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1

Introduction Colour-impaired vision, where certain colours cannot be  

E-print Network

these colours. Dark green, brown, orange, and dark red in the first row appear as almost indistinguishable olive, where he produces print graphics for daily publication and interactive web graphics. nvkelso

Jenny, Bernhard

2

Colour vision requirements of firefighters.  

PubMed

To perform their job safely firefighters must be able to identify colours on industrial gas cylinders, portable fire extinguishers, road traffic signals and several pieces of firefighting equipment. Although good colour vision is necessary we believe that the existing colour vision standard, which bars entry to the fire service to applicants who fail more than two plates of the Ishihara test, is unnecessarily stringent. We have identified and quantified the colour coded information encountered by firefighters. Colours were plotted on the CIE chromaticity diagram (1931) and isochromatic zones, which document the colour confusions of colour deficient observers, superimposed. This novel technique established possible colour confusions in different types of colour deficiency. Analysis of the results showed that red/green dichromats (protanopes and deuteranopes), severe deuteranomalous trichromats who fail the Farnsworth D15 test, and protanomalous trichromats are unsuitable for firefighting work. However, people with slight deuteranomalous trichromatism who pass the D15 test, are not disadvantaged and can be employed safely as firefighters. A new colour vision standard and a new testing procedure is recommended. PMID:8776247

Margrain, T H; Birch, J; Owen, C G

1996-04-01

3

Impairments to Vision  

MedlinePLUS

... an external Non-Government web site. Impairments to Vision Normal Vision Diabetic Retinopathy Age-related Macular Degeneration In this ... pictures, fixate on the nose to simulate the vision loss. In diabetic retinopathy, the blood vessels in ...

4

HUMAN COLOUR VISION: 2. COLOUR APPEARANCE AND CORTICAL TRANSFORMATIONS  

E-print Network

HUMAN COLOUR VISION: 2. COLOUR APPEARANCE AND CORTICAL TRANSFORMATIONS JOHN S. WERNER Department in area V1 vary much more in their colour tuning than in LGN, and they have significantly more S is a "colour centre" in the monkey brain, and it is equally unlikely to be homologous with those regions

Olshausen, Bruno

5

Ultraviolet Colour Vision and Ornamentation in Bluethroats  

Microsoft Academic Search

Many birds see in the ultraviolet (300-400 nm), but there is limited evidence for colour communication (signalling by spectral shape independently of brightness) in this 'hidden' waveband. Such data are critical for the understanding of extravagant plumage colours, some of which show considerable UV reflectance. We investigated UV colour vision in female social responses to the male UV\\/violet ornament in

Staffan Andersson; Trond Amundsen

1997-01-01

6

Limits of colour vision in dim light.  

PubMed

Humans and most vertebrates have duplex retinae with multiple cone types for colour vision in bright light, and one single rod type for achromatic vision in dim light. Instead of comparing signals from multiple spectral types of photoreceptors, such species use one highly sensitive receptor type thus improving the signal-to-noise ratio at night. However, the nocturnal hawkmoth Deilephila elpenor, the nocturnal bee Xylocopa tranquebarica and the nocturnal gecko Tarentola chazaliae can discriminate colours at extremely dim light intensities. To be able to do so, they sacrifice spatial and temporal resolution in favour of colour vision. We review what is known about colour vision in dim light, and compare colour vision thresholds with the optical sensitivity of the photoreceptors in selected animal species with lens and compound eyes. PMID:20883328

Kelber, Almut; Lind, Olle

2010-09-01

7

Occupational colour vision requirements for police officers.  

PubMed

Inclusion of public service professions in the UK Disability Discrimination Act in 2004 prompted a review of occupational colour vision requirements for police officers. Changes in the regulations which existed prior to 2003 were proposed. The aim of this study was to obtain the views of serving police officers in Northern Ireland on the importance of good colour discrimination in everyday police work and on the recruitment regulations for patrol constables introduced in 2003 in mainland UK. These views were obtained by means of a questionnaire and informal discussions. More than 65% of police officers who responded to the questionnaire considered that good colour vision was very important for effective policing. Fewer than 2% considered that colour vision was unimportant. Experienced police officers agreed that the employment of colour-deficient patrol constables, as permitted in the new regulations, would lead to reduced efficiency and organisational difficulties at the local level. A number of everyday activities were described which showed the need for accurate colour discrimination. The change in recruitment policy and the lack of clarity in the new regulations show inadequate appreciation of the needs of the occupation, of different types of colour vision anomalies and of the diagnostic function of colour vision tests. Failure to provide guidance on appropriate colour vision tests, examination procedures and counselling services is likely to result in inconsistent employment policies in different police forces. It is recommended that the colour vision standard in place prior to 2003 is reinstated at the recruitment stage. The Ishihara test should be used for screening, and colour-deficient applicants further examined with the Farnsworth D15 test as a replacement for the City University Test 2nd edition. PMID:19076554

Birch, Jennifer; Chisholm, Catharine M

2008-11-01

8

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

9

Colour vision deficiency in the medical profession.  

PubMed Central

Colour is often used as a sign in medicine, yet there have been few studies into the effects of a colour vision deficiency (CVD) on doctors' medical skills. Using a literature search, the results indicate the prevalence of CVD in the medical profession and its effects on medical skills. For the congenital form among male doctors in the United Kingdom, the prevalence is shown to be probably about the same as for the population at large; i.e. 8%. However, the data is insufficient for any estimate to be made of the small number of female doctors and for the acquired forms of CVD. The effect on skills is also shown. Because of certain features of their work, general practitioners may have special problems. Thus, it is concluded that medical students and doctors should be screened for the deficiency and advised about it, and that there should be more study of the effects of CVD on decision-making in general practice and some specialties. PMID:10562750

Spalding, J A

1999-01-01

10

The absolute threshold of colour vision in the horse.  

PubMed

Arrhythmic mammals are active both during day and night if they are allowed. The arrhythmic horses are in possession of one of the largest terrestrial animal eyes and the purpose of this study is to reveal whether their eye is sensitive enough to see colours at night. During the day horses are known to have dichromatic colour vision. To disclose whether they can discriminate colours in dim light a behavioural dual choice experiment was performed. We started the training and testing at daylight intensities and the horses continued to choose correctly at a high frequency down to light intensities corresponding to moonlight. One Shetland pony mare, was able to discriminate colours at 0.08 cd/m(2), while a half blood gelding, still discriminated colours at 0.02 cd/m(2). For comparison, the colour vision limit for several human subjects tested in the very same experiment was also 0.02 cd/m(2). Hence, the threshold of colour vision for the horse that performed best was similar to that of the humans. The behavioural results are in line with calculations of the sensitivity of cone vision where the horse eye and human eye again are similar. The advantage of the large eye of the horse lies not in colour vision at night, but probably instead in achromatic tasks where presumably signal summation enhances sensitivity. PMID:19002261

Roth, Lina S V; Balkenius, Anna; Kelber, Almut

2008-01-01

11

Estimating limits on colour vision performance in natural scenes  

E-print Network

633 Estimating limits on colour vision performance in natural scenes David H. FOSTER School scenes under different daylights. Three limits were estimated for each scene: the number of discriminable coloured surfaces under a single daylight, the relative frequency of metamerism across two daylights, and

Foster, David H.

12

Colour vision in diurnal and nocturnal hawkmoths.  

PubMed

Diurnal and nocturnal hawkmoths (Sphingidae, Lepidoptera) have three spectral types of receptor sensitive to ultraviolet, blue and green light. As avid flower visitors and pollinators, they use olfactory and visual cues to find and recognise flowers. Moths of the diurnal species Macroglossum stellatarum and the nocturnal species Deilephila elpenor, Hyles lineata and Hyles gallii use and learn the colour of flowers. Nocturnal species can discriminate flowers at starlight intensities when humans and honeybees are colour-blind. M. stellatarum can use achromatic, intensity-related cues if colour cues are absent, and this is probably also true for D. elpenor. Both species can recognise colours even under a changed illumination colour. PMID:21680465

Kelber, Almut; Balkenius, Anna; Warrant, Eric J

2003-08-01

13

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

14

[Inherited colour vision deficiencies--from Dalton to molecular genetics].  

PubMed

In recent years, great advances have been made in our understanding of the molecular basis of colour vision defects, as well as of the patterns of genetic variation in individuals with normal colour vision. Molecular genetic analyses have explained the diversity of types and degrees of severity in colour vision anomalies, their frequencies, pronounced individual variations in test results, etc. New techniques have even enabled the determination of John Dalton's real colour vision defect, 150 years after his death. Inherited colour vision deficiencies most often result from the mutations of genes that encode cone opsins. Cone opsin genes are linked to chromosomes 7 (the S or "blue" gene) and X (the L or "red" gene and the M or "green" gene). The L and M genes are located on the q arm of the X chromosome in a head-to-tail array, composed of 2 to 6 (typically 3) genes--a single L is followed by one or more M genes. Only the first two genes of the array are expressed and contribute to the colour vision phenotype. The high degree of homology (96%) between the L and M genes predisposes them to unequal recombination, leading to gene deletion or the formation of hybrid genes (comprising portions of both the L and M genes), explaining the majority of the common red-green colour vision deficiencies. The severity of any deficiency is influenced by the difference in spectral sensitivity between the opsins encoded by the first two genes of the array. A rare defect, S monochromacy, is caused either by the deletion of the regulatory region of the array or by mutations that inactivate the L and M genes. Most recent research concerns the molecular basis of complete achromatopsia, a rare disorder that involves the complete loss of all cone function. This is not caused by mutations in opsin genes, but in other genes that encode cone-specific proteins, e.g. channel proteins and transducin. PMID:16758855

Cvetkovi?, Dragana; Cvetkovi?, Dobrosav

2005-01-01

15

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

16

Correlation between dichromatic colour vision and jumping performance in horses.  

PubMed

There is general agreement that horses have dichromatic colour vision with similar capabilities to human beings with red-green colour deficiencies. However, whether colour perception has an impact on equine jumping performance and how pronounced the colour stimulus might be for a horse is unknown. The present study investigated the relationship between the colour of the fences (blue or green) and the show jumping performance of 20 horses ridden by two riders using an indoor and outdoor set of green and blue fences. In the indoor arena, significantly more touches and faults were made on blue fences in comparison to green fences (median difference of 2.5 bars). When only touched bars were included, a significant median difference of one bar was found. Mares (n?=?4) demonstrated more faults and had a significantly greater difference in touches and faults between the two colours than male horses (n?=?16). Repeating the same experiment with eight horses in an outdoor grass arena revealed no significant differences between the two colours. In order to draw any definite conclusions, more research concerning the colour perception, influence of contrast with the arena surface and sex of horse is required. PMID:25193409

Spaas, Julie; Helsen, Werner F; Adriaenssens, Maurits; Broeckx, Sarah; Duchateau, Luc; Spaas, Jan H

2014-10-01

17

Colour vision and response bias in a coral reef fish.  

PubMed

Animals use coloured signals for a variety of communication purposes, including to attract potential mates, recognize individuals, defend territories and warn predators of secondary defences (aposematism). To understand the mechanisms that drive the evolution and design of such visual signals, it is important to understand the visual systems and potential response biases of signal receivers. Here, we provide raw data on the spectral capabilities of a coral reef fish, the Picasso triggerfish Rhinecanthus aculeatus, which is potentially trichromatic with three cone sensitivities of 413 nm (single cone), 480 nm (double cone, medium sensitivity) and 528 nm (double cone, long sensitivity), and a rod sensitivity of 498 nm. The ocular media have a 50% transmission cut off at 405 nm. Behavioural experiments confirmed colour vision over their spectral range; triggerfish were significantly more likely to choose coloured stimuli over grey distractors, irrespective of luminance. We then examined whether response biases existed towards coloured and patterned stimuli to provide insight into how visual signals - in particular, aposematic colouration - may evolve. Triggerfish showed a preferential foraging response bias to red and green stimuli, in contrast to blue and yellow, irrespective of pattern. There was no response bias to patterned over monochromatic non-patterned stimuli. A foraging response bias towards red in fish differs from that of avian predators, who often avoid red food items. Red is frequently associated with warning colouration in terrestrial environments (ladybirds, snakes, frogs), whilst blue is used in aquatic environments (blue-ringed octopus, nudibranchs); whether the design of warning (aposematic) displays is a cause or consequence of response biases is unclear. PMID:23580729

Cheney, Karen L; Newport, Cait; McClure, Eva C; Marshall, N Justin

2013-08-01

18

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

19

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

20

Is screening for congenital colour vision deficiency in school students worthwhile? A review a.  

