method of obtaining serum bilirubin concentration is unreliable.

Knudsen, A; Brodersen, R

1989-01-01

277

Panoramic stereo sphere vision  

NASA Astrophysics Data System (ADS)

Conventional stereo vision systems have a small field of view (FOV) which limits their usefulness for certain applications. While panorama vision is able to "see" in all directions of the observation space, scene depth information is missed because of the mapping from 3D reference coordinates to 2D panoramic image. In this paper, we present an innovative vision system which builds by a special combined fish-eye lenses module, and is capable of producing 3D coordinate information from the whole global observation space and acquiring no blind area 360°×360° panoramic image simultaneously just using single vision equipment with one time static shooting. It is called Panoramic Stereo Sphere Vision (PSSV). We proposed the geometric model, mathematic model and parameters calibration method in this paper. Specifically, video surveillance, robotic autonomous navigation, virtual reality, driving assistance, multiple maneuvering target tracking, automatic mapping of environments and attitude estimation are some of the applications which will benefit from PSSV.

Feng, Weijia; Zhang, Baofeng; Röning, Juha; Zong, Xiaoning; Yi, Tian

2013-01-01

278

Knowledge and Use of Low Vision Services Among Persons with Age-Related Macular Degeneration  

ERIC Educational Resources Information Center

Visual impairment (blindness or low vision) is a leading cause of disability among older adults and is most often due to age-related macular degeneration (AMD). It is predicted that 2.95 million people will have AMD by 2020 (Eye Diseases Prevalence Research Group, 2004). Unfortunately, there is no cure for AMD, nor can lost vision be restored.…

Casten, Robin J.; Maloney, Eileen K.; Rovner, Barry W.

2005-01-01

279

Vision and Quality of Life: The Development of a Utility Measure  

Microsoft Academic Search

PURPOSE. To identify the content for a vision and quality of life-related utility measure (Vision Quality of Life Index (VisQoL)) for the economic evaluation of eye care and rehabil- itation programs. METHODS. Focus groups of the visually impaired elicited key concepts. Based on these and previous research, 33 items were generated. These were administered to visually impaired adults (n 70)

RoseAnne Misajon; Graeme Hawthorne; Jeff Richardson; Jodi Barton; Stuart Peacock; Angelo Iezzi; Jill Keeffe

2005-01-01

280

The Computer Vision Handbook  

NSDL National Science Digital Library

A work in progress, this site outlines resources for computer vision techniques, including societies and funding; general references and lab procedures; and indices and programs for mathematics, computer science, graphics and physics. The goal of this electronic handbook is to provide graduate students and others new to computer vision research with a useful tool because, "...the computer vision literature is vast and diverse. Furthermore, computer vision research depends on techniques from a wide range of other fields. Therefore, it is difficult for newcomers (e.g. graduate students) to assimilate enough background material to do their research," says the site's collaborative authors, scientists from the University of Wisconsin-Eau Claire, Harvey Mudd College, and the University of Iowa. This metasite is well-organized into subheadings: The Computer Vision Community, Computer Vision, Mathematics, Computer Science, Hardware, and Allied Fields, and a glossary is also available. Because it collects so much of the literature and so many Websites, the Computer Vision Handbook is an indispensable tool for graduate students and faculty in the field.

281

Physicochemical and physiological basis of dichromatic colour  

NASA Astrophysics Data System (ADS)

Out of three perceptual characteristics of the colour of any substance, the hue depends mostly on the spectral properties of a substance, while the brightness and saturation depend also on the concentration of a substance and its thickness. Here, we report that evident change of the hue of the colour (i.e., from green to red) is due to a change in concentration or the thickness of a layer in some exceptional substances such as pumpkin seed oil or an aqueous solution of bromophenol blue. In some regions of Central Europe, salad dressing is made preferably with the pumpkin seed oil, which has a strong characteristic nut-like taste and remarkable properties of the colour: it appears red in a bottle, but green when served as a salad dressing. The colour of the pumpkin seed oil was previously described as brownish yellow, dark green, dark green to red ochre or dark reddish brown to light yellow green. We elucidated the physicochemical and physiological basis of such dichromatism by Beer-Lambert law and by the characteristics of human colour perception. Our concept was corroborated by the outcome of calculations of colour from spectral properties using colour matching functions. We found that dichromatism is observed if the absorption spectrum of any substance has at least two local minima: one wide but shallow and one narrow but deep local minimum.

Kreft, Samo; Kreft, Marko

2007-11-01

282

Colloidal approach to prepare colour blends from colourants with different solubility profiles.  

PubMed

Food colouring plays a vital and a determining role in the processing and the manufacturing of food products because the appearance of products is critical for attracting consumers and influencing their food choices. However, factors such as legislative restrictions, limited number of approved colourants and the processing, formulation and stability issues of the natural colourants severely limits the application of food colouring in actual product formats. Hence, finding alternatives to the currently utilised formulation practises, represents an important area of research. Here, we report a simple colloidal approach to prepare colour blends by co-incorporating colourants with contrasting aqueous solubility profiles in composite colloidal particles. Curcumin and indigocarmine were selected as water insoluble and water soluble food-grade colourants respectively and incorporated in the colloidal particles prepared from food protein-zein. Composite particles obtained by loading of curcumin and indigocarmine (at different ratios) had mean particle size ranging from 76 to 300nm. The spherical shape of the colloidal particles was confirmed using transmission electron microscopy and the colloidal dispersions were further characterised using UV-Vis and fluorescence spectroscopy. The incorporation of colourants in colloidal particles led to the generation of different shade of colour in yellow-green-blue range. The encapsulation also led to the stabilization of individual pigments against photodegradation. Such composite colloidal particles could potentially serve as an approach for developing tuneable colouring system for food and nutraceutical applications. PMID:23790940

Patel, A R; Heussen, P C M; Dorst, E; Hazekamp, J; Velikov, K P

2013-11-15

283

Bumblebees (Bombus terrestris) and honeybees (Apis mellifera) prefer similar colours of higher spectral purity over trained colours.  

PubMed

Differences in the concentration of pigments as well as their composition and spatial arrangement cause intraspecific variation in the spectral signature of flowers. Known colour preferences and requirements for flower-constant foraging bees predict different responses to colour variability. In experimental settings, we simulated small variations of unicoloured petals and variations in the spatial arrangement of colours within tricoloured petals using artificial flowers and studied their impact on the colour choices of bumblebees and honeybees. Workers were trained to artificial flowers of a given colour and then given the simultaneous choice between three test colours: either the training colour, one colour of lower and one of higher spectral purity, or the training colour, one colour of lower and one of higher dominant wavelength; in all cases the perceptual contrast between the training colour and the additional test colours was similarly small. Bees preferred artificial test flowers which resembled the training colour with the exception that they preferred test colours with higher spectral purity over trained colours. Testing the behaviour of bees at artificial flowers displaying a centripetal or centrifugal arrangement of three equally sized colours with small differences in spectral purity, bees did not prefer any type of artificial flowers, but preferentially choose the most spectrally pure area for the first antenna contact at both types of artificial flowers. Our results indicate that innate preferences for flower colours of high spectral purity in pollinators might exert selective pressure on the evolution of flower colours. PMID:23224278

Rohde, Katja; Papiorek, Sarah; Lunau, Klaus

2013-03-01

284

Making the Grade: College Students with Visual Impairments.  

ERIC Educational Resources Information Center

This study of the transition experiences of 102 college students with visual impairments (blindness or low vision), and of the services offered for students with disabilities at 66 colleges, found that the colleges provided most of the services students need to be successful. Students also identified areas in which visually impaired high school…

McBroom, L. W.

1997-01-01

285

Identity Development in German Adolescents with and without Visual Impairments  

ERIC Educational Resources Information Center

Introduction: The study reported here assessed the exploration of identity and commitment to an identity in German adolescents with and without visual impairments. Methods: In total, 178 adolescents with visual impairments (blindness or low vision) and 526 sighted adolescents completed the Ego Identity Process Questionnaire. Results: The levels of…

Pinquart, Martin; Pfeiffer, Jens P.

2013-01-01

286

20 CFR Appendix 1 to Part 220 - Listing of Impairments  

Code of Federal Regulations, 2010 CFR

...eyes may produce loss of central or peripheral vision...diseases of arteries and veins, severe impairment may...the vasculature in the central nervous system, eyes...102.02 Impairments of central visual acuity. A...with visualization of retinal red reflex only or...

2009-04-01

287

Why `false' colours are seen by butterflies  

NASA Astrophysics Data System (ADS)

Light can be described by its intensity, spectral distribution and polarization, and normally a visual system analyses these independently to extract the maximum amount of information. Here I present behavioural evidence that this does not happen in butterflies, whose choice of oviposition substrate on the basis of its colour appears to be strongly influenced by the direction of polarization of the light reflected from the substrate. To my knowledge, this is the first record of `false' colours being perceived as a result of light polarization. This detection of false colours may help butterflies to find optimal oviposition sites.

Kelber, Almut

1999-11-01

288

Ultrarapid categorisation of natural scenes does not rely on colour cues: a study in monkeys and humans  

Microsoft Academic Search

In a rapid categorisation task, monkeys and humans had to detect a target (animal or food) in briefly flashed (32 ms) and previously unseen natural images. Removing colour cues had very little effect on average performance. Impairments were restricted to a mild accuracy drop (in some human subjects) and a small reaction time mean increase (10–15 ms) observed both in

A Delorme; G Richard; M Fabre-Thorpe

2000-01-01

289

21 CFR 886.5915 - Optical vision aid.  

Code of Federal Regulations, 2010 CFR

...SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5915 Optical vision aid. (a) Identification...magnifying lens with an accompanying AC-powered or battery-powered light source intended for use by a patient who has impaired...

2010-04-01

290

21 CFR 886.5915 - Optical vision aid.  

Code of Federal Regulations, 2010 CFR

...SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5915 Optical vision aid. (a) Identification...magnifying lens with an accompanying AC-powered or battery-powered light source intended for use by a patient who has impaired...

2009-04-01

291

Emotion-Induced Trade-Offs in Spatiotemporal Vision  

ERIC Educational Resources Information Center

It is generally assumed that emotion facilitates human vision in order to promote adaptive responses to a potential threat in the environment. Surprisingly, we recently found that emotion in some cases impairs the perception of elementary visual features (Bocanegra & Zeelenberg, 2009b). Here, we demonstrate that emotion improves fast temporal…

Bocanegra, Bruno R.; Zeelenberg, Rene

2011-01-01

292

The Impact of Vision Loss on Personality Traits  

ERIC Educational Resources Information Center

The aim of this study is to explore the differences in personality traits amongst adults with blindness, adults with low vision and sighted adults. Moreover, the relationship between the four scales of Eysenck's personality questionnaire and the demographic characteristics of participants with visual impairments was examined. There are no…

Papadopoulos, Konstantinos S.; Koustriava, Eleni; Charalampidou, Maria; Gerapostolou, Ioanna

2013-01-01

293

A Survey of Vision Aids for the Blind  

Microsoft Academic Search

The development of effective user interfaces, appropriate sensors, and information processing techniques make it possible to enable the blind to achieve additional perception of the environment. Since the beginning of the 1970's, the research of vision aids for the visually impaired people has been broadly extended. After introducing the traditional methods for guiding blind, two typical modes of mobility aid

Jihong Liu; Xiaoye Sun

2006-01-01

294

Vision in Dynamic Environments.  

National Technical Information Service (NTIS)

Research conducted on the contract was primarily concerned with real-time, three-dimensional computer vision and image understanding. Abstracts: Tracing Finite Motions without Correspondence. Group Theoretical Methods in Image Understanding; Interpreting ...

A. Rosenfeld

1989-01-01

295

Naval Aviation Vision.  

National Technical Information Service (NTIS)

Naval Aviation is critical to an evolving military shaped by war and fiscal pressures. The vision of Naval Aviation conveyed in this document is aligned to meet international responsibilities and national imperatives. As the architecture for near- and lon...

2012-01-01

296

Living with Low Vision  

MedlinePLUS Videos and Cool Tools

... Low Vision Glossary Helping a Loved One Medication Management Resources Español RESOURCES What is a comprehensive dilated ... NEI Office of Science Communications, Public Liaison, and Education. Technical questions about this website can be addressed ...

297

Retinal Detachment Vision Simulator  

MedlinePLUS

... Reduced Vision Tearing See all Symptoms > Glasses, Contacts & LASIK Contact Lenses Colored Contact Lenses Eyeglasses IOLs Refractive Surgery & LASIK Sunglasses Living EyeSmart About Ophthalmologists Adults Under 40 ...

298

Cataract Vision Simulator  

MedlinePLUS

... Reduced Vision Tearing See all Symptoms > Glasses, Contacts & LASIK Contact Lenses Colored Contact Lenses Eyeglasses IOLs Refractive Surgery & LASIK Sunglasses Living EyeSmart About Ophthalmologists Adults Under 40 ...

299

Special Session on Vision.  

National Technical Information Service (NTIS)

Graphic output devices shift the burden of integrating information generated by computers onto the human vision system: the sensory channel with the highest capacity for distributed parallel processng. The system consists of hundreds of successive two-dim...

F. S. Montalvo

1979-01-01

300

Low Vision Devices  

MedlinePLUS

... eye care professional demonstrates an electronic magnifying device. Credit: National Eye Institute, National Institutes of Health Ref#: ... appliance can help a person with low vision. Credit: National Eye Institute, National Institutes of Health Ref#: ...

301

The vision trap.  

PubMed

At Mentor Graphics Corporation, Gerry Langeler was the executive responsible for vision, and vision, he discovered, has the power to weaken a strong company. Mentor helped to invent design-automation electronics in the early 1980s, and by the end of the decade, it dominated the industry. In its early days, fighting to survive, Mentor's motto was Build Something People Will Buy. Then when clear competition emerged in the form of Daisy Systems, a startup that initially outsold Mentor, the watchword became Beat Daisy. Both "visions" were pragmatic and immediate. They gave Mentor a sense of purpose as it developed its products and gathered momentum. Once Daisy was beaten, however, company vision began to self-inflate. As Mentor grew more and more successful, Langeler formulated vision statements that were more and more ambitious, grand, and inspirational. The company traded its gritty determination to survive for a dream of future glory. The once explicit call for effective action became a fervid cry for abstract perfection. The first step was Six Boxes, a transitional vision that combined goals for success in six business areas with grandiose plans to compete with IBM at the level of billion-dollar revenues. From there, vision stepped up to the 10X Imperative, a quality-improvement program that focused on arbitrary goals and measures that were, in fact, beyond the company's control. The last escalation came when Mentor Graphics decided to Change the Way the World Designs. The company had stopped making product and was making poetry. Finally, in 1991, after six years of increasing self-infatuation, Mentor hit a wall of decreasing indicators. Langeler, who had long since begun to doubt the value of abstract visions, reinstated Build Something People Will Buy. And Mentor was back to basics, a sense of purpose back to its workplace. PMID:10117368

Langeler, G H

1992-01-01

302

Vision Systems Design  

NSDL National Science Digital Library

Vision Systems Design is a magazine that provides comprehensive information and analyses about "machine-vision and imaging components, boards, assemblies, software, and systems." Its online version is free and has many Web-exclusive features available. For example, Back to Basics is a series of technical articles about a certain topic; the February 2003 issue has articles on FireWire interfaces, infrared systems used to increase vehicle safety, and much more. Technology news and industry trends are also provided online.

2003-01-01

303

Synthetic Vision Systems  

NASA Technical Reports Server (NTRS)

A synthetic vision system is an aircraft cockpit display technology that presents the visual environment external to the aircraft using computer-generated imagery in a manner analogous to how it would appear to the pilot if forward visibility were not restricted. The purpose of this chapter is to review the state of synthetic vision systems, and discuss selected human factors issues that should be considered when designing such displays.

Prinzel, L.J.; Kramer, L.J.

2009-01-01

304

Macular colour contrast sensitivity in ocular hypertension and glaucoma: evidence for two types of defect.  

PubMed Central

Colour contrast sensitivity (CCS) of a large cohort of glaucomatous patients, ocular hypertensive patients (OH), and normal persons was measured at six-month intervals during a two-year period. The OHs were graded into high, medium, and low risk groups. 69% of glaucomatous patients and 32% of all OHs had CCS thresholds greater than the mean plus 2 SDs of the controls. Satisfactory specificity and sensitivity could not be obtained by adjusting the criterion of threshold. In abnormal eyes, progressive small increases of threshold occurred during the study, but glaucomatous eyes with normal thresholds on the first visit retained normal thresholds in the subsequent visits. Although our system is very sensitive and precise, the proportion of abnormalities detected is no greater than with other techniques. In some glaucomatous patients there is a true preservation of colour vision which does not merely reflect the limitations of the test employed.

Falcao-Reis, F. M.; O'Sullivan, F.; Spileers, W.; Hogg, C.; Arden, G. B.

1991-01-01

305

Federal regulation of vision enhancement devices for normal and abnormal vision  

NASA Astrophysics Data System (ADS)

The Food and Drug Administration (FDA) evaluates the safety and effectiveness of medical devices and biological products as well as food and drugs. The FDA defines a device as a product that is intended, by physical means, to diagnose, treat, or prevent disease, or to affect the structure or function of the body. All vision enhancement devices fulfill this definition because they are intended to affect a function (vision) of the body. In practice, however, FDA historically has drawn a distinction between devices that are intended to enhance low vision as opposed to normal vision. Most low vision aids are therapeutic devices intended to compensate for visual impairment, and are actively regulated according to their level of risk to the patient. The risk level is usually low (e.g. Class I, exempt from 510(k) submission requirements for magnifiers that do not touch the eye), but can be as high as Class III (requiring a clinical trial and Premarket Approval (PMA) application) for certain implanted and prosthetic devices (e.g. intraocular telescopes and prosthetic retinal implants). In contrast, the FDA usually does not actively enforce its regulations for devices that are intended to enhance normal vision, are low risk, and do not have a medical intended use. However, if an implanted or prosthetic device were developed for enhancing normal vision, the FDA would likely decide to regulate it actively, because its intended use would entail a substantial medical risk to the user. Companies developing such devices should contact the FDA at an early stage to clarify their regulatory status.

Drum, Bruce

2006-09-01

306

Biofeedback for Better Vision  

NASA Technical Reports Server (NTRS)

Biofeedtrac, Inc.'s Accommotrac Vision Trainer, invented by Dr. Joseph Trachtman, is based on vision research performed by Ames Research Center and a special optometer developed for the Ames program by Stanford Research Institute. In the United States, about 150 million people are myopes (nearsighted), who tend to overfocus when they look at distant objects causing blurry distant vision, or hyperopes (farsighted), whose vision blurs when they look at close objects because they tend to underfocus. The Accommotrac system is an optical/electronic system used by a doctor as an aid in teaching a patient how to contract and relax the ciliary body, the focusing muscle. The key is biofeedback, wherein the patient learns to control a bodily process or function he is not normally aware of. Trachtman claims a 90 percent success rate for correcting, improving or stopping focusing problems. The Vision Trainer has also proved effective in treating other eye problems such as eye oscillation, cross eyes, and lazy eye and in professional sports to improve athletes' peripheral vision and reaction time.