PubMed

This review analyses the literature on screening for congenital colour vision deficiency in school students, which predominantly uses the Ishihara test. The review was framed with respect to the established Wilson and Jungner criteria for screening programs. These criteria relate to the characteristics of the condition concerned, the performance of the screening test, the existence of treatment options and the performance of screening programs. The literature reviewed suggests that congenital colour vision deficiency has not been shown to increase risk of road traffic crashes and is not a preclusion to driver licensing in most developed countries. The occurrence of congenital colour vision deficiency has been used to limit entry into certain occupations; however, the value of screening school students with regard to occupational preclusion is questionable. Stronger evidence exists indicating no association between congenital colour vision deficiency and level of educational achievement. Studies showing any association between congenital colour vision deficiency and other health and lifestyle impacts were rare. The most commonly used screening test (using Ishihara pseudoisochromatic plates) performs well with respect to detecting red-green colour vision deficiencies. Finally, the only interventions we identified for congenital colour vision deficiency were management ones around the availability of specific tinted lenses and computer programs to aid colour perception in certain tasks. Given this picture, the weight of evidence appears to be in favour of not adopting (or discontinuing) routine colour vision screening programs for school students; however, it may be worthwhile for a career advisor to refer school students to an optometrist or ophthalmologist for colour vision screening, upon expression of interest in an occupation where normal colour vision is either particularly desirable or is a regulatory requirement. PMID:25039829

Ramachandran, Nishanthan; Wilson, Graham A; Wilson, Nick

2014-11-01

21

Suitability of School Textbooks for 5 to 7 Year Old Children with Colour Vision Deficiencies  

ERIC Educational Resources Information Center

Purpose: The aim of the present study was to determine, through colorimetric analysis, whether school textbooks for children aged 5 to 7 years contained tasks requiring normal colour vision discrimination for their resolution. In addition, the performance of a group of observers with diverse colour vision deficiencies was evaluated while…

Torrents, Aurora; Bofill, Francesc; Cardona, Genis

2011-01-01

22

The fiddler crab Uca mjoebergi uses colour vision in mate choice  

PubMed Central

Although the role of colour in mate choice is well known, few tests of colour vision have been based on mating behaviour. Females of the fiddler crab Uca mjoebergi have recently been shown to use claw coloration to recognize conspecific males. In this study I demonstrate that the females use colour vision for this task; preferentially approaching yellow claws over grey claws regardless of their intensity while failing to discriminate between yellow claws differing in intensity. This is one of only a handful of studies confirming the involvement of colour vision in mate choice and the first conclusive evidence in fiddler crabs. PMID:17848366

Detto, Tanya

2007-01-01

23

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

24

Polarizational colours could help polarization-dependent colour vision systems to discriminate between shiny and matt surfaces, but cannot unambiguously code surface orientation  

Microsoft Academic Search

It was hypothesized that egg-laying Papilio butterflies could use polarizational colours as a cue to detect leaf orientation and to discriminate between shiny and matt leaves. These hypotheses would be supported if the following general questions were answered positively: (1) Can surface orientation be unambiguously coded by the polarizational colours perceived by polarization-sensitive colour vision systems? (2) Are the changes

Ramón Hegedüs; Gábor Horváth

2004-01-01

25

Vision Impairment Among Older Adults Residing in Assisted Living  

PubMed Central

OBJECTIVE To examine rates of visual impairment of older adults in assisted living facilities (ALFs). METHODS Vision screening events were held at 12 ALFs in Jefferson County, Alabama for residents ?60 years of age. Visual acuity, cognitive status, and presence of eye conditions were assessed. RESULTS 144 residents were screened. 67.8% failed distance screening, 70.9% failed near screening, and 89.3% failed contrast sensitivity screening. 40.4% of residents had cognitive impairment and 89% had a least one diagnosed eye condition. Visual acuities did not differ significantly between cognitive status groups or with greater numbers of eye conditions. DISCUSSION This study is the first to provide information about vision impairment in the assisted living population. Of those screened, 70% had visual acuity worse than 20/40 for distance or near vision, and 90% had impaired contrast sensitivity. Cognitive impairment accounted for a small percentage of the variance in near vision and contrast sensitivity. PMID:23338786

Elliott, Amanda F.; McGwin, Gerald; Owsley, Cynthia

2013-01-01

26

A Modified Pseudoisochromatic Ishihara Colour Vision Test Based on Eastern Arabic Numerals  

PubMed Central

Congenital colour vision defects affect about 8% and 0.5% of the male and female population, respectively. Pseudoisochromatic Ishihara plates have shown to be successful in an early diagnosis of colour vision defects. This commonly used colour vision test was initially intended to identify those who suffered from red-green aspect of congenital colour blindness; however, it may be of use to reveal acquired colour vision defects as well. Despite the Ishihara plates’ value, there are a number of shortcomings in their current layout. We proposing a new colour plate modified from original Ishihara test. To best assist illiterates who are not able to read English, standard Ishihara plates have been translated to Eastern Arabic numerals, which are used in most parts of the Middle East, Central Asia and Africa populations. The purpose of the present modification was to present the new plates to these regions, but more research and study is required to work on the validity, reliability, and repeatability of these new plates. PMID:24600648

Heidary, Fatemeh; Gharebaghi, Reza

2013-01-01

27

Polymorphism of the long-wavelength cone in normal human colour vision  

NASA Astrophysics Data System (ADS)

Colour vision is based on the presence of multiple classes of cone each of which contains a different type of photopigment1. Colour matching tests have long revealed that the normal human has three cone types. Results from these tests have also been used to provide estimates of cone spectral sensitivities2. There are significant variations in colour matches made by individuals whose colour vision is classified as normal3-6. Some of this is due to individual differences in preretinal absorption and photopigment density, but some is also believed to arise because there is variation in the spectral positioning of the cone pigments among those who have normal colour vision. We have used a sensitive colour matching test to examine the magnitude and nature of this individual variation and here report evidence for the existence of two different long-wavelength cone mechanisms in normal humans. The different patterns of colour matches made by male and female subjects indicate these two mechanisms are inherited as an X-chromosome linked trait.

Neitz, Jay; Jacobs, Gerald H.

1986-10-01

28

Quality of life, impaired vision and social role in people with diabetes: a multicenter observational study.  

PubMed

Diabetic retinopathy may induce visual impairment. We evaluated vision-related quality of life in patients with visual acuity <5/10 in the better eye induced by retinopathy using the 25-item National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25). The NEI VFQ-25 was self-administered to 196 patients in 3 Italian centres (A, B and C; n = 64, 61 and 71, respectively) dedicated to DR screening and treatment. Patients in the 3 centres did not differ by age, gender, occupation and diabetes duration. Multivariate analysis demonstrated that reduced visual acuity was associated with decreased scores for General Vision, Near Activities, Distance Activities, Visual-Specific Social Functioning, Mental Health, Role Difficulties and Dependency, Driving, Colour Vision and Peripheral Vision (p < 0.01, all). Treatment by photocoagulation was associated with reduced scores in General Health (-8.3; p = 0.002), General Vision (-7.2; p = 0.001), Visual-Specific Role Difficulties (-8.8; p = 0.015) and Driving (-13.7; p = 0.003). Centre affiliation was associated with different scores for General Health, Ocular pain, Distance Activities, Visual-Specific Social Functioning and Role Difficulties and Peripheral Vision. Women had higher scores for General Vision (p = 0.015), Near Activities (p = 0.005), Distance Activities (p = 0.006), Visual-Specific Social Functioning (p = 0.03), Visual-Specific Mental Health (p = 0.035) and Colour Vision (p = 0.012). Diabetic retinopathy and vision loss modify the way people perceive their own ability to function autonomously. More data should be collected to confirm this interpretation and to guide the development of more appropriate settings to improve approach and support to patients. PMID:23526056

Trento, Marina; Passera, Pietro; Trevisan, Martina; Schellino, Francesca; Sitia, Elena; Albani, Stefano; Montanaro, Marcello; Bandello, Francesco; Scoccianti, Lucia; Charrier, Lorena; Cavallo, Franco; Porta, Massimo

2013-12-01

29

The intensity threshold of colour vision in a passerine bird, the blue tit (Cyanistes caeruleus).  

PubMed

Many vertebrates use colour vision for vital behaviour but their visual performance in dim light is largely unknown. The light intensity threshold of colour vision is known only for humans, horses and two parrot species. Here, we first explore this threshold in a passerine bird, the blue tit (Cyanistes caeruleus). Using classic conditioning of colour cues to food rewards in three individuals, we find a threshold ranging from 0.05 to 0.2 cd m(-2). Results are comparable to the two previously tested bird species. For tits, nest light conditions probably exceed that threshold, at least after sunrise. These results shed new light on the lively debate questioning the visual performance of cavity nesters and the evolutionary significance of egg and chick coloration. Although this needs further investigation, it is possible that blue tits exploit both colour and brightness cues when viewing their eggs, chicks or conspecifics in their nests. PMID:25214487

Gomez, Doris; Grégoire, Arnaud; Del Rey Granado, Maria; Bassoul, Marine; Degueldre, David; Perret, Philippe; Doutrelant, Claire

2014-11-01

30

Normality of colour vision in a compound heterozygous female carrying a protan and deutan defect  

PubMed Central

Background Inherited red-green colour vision defects are quite common, affecting nearly 1 in 10 males, but are less common in women, affecting about 1 in 250. However because red-green defects are X-linked, nearly 15% of females are heterozygous carriers of red-green colour deficiency. In addition, about 1 in 150 females are “double carriers”, where both of their X chromosomes have L/M gene arrays encoding a red-green defect. If a woman carries the same type of colour vision defect on each X-chromosome, she herself will be red-green colour deficient, whereas if she carries opposing defects (protan vs. deutan) on each X chromosome she will be trichromatic, owing to the process of X-inactivation. These women are referred to as compound heterozygotes, though very few have been reported. Moreover, questions remain as to whether the colour vision capacity of these women is comparable to that of “normal” trichromats. Methods We examined a compound heterozygote carrier of both protanopia and deuteranomaly. We also examined male members of her family representing both forms of red-green defect carried by the female proband. Complete colour vision testing was done, including Rayleigh matches, pseudoichromatic plates, unique hue measurements, and 100-Hue tests. Flicker-photometric ERG estimates of L:M cone ratio were obtained, as were Medmont C100 settings. Results Genetic analyses provided direct confirmation of compound heterozygosity. The compound heterozygote showed Schmidt’s sign, consistent with an extreme skew in her L:M cone ratio, and usually associated with protan carrier status. Conclusion Apart from Schmidt’s sign, we found the colour vision of the compound heterozygote to be indistinguishable from that of a normal trichromat. PMID:19473349

Tait, Diane M.; Carroll, Joseph

2012-01-01

31

Discriminating colours under LED illumination  

Microsoft Academic Search

We measured the discrimination efficiency of three LED clusters (RGB, RGB + Amber, cool White + Amber) using the desaturated Lanthony-Panel D15 colour vision test. Compared with a continuous spectrum illumination, all LED clusters impair colour discrimination, with a severe impairment for RGB LED cluster. 1. PURPOSE LED technology offers light sources with narrow spectrum in the visible range. At

Françoise Viénot; Elodie Mahler; Lucile Serreault; Margalith Harrar; Jean-Jacques Ezrati; Pierre Pérignon; Alain Bricoune

32

“Eye”Dentifying Vision Impairment in the Geriatric Patient  

Microsoft Academic Search

Vision impairment is highly prevalent yet un- detected in the elderly population. Without screening and early detection age-related vi- sion loss can lead to various adverse effects. The purpose of this review is to assess the methods of screening geriatric patients for visual impairment that can be employed by nurse practitioners in the primary care set- ting. A series of

Melissa A. Kalinowski

2008-01-01

33

Vision impairment in the Pacific region  

PubMed Central

The Western Pacific region is one of great diversity, containing the most populous country, China, and many small Pacific island countries. This review describes the prevalence of blindness and vision loss, illustrates the changing trends in the important causes of vision loss and blindness, and the stages of development of the delivery of eye care services across this region. PMID:12034678

Keeffe, J E; Konyama, K; Taylor, H R

2002-01-01

34

"Eye" dentifying vision impairment in the geriatric patient.  