1990-01-01

307

Impaired physicians.  

PubMed

Nearly every physician has encountered a doctor who is causing problems in the practice or at the hospital. These include physicians who are impaired because of drug or alcohol abuse. Managing these physicians and helping them get back on track can be difficult and daunting. This article will discuss impaired physicians with suggestions for interacting with them and helping them become valuable members of the team. PMID:24873127

Harbin, Tom; Baum, Neil

2014-01-01

308

Artist's colour rendering of HDR scenes in 3D Mondrian colour-constancy experiments  

Microsoft Academic Search

The presentation provides an update on ongoing research using three-dimensional Colour Mondrians. Two still life arrangements comprising hand-painted coloured blocks of 11 different colours were subjected to two different lighting conditions of a nearly uniform light and directed spotlights. The three-dimensional nature of these test targets adds shadows and multiple reflections, not found in flat Mondrian targets. Working from exactly

Carinna E. Parraman; John J. McCann; Alessandro Rizzi

2010-01-01

309

Stability of memory for colour in context.  

PubMed

Memory for colours presented in isolation was compared with that for colours presented as part of a clip-art image or as part of a non-meaningful, Mondrian-like image. The area under the Receiver Operating Characteristic for deciding that two colours, presented at different delay intervals, were the same or different provided an index of memory for colour. The provision of a context reduced the decay of memory, regardless of whether the context was meaningful (clip-art images) or non-meaningful (Mondrian-like images). The result was seen as a generalisation of the auditory phenomenon of profile analysis, in which memory for the amplitude of a single component of a complex sound is more stable than that for the component in isolation. PMID:10320866

Francis, M A; Irwin, R J

1998-11-01

310

The colour of the human skull.  

PubMed

The colour of the human skull was determined from 124 fresh skull samples using the tristimulus colour measurement system "Micro Color" and listed as The Commission Internationale de l'Eclairage (CIE) L*a*b*-values. The skulls were found to be relatively light (L*=72.5), nearly colourless on the a*-axis (a*=-7.4), and slightly yellow (b*=16.4). No difference was found between the colours of the outer and the inner surfaces of the skulls. Including a small number (n=8) of skulls from diabetic patients in the study, we detected no colour difference between the samples from diabetics and non-diabetics. However, a hitherto unknown correlation between the subjects' age and the yellowness (b*-value) of the skull could be demonstrated. PMID:11230946

Schafer, A T

2001-03-01

311

[Optic mixing of colours in Seurat's painting].  

PubMed

Georges Seurat is the initiator and master of the divisionism. He founds the neoimpressionism current that tries to reproduce the nature exclusively through coloured vibration. Seurat applies the colours in small touches uniformly distributed on the canvas; the colours merge if they are looked by a certain distance, through optical interference. When the spectator approaches from the picture, the special frequency decreases, the optical merging does not appear and the onlooker looks a lot of coloured spots. When the spectator moves away from the picture, the optical interference appears and the clarity of the image becomes perfectly. This current opened the way of the future's modern painting performed by Cézanne, Renoir, Van Gogh. PMID:12677811

Cernea, Paul

2002-01-01

312

Angle-Insensitive Structural Colours based on Metallic Nanocavities and Coloured Pixels beyond the Diffraction Limit  

PubMed Central

To move beyond colorant-based pigmentation display technologies, a variety of photonic and plasmonic crystal based structures have been designed and applied as colour filters. Nanostructure based colour filtering offers increased efficiencies, low power consumption, slim dimensions, and enhanced resolution. However, incident angle tolerance still needs to be improved. In this work, we propose a new scheme through localized resonance in metallic nanoslits by light funneling. Angle insensitive colour filters up to ±80 degrees have been achieved, capable of wide colour tunability across the entire visible band with pixel size beyond the diffraction limit (~?/2). This work opens the door to angle insensitive manipulation of light with structural filtering.

Wu, Yi-Kuei Ryan; Hollowell, Andrew E.; Zhang, Cheng; Guo, L. Jay

2013-01-01

313

THE COLOUR GLASS CONDENSATE: AN INTRODUCTION  

SciTech Connect

In these lectures, the authors develop the theory of the Colour Glass Condensate. This is the matter made of gluons in the high density environment characteristic of deep inelastic scattering or hadron-hadron collisions at very high energy. The lectures are self contained and comprehensive. They start with a phenomenological introduction, develop the theory of classical gluon fields appropriate for the Colour Glass, and end with a derivation and discussion of the renormalization group equations which determine this effective theory.

IANCU,E.; LEONIDOV,A.; MCLERRAN,L.

2001-08-06

314

Performance evaluation of local colour invariants  

Microsoft Academic Search

In this paper, we compare local colour descriptors to grey-value descriptors. We adopt the evaluation framework of Mikolayzcyk and Schmid. We modify the framework in several ways. We decompose the evaluation framework to the level of local grey-value invariants on which common region descriptors are based. We compare the discriminative power and invariance of grey-value invariants to that of colour

Gertjan J. Burghouts; Jan-mark Geusebroek

2009-01-01

315

Response of alate aphids to green targets on coloured backgrounds  

Microsoft Academic Search

To study the effect of background colour on aphid landing on green targets (water pan traps), two field experiments were set up in Hessen, Germany, in 2003. Traps were put onto coloured plastic sheets (13 colours, straw mulch, transparent foil, and uncovered soil, Experiment 1). In Experiment 2, green water pans were again put on coloured plastic sheets (red, white,

T. F. Doring; S. M. Kirchner; S. Kuhne; H. Saucke

2004-01-01

316

Inheritance of seed colour in turnip rape ( Brassica campestris L.)  

Microsoft Academic Search

The inheritance of seed colour was investigated in the progenies of crosses between seven yellow seeded forms and a brown seeded one of turnip rape (Brassica campestris L.). Seed colour differences were found to be determined in each case by one or two genes with epistatic effect. Moreover, independent inheritance of hilum colour was observed. Seed colour was predominantly but

A. Schwetka

1982-01-01

317

Colourful parrot feathers resist bacterial degradation  

PubMed Central

The brilliant red, orange and yellow colours of parrot feathers are the product of psittacofulvins, which are synthetic pigments known only from parrots. Recent evidence suggests that some pigments in bird feathers function not just as colour generators, but also preserve plumage integrity by increasing the resistance of feather keratin to bacterial degradation. We exposed a variety of colourful parrot feathers to feather-degrading Bacillus licheniformis and found that feathers with red psittacofulvins degraded at about the same rate as those with melanin and more slowly than white feathers, which lack pigments. Blue feathers, in which colour is based on the microstructural arrangement of keratin, air and melanin granules, and green feathers, which combine structural blue with yellow psittacofulvins, degraded at a rate similar to that of red and black feathers. These differences in resistance to bacterial degradation of differently coloured feathers suggest that colour patterns within the Psittaciformes may have evolved to resist bacterial degradation, in addition to their role in communication and camouflage.

Burtt, Edward H.; Schroeder, Max R.; Smith, Lauren A.; Sroka, Jenna E.; McGraw, Kevin J.

2011-01-01

318

Seasonal colour and antipredator behaviour in Etheostoma (Percidae).  

PubMed

This study examined how colour varies across season and sex in the fantail darter Etheostoma flabellare and the banded darter Etheostoma zonale. Etheostoma flabellare has male-only parental care and exhibited slight sexual dimorphism in overall colour, with no discernible effect of season on colour; whereas E. zonale does not have parental care and exhibited substantial sexual dimorphism in colour, but only in the breeding season. Additionally, antipredator behaviour of E. zonale was compared between males that were fully coloured during the breeding season and males that were partially coloured at that time, but the effects of colour and season were not consistent across males. PMID:24588710

Moran, R L; von Ende, C N; King, B H

2014-04-01

319

Piaget's Water-Level Task: The Impact of Vision on Performance  

ERIC Educational Resources Information Center

In the present study, the aim was to examine the differences in performance between children and adolescents with visual impairment and sighted peers in the water-level task. Twenty-eight individuals with visual impairments, 14 individuals with blindness and 14 individuals with low vision, and 28 sighted individuals participated in the present…

Papadopoulos, Konstantinos; Koustriava, Eleni

2011-01-01

320

Adaptation to Low Vision Caused by Age-Related Macular Degeneration: A Case Study  

ERIC Educational Resources Information Center

One in eight Americans aged 65 and older has an eye disease resulting in low vision, and more women than men are visually impaired, mainly because women live longer. Age-related visual impairments are an indicator of a decline in activities of daily living and self-help skills. The top eye conditions that affect older adults are macular…

Smith, Theresa Marie

2008-01-01

321

Physical Impairment  

NASA Astrophysics Data System (ADS)

Many health conditions can lead to physical impairments that impact computer and Web access. Musculoskeletal conditions such as arthritis and cumulative trauma disorders can make movement stiff and painful. Movement disorders such as tremor, Parkinsonism and dystonia affect the ability to control movement, or to prevent unwanted movements. Often, the same underlying health condition also has sensory or cognitive effects. People with dexterity impairments may use a standard keyboard and mouse, or any of a wide range of alternative input mechanisms. Examples are given of the diverse ways that specific dexterity impairments and input mechanisms affect the fundamental actions of Web browsing. As the Web becomes increasingly sophisticated, and physically demanding, new access features at the Web browser and page level will be necessary.

Trewin, Shari

322

Colour within an internalist framework: The role of 'colour' in the structure of the perceptual system  

Microsoft Academic Search

Colour is, according to prevailing orthodoxy in perceptual psychology, a kind of autonomous and unitary attribute. It is regarded as unitary or homogeneous by assuming that its core properties do not depend on the type of 'perceptual object' to which it pertains and that 'colour per se' constitutes a natural attribute in the functional architecture of the perceptual system. It

Rainer Mausfeld

323

Memory colours and colour quality evaluation of conventional and solid-state lamps.  

PubMed

A colour quality metric based on memory colours is presented. The basic idea is simple. The colour quality of a test source is evaluated as the degree of similarity between the colour appearance of a set of familiar objects and their memory colours. The closer the match, the better the colour quality. This similarity was quantified using a set of similarity distributions obtained by Smet et al. in a previous study. The metric was validated by calculating the Pearson and Spearman correlation coefficients between the metric predictions and the visual appreciation results obtained in a validation experiment conducted by the authors as well those obtained in two independent studies. The metric was found to correlate well with the visual appreciation of the lighting quality of the sources used in the three experiments. Its performance was also compared with that of the CIE colour rendering index and the NIST colour quality scale. For all three experiments, the metric was found to be significantly better at predicting the correct visual rank order of the light sources (p < 0.1). PMID:21164972

Smet, Kevin A G; Ryckaert, Wouter R; Pointer, Michael R; Deconinck, Geert; Hanselaer, Peter

2010-12-01

324

Capturing Natural-Colour 3D Models of Insects for Species Discovery and Diagnostics.  

PubMed

Collections of biological specimens are fundamental to scientific understanding and characterization of natural diversity-past, present and future. This paper presents a system for liberating useful information from physical collections by bringing specimens into the digital domain so they can be more readily shared, analyzed, annotated and compared. It focuses on insects and is strongly motivated by the desire to accelerate and augment current practices in insect taxonomy which predominantly use text, 2D diagrams and images to describe and characterize species. While these traditional kinds of descriptions are informative and useful, they cannot cover insect specimens "from all angles" and precious specimens are still exchanged between researchers and collections for this reason. Furthermore, insects can be complex in structure and pose many challenges to computer vision systems. We present a new prototype for a practical, cost-effective system of off-the-shelf components to acquire natural-colour 3D models of insects from around 3 mm to 30 mm in length. ("Natural-colour" is used to contrast with "false-colour", i.e., colour generated from, or applied to, gray-scale data post-acquisition.) Colour images are captured from different angles and focal depths using a digital single lens reflex (DSLR) camera rig and two-axis turntable. These 2D images are processed into 3D reconstructions using software based on a visual hull algorithm. The resulting models are compact (around 10 megabytes), afford excellent optical resolution, and can be readily embedded into documents and web pages, as well as viewed on mobile devices. The system is portable, safe, relatively affordable, and complements the sort of volumetric data that can be acquired by computed tomography. This system provides a new way to augment the description and documentation of insect species holotypes, reducing the need to handle or ship specimens. It opens up new opportunities to collect data for research, education, art, entertainment, biodiversity assessment and biosecurity control. PMID:24759838

Nguyen, Chuong V; Lovell, David R; Adcock, Matt; La Salle, John

2014-01-01

325

Capturing Natural-Colour 3D Models of Insects for Species Discovery and Diagnostics  

PubMed Central

Collections of biological specimens are fundamental to scientific understanding and characterization of natural diversity—past, present and future. This paper presents a system for liberating useful information from physical collections by bringing specimens into the digital domain so they can be more readily shared, analyzed, annotated and compared. It focuses on insects and is strongly motivated by the desire to accelerate and augment current practices in insect taxonomy which predominantly use text, 2D diagrams and images to describe and characterize species. While these traditional kinds of descriptions are informative and useful, they cannot cover insect specimens “from all angles” and precious specimens are still exchanged between researchers and collections for this reason. Furthermore, insects can be complex in structure and pose many challenges to computer vision systems. We present a new prototype for a practical, cost-effective system of off-the-shelf components to acquire natural-colour 3D models of insects from around 3 mm to 30 mm in length. (“Natural-colour” is used to contrast with “false-colour”, i.e., colour generated from, or applied to, gray-scale data post-acquisition.) Colour images are captured from different angles and focal depths using a digital single lens reflex (DSLR) camera rig and two-axis turntable. These 2D images are processed into 3D reconstructions using software based on a visual hull algorithm. The resulting models are compact (around 10 megabytes), afford excellent optical resolution, and can be readily embedded into documents and web pages, as well as viewed on mobile devices. The system is portable, safe, relatively affordable, and complements the sort of volumetric data that can be acquired by computed tomography. This system provides a new way to augment the description and documentation of insect species holotypes, reducing the need to handle or ship specimens. It opens up new opportunities to collect data for research, education, art, entertainment, biodiversity assessment and biosecurity control.

Nguyen, Chuong V.; Lovell, David R.; Adcock, Matt; La Salle, John

2014-01-01

326

Overview of sports vision  

NASA Astrophysics Data System (ADS)

Sports vision encompasses the visual assessment and provision of sports-specific visual performance enhancement and ocular protection for athletes of all ages, genders and levels of participation. In recent years, sports vision has been identified as one of the key performance indicators in sport. It is built on four main cornerstones: corrective eyewear, protective eyewear, visual skills enhancement and performance enhancement. Although clinically well established in the US, it is still a relatively new area of optometric specialisation elsewhere in the world and is gaining increasing popularity with eyecare practitioners and researchers. This research is often multi-disciplinary and involves input from a variety of subject disciplines, mainly those of optometry, medicine, physiology, psychology, physics, chemistry, computer science and engineering. Collaborative research projects are currently underway between staff of the Schools of Physics and Computing (DIT) and the Academy of Sports Vision (RAU).

Moore, Linda A.; Ferreira, Jannie T.

2003-03-01

327

Bio-inspired vision  

NASA Astrophysics Data System (ADS)

Nature still outperforms the most powerful computers in routine functions involving perception, sensing and actuation like vision, audition, and motion control, and is, most strikingly, orders of magnitude more energy-efficient than its artificial competitors. The reasons for the superior performance of biological systems are subject to diverse investigations, but it is clear that the form of hardware and the style of computation in nervous systems are fundamentally different from what is used in artificial synchronous information processing systems. Very generally speaking, biological neural systems rely on a large number of relatively simple, slow and unreliable processing elements and obtain performance and robustness from a massively parallel principle of operation and a high level of redundancy where the failure of single elements usually does not induce any observable system performance degradation. In the late 1980`s, Carver Mead demonstrated that silicon VLSI technology can be employed in implementing ``neuromorphic'' circuits that mimic neural functions and fabricating building blocks that work like their biological role models. Neuromorphic systems, as the biological systems they model, are adaptive, fault-tolerant and scalable, and process information using energy-efficient, asynchronous, event-driven methods. In this paper, some basics of neuromorphic electronic engineering and its impact on recent developments in optical sensing and artificial vision are presented. It is demonstrated that bio-inspired vision systems have the potential to outperform conventional, frame-based vision acquisition and processing systems in many application fields and to establish new benchmarks in terms of redundancy suppression/data compression, dynamic range, temporal resolution and power efficiency to realize advanced functionality like 3D vision, object tracking, motor control, visual feedback loops, etc. in real-time. It is argued that future artificial vision systems, if they are to succeed in demanding applications such as autonomous robot navigation, micro-manipulation or high-speed tracking, must exploit the power of the asynchronous, frame-free, biomimetic approach.

Posch, C.

2012-01-01

328

Telescopic vision contact lens  

NASA Astrophysics Data System (ADS)

We present the concept, optical design, and first proof of principle experimental results for a telescopic contact lens intended to become a visual aid for age-related macular degeneration (AMD), providing magnification to the user without surgery or external head-mounted optics. Our contact lens optical system can provide a combination of telescopic and non-magnified vision through two independent optical paths through the contact lens. The magnified optical path incorporates a telescopic arrangement of positive and negative annular concentric reflectors to achieve 2.8x - 3x magnification on the eye, while light passing through a central clear aperture provides unmagnified vision.

Tremblay, Eric J.; Beer, R. Dirk; Arianpour, Ashkan; Ford, Joseph E.

2011-02-01

329

Aging, physiology, and vision.  

PubMed

This article provides an overview of the normal, physiologic changes in vision that are a part of the aging process. Associated symptoms noted by and worrisome to many patients also are discussed. Clear explanations of the rationale and cause of these concerning complaints reduces anxiety and enables people to function more safely in environments in which visual loss is likely to have a deleterious effect. Likewise, accurate understanding of normal versus pathological vision symptoms assists health care providers, such as nurse practitioners, to better triage, assess, and treat ophthalmic-related problems. PMID:9624972

Smith, S C

1998-03-01

330

Robotics Peripheral Vision  

NSDL National Science Digital Library

This unit is designed for advanced programming classes. It leads students through a study of human vision and computer programming simulation. Students apply their previous knowledge of arrays and looping structures to implement a new concept of linked lists and RGB decomposition in order to solve the unit's Grand Challenge: writing a program to simulate peripheral vision by merging two images. This unit connects computer science to engineering by incorporating several science topics (eye anatomy, physics of light and color, mathematics, and science of computers) and guides students through the design process in order to create final simulations.

Vu Bioengineering Ret Program

331

Colour unmasks dark targets in complex displays.  