PubMed

Vision impairment is highly prevalent yet undetected in the elderly population. Without screening and early detection age-related vision loss can lead to various adverse effects. The purpose of this review is to assess the methods of screening geriatric patients for visual impairment that can be employed by nurse practitioners in the primary care setting. A series of databases were searched utilizing the key words aged, geriatric, vision, vision tests, and screening. The Snellen chart, Pinhole assessment, Ophthalmoscope, Cardiff acuity test, Amsler grid, and subjective measures are discussed. All must be utilized cautiously because research has shown that these screening methods are limited in their sensitivity and specificity in detecting ocular disease. No combination of tools is ideal for identifying age-related vision loss although implications for practice are implied. PMID:18394513

Kalinowski, Melissa A

2008-01-01

35

The spectral input systems of hymenopteran insects and their receptor-based colour vision  

Microsoft Academic Search

Spectral sensitivity functions S(?) of single photoreceptor cells in 43 different hymenopteran species were measured intracellularly with the fast spectral scan method. The distribution of maximal sensitivity values (?max) shows 3 major peaks at 340 nm, 430 nm and 535 nm and a small peak at 600 nm. Predictions about the colour vision systems of the different hymenopteran species are

Dagrnar Peitsch; Andrea Fietz; Horst Hertel; John de Souza; Dora Fix Ventura; Randolf Menzel

1992-01-01

36

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

37

Clinical analysis of colour vision deficiencies with The City University test.  

PubMed

The City University colour vision test (CUCVT) was used for the examination of 158 subjects suffering from congenital colour vision defects (36 protanopes, 122 deutanopes) and its results were compared with that of an anomaloscope and of the panel D-15. 23% of the subjects classified as protanopes and 98% of the subjects classified as deuteranopes by means of the anomaloscope were also classified as such by means of the CUCVT, while 93% of the subjects classified as protanomalous and 90% of the subjects classified as deuteranomalous by means of the anomaloscope gave normal answers at the CUCVT. The results of the CUCVT were almost the same as with panel D-15 except protanopia. The colour spots of each plate of the CUCVT were plotted on a CIE chromaticity diagram and the results of this study are also reported. PMID:310022

Ohta, Y; Kogure, S; Izutsu, Y; Miyamoto, T; Nagai, I

1978-01-01

38

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

39

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. PMID:23109740

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

2012-01-01

40

Proposed protocol for a multi-centre study to compare clinical and trade tests of colour vision in firefighters.  

PubMed

Fire-brigade recruits in the UK have their colour vision screened using the Ishihara test. This is unsatisfactory because it rejects subjects with minor deficiencies in colour vision and does not test for blue defects. The Home Office is currently reviewing its recommendations on visual standards. This paper summarizes defects in colour vision, discusses alternative clinical and trade tests for the fire-brigade, and proposes a multi-centre study to collect data on the performance of fire-brigade recruits in clinical and trade tests. PMID:7841418

Rees, H

1994-12-01

41

Causes of vision impairment and assessment of need for low vision services for students of blind schools in Nepal  

Microsoft Academic Search

Background: The present study isrst of its kind to evaluate causes of visual impairment of blind students in Nepal and assess their need for low vision rehabilitation services. Aim: To evaluate causes of vision impairment of students enrolled in blind schools in Nepal and assess the need for low vision rehabilitation services in these students. Materials and methods: A survey

Kansakar I; Thapa HB; Salma KC; Ganguly S; Kandel RP; Rajasekaran S

42

Colour Vision and Distant Visual Acuity of Elite and Junior Cricketers: Educational and Sporting Implications for Students  

Microsoft Academic Search

vidence suggests male children and adolescents spend increasingly more of their leisure time engaged in indoor activities such as the viewing of computer or television screens. Consequently, time spent on outdoor activities that require distant visual acuity or acute, sharp vision is considerably less. Furthermore, 8% of the male population are known to have colour vision problems. A study was

Afaf Tourky; Brendan Bartlett; Vikki Hill; Michael Jeh

43

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. PMID:23755352

Bompas, Aline; Kendall, Grace; Sumner, Petroc

2013-01-01

44

Photoreceptor sectral sensitivities in terrestrial animals: adaptations for luminance and colour vision  

PubMed Central

This review outlines how eyes of terrestrial vertebrates and insects meet the competing requirements of coding both spatial and spectral information. There is no unique solution to this problem. Thus, mammals and honeybees use their long-wavelength receptors for both achromatic (luminance) and colour vision, whereas flies and birds probably use separate sets of photoreceptors for the two purposes. In particular, we look at spectral tuning and diversification among ‘long-wavelength’ receptors (sensitivity maxima at greater than 500?nm), which play a primary role in luminance vision. Data on spectral sensitivities and phylogeny of visual photopigments can be incorporated into theoretical models to suggest how eyes are adapted to coding natural stimuli. Models indicate, for example, that animal colour vision—involving five or fewer broadly tuned receptors—is well matched to most natural spectra. We can also predict that the particular objects of interest and signal-to-noise ratios will affect the optimal eye design. Nonetheless, it remains difficult to account for the adaptive significance of features such as co-expression of photopigments in single receptors, variation in spectral sensitivities of mammalian L-cone pigments and the diversification of long-wavelength receptors that has occurred in several terrestrial lineages. PMID:16096084

Osorio, D; Vorobyev, M

2005-01-01

45

The evolution of the multicoloured face of mandrills: insights from the perceptual space of colour vision.  

PubMed

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. PMID:22216180

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

2011-01-01

46

Visual search performance of patients with vision impairment: effect of JPEG image enhancement  

E-print Network

Visual search performance of patients with vision impairment: effect of JPEG image enhancement Gang & Peli E. Visual search performance of patients with vision impairment: effect of JPEG image enhancement, image enhancement, low vision rehabilitation, visual search Correspondence: Gang Luo E-mail address

Peli, Eli

47

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

48

The VIVID model : accessible IT e-learning environments for the vision impaired.  

E-print Network

??Sighted learners and vision impaired learners experience different problems when accessing e-learning environments. Web designers use complex visual images and interactive features which learners with… (more)

Permvattana, Ruchireak

2012-01-01

49

VISION PROBLEMS IN THE U.S.-PREVALENCE OF ADULT VISION IMPAIRMENT AND AGE-RELATED EYE DISEASES IN AMERICA  

EPA Science Inventory

Leading causes of vision impairment and blindness in the United States. Diabetic retinopathy? Age-related macular degeneration (AMD)? Cataract? Glaucoma? The Vision Problems in the U.S. study was the result of a 2001 consensus meeting, convened by the National Eye Institute and ...

50

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

51

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

Code of Federal Regulations, 2010 CFR

...false What information must carriers give individuals with vision or hearing impairment on aircraft? 382.119 Section 382...119 What information must carriers give individuals with vision or hearing impairment on aircraft? (a) As a...

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, 2012 CFR

...false What information must carriers give individuals with vision or hearing impairment on aircraft? 382.119 Section 382...119 What information must carriers give individuals with vision or hearing impairment on aircraft? (a) As a...

2012-01-01

53

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

Code of Federal Regulations, 2011 CFR

...false What information must carriers give individuals with vision or hearing impairment on aircraft? 382.119 Section 382...119 What information must carriers give individuals with vision or hearing impairment on aircraft? (a) As a...

2011-01-01

54

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

Code of Federal Regulations, 2013 CFR

...false What information must carriers give individuals with vision or hearing impairment on aircraft? 382.119 Section 382...119 What information must carriers give individuals with vision or hearing impairment on aircraft? (a) As a...

2013-01-01

55

Vision of the active limb impairs bimanual motor tracking in young and older adults  

PubMed Central

Despite the intensive investigation of bimanual coordination, it remains unclear how directing vision toward either limb influences performance, and whether this influence is affected by age. To examine these questions, we assessed the performance of young and older adults on a bimanual tracking task in which they matched motor-driven movements of their right hand (passive limb) with their left hand (active limb) according to in-phase and anti-phase patterns. Performance in six visual conditions involving central vision, and/or peripheral vision of the active and/or passive limb was compared to performance in a no vision condition. Results indicated that directing central vision to the active limb consistently impaired performance, with higher impairment in older than young adults. Conversely, directing central vision to the passive limb improved performance in young adults, but less consistently in older adults. In conditions involving central vision of one limb and peripheral vision of the other limb, similar effects were found to those for conditions involving central vision of one limb only. Peripheral vision alone resulted in similar or impaired performance compared to the no vision (NV) condition. These results indicate that the locus of visual attention is critical for bimanual motor control in young and older adults, with older adults being either more impaired or less able to benefit from a given visual condition.

Boisgontier, Matthieu P.; Van Halewyck, Florian; Corporaal, Sharissa H. A.; Willacker, Lina; Van Den Bergh, Veerle; Beets, Iseult A. M.; Levin, Oron; Swinnen, Stephan P.

2014-01-01

56

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 ...

57

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

58

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

59

Published online 30 July 2002 The uses of colour vision: behavioural and  

E-print Network

that we learn from our experience of colour and greyscale images in photography, in the cinema and on television. However, this paper makes the case that the distinc- tiveness could arise naturally from signals or a by-product of our experience. In principle, colour images are qualitatively different from

Nottingham, University of

60

Mapping the timecourse of goal-directed attention to location and colour in human vision.  

PubMed

Goal-directed attention prioritises perception of task-relevant stimuli according to location, features, or onset time. In this study we compared the behavioural timecourse of goal-directed selection to locations and colours by varying the stimulus-onset asynchrony (SOA) between cue and target in a strategic cueing paradigm. Participants reported the presence or absence of a target following prior information regarding its location or colour. Results revealed that preparatory selection by colour is more effective at enhancing perceptual sensitivity than selection by location, even though both types of cue provided equivalent overall information. More detailed analysis revealed that this advantage arose due a limitation of spatial attention in maintaining a sufficiently broad focus (>2°) for target detection across multiple stimuli. In contrast, when target stimuli fell within 2° of the spatial attention spotlight, the strategic advantages and speed of spatial and colour attention were equated. Our findings are consistent with the conclusion that, under spatially optimal conditions, prior spatial and colour information are equally proficient at guiding top-down selection. When spatial locations are ambiguous, however, colour-based selection is the more efficient mechanism. PMID:22366727

Adams, Rachel C; Chambers, Christopher D

2012-03-01

61

Parallel evolution of angiosperm colour signals: common evolutionary pressures linked to hymenopteran vision  

PubMed Central

Flowering plants in Australia have been geographically isolated for more than 34 million years. In the Northern Hemisphere, previous work has revealed a close fit between the optimal discrimination capabilities of hymenopteran pollinators and the flower colours that have most frequently evolved. We collected spectral data from 111 Australian native flowers and tested signal appearance considering the colour discrimination capabilities of potentially important pollinators. The highest frequency of flower reflectance curves is consistent with data reported for the Northern Hemisphere. The subsequent mapping of Australian flower reflectances into a bee colour space reveals a very similar distribution of flower colour evolution to the Northern Hemisphere. Thus, flowering plants in Australia are likely to have independently evolved spectral signals that maximize colour discrimination by hymenoptera. Moreover, we found that the degree of variability in flower coloration for particular angiosperm species matched the range of reflectance colours that can only be discriminated by bees that have experienced differential conditioning. This observation suggests a requirement for plasticity in the nervous systems of pollinators to allow generalization of flowers of the same species while overcoming the possible presence of non-rewarding flower mimics. PMID:22673351

Dyer, Adrian G.; Boyd-Gerny, Skye; McLoughlin, Stephen; Rosa, Marcello G. P.; Simonov, Vera; Wong, Bob B. M.

2012-01-01

62

Is colour cognitive?  