PubMed

Recent studies have suggested that colour (meaning chromatic) variations help the visual system segment luminance-variegated displays into their illumination and reflectance layers. This leads to the prediction that colour variations should unmask partially camouflaged achromatic transparencies on luminance-variegated backgrounds. We used 'Mondrian-like' backgrounds that were either achromatic, i.e., varying only in luminance, or chromatic, which in our stimuli meant varying in both luminance and colour. Both achromatic and chromatic backgrounds had the same luminance distribution. Thresholds for detecting simulated transparency targets were found to be lower when on the chromatic compared to achromatic backgrounds. We hypothesised that the chromatic-background advantage resulted from the extra cue provided by colour as to which borders were background and which transparency, predicting that (a) randomising the colours on either side of the transparency border, (b) rotating the target to destroy its X-junctions, and (c) viewing the target eccentrically, would each destroy the chromatic-background advantage. However, none of these predictions was upheld. We suggest therefore that the chromatic-background advantage is due to a low-level, rather than border-disambiguation mechanism. We suggest that chromatic variations reduce the noise, but not the signal, in the mechanism that detects dark targets in complex displays. PMID:16226784

Kingdom, Frederick A A; Kasrai, Reza

2006-03-01

332

Grounding Our Vision: Brain Research and Strategic Vision  

ERIC Educational Resources Information Center

While recognizing the value of "vision," it could be argued that vision alone--at least in schools--is not enough to rally the financial and emotional support required to translate an idea into reality. A compelling vision needs to reflect substantive, research-based knowledge if it is to spark the kind of strategic thinking and insight capable of…

Walker, Mike

2011-01-01

333

The impact of individual characteristics in self-esteem and locus of control of young adults with visual impairments.  

PubMed

In this study the impact of personal/individual characteristics (gender, vision status, age, age at loss of sight, recency of vision loss, education level, employment status, and ability of independent movement) in locus of control (LOC) and self-esteem were examined. Eighty-four young adults with visual impairments (42 with blindness and 42 with low vision) took part in this study. The significant predictors of self-esteem were vision status, age at loss of sight, recency of vision loss and educational level. Moreover, significant predictors of LOC were vision status and independent movement. PMID:24444613

Papadopoulos, Konstantinos

2014-03-01

334

Object tracking with stereo vision  

NASA Technical Reports Server (NTRS)

A real-time active stereo vision system incorporating gaze control and task directed vision is described. Emphasis is placed on object tracking and object size and shape determination. Techniques include motion-centroid tracking, depth tracking, and contour tracking.

Huber, Eric

1994-01-01

335

Effect of colouring green stage zirconia on the adhesion of veneering ceramics with different thermal expansion coefficients  

PubMed Central

This study evaluated the adhesion of zirconia core ceramics with their corresponding veneering ceramics, having different thermal expansion coefficients (TECs), when zirconia ceramics were coloured at green stage. Zirconia blocks (N=240; 6 mm×7 mm×7 mm) were manufactured from two materials namely, ICE Zirconia (Group 1) and Prettau Zirconia (Group 2). In their green stage, they were randomly divided into two groups. Half of the specimens were coloured with colouring liquid (shade A2). Three different veneering ceramics with different TEC (ICE Ceramic, GC Initial Zr and IPS e.max Ceram) were fired on both coloured and non-coloured zirconia cores. Specimens of high noble alloys (Esteticor Plus) veneered with ceramic (VM 13) (n=16) acted as the control group. Core–veneer interface of the specimens were subjected to shear force in the Universal Testing Machine (0.5 mm?min?1). Neither the zirconia core material (P=0.318) nor colouring (P=0.188) significantly affected the results (three-way analysis of variance, Tukey's test). But the results were significantly affected by the veneering ceramic (P=0.000). Control group exhibited significantly higher mean bond strength values (45.7±8) MPa than all other tested groups ((27.1±4.1)?(39.7±4.7) and (27.4±5.6)?(35.9±4.7) MPa with and without colouring, respectively) (P<0.001). While in zirconia–veneer test groups, predominantly mixed type of failures were observed with the veneering ceramic covering <1/3 of the substrate surface, in the metal–ceramic group, veneering ceramic was left adhered >1/3 of the metal surface. Colouring zirconia did not impair adhesion of veneering ceramic, but veneering ceramic had a significant influence on the core–veneer adhesion. Metal–ceramic adhesion was more reliable than all zirconia–veneer ceramics tested.

Aktas, Guliz; Sahin, Erdal; Vallittu, Pekka; Ozcan, Mutlu; Lassila, Lippo

2013-01-01

336

Vision in Annelid Worms  

Microsoft Academic Search

In a first electrophysiological study of worm vision, electroretinograms were measured in two alciopid worms: Torrea, taken at the surface, and deep-sea Vanadis. Both forms possess a primary retina in the focal plane of the lens, and accessory retinas lying beside the lens. Such accessory retinas occur also in deepsea fishes and cephalopods. In Torrea the primary retina peaks in

George Wald; Stephen Rayport

1977-01-01

337

CONTRIBUTIONS OF VISION SCIENCES.  

ERIC Educational Resources Information Center

THE IMPLICATIONS OF RESEARCH IN THE VISION SCIENCES FOR READING INSTRUCTION ARE DISCUSSED ON THE BASIS OF (1) STUDIES ON THE PERCEPTUAL BEHAVIOR OF CHILDREN AND THE EFFECT OF LANGUAGE DIRECTIONALITY ON PERCEPTION, (2) STUDIES ON VISUAL CHARACTERISTICS, (3) STUDIES ON THE RELATIONSHIP BETWEEN MOTOR COORDINATION AND READING ABILITY, (4) LONGITUDINAL…

SPACHE, GEORGE D.

338

Two Visions of America  

ERIC Educational Resources Information Center

Since the seventeenth century, there have been two narratives about modernity in general and America in particular. The author uses the term "narrative" to include (a) facts, (b) arguments, and most important, (c) a larger vision of how one sees the world and chooses to engage the world. The first and originalist narrative is the Lockean Liberty…

Capaldi, Nicholas

2012-01-01

339

Computer Vision Systems  

NASA Astrophysics Data System (ADS)

Food quality is of paramount consideration for all consumers, and its importance is perhaps only second to food safety. By some definition, food safety is also incorporated into the broad categorization of food quality. Hence, the need for careful and accurate evaluation of food quality is at the forefront of research and development both in the academia and industry. Among the many available methods for food quality evaluation, computer vision has proven to be the most powerful, especially for nondestructively extracting and quantifying many features that have direct relevance to food quality assessment and control. Furthermore, computer vision systems serve to rapidly evaluate the most readily observable foods quality attributes - the external characteristics such as color, shape, size, surface texture etc. In addition, it is now possible, using advanced computer vision technologies, to “see” inside a food product and/or package to examine important quality attributes ordinarily unavailable to human evaluators. With rapid advances in electronic hardware and other associated imaging technologies, the cost-effectiveness and speed of computer vision systems have greatly improved and many practical systems are already in place in the food industry.

Gunasekaran, Sundaram

340

Covariant Derivatives and Vision  

Microsoft Academic Search

We describe a new theoretical approach to Image Process- ing and Vision. Expressed in mathemetical terminology, in our formalism image space is a fibre bundle, and the image itself is the graph of a sec- tion on it. This mathematical model has advantages to the conventional view of the image as a function on the plane: Based on the new

Todor Georgiev

2006-01-01

341

Peripheral Vision Lab  

NSDL National Science Digital Library

Students explore their peripheral vision by reading large letters on index cards. Then they repeat the experiment while looking through camera lenses, first a lens with a smaller focal length and then a lens with a larger focal length. Then they complete a worksheet and explain how the experiment helps them solve the challenge question introduced in lesson 1 of this unit.

Vu Bioengineering Ret Program

342

Education of Vision.  

ERIC Educational Resources Information Center

The essays in this book concern themselves with the carefully sequenced interplay between sensory, imaginative awareness and disciplined, scientific knowledge. They deal specifically with sharpening visual perception. The opening essays analyze the fundamental characteristics of visual faculties. The next group of essays deal with vision as an…

Kepes, Gyorgy, Ed.

343

Synthetic Vision Workshop 2  

NASA Technical Reports Server (NTRS)

The second NASA sponsored Workshop on Synthetic/Enhanced Vision (S/EV) Display Systems was conducted January 27-29, 1998 at the NASA Langley Research Center. The purpose of this workshop was to provide a forum for interested parties to discuss topics in the Synthetic Vision (SV) element of the NASA Aviation Safety Program and to encourage those interested parties to participate in the development, prototyping, and implementation of S/EV systems that enhance aviation safety. The SV element addresses the potential safety benefits of synthetic/enhanced vision display systems for low-end general aviation aircraft, high-end general aviation aircraft (business jets), and commercial transports. Attendance at this workshop consisted of about 112 persons including representatives from industry, the FAA, and other government organizations (NOAA, NIMA, etc.). The workshop provided opportunities for interested individuals to give presentations on the state of the art in potentially applicable systems, as well as to discuss areas of research that might be considered for inclusion within the Synthetic Vision Element program to contribute to the reduction of the fatal aircraft accident rate. Panel discussions on topical areas such as databases, displays, certification issues, and sensors were conducted, with time allowed for audience participation.

Kramer, Lynda J. (Compiler)

1999-01-01

344

Temporal analysis of the chromatic flash VEP--separate colour and luminance contrast components.  

PubMed

Temporal analysis of the chromatic flash visual evoked potential (VEP) was studied in human subjects with normal and anomalous colour vision using a deterministic pseudo-random binary stimulus (VERIS). Five experiments were carried out on four normal subjects investigating heterochromatic red-green exchange and single colour/achromatic (either red/grey or green/grey) exchange over a wide range of luminance ratios for the two stimuli, the effects of lowered mean luminance on the chromatic VEP and the effects of colour desaturation at constant mean luminance and constant luminance contrast. Finally, the performance of three dichromats, a protanope and two deuteranopes, on heterochromatic exchange VEP and on colour desaturation were investigated. In contrast to the chromatic electroretinogram, which shows great symmetry with respect to luminance ratio on opposite sides of the isoluminant point, the chromatic VEP demonstrated a distinct asymmetry when the colours exchanged included red. On the red side of isoluminance (red more luminant than green), a wave with longer latency and altered waveform became dominant. The effects of green stimulation were indistinguishable from those of achromatic stimulation at the same luminance contrast over the whole range of chromatic contrast and for all levels of desaturation studied. Desaturation of red with constant luminance contrast (desaturated red/grey stimulation) resulted in a systematic alteration in the evoked waveform. Subtraction of the achromatic first- and second-order responses from responses recorded in the red desaturation series resulted in remarkably uniform waveforms, with peak amplitudes growing linearly with saturation. The absence of interaction between achromatic and coloured components for all (including the most intense colour) stimulus parameters used suggests that the generators of these components are separate. Recordings from the dichromats showed that the contrast response minimum shifted from the point of photopic isoluminance to the point of zero cone contrast (at the silent substitution point) for the remaining cone type. The waveforms recorded with a series of luminance ratios were much simpler than those recorded from trichromats and symmetrical with respect to their isoluminant points. Despite the indication of the presence of L cones of apparently normal spectral sensitivity in the deuteranopes (on the basis of flicker photometry), there was no evidence for a red-sensitive component in the desaturation or heterochromatic stimulation series. The results are discussed in terms of the possibility of separate generation of chromatic and achromatic contributions to the VEP. PMID:10211389

Klistorner, A; Crewther, D P; Crewther, S G

1998-12-01

345

Vision for a UAV helicopter  

Microsoft Academic Search

This paper presents and overview of the basic and applied research carried out by the Computer Vision Laboratory, Linkoping University, in the WITAS UAV Project. This work includes customizing and redesigning vision methods to t the particular needs and restrictions imposed by the UAV platform, e.g., for low-level vision, motion estimation, navigation, and tracking. It also includes a new learning

Klas Nordberg; Gunnar Farneback; Gosta Granlund; Anders Moe; Johan Wiklund

346

Stereo vision using Gabor wavelets  

Microsoft Academic Search

The analysis of video images in stereo can extend machine vision to interpret the 3-D structure of a scene. Applications of stereo vision include robotics, industrial automation, autonomous land rovers and automated cartography. The simplest stereo paradigm, binocular stereo vision, provides man and many animals the capability to see the depth from two images without ambiguity. Thus, it is interesting

Tieh-Yuh Chen; W. N. Klarquist; A. C. Bovik

1994-01-01

347

Vision in water.  

PubMed

The purpose of this study is to determine visual performance in water, including the influence of pupil size. The water environment was simulated by placing goggles filled with saline in front of the eyes with apertures placed at the front of the goggles. Correction factors were determined for the different magnification under this condition in order to estimate vision in water. Experiments were conducted on letter visual acuity (seven participants), grating resolution (eight participants), and grating contrast sensitivity (one participant). For letter acuity, mean loss of vision in water, compared to corrected vision in air, varied between 1.1 log min of arc resolution (logMAR) for a 1 mm aperture to 2.2 logMAR for a 7 mm aperture. The vision in min of arc was described well by a linear relationship with pupil size. For grating acuity, mean loss varied between 1.1 logMAR for a 2 mm aperture to 1.2 logMAR for a 6 mm aperture. Contrast sensitivity for a 2 mm aperture deteriorated as spatial frequency increased with a 2 log unit loss by 3 c/°. Superimposed on this deterioration were depressions (notches) in sensitivity with the first three notches occurring at 0.45, 0.8, and 1.3 c/° with estimates for water of 0.39, 0.70, and 1.13 c/°. In conclusion, vision in water is poor. It becomes worse as pupil size increases, but the effects are much more marked for letter targets than for grating targets. PMID:24013866

Atchison, David A; Valentine, Emma L; Gibson, Georgina; Thomas, Hannah R; Oh, Sera; Pyo, Young Ah; Lacherez, Philippe; Mathur, Ankit

2013-01-01

348

myReader: an Auto-Reader for Low Vision Users  

Microsoft Academic Search

Until recently, video magnifiers - closed-circuit television systems allowing magnification and colour modification - were the most effective reading aid for the visually impaired. Humanware Ltd. has developed a practical portable consumer device, myReader, incorporating a high resolution digital image sensor and document analysis software capable of understanding complex Manhattan layouts. In addition to typical video magnifier functionality, myReader can

Phillip Pearson; Paul Seakins; David Lee; Nigel Tucker; Darryl Sherwood

349

Physical Impairment  

Microsoft Academic Search

\\u000a Many health conditions can lead to physical impairments that impact computer and Web access. Musculoskeletal conditions such\\u000a as arthritis and cumulative trauma disorders can make movement stiff and painful. Movement disorders such as tremor, Parkinsonism\\u000a and dystonia affect the ability to control movement, or to prevent unwanted movements. Often, the same underlying health condition\\u000a also has sensory or cognitive effects.

Shari Trewin

2008-01-01

350

Blue colour preference in honeybees distracts visual attention for learning closed shapes.  

PubMed

Spatial vision is an important cue for how honeybees (Apis mellifera) find flowers, and previous work has suggested that spatial learning in free-flying bees is exclusively mediated by achromatic input to the green photoreceptor channel. However, some data suggested that bees may be able to use alternative channels for shape processing, and recent work shows conditioning type and training length can significantly influence bee learning and cue use. We thus tested the honeybees' ability to discriminate between two closed shapes considering either absolute or differential conditioning, and using eight stimuli differing in their spectral characteristics. Consistent with previous work, green contrast enabled reliable shape learning for both types of conditioning, but surprisingly, we found that bees trained with appetitive-aversive differential conditioning could additionally use colour and/or UV contrast to enable shape discrimination. Interestingly, we found that a high blue contrast initially interferes with bee shape learning, probably due to the bees innate preference for blue colours, but with increasing experience bees can learn a variety of spectral and/or colour cues to facilitate spatial learning. Thus, the relationship between bee pollinators and the spatial and spectral cues that they use to find rewarding flowers appears to be a more rich visual environment than previously thought. PMID:23918312

Morawetz, Linde; Svoboda, Alexander; Spaethe, Johannes; Dyer, Adrian G

2013-10-01

351

Defect analysis of grit-blasted or spray-painted surface using Vision Sensing Techniques  

Microsoft Academic Search

The paper discusses a vision-based framework for the analysis of defects on a grit-blasted or spray-painted metal surface. The system employs commodity, off-the-shelf hardware and tailor-made software, with user- friendly interface, making it cost effective yet accurate. A picture of the surface (1mx1m) is captured by a colour CCD camera and processed by a Frame Grabber card at a resolution

G. Sen Gupta; Chris Messom; Serge Demidenko; Subhas Mukhopadhyay

352

Development of a vision non-contact sensing system for telerobotic applications  

Microsoft Academic Search

The study presented here describes a novel vision-based motion detection system for telerobotic operations such as distant surgical procedures. The system uses a CCD camera and image processing to detect the motion of a master robot or operator. Colour tags are placed on the arm and head of a human operator to detect the up\\/down, right\\/left motion of the head

M. Karkoub; M.-G. Her; M.-I. Ho; C.-C. Huang

2012-01-01

353

Visual impairment, visual functioning, and quality of life assessments in patients with glaucoma.  

PubMed Central

BACKGROUND/PURPOSE: To determine the relation between visual impairment, visual functioning, and the global quality of life in patients with glaucoma. METHODS: Visual impairment, defined with the American Medical Association Guides to the Evaluation of Permanent Impairment; visual functioning, measured with the VF-14 and the Field Test Version of the National Eye Institute-Visual Functioning Questionnaire (NEI-VFQ); and the global quality of life, assessed with the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), were determined in 147 consecutive patients with glaucoma. RESULTS: None of the SF-36 domains demonstrated more than a weak correlation with visual impairment. The VF-14 scores were moderately correlated with visual impairment. Of the twelve NEI-VFQ scales, distance activities and vision specific dependency were moderately correlated with visual impairment. Of the twelve NEI-VFQ scales, distance activities and vision specific dependency were moderately correlated with visual field impairment; vision specific social functioning, near activities, vision specific role difficulties, general vision, vision specific mental health, color vision, and driving were modestly correlated; visual pain was weakly correlated; and two were not significantly correlated. Correcting for visual actuity weakened the strength of the correlation coefficients. CONCLUSIONS: The SF-36 is unlikely to be useful in determining visual impairment in patients with glaucoma. Based on the moderate correlation between visual field impairment and the VF-14 score, this questionnaire may be generalizable to patients with glaucoma. Several of the NEI-VFQ scales correlate with visual field impairment scores in patients with a wide range of glaucomatous damage.

Parrish, R K

1996-01-01

354

The impact of the severity of vision loss on vision-specific functioning in a German outpatient population — an observational study  

Microsoft Academic Search

Background  To validate the German–translated VF-14, a vision-specific scale, and determine the relationship between the severity of vision\\u000a impairment, ocular conditions, and visual functioning.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  This was a clinic-based, cross-sectional study with 184 patients with low vision and 90 normal-sighted controls recruited\\u000a from a German eye hospital. Participants underwent a clinical examination and completed the German VF-14 scale. The validity\\u000a of the

Robert P. Finger; Eva Fenwick; Peggy Pei-Chia Chiang; Michael Petrak; Frank G. Holz; Manjula Marella; Ecosse L. Lamoureux

355

Floral colour versus phylogeny in structuring subalpine flowering communities  

PubMed Central

The relative number of seeds produced by competing species can influence the community structure; yet, traits that influence seed production, such as pollinator attraction and floral colour, have received little attention in community ecology. Here, we analyse floral colour using reflectance spectra that include near-UV and examined the phylogenetic signal of floral colour. We found that coflowering species within communities tended to be more divergent in floral colour than expected by chance. However, coflowering species were not phylogenetically dispersed, in part due to our finding that floral colour is a labile trait with a weak phylogenetic signal. Furthermore, while we found that locally rare and common species exhibited equivalent floral colour distances from their coflowering neighbours, frequent species (those found in more communities) exhibited higher colour distances from their coflowering neighbours. Our findings support recent studies, which have found that (i) plant lineages exhibit frequent floral colour transitions; and (ii) traits that influence local population dynamics contribute to community structure.