NASA Astrophysics Data System (ADS)

In recent years, colour-vision abilities have been rather generously ascribed to various invertebrates and even bacteria. This uncertainty of when to diagnose colour vision stems in part from confusing what colour vision can do with what it is. What colour vision can do is discriminate wavelength independent of intensity. However, if we take this as a definition of what colour vision is, then we might be obliged to conclude that some plants and bacteria have colour vision. Moreover, there is a similar confusion of what are necessary and what are sufficient mechanisms and behavioural abilities for colour vision. To humans, seeing in colour means seeing an image in which objects/lights have chromatic attributes—in contrast to the sensation that we have when viewing monochrome movies, or our experience in dim light when only rod vision is possible. The necessary basic equipment for this is to have at least two types of photoreceptors that differ in spectral sensitivity, and at least one type of spectrally opponent cell to compare the signals from the photoreceptors. Clearly, however, a necessary additional prerequisite for colour vision is to have vision, which entails the identification of shapes, sizes and locations of objects in the world. Thus, if an animal has colour vision, it should see an image in which distinct objects/lights have colour attributes. This distinguishes colour vision from wavelength discrimination, but also from what has historically been called wavelength-specific behaviour: a type of behaviour triggered by fixed configurations of spectral receptor signals; however, we discuss difficulties in diagnosing wavelength-specific behaviour as an indicator of the absence of colour vision. Finally, we discuss whether colour vision, by definition, contains a cognitive dimension for ordering and classifying perceptual experience.

Skorupski, Peter; Chittka, Lars

2011-03-01

63

An Overview of a UK Paediatric Visual Impaired Population and Low Vision Aid Provision  

ERIC Educational Resources Information Center

A retrospective study was carried out to evaluate the paediatric visual impaired population attending the Low Vision Clinic at Sheffield Teaching Hospitals NHS Foundation Trust, over a period of 14 years. Data were collected and analysed for children less than 17 years for prevalence, demographics, registration status, aetiologies, and types of…

Theodorou, Nana; Shipman, Tracey

2013-01-01

64

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

65

Neural Correlates of Impaired Vision in Adolescents Born Extremely Preterm and/or Extremely Low Birthweight  

PubMed Central

Background Adolescents born extremely preterm (EP; <28 weeks' gestation) and/or extremely low birthweight (ELBW; <1000 g) experience high rates of visual impairments, however the potential neural correlates of visual impairments in EP/ELBW adolescents require further investigation. This study aimed to: 1) compare optic radiation and primary visual cortical structure between EP/ELBW adolescents and normal birthweight controls; 2) investigate associations between perinatal factors and optic radiation and primary visual cortical structure in EP/ELBW adolescents; 3) investigate associations between optic radiation and primary visual cortical structure in EP/ELBW adolescents and the odds of impaired vision. Methods 196 EP/ELBW adolescents and 143 controls underwent magnetic resonance imaging at a mean age of 18 years. Optic radiations were delineated using constrained spherical deconvolution based probabilistic tractography. Primary visual cortices were segmented using FreeSurfer software. Diffusion tensor variables and tract volume of the optic radiations, as well as volume, surface area and thickness of the primary visual cortices, were estimated. Results Axial, radial and mean diffusivities within the optic radiations, and primary visual cortical thickness, were higher in the EP/ELBW adolescents than controls. Within EP/ELBW adolescents, postnatal corticosteroid exposure was associated with altered optic radiation diffusion values and lower tract volume, while decreasing gestational age at birth was associated with increased primary visual cortical volume, area and thickness. Furthermore, decreasing optic radiation fractional anisotropy and tract volume, and increasing optic radiation diffusivity in EP/ELBW adolescents were associated with increased odds of impaired vision, whereas primary visual cortical measures were not associated with the odds of impaired vision. Conclusions Optic radiation and primary visual cortical structure are altered in EP/ELBW adolescents compared with controls, with the greatest alterations seen in those exposed to postnatal corticosteroids and those born earliest. Structural alterations to the optic radiations may increase the risk of impaired vision in EP/ELBW adolescents. PMID:24663006

Kelly, Claire E.; Cheong, Jeanie L. Y.; Molloy, Carly; Anderson, Peter J.; Lee, Katherine J.; Burnett, Alice C.; Connelly, Alan; Doyle, Lex W.; Thompson, Deanne K.

2014-01-01

66

Relationship between Vision Impairment and Eye Disease to Vision-Specific Quality of Life and Function in Rural India: The Aravind Comprehensive Eye Survey  

Microsoft Academic Search

PURPOSE. To determine the impact of vision impairment and eye diseases on vision-specific quality of life and visual function in an older population of rural southern India. METHODS. Presenting and best-corrected visual acuity and bur- den of eye diseases were determined in a population aged 40 years and older, identified through a random cluster sampling strategy from 50 villages of

Praveen K. Nirmalan; James M. Tielsch; Joanne Katz; Ravilla D. Thulasiraj; Ramasamy Krishnadas; Rengappa Ramakrishnan; Alan L. Robin

2005-01-01

67

The relative impact of vision impairment and cardiovascular disease on quality of life: the example of pseudoxanthoma elasticum  

PubMed Central

Objective To investigate the impact of pseudoxanthoma elasticum (PXE), a rare hereditary disease of concurrent vision impairment (VI) and cardiovascular complications (CVCs), on vision-related (VRQoL) and health-related quality of life (HRQoL). Methods VRQoL and HRQoL were assessed using the Impact of Vision Impairment (IVI) questionnaire and the Short Form Health Survey (SF-36) in 107 PXE patients. Patients were stratified into four groups: A = no VI or CVC; B = CVCs only; C = VI only; and D = both VI and CVCs. Results Following Rasch analysis, the IVI was found to function as a vision-specific functioning and emotional well-being subscale, and the SF-36 as a health-related physical functioning and mental health subscale. The presence of VI and CVC were significant predictors of vision-specific functioning and emotional well-being (p < 0.001), with a clinically meaningful decrement in vision-specific functioning in patients with VI. No associations were found for the SF-36 Physical Functioning and Mental Health scores between any groups. Conclusions Vision impaired patients with PXE report significantly poorer vision-specific functioning than PXE patients without VI. In contrast, the relative impact of PXE on reported general HRQoL was much less. Our results suggest that vision impairment has the larger impact on QoL in this sample. PMID:22152229

2011-01-01

68

Incidence of neurological vision impairment in patients who suffer from an acquired brain injury  

Microsoft Academic Search

Between 30% and 35% of the population diagnosed with acquired brain injury (ABI) suffer from associated neurological vision impairment (NVI). Each year 1.5 million Americans sustain a traumatic brain injury (TBI) resulting in more than 4000 individuals on a daily basis (BIAUSA). The maximum incidence peaks in the 15–24 age range at 133 per 100,000 and 165 per 100,000 in

Gayle Clarke

2005-01-01

69

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. PMID:11797314

Good, W V

2001-01-01

70

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

71

Changes in colour contrast sensitivity associated with operating argon lasers.  

PubMed Central

A new test of colour vision using computer graphics has been used to obtain quantitative estimates of colour contrast sensitivity in ophthalmologists before and after they have treated patients by argon laser retinal photocoagulation. The colour vision of all subjects is normal when tested with the 100-hue test and HRR (Hardy, Rittler, Rand) plates, but colour contrast sensitivity measured along a tritan colour confusion line is selectively impaired after a treatment session. No such change occurs after a medical session spent examining patients with a fundus camera. In younger ophthalmologists the sensitivity recovers several hours after the treatment session ends, but in some persons there is a prolonged and possibly permanent elevation of threshold. PMID:2713300

Gunduz, K; Arden, G B

1989-01-01

72

Effects of peripheral and central vision impairment on mental imagery capacity. 1 Dulin, Hatwell, Pylyshyn, and Chokron  

E-print Network

and how visual disorders of peripheral or central origin lead to disorders of mental imagery capacityEffects of peripheral and central vision impairment on mental imagery capacity. 1 Dulin, Hatwell, Pylyshyn, and Chokron Effects of peripheral and central visual impairment on mental imagery capacity David

Pylyshyn, Zenon

73

Vision Impairment  

MedlinePLUS

... Schueler, MD How it Works Testimonials FAQ for Consumers FAQ for Physicians News Advertising Terms of Use Contact Us Site Map How ... yourself? About Stephen J. Schueler, M.D News Advertising How It Works FAQ for Consumers FAQ for Physicians Testimonials Site Map Terms of ...

74

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

75

Self-reported visual impairment and impact on vision-related activities in an elderly Nigerian population: report from the Ibadan Study of Ageing  

PubMed Central

Background Studies have shown an association between visual impairment and poor overall function. Studies from Africa and developing countries show high prevalence of visual impairment. More information is needed on the community prevalence and impact of visual impairment among elderly Africans. Methods A multi-stage stratified sampling of households was implemented to select persons aged 65 years and over in the south-western and north-central parts of Nigeria. Impairments of distant and near vision were based on subjective self-reports obtained with the use of items derived from the World Health Organization multi-country World Health Survey questionnaire. Impairment was defined as reporting much difficulty to questions on distant and near vision. Disabilities in activities of daily living (ADL) and instrumental activities of daily living (IADL) were evaluated by interview, using standardized scales. Results A total of 2054 subjects 957 (46.6%) males and 1097 (53.4) females responded to the questions on vision. 22% (n=453) of the respondents reported distant vision impairment, and 18% (n=377) reported near vision impairment (not mutually exclusive). 15% (n= 312) however reported impairment for both far and near vision. Impairment of distant vision increased progressively with age (P < 0.01). Persons with self reported near vision impairment had elevated risk of functional disability in several IADLs and ADLs than those with out. Distant vision impairment was less associated with role limitations in both ADLs and IADLs. Conclusion The prevalence of self reported distant visual impairment was high but that for near visual impairment was less than expected in this elderly African population. Impairment of near vision was found to carry with it a higher burden of functional disability than that of distant vision. PMID:18780258

Bekibele, CO; Gureje, Oye

2010-01-01

76

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. PMID:9440191

Van Newkirk, M R

1997-01-01

77

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. PMID:24008790

Abu Bakar, Nurul Farhana; Chen, Ai-Hong

2014-01-01

78

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. PMID:23619499

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

2014-01-01

79

No rainbow for grey bamboo sharks: evidence for the absence of colour vision in sharks from behavioural discrimination experiments.  

PubMed

Despite convincing data collected by microspectrophotometry and molecular biology, rendering sharks colourblind cone monochromats, the question of whether sharks can perceive colour had not been finally resolved in the absence of any behavioural experiments compensating for the confounding factor of brightness. The present study tested the ability of juvenile grey bamboo sharks to perceive colour in an experimental design based on a paradigm established by Karl von Frisch using colours in combination with grey distractor stimuli of equal brightness. Results showed that contrasts but no colours could be discriminated. Blue and yellow stimuli were not distinguished from a grey distractor stimulus of equal brightness but could be distinguished from distractor stimuli of varying brightness. In addition, different grey stimuli were distinguished significantly above chance level from one another. In conclusion, the behavioural results support the previously collected physiological data on bamboo sharks, which mutually show that the grey bamboo shark, like several marine mammals, is a cone monochromate and colourblind. PMID:25245080

Schluessel, V; Rick, I P; Plischke, K

2014-11-01

80

Comparison of Accessibility among Vision-impaired Patients Visiting Mobile and Stationary Hospitals in Rural Bangladesh  

PubMed Central

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

Chongsuvivatwong, Virasakdi; Mahmud, Hasib; Gupta, Pradip Sen

2013-01-01

81

Special home adaptation grants for members of the Armed Forces and veterans with certain vision impairment. Final rule.  

PubMed

The Department of Veterans Affairs (VA) is issuing a final rule to amend its adjudication regulations regarding special home adaptation grants for members of the Armed Forces and veterans with certain vision impairment. This regulatory amendment is necessary to conform the regulations to changes mandated in the Honoring America's Veterans and Caring for Camp Lejeune Families Act of 2012. PMID:25233534

2014-09-12

82

Colour Stability in Live Image Capturing Guy K. Kloss, Napoleon H. Reyes and Ken A. Hawick  

E-print Network

with a window (no artificial light) and an overcast sky (quite "neutral" daylight illumination). The weather vision; computer vision; digital video imaging; artificial intelligence; colour con- stancy; colour

Hawick, Ken

83

Epidemiological associations of vision impairment and health among a national cohort of 87,134 adults in Thailand  

PubMed Central

To date, over 300 million people worldwide live with low vision and blindness, imposing social and economic burdens on individual and families. Data derived from a cohort of 87,134 Thai adults. We report Odds Ratios (ORs) from logistic regression and derive Population Attributable Fractions (PAFs). Approximately 28% of the cohort members reported refractive errors and 8% had uncorrectable vision impairment. Awareness of refractive errors was associated with higher income and urban residence. Both types of vision impairment were positively associated with poor self-assessed health (adjusted ORs 1.23 to 2.03) and poor psychological health (adjusted ORs 1.13 to 1.63). PAFs show that correctable and uncorrectable vision impairments explain respectively 6.1% and 7.5% of poor self-assessed health, 3.5% and 4.7% of poor psychological health, and 2.2% and 3.1% of falls in the last year. Incorporating early detection and prevention at the primary healthcare level will help to promote the health of Thais. PMID:22247107

Yiengprugsawan, Vasoontara; Seubsman, Sam-ang; Sleigh, Adrian C

2013-01-01

84

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. PMID:23145224

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

2011-01-01

85

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. PMID:24620705

Pal, Joyojeet; Cutrell, Edward

2013-01-01

86

The contrast sensitivity of human colour vision to red-green and blue-yellow chromatic gratings.  

PubMed Central

A method of producing red-green and blue-yellow sinusoidal chromatic gratings is used which permits the correction of all chromatic aberrations. A quantitative criterion is adopted to choose the intensity match of the two colours in the stimulus: this is the intensity ratio at which contrast sensitivity for the chromatic grating differs most from the contrast sensitivity for a monochromatic luminance grating. Results show that this intensity match varies with spatial frequency and does not necessarily correspond to a luminance match between the colours. Contrast sensitivities to the chromatic gratings at the criterion intensity match are measured as a function of spatial frequency, using field sizes ranging from 2 to 23 deg. Both blue-yellow and red-green contrast sensitivity functions have similar low-pass characteristics, with no low-frequency attenuation even at low frequencies below 0.1 cycles/deg. These functions indicate that the limiting acuities based on red-green and blue-yellow colour discriminations are similar at 11 or 12 cycles/deg. Comparisons between contrast sensitivity functions for the chromatic and monochromatic gratings are made at the same mean luminances. Results show that, at low spatial frequencies below 0.5 cycles/deg, contrast sensitivity is greater to the chromatic gratings, consisting of two monochromatic gratings added in antiphase, than to either monochromatic grating alone. Above 0.5 cycles/deg, contrast sensitivity is greater to monochromatic than to chromatic gratings. PMID:3999044

Mullen, K T

1985-01-01

87

Bumblebees Bombus terrestris are important pollinators of angiosperms and use their colour vision both to detect flowers  

E-print Network

is the tomato Lycopersicon esculentum Mill. (Morandin et al., 2001a­c). The pollination of tomato plant flowers is the product of the spectral properties of the flower's pigments and the spectral quality of the radiation vision both to detect flowers (Spaethe et al., 2001) and to choose between flowers (Chittka et al., 1997

Chittka, Lars

88

"They Think They Know What's Best for Me": An Interpretative Phenomenological Analysis of the Experience of Inclusion and Support in High School for Vision-Impaired Students with Albinism  

ERIC Educational Resources Information Center

The challenges of social inclusion and access to the curriculum facing students with visual impairment in schools are well documented. The refreshed UK Vision Strategy (2013) seeks to improve education for students with vision impairment. In order to do this, it is important to understand how students with visual impairment experience education.…

Thurston, Mhairi

2014-01-01

89

Prevention of vision loss protects against age-related impairment in learning and memory performance in DBA/2J mice  

PubMed Central

The DBA/2J mouse is a model of pigmentary glaucoma in humans as it shows age-related increases in intraocular pressure (IOP), retinal ganglion cell death and visual impairment. Previously, we showed that visual ability declines from 9 to 12 months of age and visual impairment is correlated with poor learning and memory performance in visuo-spatial tasks but not in tasks that do not depend on visual cues. To test the “sensory impairment” hypothesis of aging, which postulates that sensory impaired individuals are disadvantaged in their performance on psychometric tests as a direct result of difficulties in sensory perception, we treated DBA/2J mice with a conventional glaucoma medication used in humans (Timoptic-XE, 0.00, 0.25, or 0.50%) daily from 9 weeks to 12 months of age to determine whether prevention of vision loss prevented the decline in visuo-spatial learning and memory performance. At all ages tested (3, 6, 9, and 12 months of age), mice treated with Timoptic-XE (0.25 and 0.50%) maintained a high level of performance, while 12 month old control mice (0.00%) exhibited impaired performance in visually-dependent, but not non-visual tasks. These results demonstrate that when sensory function is preserved, cognitive performance is normalized. Thus, as in many aging humans, DBA/2J mice show age-related decrements in performance on visually presented cognitive tests, not because of cognitive impairment but as a direct consequence of poor visual ability. Our results demonstrate that age-related impairment in performance in visuo-spatial tasks in DBA/2J mice can be prevented by the preservation of visual ability. PMID:24065919

Wong, Aimée A.; Brown, Richard E.

2013-01-01

90

Essay/Book review to appear in The Gerontologist VISION IMPAIRMENT AND REHABILITATION  

E-print Network

to consider contemporary studies that map out the functional geography of the cerebral cortex. Those of us and arrows. All sorts of things can go wrong, and often more than one does. These include genetic errors the recognition during the last two decades that good vision is not merely a medical issue; it is equally an issue

Sekuler, Robert

91

The Use of Visual Feedback during Signing: Evidence from Signers with Impaired Vision  

ERIC Educational Resources Information Center

The role of visual feedback during the production of American Sign Language was investigated by comparing the size of signing space during conversations and narrative monologues for normally sighted signers, signers with tunnel vision due to Usher syndrome, and functionally blind signers. The interlocutor for all groups was a normally sighted deaf…

Emmorey, Karen; Korpics, Franco; Petronio, Karen

2009-01-01

92

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

MedlinePLUS

... 4,195,966 Blindness 1,288,275 Low Vision 2,907,691 Myopia ? 1.0 diopters 34,119,279 Hyperopia ? 3.0 diopters 14,186,819 AMD* 2,069,403 Cataract 24,409,978 Diabetic Retinopathy 7,685,237 Glaucoma 2,719,379 * Age-related macular degeneration, age 50 and older E-mail ...

93

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

94

Applications of Colour Processing In Optical Inspection  

NASA Astrophysics Data System (ADS)

Humans are endowed with the facility to perceive colour. This not only provides an additional aesthetic dimension but also helps perform visual tasks efficiently. There are many occupations, including inspection, not open to those with defective colour vision. Todays machine vision systems are virtually all colour-blind. Yet there are applications where colour is intrinsic. Consider for example the inspection and grading of fruit, vegetables, biscuits and other food products. Consider also the widespread use of colour coding for wiring and components in the electrical and electronic industries. Automatic optical inspection of such things cannot be done without relating to colour. There are other applications where colour is not directly relevant but the additional information provided can help simplify and speed up the processing task. This paper reviews the nature of colour, relating the psychophysical aspects of colour perception and the physical properties of available sensors to the needs of an automatic inspection system. The theory of colour perception is based on the tri-stimulus theory which says that any colour may be matched using appropriate proportions of three primary colours. Although later experiments have suggested human colour perception is more complex, most electronic video sensors employ a three colour system. Usually the red, green and blue primary components are derived and may be used directly as sensory inputs to a vision system. However the primary representation of colour is not the most efficient means of encoding nor is it the most useful basis for interpretive processing. The R,G and B primary signals may be simply transformed into a new coordinate system where one of the axes represents true object colour or hue. Using this new colour space simplifies processing. These ideas are illustrated by an inspection example. The colour coded wires of a European power cable are identified to ensure that a power plug is safely wired. For this application a straightforward and reliable inspection system can only be produced using colour information.

Thomas, W. V.; Connolly, C.

1986-11-01

95

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

96

Relationship between vision and motor impairment in children with spastic cerebral palsy: new evidence from electrophysiology  

Microsoft Academic Search

The aim of the present study was to measure visual acuity (VA) by the sweep visual evoked potential method (sVEP) and relate it to the degree of motor impairment in children with spastic cerebral palsy (SCP). Monocular VA was estimated in 37 SCP children aged from 6 to 48 months, classified as tetraplegic ( n = 14), diplegic (n =

Solange Rios Salomão; Adriana Berezovsky; Filomena Maria de Haro; Dora Fix Ventura

2003-01-01

97

Vision Impairs the Abilities of Bats to Avoid Colliding with Stationary Obstacles  

PubMed Central

Background Free-flying insectivorous bats occasionally collide with stationary objects they should easily detect by echolocation and avoid. Collisions often occur with lighted objects, suggesting ambient light may deleteriously affect obstacle avoidance capabilities. We tested the hypothesis that free-flying bats may orient by vision when they collide with some obstacles. We additionally tested whether acoustic distractions, such as “distress calls” of other bats, contributed to probabilities of collision. Methodology/Principal Findings To investigate the role of visual cues in the collisions of free-flying little brown bats (Myotis lucifugus) with stationary objects, we set up obstacles in an area of high bat traffic during swarming. We used combinations of light intensities and visually dissimilar obstacles to verify that bats orient by vision. In early August, bats collided more often in the light than the dark, and probabilities of collision varied with the visibility of obstacles. However, the probabilities of collisions altered in mid to late August, coincident with the start of behavioural, hormonal, and physiological changes occurring during swarming and mating. Distress calls did not distract bats and increase the incidence of collisions. Conclusions/Significance Our findings indicate that visual cues are more important for free-flying bats than previously recognized, suggesting integration of multi-sensory modalities during orientation. Furthermore, our study highlights differences between responses of captive and wild bats, indicating a need for more field experiments. PMID:21085481

Orbach, Dara N.; Fenton, Brock

2010-01-01

98

Relationship between vision and motor impairment in children with spastic cerebral palsy: new evidence from electrophysiology  

Microsoft Academic Search

The aim of the present study was to measure visual acuity (VA) by the sweep visual evoked potential method (sVEP) and relate it to the degree of motor impairment in children with spastic cerebral palsy (SCP). Monocular VA was estimated in 37 SCP children aged from 6 to 48 months, classified as tetraplegic (n=14), diplegic (n=13), and hemiplegic (n=10), without

Marcelo Fernandes da Costa; Solange Rios Salomão; Adriana Berezovsky; Filomena Maria de Haro; Dora Fix Ventura

2004-01-01

99

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

PubMed

Mutations in the CACNA1F gene encoding the Cav1.4 Ca (2+) 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 mutant (2)-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. PMID:24051672

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

2013-01-01

100

Monitor, a Vibrotactile Aid for Environmental Perception: A Field Evaluation by Four People with Severe Hearing and Vision Impairment  

PubMed Central

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

Stenstrom, Ingeborg

2013-01-01

101

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

102

Vision-based measurement of temperature distribution in a 500kW model furnace using the two-colour method  

Microsoft Academic Search

This paper describes the design and evaluation of a novel optical instrumentation system that has been developed for the on-line continuous measurement of temperature distribution in a furnace. The system comprises optical filters, a CCD camera, a frame-grabber and associated software. Based on the two-colour method, the average temperature of the flame field is calculated from the ratio of averaged

Y. Huang; Y. Yan; G. Riley

2000-01-01

103

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...

104

Anim. Behav., 1997, 53, 10431052 Innate colour preferences and flexible colour learning in the  

E-print Network

interactions between flowering plants and their pollinators are the result of a long coevolutionary history, and the evolutionary history of their relationships, it is necessary to understand the sensory and behavioural colours with sugar rewards. Colour vision is an important component of intra- and inter

Weiss, Martha R.

105

A Model for Developing Programs To Improve the Use of Vision in Students Who Are Visually Impaired with Multiple Disabilities.  