McEwen, Jamie R.; Vamosi, Jana C.

2010-01-01

356

Objective Methods to Test Visual Dysfunction in the Presence of Cognitive Impairment.  

National Technical Information Service (NTIS)

Purpose: to develop and validate objective tests to diagnose vision deficits in patients with cognitive impairment and ensure effective monitoring of their treatment. Scope: objective methods to monitor visual function include 1) the pupil light reflex, 2...

R. Kardon

2011-01-01

357

Quantum entanglement of quark colour states  

SciTech Connect

An analysis of quantum entanglement between the states of static colour charges in the vacuum of pure Yang-Mills theory is carried out. Hilbert space of physical states of the fields and the charges is endowed with a direct product structure by attaching an infinite Dirac string to each charge.

Buividovich, P. V. [JIPNR, National Academy of Science, 220109 Belarus, Minsk, Acad. Krasin str. 99 (Belarus); ITEP, 117218 Russia, Moscow, B. Cheremushkinskaya str. 25 (Russian Federation); Kuvshinov, V. I. [JIPNR, National Academy of Science, 220109 Belarus, Minsk, Acad. Krasin str. 99 (Belarus)

2010-03-24

358

Fast Synthesis of Dynamic Colour Textures  

Microsoft Academic Search

Textural appearance of many real word materials is not static but shows progress in time. If such a progress is spa- tially and temporally homogeneous these materials can be represented by means of dynamic texture (DT). DT mod- elling is a challenging problem which can add new quality into computer graphics applications. We propose a novel hybrid method for colour

Jirí Filip; Michal Haindl; Dmitry Chetverikov

2006-01-01

359

Genetics of human iris colour and patterns.  

PubMed

The presence of melanin pigment within the iris is responsible for the visual impression of human eye colouration with complex patterns also evident in this tissue, including Fuchs' crypts, nevi, Wolfflin nodules and contraction furrows. The genetic basis underlying the determination and inheritance of these traits has been the subject of debate and research from the very beginning of quantitative trait studies in humans. Although segregation of blue-brown eye colour has been described using a simple Mendelian dominant-recessive gene model this is too simplistic, and a new molecular genetic perspective is needed to fully understand the biological complexities of this process as a polygenic trait. Nevertheless, it has been estimated that 74% of the variance in human eye colour can be explained by one interval on chromosome 15 that contains the OCA2 gene. Fine mapping of this region has identified a single base change rs12913832 T/C within intron 86 of the upstream HERC2 locus that explains almost all of this association with blue-brown eye colour. A model is presented whereby this SNP, serving as a target site for the SWI/SNF family member HLTF, acts as part of a highly evolutionary conserved regulatory element required for OCA2 gene activation through chromatin remodelling. Major candidate genes possibly effecting iris patterns are also discussed, including MITF and PAX6. PMID:19619260

Sturm, Richard A; Larsson, Mats

2009-10-01

360

Iris Recognition System Using Combined Colour Statistics  

Microsoft Academic Search

This paper proposes a high performance iris recognition system based on the probability distribution functions (PDF) of pixels in different colour channels. The PDFs of the segmented iris images are used as statistical feature vectors for the recognition of irises by minimizing the Kullback-Leibler distance (KLD) between the PDF of a given iris and the PDFs of irises in the

Hasan Demirel; G. Anbarjafari

2008-01-01

361

Colour Interest Points for Image Retrieval  

Microsoft Academic Search

In image retrieval scenarios, many methods use interest point detection at an early stage to find regions in which descriptors are calculated. Finding salient locations in image data is crucial for these tasks. Observing that most current methods use only the luminance information of the images, we investigate the use of colour information in in- terest point detection. Based on

Nicu Sebe; Theo Gevers; Allan Hanbury

2007-01-01

362

New Evidence for Infant Colour Categories  

ERIC Educational Resources Information Center

Bornstein, Kessen, and Weiskopf (1976) reported that pre-linguistic infants perceive colour categorically for primary boundaries: Following habituation, dishabituation only occurred if the test stimulus was from a different adult category to the original. Here, we replicated this important study and extended it to include secondary boundaries,…

Franklin, Anna; Davies, Ian R. L.

2004-01-01

363

Dual-colour imaging with GFP variants  

Microsoft Academic Search

Green fluorescent protein (GFP) has become an important tool in cell biology and is widely used as a reporter for imaging intracellular proteins and structures in live cells. Recently, spectral variants of GFP with red- and blue-shifted fluorescence emissions have been characterized, opening the possibility of double labelling with two different-coloured GFP fusion proteins. This article reviews recent advances in

Jan Ellenberg; Jennifer Lippincott-Schwartz; John F. Presley

1999-01-01

364

Colour-dependent target detection by bees  

Microsoft Academic Search

The distance over which an object is detected by bees depends on the subtended visual angle and on spectral cues. At large angular subtenses detection is mediated only by chromatic cues. Achromatic targets, however, are also detectable. We investigated how chromatic and achromatic cues interact in detecting large-size targets. Coloured targets were used, with varied chromatic contrast that either did

C. Niggebrügge; N. Hempel de Ibarra

2003-01-01

365

The Coloured Product of the Sakaguchi Reaction  

Microsoft Academic Search

WE have already reported1 that the coloured product of the Sakaguchi reaction2 (between arginine and alpha-naphthol) behaves as a typical acid-base indicator, being red in alkali and yellow3 in acid. It has now been found that the compound behaves as an oxidation-reduction indicator also.

Kshirod R. Bhattacharya

1959-01-01

366

Demonstration of the Colour Range of Indicators  

ERIC Educational Resources Information Center

Describes the construction of a box that is filled with indicator of a particular concentration. A little acid is added to one side and a little alkali to the other so that the complete colour range of the indicator is observable. (GS)

Woods, G. T.

1975-01-01

367

Colour thresholding and objective quantification in bioimaging.  

PubMed

Computer imaging is rapidly becoming an indispensable tool for the quantification of variables in research and medicine. Whilst its use in medicine has largely been limited to qualitative observations, imaging in applied basic sciences, medical research and biotechnology demands objective quantification of the variables in question. In black and white densitometry (0-256 levels of intensity) the separation of subtle differences between closely related hues from stains is sometimes very difficult. True-colour and real-time video microscopy analysis offer choices not previously available with monochrome systems. In this paper we demonstrate the usefulness of colour thresholding, which has so far proven indispensable for proper objective quantification of the products of histochemical reactions and/or subtle differences in tissue and cells. In addition, we provide interested, but untrained readers with basic information that may assist decisions regarding the most suitable set-up for a project under consideration. Data from projects in progress at Tulane are shown to illustrate the advantage of colour thresholding over monochrome densitometry and for objective quantification of subtle colour differences between experimental and control samples. PMID:1527795

Fermin, C D; Gerber, M A; Torre-Bueno, J R

1992-07-01

368

Specific Language Impairment  

MedlinePLUS

... Voice, Speech and Language Specific Language Impairment Specific Language Impairment On this page: What is specific language ... percent of children in kindergarten. What is specific language impairment? Specific language impairment (SLI) is a language ...

369

Honey characterization using computer vision system and artificial neural networks.  

PubMed

This paper reports the development of a computer vision system (CVS) for non-destructive characterization of honey based on colour and its correlated chemical attributes including ash content (AC), antioxidant activity (AA), and total phenolic content (TPC). Artificial neural network (ANN) models were applied to transform RGB values of images to CIE L*a*b* colourimetric measurements and to predict AC, TPC and AA from colour features of images. The developed ANN models were able to convert RGB values to CIE L*a*b* colourimetric parameters with low generalization error of 1.01±0.99. In addition, the developed models for prediction of AC, TPC and AA showed high performance based on colour parameters of honey images, as the R(2) values for prediction were 0.99, 0.98, and 0.87, for AC, AA and TPC, respectively. The experimental results show the effectiveness and possibility of applying CVS for non-destructive honey characterization by the industry. PMID:24767037

Shafiee, Sahameh; Minaei, Saeid; Moghaddam-Charkari, Nasrollah; Barzegar, Mohsen

2014-09-15

370

The VISIONS Science  

NASA Astrophysics Data System (ADS)

VISIONS sounding rocket mission (VISualizing Ion Outflow via Neutral atom imaging during a Substorm) has been awarded to NASA/GSFC (PI Rowland) in order to provide the first combined remote sensing and in situ measurements of the regions where ion acceleration to above 5 eV is occurring, and of the sources of free energy and acceleration mechanisms that accelerate the ions. The key science question of VISIONS is how, when, and where, are ions accelerated to escape velocities in the auroral zone below 1000 km, following substorm onset? Sources of free energy that power this ion acceleration process include (but not limited) electron precipitation, field-aligned currents, velocity shears, and Alfvénic Poynting flux. The combine effect of all these processes on ionospheric ion outflows will be investigated in a framework of the kinetic model that has been developed by Khazanov et al. in order to study the polar wind transport in the presence of photoelectrons.

Khazanov, G. V.; Rowland, D. E.; Moore, T. E.; Collier, M. R.

2011-12-01

371

Colour-scent associations in a tropical orchid: three colours but two odours.  

PubMed

Colour and scent are the major pollinator attractants to flowers, and their production may be linked by shared biosynthetic pathways. Species with polymorphic floral traits are particularly relevant to study the joint evolution of floral traits. We used in this study the tropical orchid Calanthe sylvatica from Réunion Island. Three distinct colour varieties are observed, presenting lilac, white or purple flowers, and named respectively C. sylvaticavar.lilacina (hereafter referred as var. lilacina), C. sylvaticavar. alba (var. alba) and C. sylvatica var. purpurea (var. purpurea). We investigated the composition of the floral scent produced by these colour varieties using the non-invasive SPME technique in the wild. Scent emissions are dominated by aromatic compounds. Nevertheless, the presence of the terpenoid (E)-4,8-dimethylnona-1,3,7-triène (DMNT) is diagnostic of var. purpurea, with the volatile organic compounds (VOC) produced by some individuals containing up to 60% of DMNT. We evidence specific colour-scent associations in C. sylvatica, with two distinct scent profiles in the three colour varieties: the lilacina-like profile containing no or very little DMNT (<2%) and the purpurea-like profile containing DMNT (>2%). Calanthe sylvatica var. alba individuals group with one or the other scent profile independently of their population of origin. We suggest that white-flowered individuals have evolved at least twice, once from var. lilacina and at least once from var. purpurea after the colonisation of la Réunion. White-flowered individuals may have been favoured by the particular pollinator fauna characterising the island. These flowering varieties of C. sylvatica, which display three colours but two scents profiles prove that colour is not always a good indicator of odour and that colour-scent associations may be complex, depending on pollination ecology of the populations concerned. PMID:21377705

Delle-Vedove, Roxane; Juillet, Nicolas; Bessière, Jean-Marie; Grison, Claude; Barthes, Nicolas; Pailler, Thierry; Dormont, Laurent; Schatz, Bertrand

2011-06-01

372

Colour based human motion tracking for home-based rehabilitation  

Microsoft Academic Search

Abstract - In this paper, we propose a colour based trackingal gorithm for capturing the motionof hu man body parts for home-based rehabilitation. Different colour belts are attached to the bodyjo ints ofin terest andtra cked in the video sequence. The performance of the colour-based tracking algorithm is ,analysed by comparing the tracking results with the results from a commercial

Yaqin Tao; Huosheng Hu

2004-01-01

373

Visual effects of wall colours in living rooms  

Microsoft Academic Search

The visual effects of wall colours were quantified as the purpose of basic research to create a comfortable atmosphere by applying the visual effects of colours to interior colour design. The experiment was conducted at three different temperatures of 10, 25 and 40°C, and at a constant relative humidity of 60%. Slides of 1\\/10-scale living room models of different wall

MICHIKO KUNISHIMA; TAKUKO YANASE

1985-01-01

374

Evolutionary genetics of dorsal wing colour in Colias butterflies  

Microsoft Academic Search

The evolution of butterfly wing colouration is strongly affected by its multiple functions and by the correlated evolution of wing colour elements. Both factors may prevent local adaptation to ecological conditions. We investigated one aspect of wing colouration, the degree of dorsal wing melanization, in the butterfly Colias philodice eriphyle across an elevational gradient and its correlation with another aspect

J. Ellers; C. L. Boggs

2004-01-01

375

Teaching Math to Visually Impaired Students  

NSDL National Science Digital Library

This page has the following resources for math teachers of the visually impaired: teaching strategies, math education and Nemeth Code, tactile math graphics, abacus information, calculators, math tools, math resources, adaptive tools and technology for accessible mathematics, suggested adaptive tools and materials for low vision students in algebra and geometry, suggested adaptive tools and materials for Braille students in algebra and geometry, and adaptive tools and technology for accessible mathematics equipment.

Osterhaus, Susan

2007-02-07

376

Assessment of novel binocular colour, motion and contrast tests in glaucoma.  

PubMed

The effects of glaucoma on binocular visual sensitivity for the detection of various stimulus attributes are investigated at the fovea and in four paracentral retinal regions. The study employed a number of visual stimuli designed to isolate the processing of various stimulus attributes. We measured absolute contrast detection thresholds and functional contrast sensitivity by using Landolt ring stimuli. This psychophysical Landolt C-based contrast test of detection and gap discrimination allowed us to test parafoveally at 6 ° from fixation and foveally by employing interleaved testing locations. First-order motion perception was examined by using moving stimuli embedded in static luminance contrast noise. Red/green (RG) and yellow/blue (YB) colour thresholds were measured with the Colour Assessment and Diagnosis (CAD) test, which utilises random dynamic luminance contrast noise (± 45 %) to ensure that only colour and not luminance signals are available for target detection. Subjects were normal controls (n = 65) and glaucoma patients with binocular visual field defects (n = 15) classified based on their Humphrey Field Analyzer mean deviation (MD) scores. The impairment of visual function varied depending on the stimulus attribute and location tested. Progression of loss was noted for all tests as the degree of glaucoma increased. For subjects with mild glaucoma (MD -0.01 dB to -6.00 dB) significantly more data points fell outside the normal age-representative range for RG colour thresholds than for any other visual test, followed by motion thresholds. This was particularly the case for the parafoveal data compared with the foveal data. Thus, a multifaceted measure of binocular visual performance, incorporating RG colour and motion test at multiple locations, might provide a better index for comparison with quality of life measures in glaucoma. PMID:23812834

Rauscher, Franziska G; Chisholm, Catharine M; Edgar, David F; Barbur, John L

2013-08-01

377

The coding of uniform colour figures in monkey visual cortex  

PubMed Central

Psychophysical studies indicate that perception of the colour and brightness of a surface depends on neural signals evoked by the borders of the surface rather than its interior. The visual cortex emphasizes contrast borders, but it is unclear whether colour surface signals also exist, whether colour border signals are orientation selective or mainly non-oriented, and whether cortical processing tends to separate colour and form information. To address these questions we examined the representation of uniform colour figures by recording single neuron activity from areas V1 and V2 in alert macaque monkeys during behaviourally induced fixation. Three aspects of coding were quantified: colour, orientation and edge selectivity. The occurrence of colour selectivity was not correlated with orientation or edge selectivity. The fraction of colour-selective cells was the same (64 % in layers 2 and 3 of V1, 45 % in V2) for oriented and non-oriented cells, and for edge-selective and surface-responsive cells. Oriented cells were often highly selective in colour space, and about 40 % of them were selective for edge polarity or border ownership. Thus, contrary to the idea of feature maps, colour, orientation and edge polarity are multiplexed in cortical signals. The results from V2 were similar to those from upper-layer V1, indicating that cortical processing does not strive to separate form and colour information. Oriented cells were five times more frequent than non-oriented cells. Thus, the vast majority of colour-coded cells are orientation tuned. Based on response profiles across a 4 deg square figure, and the relative frequency of oriented and non-oriented cells, we estimate that the cortical colour signal is 5–6 times stronger for the edges than for the surface of the figure. The frequency of oriented colour cells and their ability to code edge polarity indicate that these cells play a major role in the representation of surface colour.

Friedman, Howard S; Zhou, Hong; von der Heydt, Rudiger

2003-01-01

378

Genetic analyses of the human eye colours using a novel objective method for eye colour classification.  

PubMed

In this study, we present a new objective method for measuring the eye colour on a continuous scale that allows researchers to associate genetic markers with different shades of eye colour. With the use of the custom designed software Digital Iris Analysis Tool (DIAT), the iris was automatically identified and extracted from high resolution digital images. DIAT was made user friendly with a graphical user interface. The software counted the number of blue and brown pixels in the iris image and calculated a Pixel Index of the Eye (PIE-score) that described the eye colour quantitatively. The PIE-score ranged from -1 to 1 (brown to blue). The software eliminated the need for user based interpretation and qualitative eye colour categories. In 94% (570) of 605 analyzed eye images, the iris region was successfully extracted and a PIE-score was calculated. A very high correlation between the PIE-score and the human perception of eye colour was observed. The correlations between the PIE-scores and the six IrisPlex SNPs (HERC2 rs12913832, OCA2 rs1800407, SLC24A4 rs12896399, TYR rs1393350, SLC45A2 rs16891982 and IRF4 rs12203592) were analyzed in 570 individuals. Significant differences (p<10(-6)) in the PIE-scores of the individuals typed as HERC2 rs12913832 G (PIE=0.99) and rs12913832 GA (PIE=-0.71) or A (PIE=-0.87) were observed. We adjusted for the effect of HERC2 rs12913832 and showed that the quantitative PIE-scores were significantly associated with SNPs with minor effects (OCA2 rs1800407, SLC24A4 rs12896399 and TYR rs1393350) on the eye colour. We evaluated the two published prediction models for eye colour (IrisPlex [1] and Snipper[2]) and compared the predictions with the PIE-scores. We found good concordance with the prediction from individuals typed as HERC2 rs12913832 G. However, both methods had difficulties in categorizing individuals typed as HERC2 rs12913832 GA because of the large variation in eye colour in HERC2 rs12913832 GA individuals. With the use of the DIAT software and the PIE-score, it will be possible to automatically compare the iris colour of large numbers of iris images obtained by different studies and to perform large meta-studies that may reveal loci with small effects on the eye colour. PMID:23948321

Andersen, Jeppe D; Johansen, Peter; Harder, Stine; Christoffersen, Susanne R; Delgado, Mikaela C; Henriksen, Sarah T; Nielsen, Mette M; Sørensen, Erik; Ullum, Henrik; Hansen, Thomas; Dahl, Anders L; Paulsen, Rasmus R; Børsting, Claus; Morling, Niels

2013-09-01

379

Visual–vestibular interaction during goal directed locomotion: effects of aging and blurring vision  

Microsoft Academic Search

Normal vision overrides perturbed vestibular information for the optimization of performance during goal directed locomotion, suggesting down-regulation of vestibular gain. However, it is not known if the responses to vestibular perturbation are accentuated when vision is impaired. Furthermore, both visual and vestibular systems deteriorate with age. It is not clear, however, how age-related decline in these sensory systems influences visual–vestibular

Nandini Deshpande; Aftab E. Patla

2007-01-01

380

Prevalence and causes of blindness and low vision in the Casteldaccia Eye Study  

Microsoft Academic Search

In a population-based survey performed on the middleaged and elderly population of Casteldaccia, Sicily, we found that the prevalence of blindness was 0.47% and the prevalence of low vision 1.22%. Unilateral blindness affected 2.81% of the population and unilateral low vision 4.12%. Visual impairment was much more frequently seen in subjects aged 70 years or more than in younger persons.

Francesco Ponte; Giuseppe Giuffre; Raimondo Giammanco

1994-01-01

381

Goals with limited vision: A qualitative study of coping with vision-related goal interference in midlife  

PubMed Central

Objective To investigate how middle-aged adults manage their goal pursuits in the face of visual disability. Design Cross-sectional qualitative study Setting Vision rehabilitation agency Subjects 216 middle-aged adults with visual impairment Methods Telephone interviews composed of structured and open-ended assessments of life goals and the strategies used to cope with vision-related goal interference. Results Individuals reported strategies that reflected the broader domains found in prior research with older adults: Internal Resource Use, New Approach Use, Technology Use, Help Use, and Psychological Self-regulation. The most frequently reported strategy was Help Use (N = 192), followed by New Approach Use (N = 166), Internal Resource Use (N = 162), Technology Use (N = 159) and Psychological Self-regulation (N = 130). Across domains, the most frequently reported strategies were Instrumental Informal Help, Instrumental Formal Help, Optical Aids, and Invest Effort. Specific strategy domains emerged as more typical in response to interference with particular types of goals; for example, Help Use was reported by a majority for interference with functional and psychological goals, but only by half for interference with social goals. Conclusions Study findings revealed a rich array of strategies used by middle-aged adults with vision impairment in their daily lives to deal with vision-related goal interference. Results suggest that rehabilitation services should consider multiple methods of coping and their goal-related function when working with middle-aged adults with disabilities.

Boerner, Kathrin; Wang, Shu-wen

2011-01-01

382

Diagnosing synaesthesia with online colour pickers: maximising sensitivity and specificity.  

PubMed

The most commonly used method for formally assessing grapheme-colour synaesthesia (i.e., experiencing colours in response to letter and/or number stimuli) involves selecting colours from a large colour palette on several occasions and measuring consistency of the colours selected. However, the ability to diagnose synaesthesia using this method depends on several factors that have not been directly contrasted. These include the type of colour space used (e.g., RGB, HSV, CIELUV, CIELAB) and different measures of consistency (e.g., city block and Euclidean distance in colour space). This study aims to find the most reliable way of diagnosing grapheme-colour synaesthesia based on maximising sensitivity (i.e., ability of a test to identify true synaesthetes) and specificity (i.e., ability of a test to identify true non-synaesthetes). We show, applying ROC (receiver operating characteristics) to binary classification of a large sample of self-declared synaesthetes and non-synaesthetes, that the consistency criterion (i.e., cut-off value) for diagnosing synaesthesia is considerably higher than the current standard in the field. We also show that methods based on perceptual CIELUV and CIELAB colour models (rather than RGB and HSV colour representations) and Euclidean distances offer an even greater sensitivity and specificity than most currently used measures. Together, these findings offer improved heuristics for the behavioural assessment of grapheme-colour synaesthesia. PMID:23458658

Rothen, Nicolas; Seth, Anil K; Witzel, Christoph; Ward, Jamie

2013-04-30

383

Colour appearance descriptors for image browsing and retrieval  

NASA Astrophysics Data System (ADS)

In this paper, we focus on the development of whole-scene colour appearance descriptors for classification to be used in browsing applications. The descriptors can classify a whole-scene image into various categories of semantically-based colour appearance. Colour appearance is an important feature and has been extensively used in image-analysis, retrieval and classification. By using pre-existing global CIELAB colour histograms, firstly, we try to develop metrics for whole-scene colour appearance: "colour strength", "high/low lightness" and "multicoloured". Secondly we propose methods using these metrics either alone or combined to classify whole-scene images into five categories of appearance: strong, pastel, dark, pale and multicoloured. Experiments show positive results and that the global colour histogram is actually useful and can be used for whole-scene colour appearance classification. We have also conducted a small-scale human evaluation test on whole-scene colour appearance. The results show, with suitable threshold settings, the proposed methods can describe the whole-scene colour appearance of images close to human classification. The descriptors were tested on thousands of images from various scenes: paintings, natural scenes, objects, photographs and documents. The colour appearance classifications are being integrated into an image browsing system which allows them to also be used to refine browsing.

Othman, Aniza; Martinez, Kirk

2008-01-01

384

Colour vision and speciation in Lake Victoria cichlids of the genus Pundamilia  

Microsoft Academic Search

Lake Victoria cichlids are one of the most speciose groups of vertebrates. Selection on colora- tion is likely playing an important role in their rapid speciation. To test the hypothesis that sensory biases could explain species differences in mating preferences and nuptial coloration, we studied seven populations of four closely related species of the genus Pundamilia that differ in visual

KAREN L. C ARLETON; JULIET W. L. P ARRY; JAMES K. B OWMAKER; DAVID M. H UNT; OLE SEEHAUSEN

2005-01-01

385

The Evolution of the Multicoloured Face of Mandrills: Insights from the Perceptual Space of Colour Vision  

Microsoft Academic Search

Multicomponent signals consist of several traits that are perceived as a whole. Although many animals rely on multicomponent signals to communicate, the selective pressures shaping these signals are still poorly understood. Previous work has mainly investigated the evolution of multicomponent signals by studying each trait individually, which may not accurately reflect the selective pressures exerted by the holistic perception of

Julien P. Renoult; H. Martin Schaefer; Bettina Sallé; Marie J. E. Charpentier

2011-01-01

386

Textbooks, Teachers and Full-Colour Vision: Some Thoughts on Evaluating Environmental Education "Performance".  

ERIC Educational Resources Information Center

Discusses the problem of environmental bias and critiques Michael Sanera's approach to evaluation of environmental education performance. Notes that problems result from bias in curriculum materials. Contains 20 references. (DDR)

Courtenay-Hall, Pamela

1998-01-01

387

Spectral imaging system for non-contact colour measurement  

NASA Astrophysics Data System (ADS)

This paper describes the development of a non-contact system for measuring colour of printed material at web speeds. The system proposed uses a non-contact spectrophotometer based on a holographic grating, in conjunction with a conventional monochrome area scan camera, from which colour spectral data is extracted, whilst a xenon flash is used to illuminate colour samples. Software and hardware details of the system are given, along with the underlying mathematics for colour space conversion and measurement. Conversion equations from X, Y, Z chromaticity co-ordinates to the RGB system are presented, and also equations to convert from the L ?a ?b ? colour space to X, Y, Z chromaticity co-ordinates. Experimental results are presented whereby the non-contact spectral system is shown to perform to a colour tolerance exceeding that of conventional colour video systems.

Brown, N.; Peng, J.; Jackson, M. R.; Parkin, R. M.

2001-03-01

388

The functional anatomy of imagining and perceiving colour.  

PubMed

We report two functional magnetic resonance imaging experiments which reveal similarities and differences between perceptual and imaginal networks within the single visual submodality of colour. The first experiment contrasted viewing of a coloured and grey-scale Mondrian display, while the second contrasted a relative colour judgement with a spatial task and required the generation of mental images. Our results show that colour perception activates the posterior fusiform gyrus bilaterally (area V4), plus right-sided anterior fusiform and lingual gyri, striate cortex (area V1), and the left and right insula. Colour imagery activated right anterior fusiform gyrus, left insula, right hippocampus and parahippocampal gyrus, but not V4 or V1. The findings reconcile neurological case studies suggesting a double dissociation between deficits in colour imagery and perception and point to anterior fusiform, parahippocampal gyri and hippocampus as the location for stored representations of coloured objects. PMID:9601660

Howard, R J; ffytche, D H; Barnes, J; McKeefry, D; Ha, Y; Woodruff, P W; Bullmore, E T; Simmons, A; Williams, S C; David, A S; Brammer, M

1998-04-20

389

Colour biases in territorial aggression in a Neotropical cichlid fish.  

PubMed

Discrete colour morphs have provided important insights into the evolution of phenotypic diversity. One of the mechanisms that can help to explain coexistence of ecologically similar colour morphs and incipient species is (colour) biased aggression, which has the potential to promote continued existence of the morphs in a frequency-dependent manner. I addressed colour biases in territorial aggression in a field-based study on a Neotropical cichlid fish species, Amphilophus sagittae, which has two ecologically indistinguishable colour morphs that mate assortatively. I found that A. sagittae, in particular females, were more aggressive towards models of their own colour than those mimicking colours of the other morph. Such a behavioural pattern should result in a selection regime that benefits the rarer morph, and hence could help explain how novel, rare phenotypes may avoid competitive exclusion. PMID:24414236

Lehtonen, Topi K

2014-05-01

390

Quantification of Japanese quail eggshell colour by image analysis.  

PubMed

The Japanese quail lays eggs with colourful and patterned shells which make the eggshell colour difficult to classify. In this study, the method of measuring colour of patchy eggs using image analyses and its power to discriminate among individual variation were established. Estimated repeatability for egg colour and proportion of patterned areas was high (>0.58), suggesting intermedíate or high heritability of eggshell colour characteristics. Three components have been identified as significant in discriminant function analysis. These three components explained 91.4% of the total variance in egg colour characteristics. In cluster analysis, 78.3% of the eggs that were collected from 15 females were correctly classified. This study indicates that eggshell colour characteristics can be reliably studied by image analyses and that this method can provide a unified character list for future examinations and interpretations of quail egg characteristics. PMID:19621137

Sezer, Metin; Tekelioglu, Oguz

2009-01-01

391

[Physical models of color vision].  

PubMed

Models of color vision are discussed on the basis of determining the difference between the signals of sensors of white (rods) and color (cones) vision. It was shown that the whole optical spectrum (RGB) can be obtained, provided only two and four types of sensors are used within a three-component model of color detection. The described models provide for comprehensive explanations to extensive experimental data on color vision. PMID:12872635

Blinov, N N

2003-01-01

392

The epistemics of ayahuasca visions  

Microsoft Academic Search

In this paper, I discuss substance-induced visions and consider their epistemic status, meaning, and modes of proper interpretation.\\u000a I focus on the visions induced by ayahuasca, a powerful psychoactive plant-made brew that has had a central status and role\\u000a in the indigenous tribal cultures of the upper Amazonian region. The brew is especially famous for the visions seen with it.

Benny Shanon

2010-01-01

393

Review of night vision technology  

NASA Astrophysics Data System (ADS)

Night vision based on technology of image intensifier tubes is the oldest electro-optical surveillance technology. However, it receives much less attention from international scientific community than thermal imagers or visible/NIR imagers due to series of reasons. This paper presents a review of a modern night vision technology and can help readers to understand sophisticated situation on the international night vision market.

Chrzanowski, K.

2013-06-01

394

Thermodynamics of two-colour QCD  

NASA Astrophysics Data System (ADS)

We discuss the thermodynamics of two-colour QCD with four flavours of staggered quarks on 8 3 × 4 and 16 3 × 4 lattices. In our simulations we use the Naik action for the fermions and a (1,2) tree-level improved gauge action. We analyze the deconfinement and chiral phase transitions for four different quark masses (m=0.1,0.05,0.025,0.015). Contrary to three-colour QCD the peak in the Polyakov loop susceptibility decreases with decreasing quark mass. This reflects an early breaking of the string in the heavy quark potential, which we verify explicitly by calculating the heavy quark potential at finite temperature using Polyakov loop correlations.

Kaczmarek, O.; Karsch, F.; Laermann, E.

1999-03-01

395

Tensor Processing for Texture and Colour Segmentation  

Microsoft Academic Search

\\u000a In this paper, we propose an original approach for texture and colour segmentation based on the tensor processing of the nonlinear\\u000a structure tensor. While the tensor structure is a well established tool for image segmentation, its advantages were only partly\\u000a used because of the vector processing of that information. In this work, we use more appropriate definitions of tensor distance

Rodrigo De Luis García; Rachid Deriche; Mikaël Rousson; Carlos Alberola-lópez

2005-01-01

396

How to Calculate Colourful Cross Sections Efficiently  

SciTech Connect

Different methods for the calculation of cross sections with many QCD particles are compared. To this end, CSW vertex rules, Berends-Giele recursion and Feynman-diagram based techniques are implemented as well as various methods for the treatment of colours and phase space integration. We find that typically there is only a small window of jet multiplicities, where the CSW technique has efficiencies comparable or better than both of the other two methods.

Gleisberg, Tanju; Hoeche, Stefan; Krauss, Frank

2008-09-03

397

Designs for two-colour microarray experiments  

Microsoft Academic Search

Designs for two-colour microarray experiments can be viewed as block designs with two treatments per block. Explicit formulae for the A- and D-criteria are given for the case that the number of blocks is equal to the number of treatments. These show that the A- and D-optimality criteria conflict badly if there are 10 or more treatments. A similar analysis

R. A. Bailey

2007-01-01

398

Evolution of Vision  

NASA Astrophysics Data System (ADS)

The evolution of photoreception, giving rise to eye, offers a kaleidoscopic view on selection acting at both the organ and molecular levels. The molecular level is mainly considered in the lecture. The greatest progress to date has been made in relation to the opsin visual pigments. Opsins appeared before eyes did. Two- and three-dimensional organization for rhodopsin in the rod outer segment disk membrane, as well as molecular mechanisms of visual pigments spectral tuning, photoisomerization and also opsin as a G-protein coupled receptor are considered. Molecular mechanisms of visual pigments spectral tuning, namely switching of chromophore (physiological time scale) and amino acid changes in the chromophore site of opsin (evolutionary time scale) is considered in the lecture. Photoisomerization of rhodopsin chromophore, 11-cis retinal is the only photochemical reaction in vision. The reaction is extemely fast (less that 200 fs) and high efficient (. is 0.65). The rhodopsin photolysis and kinetics of the earlier products appearance, photo- and bathorhodopsin, is considered. It is known that light is not only a carrier of information, but also a risk factor of damage to the eye. This photobiological paradox of vision is mainly due to the nature of rhodopsin chromophore. Photooxidation is the base of the paradox. All factors present in the phototrceptor cells to initiate free-radical photooxidation: photosensitizers, oxygen and substrates of oxidation: lipids and proteins (opsin). That is why photoprotective system of the eye structures appeared in the course of evolution. Three lines of protective system to prevent light damage to the retina and retina pigment epithelium is known: permanent renewal of rod and cone outer segment, powerful antioxidant system and optical media as cut-off filters where the lens is a key component. The molecular mechanisms of light damage to the eye and photoprotective system of the eye is considered in the lecture. The molecular mechanisms of phototransduction in vertebrates eye is also briefly considered in the lecture. Evolution of vision is an enormous subject for thought and investigation. In the postgenomic era evolutionary molecular physiology as a whole and evolutionary molecular physiology of vision can be considered as a key approach for understanding how genome is working.

Ostrovsky, Mikhail

399

Colour Magnitude Diagrams of Transiting Exoplanets  

NASA Astrophysics Data System (ADS)

Colour-Magnitude diagrams form a traditional way of representing luminous objects in the Universe and compare them to each others. Here, the photometric distances of 44 transiting exoplanetary systems were estimated. For seven of those, parallaxes confirm the methodology. From the combination of those measurements with fluxes obtained while planets were occulted by their host stars, colour-magnitude diagrams are composed in the near and mid IR. When possible, planets are plotted with field brown dwarfs who often have similar sizes and equilibrium temperatures, thus offering a natural empirical comparison sample. Exoplanets are also compared to the expected loci of pure blackbodies. In general planets do not agree with the brown dwarfs sequences, and neither do they match blackbodies. It is however possible to affirm that they are not featureless and that they display an increasing diversity in colour with decreasing intrinsic luminosity. A missing source of absorption within the [4.5 ?m] band, for some planets, would generally reconcile hot Jupiters with brown dwarfs’ cool atmospheres. Alternatively, measuring the emission of gas giants cooler than 1 000 K would disentangle whether planets’ atmospheres behave like brown dwarfs’ atmospheres, like blackbodies, or whether they form their own sequence.

Triaud, Amaury H. M. J.

2014-06-01

400

Evolution of ultraviolet vision in shorebirds (Charadriiformes)  

PubMed Central

Diurnal birds belong to one of two classes of colour vision. These are distinguished by the maximum absorbance wavelengths of the SWS1 visual pigment sensitive to violet (VS) and ultraviolet (UVS). Shifts between the classes have been rare events during avian evolution. Gulls (Laridae) are the only shorebirds (Charadriiformes) previously reported to have the UVS type of opsin, but too few species have been sampled to infer that gulls are unique among shorebirds or that Laridae is monomorphic for this trait. We have sequenced the SWS1 opsin gene in a broader sample of species. We confirm that cysteine in the key amino acid position 90, characteristic of the UVS class, has been conserved throughout gull evolution but also that the terns Anous minutus, A. tenuirostris and Gygis alba, and the skimmer Rynchops niger carry this trait. Terns, excluding Anous and Gygis, share the VS conferring serine in position 90 with other shorebirds but it is translated from a codon more similar to that found in UVS shorebirds. The most parsimonious interpretation of these findings, based on a molecular gene tree, is a single VS to UVS shift and a subsequent reversal in one lineage.

Odeen, Anders; Hastad, Olle; Alstrom, Per

2010-01-01

401

Artist's colour rendering of HDR scenes in 3D Mondrian colour-constancy experiments  

NASA Astrophysics Data System (ADS)

The presentation provides an update on ongoing research using three-dimensional Colour Mondrians. Two still life arrangements comprising hand-painted coloured blocks of 11 different colours were subjected to two different lighting conditions of a nearly uniform light and directed spotlights. The three-dimensional nature of these test targets adds shadows and multiple reflections, not found in flat Mondrian targets. Working from exactly the same pair of scenes, an author painted them using watercolour inks and paints to recreate both LDR and HDR Mondrians on paper. This provided us with a second set of appearance measurements of both scenes. Here we measured appearances by measuring reflectances of the artist's rendering. Land's Colour Mondrian extended colour constancy from a pixel to a complex scene. Since it used a planar array in uniform illumination, it did not measure the appearances of real life 3-D scenes in non-uniform illumination. The experiments in this paper, by simultaneously studying LDR and HDR renditions of the same array of reflectances, extend Land's Mondrian towards real scenes in non-uniform illumination. The results show that the appearances of many areas in complex scenes do not correlate with reflectance.