ERIC Educational Resources Information Center

This article discusses a program that, by emphasizing individuality, integration, adaptability, and functionality (the IIAF model), improves the visual functioning of students who are visually impaired, have multiple disabilities, and function at a severely or profoundly impaired level. Examples of recommended visual learning activities are…

Li, Alicia

2003-01-01

106

In Support of Specialized Programs for Blind and Visually Impaired Children: The Impact of Vision Loss on Learning.  

ERIC Educational Resources Information Center

The learning needs of blind and visually impaired children can be categorized into three groups: (1) needs met by adapting the curriculum; (2) needs met by changing the instructional methodology; and (3) developmental and educational needs unique to these students. (Author/CB)

Hatlen, P. H.; Curry, S. A.

1987-01-01

107

Colour Guided Colour Image Steganography  

E-print Network

Information security has become a cause of concern because of the electronic eavesdropping. Capacity, robustness and invisibility are important parameters in information hiding and are quite difficult to achieve in a single algorithm. This paper proposes a novel steganography technique for digital color image which achieves the purported targets. The professed methodology employs a complete random scheme for pixel selection and embedding of data. Of the three colour channels (Red, Green, Blue) in a given colour image, the least two significant bits of any one of the channels of the color image is used to channelize the embedding capacity of the remaining two channels. We have devised three approaches to achieve various levels of our desired targets. In the first approach, Red is the default guide but it results in localization of MSE in the remaining two channels, which makes it slightly vulnerable. In the second approach, user gets the liberty to select the guiding channel (Red, Green or Blue) to guide the r...

Amirtharajan, R; Swarup, Motamarri Abhilash; K, Mohamed Ashfaaq; Rayappan, John Bosco Balaguru

2010-01-01

108

Floral colour diversity in plant communities, bee colour space and a null model  

PubMed Central

Evolutionary biologists have long hypothesized that the diversity of flower colours we see is in part a strategy to promote memorization by pollinators, pollinator constancy, and therefore, a directed and efficient pollen transfer between plants. However, this hypothesis has never been tested against a biologically realistic null model, nor were colours assessed in the way pollinators see them. Our intent here is to fill these gaps. Throughout one year, we sampled floral species compositions at five ecologically distinct sites near Berlin, Germany. Bee-subjective colours were quantified for all 168 species. A model of colour vision was used to predict how similar the colours of sympatric and simultaneously blooming flowers were for bees. We then compared flower colour differences in the real habitats with those of random plant communities. We did not find pronounced deviations from chance when we considered common plants. When we examined rare plants, however, we found significant divergence in two of the five plant communities. At one site, similarly coloured species were found to be more frequent than expected, and at the other two locations, flower colours were indistinguishable from a random distribution. These results fit theoretical considerations that rare plants are under stronger selective pressure to secure pollination than common plants. Our study illustrates the power of linking such distinct biological traditions as community ecology and the neuroethology of bee vision.

Gumbert, A.; Kunze, J.; Chittka, L.

1999-01-01

109

The colour centre in the cerebral cortex of man  

Microsoft Academic Search

ANATOMICAL and physiological studies have shown that there is an area specialized for the processing of colour (area V4) in the prestriate cortex of macaque monkey brain1. Earlier this century, suggestive clinical evidence for a colour centre in the brain of man2,3 was dismissed4-8 because of the association of other visual defects with the defects in colour vision4,5,7. However, since

C. J. Lueck; S. Zeki; K. J. Friston; M.-P. Deiber; P. Cope; V. J. Cunningham; A. A. Lammertsma; C. Kennard; R. S. J. Frackowiak

1989-01-01

110

Cognitive Impairment and Age-Related Vision Disorders: Their Possible Relationship and the Evaluation of the Use of Aspirin and Statins in a 65 Years-and-Over Sardinian Population  

PubMed Central

Neurological disorders (Alzheimer’s disease, vascular and mixed dementia) and visual loss (cataract, age-related macular degeneration, glaucoma, and diabetic retinopathy) are among the most common conditions that afflict people of at least 65?years of age. An increasing body of evidence is emerging, which demonstrates that memory and vision impairment are closely, significantly, and positively linked and that statins and aspirin may lessen the risk of developing age-related visual and neurological problems. However, clinical studies have produced contradictory results. Thus, the intent of the present study was to reliably establish whether a relationship exist between various types of dementia and age-related vision disorders, and to establish whether statins and aspirin may or may not have beneficial effects on these two types of disorders. We found that participants with dementia and/or vision problems were more likely to be depressed and displayed worse functional ability in basic and instrumental activities of daily living than controls. Mini mental state examination scores were significantly lower in patients with vision disorders compared to subjects without vision disorders. A closer association with macular degeneration was found in subjects with Alzheimer’s disease than in subjects without dementia or with vascular dementia, mixed dementia, or other types of age-related vision disorders. When we considered the associations between different types of dementia and vision disorders and the use of statins and aspirin, we found a significant positive association between Alzheimer’s disease and statins on their own or in combination with aspirin, indicating that these two drugs do not appear to reduce the risk of Alzheimer’s disease or improve its clinical evolution and may, on the contrary, favor its development. No significant association in statin use alone, aspirin use alone, or the combination of these was found in subjects without vision disorders but with dementia, and, similarly, none in subjects with vision disorders but without dementia. Overall, these results confirm the general impression so far; namely, that macular degeneration may contribute to cognitive disorders (Alzheimer’s disease in particular). In addition, they also suggest that, while statin and aspirin use may undoubtedly have some protective effects, they do not appear to be magic pills against the development of cognitive impairment or vision disorders in the elderly. PMID:25426067

Mandas, Antonella; Mereu, Rosa Maria; Catte, Olga; Saba, Antonio; Serchisu, Luca; Costaggiu, Diego; Peiretti, Enrico; Caminiti, Giulia; Vinci, Michela; Casu, Maura; Piludu, Stefania; Fossarello, Maurizio; Manconi, Paolo Emilio; Dessí, Sandra

2014-01-01

111

Polymorphism and Adaptation of Primate Colour Vision  

E-print Network

, University of Chester, Chester, UK C. M. Schaffner Á F. Aureli Instituto de Neuroetologia, Universidad, Linda M. Fedigan, Colleen M. Schaffner, Filippo Aureli and Shoji Kawamura Abstract Opsins provide Veracruzana, Xalapa, Mexico F. Aureli Research Centre in Evolutionary Anthropology and Palaeoecology

Fedigan, Linda M.

112

Frugal Colouring of Graphs  

Microsoft Academic Search

A k-frugal colouring of a graph G is a proper colouring of the vertices of G such that no colour appears more than k times in the neighbourhood of a vertex. This type of colouring was introduced by Hind, Molloy and Reed in 1997. In this paper, we study the frugal chromatic number of planar graphs, planar graphs with large

Omid Amini; Louis Esperet; Jan Van Den Heuvel

2007-01-01

113

SPRWeb: Preserving Subjective Responses to Website Colour Schemes through Automatic Recolouring  

E-print Network

with `warm' colour scheme, deuteranopic CVD simulation, standard recolouring, SPRWeb recolouring. ABSTRACT a subset of all colours because they have colour vision deficiency (CVD), resulting in an unequal and less-rich user experience on the Web. Traditionally, people with CVD have been supported by recolouring tools

Chen, Yiling

114

Aging and Vision  

PubMed Central

Given the increasing size of the older adult population in many countries, there is a pressing need to identify the nature of aging-related vision impairments, their underlying mechanisms, and how they impact older adults’ performance of everyday visual tasks. The results of this research can then be used to develop and evaluate interventions to slow or reverse aging-related declines in vision, thereby improving quality of life. Here we summarize salient developments in research on aging and vision over the past 25 years, focusing on spatial contrast sensitivity, vision under low luminance, temporal sensitivity and motion perception, and visual processing speed. PMID:20974168

Owsley, Cynthia

2010-01-01

115

Structural colouration of mammalian skin: convergent evolution of coherently scattering dermal collagen arrays  

E-print Network

in mammals In contrast with invertebrates and other vertebrate classes, integumentary structural colouration is rare in mammals (Fox, 1976). In all, violet, blue or green skin is known from only a few genera in the orders of marsupials and primates (Fig.?1... in heterozygous females only (Surridge et al., 2003). The evolution of structurally coloured skin only within mammalian lineages that have advanced, trichromatic colour vision supports the hypothesis that these integumentary colours function in intraspecific...

Prum, R. O.; Torres, Rodolfo H.

2004-05-01

116

Seasonal Changes in Colour: A Comparison of Structural, Melanin- and Carotenoid-Based Plumage Colours  

PubMed Central

Background Plumage coloration is important for bird communication, most notably in sexual signalling. Colour is often considered a good quality indicator, and the expression of exaggerated colours may depend on individual condition during moult. After moult, plumage coloration has been deemed fixed due to the fact that feathers are dead structures. Still, many plumage colours change after moult, although whether this affects signalling has not been sufficiently assessed. Methodology/Principal Findings We studied changes in coloration after moult in four passerine birds (robin, Erithacus rubecula; blackbird, Turdus merula; blue tit, Cyanistes caeruleus; and great tit, Parus major) displaying various coloration types (melanin-, carotenoid-based and structural). Birds were caught regularly during three years to measure plumage reflectance. We used models of avian colour vision to derive two variables, one describing chromatic and the other achromatic variation over the year that can be compared in magnitude among different colour types. All studied plumage patches but one (yellow breast of the blue tit) showed significant chromatic changes over the year, although these were smaller than for a typical dynamic trait (bill colour). Overall, structural colours showed a reduction in relative reflectance at shorter wavelengths, carotenoid-based colours the opposite pattern, while no general pattern was found for melanin-based colours. Achromatic changes were also common, but there were no consistent patterns of change for the different types of colours. Conclusions/Significance Changes of plumage coloration independent of moult are probably widespread; they should be perceivable by birds and have the potential to affect colour signalling. PMID:20644723

Delhey, Kaspar; Burger, Claudia; Fiedler, Wolfgang; Peters, Anne

2010-01-01

117

Colour and lighting in hospital design  

NASA Astrophysics Data System (ADS)

Little information or guidance has been available to assist the development of a hospital's visual environment. A report on lighting and colour design schemes, accessible to non professionals with responsibility for refurbishment strategies, was required by NHS Estates. Firstly, 20 hospitals were audited to establish a picture of current practice and to identify key issues where colour design could broadly enhance the environment for patients, staff and visitors. Critical areas were outlined in this report, where colour design can be utilised and applied, for the benefit of all users, from ambience to essential legal requirements such as colour contrast for the visually impaired. Provision of staff relaxation rooms that are different in terms of colour and lux levels from immediate work spaces, or thoughtfully designed areas for patients awaiting intensive treatment, have been shown to have some beneficial effects on a sense of well being. Colour and design have not been established as a definite cure for sickness and ill health, but certainly monotony and poor conditions in premises that have not been refurbished with any care, have had a detrimental affect on recovery rates and staff morale. The realisation that a well balanced and attractive environment is of major importance to patients' health is, in no way new; Florence Nightingale observed that 'a variety of form and brilliance of colour in the objects presented to patients are an actual means of recovery'.

Dalke, Hilary; Little, Jenny; Niemann, Elga; Camgoz, Nilgun; Steadman, Guillaume; Hill, Sarah; Stott, Laura

2006-06-01

118

Colourful Simplicial Depth  

Microsoft Academic Search

Inspired by Barany's Colourful Caratheodory Theorem (4), we introduce a colourful generalization of Liu's simplicial depth (13). We prove a parity property and con- jecture that the minimum colourful simplicial depth of any core point in any d-dimensional configuration is d 2 + 1 and that the maximum is d d+1 + 1. We exhibit configurations attain- ing each of

Antoine Deza; Sui Huang; Tamon Stephen; Tamás Terlaky

2006-01-01

119

Does Colour Preference Have a Role in Colour Term Acquisition?  

ERIC Educational Resources Information Center

A developmental association exists between colour preference and emerging colour term acquisition in young children. Colour preference might influence colour term acquisition by directing attention towards or away from a particular colour, making it more or less memorable. To investigate the role that colour preference may have in the acquisition…

Pitchford, Nicola J.; Davis, Emma E.; Scerif, Gaia

2009-01-01

120

Colours experienced in dreams.  