Parraman, Carinna E.; McCann, John J.; Rizzi, Alessandro

2010-01-01

402

2020 Vision Project Summary  

SciTech Connect

Since the 2020 Vision project began in 1996, students from participating schools have completed and submitted a variety of scenarios describing potential world and regional conditions in the year 2020 and their possible effect on US national security. This report summarizes the students' views and describes trends observed over the course of the 2020 Vision project's five years. It also highlights the main organizational features of the project. An analysis of thematic trends among the scenarios showed interesting shifts in students' thinking, particularly in their views of computer technology, US relations with China, and globalization. In 1996, most students perceived computer technology as highly beneficial to society, but as the year 2000 approached, this technology was viewed with fear and suspicion, even personified as a malicious, uncontrollable being. Yet, after New Year's passed with little disruption, students generally again perceived computer technology as beneficial. Also in 1996, students tended to see US relations with China as potentially positive, with economic interaction proving favorable to both countries. By 2000, this view had transformed into a perception of China emerging as the US' main rival and ''enemy'' in the global geopolitical realm. Regarding globalization, students in the first two years of the project tended to perceive world events as dependent on US action. However, by the end of the project, they saw the US as having little control over world events and therefore, we Americans would need to cooperate and compromise with other nations in order to maintain our own well-being.

Gordon, K.W.; Scott, K.P.

2000-11-01

403

Genetics Home Reference: Color vision deficiency  

MedlinePLUS

... types of light receptor cells called rods and cones. These cells transmit visual signals from the eye ... Rods are responsible for vision in low light. Cones provide vision in bright light, including color vision. ...

404

21 CFR 886.5870 - vision telescope.  

Code of Federal Regulations, 2010 CFR

...Devices] [Sec. 886.5870 Low - vision telescope.] 21 FOOD AND DRUGS 8 1996-04-01...Devices Sec. 886.5870 Low-vision telescope. (a) Identification. A low-vision telescope is a device that consists of an...

1996-04-01

405

Filling-in with colour: different modes of surface completion.  

PubMed

We investigated the figural dynamics of filling-in processes in figures with more than one possible figure-ground organisation. Using a central disk and two concentric rings as well as similar stimuli consisting of three nested squares or parallel stripes, we tested for filling-in with different equiluminant colour combinations. We observed four modes of filling-in: First, in most of the cases, the inner ring assumed the colour of the central disk and outer ring (M1). Second, the central disk became filled-in with the colour of the inner ring, without any colour change on the outer ring (M2). Third, in a first step, the colour of the inner ring spread onto the central disk; then, in a second step, the colour of the outer ring spread over the whole stimulus (M3). This two step filling-in process has not been reported so far. Fourth, a mode (M4) was sometimes observed that was characterised by the central disk and outer ring assuming the colour of the inner ring. Thus, colour filling-in or colour spreading proceeded both in a centripetal (periphery to fovea) as well as a centrifugal direction. The colours red and yellow proved to be stronger inducers than blue and green. Conversely, the latter colours became filled-in more easily than the former. The filled-in colour was always that of the inducing stimulus, i.e., there was no colour mixture. This suggests a long-range, neural process underlying filling-in under these conditions. PMID:16197977

Hamburger, Kai; Prior, Helmut; Sarris, Viktor; Spillmann, Lothar

2006-03-01

406

Educational Leadership with a Vision  

ERIC Educational Resources Information Center

By answering one fundamental question--"What will success look like?"--an educational institution has begun a process of defining its vision. It is undeniable that an institution will ever be greater than its dream; therefore, what is needed first and foremost is an articulated vision to propel an educational institution into a preferred future.…

Calder, Wm. Berry

2006-01-01

407

Iowa's Shared Vision: Early Childhood.  

ERIC Educational Resources Information Center

This is a revised version of a 1990 document which identifies a direction for Iowa early childhood education through the year 2000. The document defines Iowa's shared vision for young children as: to ensure quality early childhood opportunities for all Iowa's young children. This vision is shared through the Iowa Department of Education's efforts…

Iowa State Dept. of Education, Des Moines.

408

The IT Vision in FM.  

ERIC Educational Resources Information Center

Provides a forward-looking vision, including goals, objectives, and principles, of information technology (IT) use within facilities management (FM). This vision includes the evolution of the FM/IT organization from an operational role to a strategic role--from an FM divisional role to an enterprise role. (EV)

NeSmith, Jerry

2002-01-01

409

Novel applications of hyperstereo vision  

Microsoft Academic Search

Recent stereo vision experiments show potential in enhancing vehicular navigation, target acquisition, and optical turbulence mitigation. The experiments involved the use of stereo vision headsets connected to visible and 8-12 micrometers IR imagers. The imagers were separated by up to 50 m and equipped with telescopes for viewing at ranges of tens of meters up to 4 km. The important

Wendell R. Watkins; Jay B. Jordan; Mohan M. Trivedi

1997-01-01

410

Is Binocular Vision Always Monocular?  

Microsoft Academic Search

Visual sensitivity of one eye was determined under binocular stimulus conditions yielding apparent fusion, stereopsis, monocular dominance, and monocular suppression. Marked losses in sensitivity accompanied monocular suppression but were not evident during stable single vision. The results are inconsistent with the hypothesis that suppression alone mediates binocular single vision.

Randolph Blake; John Camisa

1978-01-01

411

An overview of computer vision  

NASA Technical Reports Server (NTRS)

An overview of computer vision is provided. Image understanding and scene analysis are emphasized, and pertinent aspects of pattern recognition are treated. The basic approach to computer vision systems, the techniques utilized, applications, the current existing systems and state-of-the-art issues and research requirements, who is doing it and who is funding it, and future trends and expectations are reviewed.

Gevarter, W. B.

1982-01-01

412

Active and Passive Perceptual Learning in the Visually Impaired.  

ERIC Educational Resources Information Center

Active and passive perceptual training methods were tested with 30 macular degeneration patients to improve their residual vision. The main conclusion was that perceptual training may contribute to successful visual adjustment and that the effect of training is not limited to a particular level of visual impairment. (Author/CL)

Conrod, Beverley E.; And Others

1986-01-01

413

Multiple Disabilities and Visual Impairment: An Action Research Project  

ERIC Educational Resources Information Center

Children with visual and motor disabilities constitute a distinct group with a unique set of educational needs. Such children are often grouped with the broader population of children with multiple disabilities and visual impairments (that is, those who are blind or have low vision) (Erin, 2000; McLinden, 1997). The chief characteristic of…

Argyropoulos, Vassilios; Thymakis, Paraskevas

2014-01-01

414

Stereotyped Movements among Children Who Are Visually Impaired  

ERIC Educational Resources Information Center

Does the severity of visual impairment affect the prevalence and severity of stereotyped movements? In this study, children who were blind or had low vision, half of whom had intellectual disabilities, were assessed. The results revealed that blindness and global delays were associated with more sensory processing dysfunction and more stereotyped…

Gal, Eynat; Dyck, Murray J.

2009-01-01

415

The Abacus: Instruction by Teachers of Students with Visual Impairments  

ERIC Educational Resources Information Center

Introduction: This article, based on a study of 196 teachers of students with visual impairments, reports on the experiences with and opinions related to their decisions about instructing their students who are blind or have low vision in the abacus. Methods: The participants completed an online survey on how they decide which students should be…

Amato, Sheila; Hong, Sunggye; Rosenblum, L. Penny

2013-01-01

416

Neural-Based Visual Stimulation with Infants with Cortical Impairment.  

ERIC Educational Resources Information Center

In order to shed light on the needs of children with cortical visual impairments, normal visual development of infants is described. Infant preferences for motion, faces, and black-and-white patterns are explained. Colors useful in stimulating vision development and the time needed for exposure to visual stimuli are discussed. (CR)

Powell, S. A.

1996-01-01

417

Sex Education Instruction for Students Who Are Visually Impaired: Recommendations to Guide Practitioners  

ERIC Educational Resources Information Center

Individuals with visual impairments (that is, those who are blind or have low vision) do not have the same opportunities to develop their knowledge of sexual health and participate in sex education as their sighted peers (Krupa & Esmail, 2010), although young adults with visual impairments participate in sexual activities at similar rates as their…

Kapperman, Gaylen; Kelly, Stacy M.

2013-01-01

418

Orientation and Mobility Skills of Secondary School Students with Visual Impairments. Facts from NLTS2.  

National Technical Information Service (NTIS)

For the purpose of special education eligibility, federal regulations define visual impairment (including blindness) as an impairment in vision that, even with correction, adversely affects a childs educational performance (34 C.F.R. Sec. 300.8(c)(13)). S...

K. Nagle R. Cameto

2007-01-01

419

Consumers' Perspectives on Effective Orientation and Mobility Services for Diabetic Adults Who Are Visually Impaired  

ERIC Educational Resources Information Center

The authors interviewed and videotaped diabetic adults with visual impairments about their perceptions of orientation and mobility (O&M) services that they had received. The visual impairments of these middle-aged adults ranged from totally blind to low vision. The interview questions focused on demographic information about the interviewees, the…

Griffin-Shirley, Nora; Kelley, Pat; Matlock, Dwayne; Page, Anita

2006-01-01

420

Corneoplastique: art of vision surgery.  

PubMed

Corneoplastique incorporates the entire spectrum of Vision corrective surgery including Lasik, premium cataract surgery, corneal surgery, ocular surface surgery and the full range of anterior segment surgery itself in manipulating the optics of every eye towards unaided emmetropia to define each and every eye surgeon as a "Vision Corrective Surgeon". This concept of approaching each case individually and designing vision therewith enables surgeons to correct not only virgin eyes but also approach complex cases and complications with the goal of 20/20 vision. Armed with this holistic approach, eye surgeons can use minimally invasive, aesthetically pleasing and visually focused surgery in single or staged process aiming for each patient's Best Vision Potential (BVP) raising eye surgery itself then to an Art! PMID:24492495

Gulani, Arun C

2014-01-01

421

Vision in albinism.  

PubMed Central

PURPOSE: The purpose of this investigation was to study vision in albinism from 3 perspectives: first, to determine the characteristics of grating acuity development in children with albinism; second, to study the effect of illumination on grating acuity; and third, to define the effect of melanin pigment in the macula on visual acuity. METHODS: I. Binocular and monocular grating acuity was measured with the acuity card procedure in 40 children with albinism during the first 3 years of life. Recognition acuity was eventually measured in 27 of these patients. Ocular pigment was documented by a previously established method of grading iris transillumination and macular transparency. II. Grating acuity under standard and increased illumination levels was measured in 20 adults with albinism (group I) compared with that in 20 adults with nystagmus due to conditions other than albinism (group II) and 20 adults without ocular abnormalities (group III). Recognition acuity measured with the ETDRS charts was also recorded for each group. III. Best-corrected binocular acuity was measured in 29 patients with albinism who were identified with melanin pigment in their maculas by direct ophthalmoscopy. RESULTS: I. Both binocular and monocular grating acuity was reduced 2 to 3 octaves below the norm for ages 6 months to 3 years. Limited data available in the first 6 months of life did not show failure of vision to develop. Grating acuity measurements overestimated eventual recognition acuity. Mean recognition acuity was 20/111. A relationship between grating acuity development and presence or absence of ocular pigment was not found. II. Grating acuity was significantly better for groups I and II under the condition of increased illumination (P < .03). For patients with albinism, grating acuity under standard illumination was significantly better than recognition acuity (P < .001). For all groups, grating acuity under increased illumination was significantly better than recognition acuity (P < .01). III. Mean recognition acuity in patients with albinism and melanin pigment in their maculas (20/47) was significantly better than measured recognition acuity in Project I (P < .001). All had foveal hypoplasia, but 8 patients had an incompletely developed annular reflex in the macula, 6 patients showed stereoacuity, and 3 patients had no nystagmus. CONCLUSIONS: I. Grating acuity development in albinism seems to progress along a curve that is asymptotic to visual development in a normal population. II. Increasing illumination does not reduce grating acuity in patients with albinism. Grating acuity overestimates recognition acuity in these patients. III. Ophthalmoscopic detection of melanin pigment in the macula in patients with albinism is associated with better vision. Images FIGURE 1 FIGURE 2 FIGURE 6 FIGURE 7 FIGURE 9 FIGURE 10A FIGURE 10B FIGURE 13A FIGURE 13B

Summers, C G

1996-01-01

422

Vision and vestibular adaptation.  

PubMed

This article summarizes six recent degree-of-freedom studies of visual-vestibular interaction during natural activities and relates the findings to canal-otolith interactions evaluated during eccentric axis rotations. Magnetic search coils were used to measure angular eye and head movements of young and elderly subjects. A flux gate magnetometer was used to measure three-dimensional head translation. Three activities were studied: standing quietly, walking in place, and running in place. Each activity was evaluated with three viewing conditions: a visible target viewed normally, a remembered target in darkness, and a visible target viewed with x2 binocular telescopic spectacles. Canal-otolith interaction was assessed with passive, whole-body, transient, and steady-state rotations in pitch and yaw at multiple frequencies about axes that were either oculocentric or eccentric to the eyes. For each rotational axis, subjects regarded visible and remembered targets located at various distances. Horizontal and vertical angular vestibulo-ocular reflexes were demonstrable in all subjects during standing, walking, and running. When only angular gains were considered, gains in both darkness and during normal vision were less than 1.0 and were generally lower in elderly than in young subjects. Magnified vision with x2 telescopic spectacles produced only small gain increases as compared with normal vision. During walking and running all subjects exhibited significant mediolateral and dorsoventral head translations that were antiphase locked to yaw and pitch head movements, respectively. These head translations and rotations have mutually compensating effects on gaze in a target plane for typical viewing distances and allow angular vestibulo-ocular reflex gains of less than 1.0 to be optimal for gaze stabilization during natural activities. During passive, whole-body eccentric pitch and yaw head rotations, vestibulo-ocular reflex gain was modulated as appropriate to stabilize gaze on targets at the distances used. This modulation was evident within the first 80 msec of onset of head movement, too early to be caused by immediate visual tracking. Modeling suggests a linear interaction between canal signals and otolith signals scaled by the inverse of target distance. Vestibulo-ocular reflex performance appears to be adapted to stabilize gaze during translational and rotational perturbations that occur during natural activities, as is appropriate for relevant target distances. Although immediate visual tracking contributes little to gaze stabilization during natural activities, visual requirements determine the performance of vestibulo-ocular reflexes arising from both canals and otoliths. PMID:9674518

Demer, J L; Crane, B T

1998-07-01

423

Clinical effect of low vision aids.  

PubMed

The number of patients with low vision is increasing as life expectancy increases. In addition, the interest and demand for low vision aids are also increasing with improved socioeconomic status and the development of mass media. Therefore, it is imperative to recognize the importance of low vision aids. We reviewed the clinical records of 118 patients who visited our low vision clinic more than twice. According to the data analyzed, optic nerve atrophy, retinal degeneration, diabetic retinopathy and age-related macular degeneration were the most common causes of low vision in these patients. The best corrected visual acuities without low vision aids were less than 0.3, but with the help of low vision aids, vision improved to more than 0.4 in 87% of the patients for near vision, and 56% for distant vision. The patients had complained that they could not read books, see a blackboard, recognize a person at a distance, and had other problems because of low vision. However, with the use of low vision aids their satisfaction with their vision rose to 70%. Hand magnifiers, high-powered spectacle lenses, and stand magnifiers were the low vision aids commonly used by people for near vision, while the Galilean telescope and Keplerian telescope were the most popular devices used for distant vision. In conclusion, low vision aids are very helpful devices to patients with low vision. PMID:10761398

Ji, Y H; Park, H J; Oh, S Y

1999-06-01

424

Efficient colour splitters for high-pixel-density image sensors  

NASA Astrophysics Data System (ADS)

When the pixel size of image sensors shrinks to the wavelength of light, this results in low signal levels for a given photon flux per pixel as a result of scaling laws. Because many image sensors require colour filters, it becomes crucial for small-pixel sensors to have an efficient filtering method that can capture all incident photons without absorbing them. Here, we propose a new method to split colours by using a microscale plate-like structure with a transparent medium that has a higher refractive index than the surrounding material. We experimentally demonstrate that this principle of colour splitting based on near-field deflection can generate colour images with minimal signal loss. From comparisons of the sum of the total integrated values for the colour channels, we confirm the amount of light received is 1.85 times that of the conventional colour filter method of the Bayer array, while maintaining the same level of resolution.

Nishiwaki, Seiji; Nakamura, Tatsuya; Hiramoto, Masao; Fujii, Toshiya; Suzuki, Masa-Aki

2013-03-01

425

Aggregate colour centres in impurity LiF crystals  

SciTech Connect

LiF crystals with colour centres exhibiting a zero-phonon line (ZPL) at 1080 nm in absorption and luminescence are studied. The decay time of luminescence of colour centres at 10 K is 260 - 280 ns, the ZPL half-width is 4.7 cm{sup -1}, and colour centres are characterised by a weak electron - phonon interaction (the Huang - Rhys factor is S < 0.11). The polarisation analysis of luminescence showed that the transition dipole moments of colour centres are oriented along the crystal axes [100], [010], and [001]. The model of aggregate F{sub 4} colour centres having a spatial structure with three symmetry axes C{sub 2} may correspond to the colour centres studied in the paper. (active media. lasers)

Basiev, Tasoltan T; Karasik, Aleksandr Ya; Konyushkin, V A; Papashvili, A G; Pukhov, K K [Laser Materials and Technology Research Center, A. M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Ermakov, I V; Gellermann, V [Department of Physics, University of Utah (United States)

2002-08-31

426

Multiparameter vision testing apparatus  

NASA Technical Reports Server (NTRS)

Compact vision testing apparatus is described for testing a large number of physiological characteristics of the eyes and visual system of a human subject. The head of the subject is inserted into a viewing port at one end of a light-tight housing containing various optical assemblies. Visual acuity and other refractive characteristics and ocular muscle balance characteristics of the eyes of the subject are tested by means of a retractable phoroptor assembly carried near the viewing port and a film cassette unit carried in the rearward portion of the housing (the latter selectively providing a variety of different visual targets which are viewed through the optical system of the phoroptor assembly). The visual dark adaptation characteristics and absolute brightness threshold of the subject are tested by means of a projector assembly which selectively projects one or both of a variable intensity fixation target and a variable intensity adaptation test field onto a viewing screen located near the top of the housing.

Hunt, S. R., Jr.; Homkes, R. J.; Poteate, W. B.; Sturgis, A. C. (inventors)

1975-01-01

427

Machine Vision Online: Tips for Successfully Applying Machine Vision  

NSDL National Science Digital Library

This Web site provides many articles and educational resources related to machine vision. Most of the materials come from companies with significant experience with the topic, including Ford Motor Company, Adept Technology, and many others. Visitors to the site can read about the basics of machine vision and learn how to successfully implement and design a system. Inexperienced people should start with the Strategies for New Users section, which contains a glossary of terms and a couple brief introductions. The Technical Papers section has information on the various components of a machine vision system, and Applications by Industry has case studies of several different operations.

428

Perceptual organization in colour perception: Inverting the gamut expansion effect  

PubMed Central

In the well-known gamut expansion effect, uniformly coloured target patches are perceived as more colourful when they are embedded in a uniform grey surround than when they are embedded in a variegated one. Here, we provide a demonstration showing that this effect can be inverted when the uniformly coloured target patches are replaced by variegated ones. This observation suggests that the gamut expansion effect is due to mechanisms of transparency perception rather than due to contrast adaptation.

Ekroll, Vebj?rn; Faul, Franz

2013-01-01

429

A Visual Survey of Colour on Paper and Colour Changes During Exposure to Light  

Microsoft Academic Search

This paper presents how inkjet colour is affected by firstly the substrate and secondly exposure to light and the combination of both. The research uses both pigmented and dye based inks printed onto coated and uncoated fine art papers, and are subjected to light conditions that are constantly changing through out the day and consequently the year. Although benchmark conditions

Carinna Parraman

2003-01-01

430

Spatio-temporal colour correction of strongly degraded movies  

NASA Astrophysics Data System (ADS)

The archives of motion pictures represent an important part of precious cultural heritage. Unfortunately, these cinematography collections are vulnerable to different distortions such as colour fading which is beyond the capability of photochemical restoration process. Spatial colour algorithms-Retinex and ACE provide helpful tool in restoring strongly degraded colour films but, there are some challenges associated with these algorithms. We present an automatic colour correction technique for digital colour restoration of strongly degraded movie material. The method is based upon the existing STRESS algorithm. In order to cope with the problem of highly correlated colour channels, we implemented a preprocessing step in which saturation enhancement is performed in a PCA space. Spatial colour algorithms tend to emphasize all details in the images, including dust and scratches. Surprisingly, we found that the presence of these defects does not affect the behaviour of the colour correction algorithm. Although the STRESS algorithm is already in itself more efficient than traditional spatial colour algorithms, it is still computationally expensive. To speed it up further, we went beyond the spatial domain of the frames and extended the algorithm to the temporal domain. This way, we were able to achieve an 80 percent reduction of the computational time compared to processing every single frame individually. We performed two user experiments and found that the visual quality of the resulting frames was significantly better than with existing methods. Thus, our method outperforms the existing ones in terms of both visual quality and computational efficiency.

Islam, A. B. M. Tariqul; Farup, Ivar

2011-01-01

431

REFLECTANCE, ILLUMINATION, AND EDGES IN 3-D MONDRIAN COLOUR-CONSTANCY EXPERIMENTS  

Microsoft Academic Search

Colour constancy remains an important topic in colour research today, as it has for more than a century. Technological advances in digital capture and image processing have expanded studies of this constancy from individual colour patches to entire complex images. In Land's Colour Mondrian experiment he controlled uniform illumination over an array of more than 100 coloured papers to demonstrate

John McCann; Carinna Parraman; Alessandro Rizzi

432

Another look at category effects on colour perception and their left hemispheric lateralisation: no evidence from a colour identification task.  

PubMed

The present study aimed to replicate category effects on colour perception and their lateralisation to the left cerebral hemisphere (LH). Previous evidence for lateralisation of colour category effects has been obtained with tasks where a differently coloured target was searched within a display and participants reported the lateral location of the target. However, a left/right spatial judgment may yield LH-laterality effects per se. Thus, we employed an identification task that does not require a spatial judgment and used the same colour set that previously revealed LH-lateralised category effects. The identification task was better performed with between-category colours than with within-category task both in terms of accuracy and latency, but such category effects were bilateral or RH-lateralised, and no evidence was found for LH-laterality effects. The accuracy scores, moreover, indicated that the category effects derived from low sensitivities for within-blue colours and did not reflect the effects of categorical structures on colour perception. Furthermore, the classic "category effects" were observed in participants' response biases, instead of sensitivities. The present results argue against both the LH-lateralised category effects on colour perception and the existence of colour category effects per se. PMID:24430783

Suegami, Takashi; Aminihajibashi, Samira; Laeng, Bruno

2014-05-01

433

Human tracking using distributed vision systems  

Microsoft Academic Search

We present a wide area human tracking method using distributed computer vision systems. Each vision system consists of a camera and an image processor and they are all connected through a computer network. In this paper, we propose a method for human tracking and for coordination of all the vision systems. The human tracking method works on each vision system

Atsushi NAKAZAWA; Hirokazu KATO; Seiji INOKUCHI

1998-01-01

434

Fast Vision-guided Mobile Robot Navigation Using Model-based Reasoning And Prediction Of Uncertainties  

Microsoft Academic Search

We have designed a model-based reasoning and control architecture that allows a mobile robot to navigate indoors at an average speed of 8 to 10 meters\\/minute using ordinary laboratory computing hardware of approxirmately 16 MIPS power. The navigation capabilities of the robot are not impaired by the presence of the stationary or moving obstacles. The vision system maintains a model

Akio Kosaka; Avi Kak

1992-01-01

435

Promoting a Message on Vision Loss to Diverse Groups of Adults: Research Report  

ERIC Educational Resources Information Center

Visual impairment is the second most prevalent disability among older adults (National Center for Health Statistics, 1993), affecting about 2.9 million Americans aged 65 and older (Eye Diseases Prevalence Research Group, 2004). As the population ages, the number of individuals who will experience age-related vision loss will also increase.…

Cimarolli, Verena R.; Stuen, Cynthia; Sussman-Skalka, Carol J.

2006-01-01

436

Interdisciplinary Approach to the Rehabilitation of Low Vision Patients in Japan.  

ERIC Educational Resources Information Center

Visually impaired persons (N=1,657) from 20 national rehabilitation centers in Japan and 230 patients of a low vision clinic were surveyed to gather information on patients' age, sex, cause of disorder, visual acuity, and results of treatment and rehabilitation. (Author/JDD)

Yanashima, K.; And Others

1990-01-01

437

A National Study of Parents' Perspectives on Dual-Certified Vision Professionals  

ERIC Educational Resources Information Center

A national survey of and telephone interviews with parents of children served by dual-certified vision education professionals was conducted to determine the parents' perspectives on the efficacy of this service delivery model for students with visual impairments. The study identified the parents' perceptions of the effectiveness of these…

Grimmett, Eric S.; Pogrund, Rona L.; Griffin-Shirley, Nora

2011-01-01

438

Ability to Read Medication Labels Improved by Participation in a Low Vision Rehabilitation Program  

ERIC Educational Resources Information Center

Demographic projections indicate that the population of the Western world is aging, and evidence suggests an increase in the incidence of conditions, such as age-related macular degeneration (AMD), that produce visual impairments and result in low vision (Maberley et al., 2006). It is expected that in the United States and Canada, the annual…

Markowitz, Samuel N.; Kent, Christine K.; Schuchard, Ronald A.; Fletcher, Donald C.

2008-01-01

439

Estimated Number of Persons Eligible for Vision Rehabilitation Services Under Expanded Medicare. Research Report  

ERIC Educational Resources Information Center

It has been well documented by researchers that the incidence of visual impairment (both blindness and low vision) increases as people age (see, for example, Congdon et al., 2004; Crews, 1994; Lighthouse International, 2001; Rubin, 2000) and that these physical declines can adversely affect an individual's ability to perform activities that…

Cavenaugh, Brenda S.; Steinman, Bernard A.

2005-01-01

440

Contact Lenses for Vision Correction  

MedlinePLUS

... Reduced Vision Tearing See all Symptoms > Glasses, Contacts & LASIK Contact Lenses Colored Contact Lenses Eyeglasses IOLs Refractive Surgery & LASIK Sunglasses Living EyeSmart About Ophthalmologists Adults Under 40 ...

441

Bayesian Vision for Shape Recovery.  

National Technical Information Service (NTIS)

We present a new Bayesian vision technique that aims at recovering a shape from two or more noisy observations taken under similar lighting conditions. The shape is parametrized by a piecewise linear height field, textured by a piecewise linear irradiance...

A. Jalobeanu

2004-01-01

442

Do You Have Cultural Vision?  

ERIC Educational Resources Information Center

Maintains that child care teachers can help remedy cultural tunnel vision by promoting cultural diversity and understanding as they work with children and communicate with parents about what they are doing. (BB)

Gonzalez-Mena, Janet

1991-01-01

443

Vision of a smart city.  

National Technical Information Service (NTIS)

The vision of 'Smart Cities' is the urban center of the future, made safe, secure environmentally green, and efficient because all structures--whether for power, water, transportation, etc. are designed, constructed, and maintained making use of advanced,...

R. E. Hall B. Bowerman J. Braverman J. Taylor H. Todosow U. Von Wimmersperg

2000-01-01

444

A New View of Vision.  

ERIC Educational Resources Information Center

Reviews research done on the nature of vision from a neurologic perspective. Proposes a multiplex filter model to explain patterns in the signals transmitted to the brain from the retina. Describes experiments done to test the model. (CW)

Vaughan, Christopher

1988-01-01

445

Vision Technologies for Intelligent Vehicles  

Microsoft Academic Search

This paper surveys the different technologies involved in the development of computer vision applications for Intelligent Vehicles de- rived from the 15 year experience of VisLab. Some illustrative examples are also discussed.

Massimo Bertozzi; Alberto Broggi; Luca Bombini; C. Caraffi; Stefano Cattani; Pietro Cerri; Alessandra Fascioli; M. Felisa; Rean Isabella Fedriga; Stefano Ghidoni; Paolo Grisleri; Paolo Medici; M. Paterlini; P. P. Porta; M. Posterli; Paolo Zani

2007-01-01

446

The Earth Science Vision  

NASA Technical Reports Server (NTRS)

NASA's Earth Science Enterprise's long range vision is to enable the development of a national proactive environmental predictive capability through targeted scientific research and technological innovation. Proactive environmental prediction means the prediction of environmental events and their secondary consequences. These consequences range from disasters and disease outbreak to improved food production and reduced transportation, energy and insurance costs. The economic advantage of this predictive capability will greatly outweigh the cost of development. Developing this predictive capability requires a greatly improved understanding of the earth system and the interaction of the various components of that system. It also requires a change in our approach to gathering data about the earth and a change in our current methodology in processing that data including its delivery to the customers. And, most importantly, it requires a renewed partnership between NASA and its sister agencies. We identify six application themes that summarize the potential of proactive environmental prediction. We also identify four technology themes that articulate our approach to implementing proactive environmental prediction.

Schoeberl, Mark; Rychekewkitsch, Michael; Andrucyk, Dennis; McConaughy, Gail; Meeson, Blanche; Hildebrand, Peter; Einaudi, Franco (Technical Monitor)

2000-01-01

447

Computational color vision model  

NASA Astrophysics Data System (ADS)

Previously a computational model of human color vision was described which simulates the main retinal and cortical processes involved in color perception and which makes predictions about responses to spatiochromatic stimuli. The emphasis from early on was on ensuring validation of the model as it developed, but its growing complexity combined with considerations of linking it to a multiscale contrast model made the development increasingly cumbersome. The model was therefore completely rewritten as a set of Khoros (Khoral Research Inc) utilities which provide user friendly access to the model and its components via the visual programming interface. This paper describes the details of Khoros implementation and presents examples of the quantitative predictions made by the model for different simulated psychophysical experiments including increment threshold, grating sensitivity and grating masking. Current areas of activity include examining different gain processes at different stages of the model and their implications as possible components of color constancy mechanisms, and the impact of different types of cortical demultiplexing processes on the predictions made by the model.

Moorhead, Ian R.

1998-07-01

448

[Acquired disorders of color vision].  

PubMed

This article is a general view of acquired disorders of color vision. The revision of the best known methods and of the etiopathogenic classification is not very important in ophthalmology but on the other hand, the detection of the blue defect advertise and associated ocular pathology. There is a major interest in serious diseases as multiple sclerosis, AIDS, diabetes melitus, when the first ocular sign can be a defect in the color vision. PMID:12677792

Lascu, Lidia; Bala?, Mihaela

2002-01-01

449

Contributions of magno- and parvocellular channels to conscious and non-conscious vision.  

PubMed

The dorsal and ventral cortical pathways, driven predominantly by magnocellular (M) and parvocellular (P) inputs, respectively, assume leading roles in models of visual information processing. Although in prior proposals, the dorsal and ventral pathways support non-conscious and conscious vision, respectively, recent modelling and empirical developments indicate that each pathway plays important roles in both non-conscious and conscious vision. In these models, the ventral P-pathway consists of one subpathway processing an object's contour features, e.g. curvature, the other processing its surface attributes, e.g. colour. Masked priming studies have shown that feed-forward activity in the ventral P-pathway on its own supports non-conscious processing of contour and surface features. The dorsal M-pathway activity contributes directly to conscious vision of motion and indirectly to object vision by projecting to prefrontal cortex, which in turn injects top-down neural activity into the ventral P-pathway and there 'ignites' feed-forward-re-entrant loops deemed necessary for conscious vision. Moreover, an object's shape or contour remains invisible without the prior conscious registration of its surface properties, which for that reason are taken to comprise fundamental visual qualia. Besides suggesting avenues for future research, these developments bear on several recent and past philosophical issues. PMID:24639584

Breitmeyer, Bruno G

2014-05-01

450

The Relationship of Cognitive Style Variables to Optimal Test Performance in Hearing-Impaired Children.  

ERIC Educational Resources Information Center

The relationship of cognitive style variables and conditions of test administration was investigated in cognitive assessments of hearing-impaired children, aged six through eleven. One hundred-twenty children were given the Raven Coloured Progressive Matrices (CPM) and a Piagetian battery under one of six conditions of testing: (1) standard; (2)…

Dillon, Ronna F.

451

Human vision and electronic imaging  

NASA Astrophysics Data System (ADS)

The field of electronic imaging has made incredible strides over the past decade producing systems with higher signal quality, complex data formats, sophisticated operations for analyzing and visualization information, advanced interfaces, and richer image environments. Since electronic imaging systems and applications are designed for human users, the success of these systems depends on the degree to which they match the features of human vision and cognition. This paper reviews the interplay between human vision and electronic imaging, describing how the methods, models and experiments in human vision have influenced the development of imaging systems, and how imaging technologies and applications have raised new research questions for the vision community. Using the past decade of papers from the IS&T/SPIE Conference on Human Vision and Electronic Imaging as a lens, we trace a path up the `perceptual food chain,' showing how research in low-level vision has influenced image quality metrics, image compression algorithms, rendering techniques and display design, how research in attention and pattern recognition have influenced the development of image analysis, visualization, and digital libraries systems, and how research in higher-level functions is involved in the design of emotional, aesthetic, and virtual systems.

Rogowitz, Bernice E.; Pappas, Thrasyvoulos N.; Allebach, Jan P.

2001-01-01

452

Current CIE work to Achieve Physiologically Correct Colour Metrics  

Microsoft Academic Search

CIE colorimetry was introduced 65 years ago to describe the colorimetric properties of coloured lights and signals. Soon after establishment it turned out that it is most capable to describe the colorimetry of reflective media and is now widely applied in all branches of the colouring industries (e.g. in the textile, paper and automotive industry), where the aim is to

János Schanda

453

Searching for AN Optimal Lattice Colour Dielectric Theory  

Microsoft Academic Search

We investigate the use of renormalization group transformations (RGTs) to define an effective colour dielectric theory on the lattice. Starting from the pure gauge sector of SU(2), we try to find an optimal RGT which leads to an effective action with few parameters. We test this effective action by simulating the colour dielectric theory on the lattice and checking for

B. Grossmann; H. J. Pirner; A. I. Signal; R. Baier; J. Wroldsen

1991-01-01

454

Classical Confining Solutions of a Tensor Gauge Theory Incorporating Colour.  

National Technical Information Service (NTIS)

A mass-modified Einstein-Weyl gauge theory of colour carrying spin-two mesons is formulated. A classical solution is exhibited for the case of internal SU(2) symmetry which may confine quarks in colour singlets. (Atomindex citation 09:384252)

A. Salam J. Strathdee

1977-01-01

455

An urban traffic network model via coloured timed Petri nets  

Microsoft Academic Search

This paper deals with modelling of traffic networks (TNs) for control purposes. A modular framework based on coloured timed Petri nets (CTPNs) is proposed to model the dynamics of signalized TN systems: places represent link cells and crossing sections, tokens are vehicles and token colours represent the routing of the corresponding vehicle. In addition, ordinary timed Petri nets model the

Mariagrazia Dotoli; Maria Pia Fanti

2006-01-01

456

The development of artists' novel colour palettes for inkjet printing  

NASA Astrophysics Data System (ADS)

In this changing environment in which the artist and designer has access to a wide range of digital imaging tools and technologies, that on first glance, are dedicated to the creation of colour mixtures, why is the digital interface and colour outcome often disappointing? It appears that hardware, software tools and methods for digital printing are not necessarily suited to the specific requirements of the artist. In fact, they are too generalised to obtain a high degree of quality and too inflexible to allow artists to obtain precision and predictability. Is it possible for an artist to mix and print a colour that captures their creative imagination? The motivation for this research is based on how artists mix and print colour by traditional means (painting and printmaking) and how these differ from colour picker tools, slider bars and methods developed for digital printing, and whether it is possible to incorporate both? The paper provides a brief historical background to artists who have developed colour systems to assist their particular colour choices. Based on existing hardware and software, the paper suggests alternative approaches to colour selection, demonstrates methods for the creation of novel inkjet printed palettes, and how these can be visualised and compared.

Parraman, Carinna

2010-01-01

457

Nestling mouth colour: ecological correlates of a begging signal  

Microsoft Academic Search

The mouths of begging nestlings vary widely in colour, ranging from yellow in robins,Erithacus rubecula, to red in reed buntings,Emberiza schoeniclus. Two functions have been suggested for bright nestling mouth colour: (1) it may improve the detectability of chicks, particularly in poorly lit nests and (2) within species, it may signal need. We tested these hypotheses in a comparative analysis,

R. KILNER; N. B. DAVIES

1998-01-01

458

What drives the ultraviolet colours of passive galaxies?  

NASA Astrophysics Data System (ADS)

We present and analyse optical and ultraviolet (UV) colours for passive and optically-red Coma cluster galaxies for which we have spectroscopic age and element abundance estimates. Our sample of 150 objects covers a wide range in mass, from giant ellipticals down to the bright end of the dwarf-galaxy regime. Galaxies with ongoing star formation have been removed using strict H? emission-line criteria. We focus on the colours FUV-i, NUV-i, FUV-NUV, u*-g and g-i. We find that all of these colours are correlated with both luminosity and velocity dispersion at the >5? level, with FUV-i and FUV-NUV becoming bluer with increasing 'mass' while the other colours become redder. We perform a purely empirical analysis to assess what fraction of the variation in each colour can be accounted for by variations in the average stellar populations, as traced by the optical spectra. For the optical colours, u*-g and g-i, most of the observed scatter (˜80 per cent after allowing for measurement errors and for systematic errors in u*-g) is attributable to stellar population variations, with colours becoming redder with increasing age and metallicity (Mg/H). The FUV-i colour becomes bluer with increasing age and with increasing Mg/H, favouring the 'metal-rich single-star' origin for the UV upturn. However, correlations with the optically-dominant stellar populations account for only about half of the large observed scatter. We propose that the excess scatter in FUV-i may be due to a varying proportion of ancient stars in galaxies with younger [simple stellar population (SSP) equivalent] average ages. The NUV-i colour is sensitive to SSP-equivalent age and Mg/H (in the same sense as optical colours), but also exhibits excess scatter that can be attributed to 'leakage' of the far-UV-dominant (FUV-dominant) old hot population. After applying a correction based on the FUV-i colour, the much of the remaining variance in NUV-i is attributable to variations in the spectroscopic parameters, similar to the results for optical colours. Finally, the FUV-NUV colour is surprisingly well behaved, showing strong correlations with age and metallicity, and little residual scatter. Interpreting this colour is complicated, however, since it mixes the effects of the main-sequence turn-off, in the near-UV, with the variation in the hot post-red giant branch content dominating the FUV.