PubMed

Colours seen in dreams by six observers were recorded from memory and plotted on a CIE u, v, chromaticity diagram. Only about half the dreams recorded contained colour, and in those in which colour appeared the more saturated purples, blues and blue greens were absent. It is suggested that during achromatic dreams the areas of the visual cortex which seem to respond only to colour may be inoperative. The paucity of blue in dreams could be anatomically related to the small population of blue units in the colour areas of the cortex. PMID:165850

Padgham, C A

1975-02-01

121

Practical colour management  

NASA Astrophysics Data System (ADS)

Spectrophotometers have been successfully used for colour measurement. This paper addresses digital imaging as a complementary and alternative method of colour measurement and appearance and an effective communication tool as part of a practical colour management programme within the supply chain of a textile retailer. The specific needs—to measure and communicate textured dyed material and printed fabric—are discussed, as well as the colour specification and quality control (QC) of currently un-measurable fabrics and accessories. A unique method of using digital imaging for the assessment of colour fastness will also be discussed.

Williams, Susan

2006-06-01

122

Colour Measurements and Modeling  

NASA Astrophysics Data System (ADS)

The most common property to measure quality of any material is its appearance. Appearance includes colour, shape, size and surface conditions. The analysis of colour is especially an important consideration when determining the efficacy of variety of postharvest treatments. Consumers can easily be influenced by preconceived ideas of how a particular fruit or vegetable or a processed food should appear, and marketers often attempt to improve upon what nature has painted. Recently colour measurements have also been used as quality parameters and indicator of some inner constituents of the material. In spite of the significance of colour in food industries, many continue to analyze it inadequately. This chapter deals with theory of colour, colour scales and its measurement, sampling techniques, and modeling of colour values for correlating them with some internal quality parameters of selected fruits.

Jha, Shyam N.

123

Optimality of the basic colour categories for classification  

PubMed Central

Categorization of colour has been widely studied as a window into human language and cognition, and quite separately has been used pragmatically in image-database retrieval systems. This suggests the hypothesis that the best category system for pragmatic purposes coincides with human categories (i.e. the basic colours). We have tested this hypothesis by assessing the performance of different category systems in a machine-vision task. The task was the identification of the odd-one-out from triples of images obtained using a web-based image-search service. In each triple, two of the images had been retrieved using the same search term, the other a different term. The terms were simple concrete nouns. The results were as follows: (i) the odd-one-out task can be performed better than chance using colour alone; (ii) basic colour categorization performs better than random systems of categories; (iii) a category system that performs better than the basic colours could not be found; and (iv) it is not just the general layout of the basic colours that is important, but also the detail. We conclude that (i) the results support the plausibility of an explanation for the basic colours as a result of a pressure-to-optimality and (ii) the basic colours are good categories for machine vision image-retrieval systems. PMID:16849219

Griffin, Lewis D

2005-01-01

124

Rockpool gobies change colour for camouflage.  

PubMed

Camouflage is found in a wide range of species living in numerous habitat types, offering protection from visually guided predators. This includes many species from the intertidal zone, which must cope with background types diverse in appearance and with multiple predator groups foraging at high and low tide. Many animals are capable of either relatively slow (hours, days, weeks) or rapid (seconds and minutes) colour change in order to better resemble the background against which they are found, but most work has been restricted to a few species or taxa. It is often suggested that many small intertidal fish are capable of colour change for camouflage, yet little experimental work has addressed this. Here, we test rock gobies (Gobius paganellus) for colour change abilities, and whether they can tune their appearance to match the background. In two experiments, we place gobies on backgrounds of different brightness (black or white), and of different colours (red and blue) and use digital image analysis and modelling of predator (avian) vision to quantify colour and luminance (perceived lightness) changes and camouflage. We find that gobies are capable of rapid colour change (occurring within one minute), and that they can change their luminance on lighter or darker backgrounds. When presented on backgrounds of different colours, gobies also change their colour (hue and saturation) while keeping luminance the same. These changes lead to predicted improvements in camouflage match to the background. Our study shows that small rockpool fish are capable of rapid visual change for concealment, and that this may be an important mechanism in many species to avoid predation, especially in complex heterogeneous environments. PMID:25333382

Stevens, Martin; Lown, Alice E; Denton, Alexander M

2014-01-01

125

Rockpool Gobies Change Colour for Camouflage  

PubMed Central

Camouflage is found in a wide range of species living in numerous habitat types, offering protection from visually guided predators. This includes many species from the intertidal zone, which must cope with background types diverse in appearance and with multiple predator groups foraging at high and low tide. Many animals are capable of either relatively slow (hours, days, weeks) or rapid (seconds and minutes) colour change in order to better resemble the background against which they are found, but most work has been restricted to a few species or taxa. It is often suggested that many small intertidal fish are capable of colour change for camouflage, yet little experimental work has addressed this. Here, we test rock gobies (Gobius paganellus) for colour change abilities, and whether they can tune their appearance to match the background. In two experiments, we place gobies on backgrounds of different brightness (black or white), and of different colours (red and blue) and use digital image analysis and modelling of predator (avian) vision to quantify colour and luminance (perceived lightness) changes and camouflage. We find that gobies are capable of rapid colour change (occurring within one minute), and that they can change their luminance on lighter or darker backgrounds. When presented on backgrounds of different colours, gobies also change their colour (hue and saturation) while keeping luminance the same. These changes lead to predicted improvements in camouflage match to the background. Our study shows that small rockpool fish are capable of rapid visual change for concealment, and that this may be an important mechanism in many species to avoid predation, especially in complex heterogeneous environments. PMID:25333382

Stevens, Martin; Lown, Alice E.; Denton, Alexander M.

2014-01-01

126

Hearing Impairment and Dual Sensory Impairment Are Associated with Increased Mortality in Older Men  

MedlinePLUS

... Impairment are Associated with Increased Mortality in Older Men Researchers from the National Institutes of Health (NIH) ... impairment (vision and hearing impairment combined) in older men are associated with increased mortality from cardiovascular disease ( ...

127

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. PMID:20580907

Owsley, Cynthia; McGwin, Gerald

2010-01-01

128

(Computer) Vision without Sight  

PubMed Central

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

129

The colour preference control based on two-colour combinations  

NASA Astrophysics Data System (ADS)

This paper proposes a framework of colour preference control to satisfy the consumer's colour related emotion. A colour harmony algorithm based on two-colour combinations is developed for displaying the images with several complementary colour pairs as the relationship of two-colour combination. The colours of pixels belonging to complementary colour areas in HSV colour space are shifted toward the target hue colours and there is no colour change for the other pixels. According to the developed technique, dynamic emotions by the proposed hue conversion can be improved and the controlled output image shows improved colour emotions in the preference of the human viewer. The psychophysical experiments are conducted to investigate the optimal model parameters to produce the most pleasant image to the users in the respect of colour emotions.

Hong, Ji Young; Kwak, Youngshin; Park, Du-Sik; Kim, Chang Yeong

2008-02-01

130

In Colour for Architecture, published in 1976, the editors, Tom Porter and Byron Mikellides, explain that their book was "produced out of an awareness that colour,  

E-print Network

by pigments in the cones (photoreceptors used for color vision) at the back of the eye. The response color was then especially salient in Britain--where the book was published--which had just begun by fields of bright color. The mood is more optimistic in Colour for Architecture's successor, Colour

Hilber, David

131

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

132

Colouring planar graphs  

Microsoft Academic Search

There is no known polynomial time 4-colouring algorithm for planar graphs, except the algorithms that can be derived from\\u000a the proofs of Appel et al. and Robertson et al. An alternative way to colour planar graphs is to investigate the problem of finding nowhere-zero k-flows in graphs.

Paulette Lieby

133

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

134

Adaptive coat colour polymorphism in the Kermode bear of coastal British Columbia  

E-print Network

bear (Ursus americanus kermodei Hornaday) occurring on several small islands off the mid vision ­ Ursus americanus kermodei. INTRODUCTION The diversity of general coat colours among terres polymorphisms in a large vertebrate occurs in the coat colour of black bear (Ursus americanus). Throughout most

Reimchen, Thomas E.

135

Quantitative Luminance And Colour Representation With CRT Displays  

NASA Astrophysics Data System (ADS)

Colour displays in image processing admit grey scales as well as colour scales for the visual representation of image information. Pseudocolours can be used to enhance the discriminability of different parts of the image. Luminance scales, on the other hand, are preferred for representing fine detail as human colour vision is limited to relatively low spatial frequencies. In the present paper, the generation of quantitative luminance and colour scales with CRT displays is discussed. This includes the colour characteristics of CRTs as well as a recapitulation of the CIE 1931 (X, Y, Z) tristimulus colorimetry system. The CIE 1976 UCS diagram (u', v') is used as an approximation to a perceptually uniform representation of chromaticity. On this basis, it is shown how, for each pixel, luminance and colour (hue) can be chosen independently. In order to add colour as a further visual dimension to greyscale images, a set of equiluminant hues is proposed for each luminance level. The hues are chosen from equidistant steps around a circle in the (u', v') chromaticity diagram. This choice of colours is particularly suitable for the visual representation of a cyclic quantity like phase angle.

Brettel, Hans

1989-03-01

136

Increased conspicuousness can explain the match between visual sensitivities and blue plumage colours in fairy-wrens.  

PubMed

Colour signals are expected to match visual sensitivities of intended receivers. In birds, evolutionary shifts from violet-sensitive (V-type) to ultraviolet-sensitive (U-type) vision have been linked to increased prevalence of colours rich in shortwave reflectance (ultraviolet/blue), presumably due to better perception of such colours by U-type vision. Here we provide the first test of this widespread idea using fairy-wrens and allies (Family Maluridae) as a model, a family where shifts in visual sensitivities from V- to U-type eyes are associated with male nuptial plumage rich in ultraviolet/blue colours. Using psychophysical visual models, we compared the performance of both types of visual systems at two tasks: (i) detecting contrast between male plumage colours and natural backgrounds, and (ii) perceiving intraspecific chromatic variation in male plumage. While U-type outperforms V-type vision at both tasks, the crucial test here is whether U-type vision performs better at detecting and discriminating ultraviolet/blue colours when compared with other colours. This was true for detecting contrast between plumage colours and natural backgrounds (i), but not for discriminating intraspecific variability (ii). Our data indicate that selection to maximize conspicuousness to conspecifics may have led to the correlation between ultraviolet/blue colours and U-type vision in this clade of birds. PMID:23118438

Delhey, Kaspar; Hall, Michelle; Kingma, Sjouke A; Peters, Anne

2013-01-01

137

Increased conspicuousness can explain the match between visual sensitivities and blue plumage colours in fairy-wrens  

PubMed Central

Colour signals are expected to match visual sensitivities of intended receivers. In birds, evolutionary shifts from violet-sensitive (V-type) to ultraviolet-sensitive (U-type) vision have been linked to increased prevalence of colours rich in shortwave reflectance (ultraviolet/blue), presumably due to better perception of such colours by U-type vision. Here we provide the first test of this widespread idea using fairy-wrens and allies (Family Maluridae) as a model, a family where shifts in visual sensitivities from V- to U-type eyes are associated with male nuptial plumage rich in ultraviolet/blue colours. Using psychophysical visual models, we compared the performance of both types of visual systems at two tasks: (i) detecting contrast between male plumage colours and natural backgrounds, and (ii) perceiving intraspecific chromatic variation in male plumage. While U-type outperforms V-type vision at both tasks, the crucial test here is whether U-type vision performs better at detecting and discriminating ultraviolet/blue colours when compared with other colours. This was true for detecting contrast between plumage colours and natural backgrounds (i), but not for discriminating intraspecific variability (ii). Our data indicate that selection to maximize conspicuousness to conspecifics may have led to the correlation between ultraviolet/blue colours and U-type vision in this clade of birds. PMID:23118438

Delhey, Kaspar; Hall, Michelle; Kingma, Sjouke A.; Peters, Anne

2013-01-01

138

Can Impaired Vision be Easily, Quickly and Safely Restored toward Health and Maintained Wellness, Using McLeod's Patent Pending Naturoptics Methods?  