Smith, Russell J.; Lucey, John R.; Carter, David

2012-04-01

459

Camouflage, communication and thermoregulation: lessons from colour changing organisms  

PubMed Central

Organisms capable of rapid physiological colour change have become model taxa in the study of camouflage because they are able to respond dynamically to the changes in their visual environment. Here, we briefly review the ways in which studies of colour changing organisms have contributed to our understanding of camouflage and highlight some unique opportunities they present. First, from a proximate perspective, comparison of visual cues triggering camouflage responses and the visual perception mechanisms involved can provide insight into general visual processing rules. Second, colour changing animals can potentially tailor their camouflage response not only to different backgrounds but also to multiple predators with different visual capabilities. We present new data showing that such facultative crypsis may be widespread in at least one group, the dwarf chameleons. From an ultimate perspective, we argue that colour changing organisms are ideally suited to experimental and comparative studies of evolutionary interactions between the three primary functions of animal colour patterns: camouflage; communication; and thermoregulation.

Stuart-Fox, Devi; Moussalli, Adnan

2008-01-01

460

Tests of commercial colour CMOS cameras for astronomical applications  

NASA Astrophysics Data System (ADS)

We present some results of testing commercial colour CMOS cameras for astronomical applications. Colour CMOS sensors allow to perform photometry in three filters simultaneously that gives a great advantage compared with monochrome CCD detectors. The Bayer BGR colour system realized in colour CMOS sensors is close to the astronomical Johnson BVR system. The basic camera characteristics: read noise (e^{-}/pix), thermal noise (e^{-}/pix/sec) and electronic gain (e^{-}/ADU) for the commercial digital camera Canon 5D MarkIII are presented. We give the same characteristics for the scientific high performance cooled CCD camera system ALTA E47. Comparing results for tests of Canon 5D MarkIII and CCD ALTA E47 show that present-day commercial colour CMOS cameras can seriously compete with the scientific CCD cameras in deep astronomical imaging.

Pokhvala, S. M.; Reshetnyk, V. M.; Zhilyaev, B. E.

2013-12-01

461

An examination of ham colour fading using optical fibre methods  

NASA Astrophysics Data System (ADS)

Sliced ham products undergo significant discolouration and fading when placed in retail display cabinets. This is due to factors such as illumination of the display cabinet, packaging, i.e. low OTR (Oxygen Transmission Rate) or very low OTR packaging, product to headspace ratio and percentage of residual oxygen. This paper presents initial investigations into the development of a sensor to measure rate of colour fading in cured ham, in order to predict an optimum colour sell-by-date. An investigation has been carried out that shows that spectral reflections offer more reproducibility than CIE L*a*b* readings, which are, at present, most often used to measure meat colour. Self-Organising Maps were then used to classify the data into five colour fading stages, from very pink to grey. The results presented here show that this classifier could prove an effective system for determining the rate of colour fading in ham.

Sheridan, Cormac; O'Farrell, Marion; Lewis, Elfed; Flanagan, Colin; Kerry, John F.; Jackman, Nick

2006-10-01

462

Clinical application of low vision rehabilitation strategies after completion of a computer-based training module.  

PubMed

ABSTRACT This study evaluated changes in occupational therapists' practice behaviors after completion of an online continuing education (CE) program delivered over a hospital Intranet system. The setting was a large rural medical system covering parts of two southeastern states. A convenience sample of 28 occupational therapists and occupational therapy assistants was recruited from the facility therapy staff. A CE module on low vision assessment and treatment was delivered using the hospital Intranet and a follow-up survey assessing practice change was carried out 8 weeks later. Most participants reported an increase in their comfort level when treating clients with low vision after course completion. Fifty percent of participants reported screening for vision impairments, increased use of environmental modifications, and more referrals to other vision specialists. Outcomes suggest that Internet-delivered CE programs can improve knowledge and affect practice. PMID:24971896

Nipp, Cheri M; Vogtle, Laura K; Warren, Mary

2014-07-01

463

Micro-Raman analysis of coloured lithographs.  

PubMed

Raman micro-spectroscopy was chosen for analysis and identification of the pigments present in four nineteenth-century hand-coloured lithographs, as this technique has several advantages over others for this purpose. The possibility of performing completely non-destructive analysis without any sampling is probably one of its most favourable qualities for art analysis. Raman spectroscopy can also be used to determine some pigments that cannot be detected using FTIR, such as vermilion, carbon blacks, cadmium pigments, etc. Among others, Prussian blue, ultramarine blue, carbon black, chrome yellow, yellow ochre, red lead, red iron oxide, burnt Sienna, indigo blue, chrome orange, phthalocyanine green, and some other organic pigments, were determined in the specimens. The results obtained have led to doubts about the age of the lithographs. PMID:15127178

Castro, K; Vandenabeele, P; Rodríguez-Laso, M D; Moens, L; Madariaga, J M

2004-06-01

464

Beyond the colour of my skin: How skin colour affects the sense of body-ownership  

PubMed Central

Multisensory stimulation has been shown to alter the sense of body-ownership. Given that perceived similarity between one’s own body and those of others is crucial for social cognition, we investigated whether multisensory stimulation can lead participants to experience ownership over a hand of different skin colour. Results from two studies using introspective, behavioural and physiological methods show that, following synchronous visuotactile (VT) stimulation, participants can experience body-ownership over hands that seem to belong to a different racial group. Interestingly, a baseline measure of implicit racial bias did not predict whether participants would experience the RHI, but the overall strength of experienced body-ownership seemed to predict the participants’ post-illusion implicit racial bias with those who experienced a stronger RHI showing a lower bias. These findings suggest that multisensory experiences can override strict ingroup/outgroup distinctions based on skin colour and point to a key role for sensory processing in social cognition.

Farmer, Harry; Tajadura-Jimenez, Ana; Tsakiris, Manos

2013-01-01

465

New results with colour-sextet quarks.  

SciTech Connect

We study QCD with 2 and 3 flavours of colour-sextet quarks. The 2-flavour theory is a candidate Walking Technicolor theory. Since we are attempting to distinguish whether this theory is walking or conformal, we also study the 3-flavour theory, which is believed to be conformal, for comparison. We simulate lattice QCD with 2 and 3 flavours of colour-sextet staggered quarks at finite temperatures to determine the scales of confinement and chiral-symmetry breaking from the positions of the deconfinement and chiral-symmetry restoration transitions. Unlike the case with fundamental quarks, these transitions are far apart. For 2 flavours the values of {beta} = 6/g{sup 2} for both transitions increase as Ta is decreased from 1/4 to 1/6 to 1/8, as expected for a theory whose coupling runs to smaller values as the lattice spacing is decreased. However, for the chiral transition, the increase in {beta} between Ta = 1/4 and Ta = 1/6 is much larger than the increase between Ta = 1/6 and Ta = 1/8. This suggests that between Ta = 1/4 and Ta = 1/6 we are at strong coupling where the theory is effectively quenched, while between Ta = 1/6 and Ta = 1/8 we are emerging into the weak coupling regime. It will require even smaller Ta values to determine whether the running of the chiral-transition coupling is controlled by asymptotic freedom and the theory walks, or if it reaches a non-zero limit when the transition becomes a bulk transition and the theory is conformal. The 3 flavour case at Ta = 1/4 and Ta = 1/6 behaves similarly to the 2 flavour case. Since this theory is expected to be conformal, the interpretation that we are seeing strong-coupling behaviour, inaccessible from the weak-coupling limit (continuum) is the most likely interpretation.

Sinclair, D. K.; Kogut, J. B. (High Energy Physics); (Univ. of Maryland); (DOE-HEP)

2010-01-01

466

On auroral electron precipitation and colour ratios  

NASA Astrophysics Data System (ADS)

Auroral electron precipitation spectra can be retrieved from several complementary techniques, either ground-based or satellite. They include for example inversions of electron density profiles (measured for instance by incoherent scatter radars, IS), inversions of volume emission rate profiles (optical instruments), and the use of multi-spectral imaging in combination with ionospheric modelling (optical emission ratios). This study investigates several well-known colour ratios in discrete aurorae at Earth, such as N2+ 391.4 nm / 427.8 nm or O2+ 5620 / OI 777.4 nm, in order to determine the uncertainties of these inversion techniques. Their theoretical dependence to parameters such as the neutral atmosphere, the electron precipitation distribution and the cross section is presented. In a second step, comparison of these simulations with real data is proposed. The multi-spectral multi-station Auroral Large Imaging System (ALIS) was operated in March 2008 in Northern Scandinavia during a joint campaign with the EISCAT UHF radar in Tromso. Colour ratios, such as OI 844.6 nm / N2+ 427.8 nm and OI 630.0 nm / N2+ 427.8 nm, observed nearly simultaneously, are extracted and give access to the characteristic energy of the precipitation. They are shown to be consistent with electron spectra retrieved by IS radar. Perspectives are given for planetary studies, for which a global view of electron precipitation mechanisms and their impact on the atmosphere is needed to complement the limited number of observations and instruments aboard planetary space missions.

Simon Wedlund, C.; Gronoff, G.; Mertens, C. J.; Lamy, H.; Gustavsson, B.

2012-12-01

467

The phylogenetic significance of colour patterns in marine teleost larvae  

PubMed Central

Ichthyologists, natural-history artists, and tropical-fish aquarists have described, illustrated, or photographed colour patterns in adult marine fishes for centuries, but colour patterns in marine fish larvae have largely been neglected. Yet the pelagic larval stages of many marine fishes exhibit subtle to striking, ephemeral patterns of chromatophores that warrant investigation into their potential taxonomic and phylogenetic significance. Colour patterns in larvae of over 200 species of marine teleosts, primarily from the western Caribbean, were examined from digital colour photographs, and their potential utility in elucidating evolutionary relationships at various taxonomic levels was assessed. Larvae of relatively few basal marine teleosts exhibit erythrophores, xanthophores, or iridophores (i.e. nonmelanistic chromatophores), but one or more of those types of chromatophores are visible in larvae of many basal marine neoteleosts and nearly all marine percomorphs. Whether or not the presence of nonmelanistic chromatophores in pelagic marine larvae diagnoses any major teleost taxonomic group cannot be determined based on the preliminary survey conducted, but there is a trend toward increased colour from elopomorphs to percomorphs. Within percomorphs, patterns of nonmelanistic chromatophores may help resolve or contribute evidence to existing hypotheses of relationships at multiple levels of classification. Mugilid and some beloniform larvae share a unique ontogenetic transformation of colour pattern that lends support to the hypothesis of a close relationship between them. Larvae of some tetraodontiforms and lophiiforms are strikingly similar in having the trunk enclosed in an inflated sac covered with xanthophores, a character that may help resolve the relationships of these enigmatic taxa. Colour patterns in percomorph larvae also appear to diagnose certain groups at the interfamilial, familial, intergeneric, and generic levels. Slight differences in generic colour patterns, including whether the pattern comprises xanthophores or erythrophores, often distinguish species. The homology, ontogeny, and possible functional significance of colour patterns in larvae are discussed. Considerably more investigation of larval colour patterns in marine teleosts is needed to assess fully their value in phylogenetic reconstruction.

Baldwin, Carole C

2013-01-01

468

The role of meaning in grapheme-colour synaesthesia.  

PubMed

When the synaesthete, J, is shown black graphemes, in addition to perceiving the black digits or letters she also experiences highly specific colours that overlay the graphemes (e.g., 5 is pink, S is green). We used ambiguous graphemes in a Stroop-type task to show that the exact same forms (e.g., 5) can elicit different synaesthetic colours depending on whether they are interpreted as digits or letters. J was shown strings of black digits (e.g., 3 4 5 6 7) or words (e.g., M U S I C for 1 sec. All but one of the graphemes then disappeared and the remaining grapheme changed to a colour that J had to name as quickly as possible. The key trials involved coloured graphemes that were ambiguous (e.g., the 5 in the strings above could be interpreted either as a digit or as a letter). On congruent trials, the colour of the ambiguous target grapheme was the same as J's photism for the digit or letter interpretations of the grapheme. On incongruent trials, the colours of the ambiguous target graphemes were different than the colours of J's photisms for the digit or letter interpretations of the graphemes. On digit-context incongruent trials, the ambiguous graphemes were presented in J's colour for the letter-interpretations of the graphemes, whereas on letter-context incongruent trials, the ambiguous graphemes were presented in J's colours for the digit-interpretations of the graphemes. Thus the same ambiguous grapheme (e.g., a pink 5) served as a congruent stimulus in one context and an incongruent stimulus in another context. J's response times showed that ambiguous graphemes elicited different photisms depending on whether they were interpreted as digits or letters. This finding suggests that it is not the form but the meaning of graphemes (whether they are interpreted as digits or letters) that determines the colours of synaesthetic photisms. PMID:16683498

Dixon, Mike J; Smilek, Daniel; Duffy, Patricia L; Zanna, Mark P; Merikle, Philip M

2006-02-01

469

Three cortical stages of colour processing in the human brain.  

PubMed

We used the technique of functional magnetic resonance imaging to chart the colour pathways in the human brain beyond V4. We asked subjects to view objects that were dressed in natural and unnatural colours as well as their achromatic counterparts and compared the activity produced in the brain by each condition. The results showed that both naturally and unnaturally coloured objects activate a pathway extending from V1 to V4, though not overlapping totally the activity produced by viewing abstract coloured Mondrian scenes. Normally coloured objects activated, in addition, more anterior parts of the fusiform gyrus, the hippocampus and the ventrolateral frontal cortex. Abnormally coloured objects, by contrast, activated the dorsolateral frontal cortex. A study of the cortical covariation produced by these activations revealed that activity in large parts of the occipital lobe covaried with each. These results, considered against the background of previous physiological and clinical studies, allow us to discern three broad cortical stages of colour processing in the human brain. The first is based on V1 and possibly V2 and is concerned mainly with registering the presence and intensity of different wavelengths, and with wavelength differencing. The second stage is based on V4 and is concerned with automatic colour constancy operations, without regard to memory, judgement and learning. The third stage, based on the inferior temporal and frontal cortex, is more concerned with object colours. The results we report, as well as the schema that we suggest, also allow us to reconcile the computational theory of Land, implemented without regard to cognitive factors such as memory and learning, and the cognitive systems of Helmholtz and Hering, which view such factors as critical in the determination of colours. PMID:9762956

Zeki, S; Marini, L

1998-09-01

470

Virtual environment to quantify the influence of colour stimuli on the performance of tasks requiring attention  

PubMed Central

Background Recent studies indicate that the blue-yellow colour discrimination is impaired in ADHD individuals. However, the relationship between colour and performance has not been investigated. This paper describes the development and the testing of a virtual environment that is capable to quantify the influence of red-green versus blue-yellow colour stimuli on the performance of people in a fun and interactive way, being appropriate for the target audience. Methods An interactive computer game based on virtual reality was developed to evaluate the performance of the players. The game's storyline was based on the story of an old pirate who runs across islands and dangerous seas in search of a lost treasure. Within the game, the player must find and interpret the hints scattered in different scenarios. Two versions of this game were implemented. In the first, hints and information boards were painted using red and green colours. In the second version, these objects were painted using blue and yellow colours. For modelling, texturing, and animating virtual characters and objects the three-dimensional computer graphics tool Blender 3D was used. The textures were created with the GIMP editor to provide visual effects increasing the realism and immersion of the players. The games were tested on 20 non-ADHD volunteers who were divided into two subgroups (A1 and A2) and 20 volunteers with ADHD who were divided into subgroups B1 and B2. Subgroups A1 and B1 used the first version of the game with the hints painted in green-red colors, and subgroups A2 and B2 the second version using the same hints now painted in blue-yellow. The time spent to complete each task of the game was measured. Results Data analyzed with ANOVA two-way and posthoc TUKEY LSD showed that the use of blue/yellow instead of green/red colors decreased the game performance of all participants. However, a greater decrease in performance could be observed with ADHD participants where tasks, that require attention, were most affected. Conclusions The game proved to be a user-friendly tool capable to detect and quantify the influence of color on the performance of people executing tasks that require attention and showed to be attractive for people with ADHD.

2011-01-01

471

Memory Impairment in Children with Language Impairment  

ERIC Educational Resources Information Center

Aim: The aim of this study was to assess whether any memory impairment co-occurring with language impairment is global, affecting both verbal and visual domains, or domain specific. Method: Visual and verbal memory, learning, and processing speed were assessed in children aged 6 years to 16 years 11 months (mean 9y 9m, SD 2y 6mo) with current,…

Baird, Gillian; Dworzynski, Katharina; Slonims, Vicky; Simonoff, Emily

2010-01-01

472

A Telemedicine Program for Diabetic Retinopathy in a Veterans Affairs Medical Center—the Joslin Vision Network Eye Health Care Model  

Microsoft Academic Search

? PURPOSE: To extend access to diabetic eye care and characterize the extent of diabetic retinopathy {DR) and other ocular findings using the Joslin Vision Network (JVN). ? DESIGN: Retrospective observational cohort study. ? METHODS: Outpatients at the Togus VA Medical Center with diabetes mellitus, impaired fasting glu- cose, or impaired glucose tolerance underwent JVN protocol imaging. Images were transmitted

ANTHONY A. CAVALLERANO; JERRY D. CAVALLERANO; PAULA KATALINIC; BEATRICE BLAKE; MICHAEL RYNNE; PAUL R. CONLIN; KRISTEN HOCK; PAUL AIELLO; LLOYD M. AIELLO

473

Reliable vision-guided grasping  

NASA Technical Reports Server (NTRS)

Automated assembly of truss structures in space requires vision-guided servoing for grasping a strut when its position and orientation are uncertain. This paper presents a methodology for efficient and robust vision-guided robot grasping alignment. The vision-guided grasping problem is related to vision-guided 'docking' problems. It differs from other hand-in-eye visual servoing problems such as tracking in that the distance from the target is a relevant servo parameter. The methodology described in this paper is a hierarchy of levels in which the vision/robot interface is decreasingly 'intelligent', and increasingly fast. Speed is achieved primarily by information reduction. This reduction exploits the use of region-of-interest windows in the image plane and feature motion prediction. These reductions invariably require stringent assumptions about the image. Therefore, at a higher level, these assumptions are verified using slower, more reliable methods. This hierarchy provides for robust error recovery in that when a lower-level routine fails, the next-higher routine will be called and so on. A working system is described which visually aligns a robot to grasp a cylindrical strut. The system uses a single camera mounted on the end effector of a robot and requires only crude calibration parameters. The grasping procedure is fast and reliable, with a multi-level error recovery system.

Nicewarner, Keith E.; Kelley, Robert B.

1992-01-01