NASA Astrophysics Data System (ADS)

A healthy eye has its large set of diffraction patterns, generated by the viewed scene, spread across the visible spectrum. Only the two of these simultaneously coincident with foveal cones, and rods, or with extra-foveal cones, are visually useful. This fact and pupil diameter changes with illumination, which cause proportional wavelength changes, drives the healthy visual state. A quasi-monochromatic interval is coincident with foveal cones, and rods. A shorter, partially overlapping interval aligns with extrafoveal cones, with about twenty nanometers separation. Wavelengths follow the Airy disk radius formula. An unhealthy eye is an eyeball deformed by self- induced vision abuse. Incorrect and effectively static stresses in the large external eye muscles displace and distort the patterns. Rebalancing the proper vision and muscle state are safely, quickly and rapidly restored by mimicking natural eye and head movements with naturoptics.

Courtmanche, Amanda; McLeod, Roger; McLeod, David

2006-10-01

139

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

140

Animat Vision: Active Vision in  

E-print Network

Article 1 Animat Vision: Active Vision in Artificial Animals Demetri Terzopoulos, Tamer F. Rabie Videre: Journal of Computer Vision Research Quarterly Journal Fall 1997, Volume 1, Number 1 The MIT Press Videre: Journal of Computer Vision Research (ISSN 1089-2788) is a quarterly journal published

Terzopoulos, Demetri

141

Improvement of the colour discrimination ability of colour deficient people by modifying the parameters of the illumination  

Microsoft Academic Search

At the Department of Mechatronics, Optics and Engineering Informatics of BME the researches led by Dr. György Ábraham and Dr. Klára Wenzel have shown that defective color vision can be improved by specific spectral transmission color filters which modify the spectral characteristics of the lights reflected by different coloured surfaces so that the difference between colors will be increased. These

Ingrid Langer

2011-01-01

142

Craven and Foster Page 1 Vision Research Author manuscript  

E-print Network

vision; colour constancy; Munsell papers; daylight; colour discrimination; perceptual invariants; surface: Department of Product Design Engineering, Glasgow School of Art, 167 Renfrew Street, Glasgow G3 6RQ, UK; email: ben@bencraven.org.uk 3 Present address: School of Electrical and Electronic Engineering

Foster, David H.

143

Measuring colour rivalry suppression in amblyopia  

PubMed Central

AIMS—To determine if the colour rivalry suppression is an index of the visual impairment in amblyopia and if the stereopsis and fusion evaluator (SAFE) instrument is a reliable indicator of the difference in visual input from the two eyes.?METHODS—To test the accuracy of the SAFE instrument for measuring the visual input from the two eyes, colour rivalry suppression was measured in six normal subjects. A test neutral density filter (NDF) was placed before one eye to induce a temporary relative afferent defect and the subject selected the NDF before the fellow eye to neutralise the test NDF. In a non-paediatric private practice, 24 consecutive patients diagnosed with unilateral amblyopia were tested with the SAFE. Of the 24 amblyopes, 14 qualified for the study because they were able to fuse images and had no comorbid disease. The relation between depth of colour rivalry suppression, stereoacuity, and interocular difference in logMAR acuity was analysed.?RESULTS—In normal subjects, the SAFE instrument reversed temporary defects of 0.3 to 1.8 log units to within 0.6 log units. In amblyopes, the NDF to reverse colour rivalry suppression was positively related to interocular difference in logMAR acuity (?=1.21, p<0.0001), and negatively related to stereoacuity (?=?0.16, p=0.019). The interocular difference in logMAR acuity was negatively related to stereoacuity (?=?0.13, p=0.009).?CONCLUSIONS—Colour rivalry suppression as measured with the SAFE was found to agree closely with the degree of visual acuity impairment in non-paediatric patients with amblyopia.?? PMID:10535858

Hofeldt, T.; Hofeldt, A.

1999-01-01

144

Failing Vision Tied to Shorter Lifespans for Seniors  

MedlinePLUS

... features on this page, please enable JavaScript. Failing Vision Tied to Shorter Lifespans for Seniors Link could ... August 21, 2014 Related MedlinePlus Pages Seniors' Health Vision Impairment and Blindness THURSDAY, Aug. 21, 2014 (HealthDay ...

145

Vision Screening  

MedlinePLUS

... regular well care office visits. In addition, many day care programs, churches, schools and health departments offer vision ... addition to vision screening that is offered at day care, school or church. In some states a documented ...

146

A novel illumination-invariant colour constancy algorithm  

NASA Astrophysics Data System (ADS)

The human brain is able to extract the colour of objects no matter the existing illumination conditions which may affect the appearance of their colour. For a person, an object that is red, it will be red regardless of the type of illumination source. However, for a computer algorithm to achieve the same task is not as simple. For vision and robotics applications were feature extraction is essential having such an algorithm is crucial. It is well known from the literature that the colour of an object does not only depend on the chemical composition and shape of its surface but also on the illumination conditions, the intensity, number, location and colour of the sources of illumination as well as the intrinsic and extrinsic characteristics of the sensor used. Based on that knowledge, we propose a simple colour constancy algorithm that uses the quaternion representation of each pixel in the image instead of the commonly used RGB model. We assume linearity in the reception of the luminance spectrum of the charge-coupled device of the camera before variations in the illumination. We have tested our colour constancy algorithm in a variety of images containing different colour objects under different illumination conditions. Our experimental results show the feasibility of the proposed method.

Torres-Méndez, L. A.; Quiñones Muñoz, M. L.; Olaya-Benítez, E. J.

2011-08-01

147

Colour in flux: describing and printing colour in art  

NASA Astrophysics Data System (ADS)

This presentation will describe artists, practitioners and scientists, who were interested in developing a deeper psychological, emotional and practical understanding of the human visual system who were working with wavelength, paint and other materials. From a selection of prints at The Prints and Drawings Department at Tate London, the presentation will refer to artists who were motivated by issues relating to how colour pigment was mixed and printed, to interrogate and explain colour perception and colour science, and in art, how artists have used colour to challenge the viewer and how a viewer might describe their experience of colour. The title Colour in Flux refers, not only to the perceptual effect of the juxtaposition of one colour pigment with another, but also to the changes and challenges for the print industry. In the light of screenprinted examples from the 60s and 70s, the presentation will discuss 21 st century ideas on colour and how these notions have informed the Centre for Fine Print Research's (CFPR) practical research in colour printing. The latter part of this presentation will discuss the implications for the need to change methods in mixing inks that moves away from existing colour spaces, from non intuitive colour mixing to bespoke ink sets, colour mixing approaches and colour mixing methods that are not reliant on RGB or CMYK.

Parraman, Carinna

2008-01-01

148

Colouring as a special list-colouring problem  

Microsoft Academic Search

Colouring of planar graphs can be treated as a special list-colouring problem\\u000awith selected lists for near-triangulations. The new idea is to use sublists of\\u000aa common list of four colours, to enforce a common colour in all lists, and to\\u000aadmit on the bounding cycle at most one vertex with a list of at least two\\u000acolours. By these

Peter Doerre

2004-01-01

149

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

150

Ultrasonic colour Doppler imaging  

PubMed Central

Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been found to be of great value in assessing blood flow in many clinical conditions. Although the method for obtaining the velocity information is in many ways similar to the method for obtaining the anatomical information, it is technically more demanding for a number of reasons. It also has a number of weaknesses, perhaps the greatest being that in conventional systems, the velocities measured and thus displayed are the components of the flow velocity directly towards or away from the transducer, while ideally the method would give information about the magnitude and direction of the three-dimensional flow vectors. This review briefly introduces the principles behind colour Doppler imaging and describes some clinical applications. It then describes the basic components of conventional colour Doppler systems and the methods used to derive velocity information from the ultrasound signal. Next, a number of new techniques that seek to overcome the vector problem mentioned above are described. Finally, some examples of vector velocity images are presented. PMID:22866227

Evans, David H.; Jensen, J?rgen Arendt; Nielsen, Michael Bachmann

2011-01-01

151

The Four-Colour Theorem  

Microsoft Academic Search

The four-colour theorem, that every loopless planar graph admits a vertex-colouring with at most four different colours, was proved in 1976 by Appel and Haken, using a computer. Here we give another proof, still using a computer, but simpler than Appel and Haken's in several respects.

Neil Robertson; Daniel P. Sanders; Paul D. Seymour; Robin Thomas

1997-01-01

152

Specifying colour and maintaining colour accuracy for 3D printing  

NASA Astrophysics Data System (ADS)

Advances in rapid prototyping technologies have led to the emergence of three-dimensional printers which can fabricate physical artefacts, including the application of surface colours. In light of these developments, this paper asserts that the need to print colour accurately is just as important for designers using three-dimensional colour printing as it is for two-dimensional inkjet printing. Parallels can be made with two-dimensional digital Inkjet printing and 2D common problems include: on screen previsualisation, colour management methods, colour gamut and maintaining colour accuracy. However, for three dimensional colour printed objects, there are more variables that will affect the finished colour. These are: the powder and process inks, unevenness of the surface, wax post-processing and other infiltration media and procedures. Furthermore, in some 3D printers, the K channel is replaced by the binder and so the printer is only using the cyan, magenta and yellow channels. The paper will suggest methods for improving pre-visualisation and accurate pre-viewing of the colours through the manufacture of three-dimensional colour charts as a reference guide for designers so that they can make accurate coloured artefacts. A series of case studies will be demonstrated.

Parraman, Carinna; Walters, Peter; Reid, Brendan; Huson, David

2008-02-01

153

Prevalence and Causes of Blindness and Visual Impairment in Sokoto State, Nigeria: Baseline Data for Vision 2020: The Right to Sight Eye Care Programme  

PubMed Central

Purpose: To estimate the prevalence of low vision and blindness, identify the causes, and suggest policies for an effective eye care program based on 2005 data from Sokoto State, Nigeria. Materials and Methods: A stratified two-stage cluster sampling method was used to quantify the prevalence of blindness and the causes from 4 health zones in Sokoto State. Subjects were evaluated using a magnifying loupe, direct ophthalmoscope and torchlight. Data were collected based on the World Health Organization prevention of blindness coding for an eye examination. Prevalences with 95% confidence intervals (CI) were calculated and surgical coverage for causes of blindness was also analyzed. Results: The response rate was 91%. The prevalence of bilateral blindness was 1.9% (95% CI: 1.5–2.3%) ranging from 1.6% to 2.0% across the four health zones. The prevalence was 2.1% (95% CI: 1.6–2.6%) in males and 1.6% (95% CI: 1.1–2.1%) in females. The leading cause of bilateral blindness was cataract (51.6%), followed by uncorrected aphakia (20.9%) and glaucoma (11%). The prevalence of bilateral operable cataract was 1.9% (95% CI: 1.5–2.3%). The cataract surgical coverage (individuals with visual acuity <6/60) for the study was lower than the couching coverage (4.4% vs. 14.9%, respectively). Surgical coverage for trichiasis was 4.4%. The major barrier to cataract and glaucoma management was cost. Conclusions: The prevalence of blindness in Sokoto State is high yet the main causes are largely avoidable. Barriers can be reduced by appropriate health education regarding the eye care program and the provision of integrated, sustainable, affordable and equitable services. PMID:21731322

Muhammad, Nasiru; Mansur, Rabiu M.; Dantani, Adamu M.; Elhassan, Elizabeth; Isiyaku, Sunday

2011-01-01

154

ORIGINAL ARTICLE Vision Multiplexing: an Engineering Approach  

E-print Network

the elderly. Consequently, both the absolute number of people with visual impairment and the proportion-resolution vision. Loss of central vision reduces the patient's ability to read, recognize faces, watch TV An esti- mated 20 to 33.3 per 100,000 individuals suffer from RP.4, 5 Although the problem of reading can

Peli, Eli

155

Early-onset Alzheimers and Cortical Vision Impairment in a Woman With Valosin-containing Protein Disease Associated With 2 APOE [Latin Small Letter Open E]4/APOE [Latin Small Letter Open E]4 Genotype.  

PubMed

Hereditary inclusion body myopathy is a heterogeneous group of disorders characterized by rimmed vacuoles and by the presence of filamentous cytoplasmic and intranuclear inclusions. Inclusion body myopathy with Paget disease of bone and frontotemporal dementia is a progressive autosomal dominant disorder associated with a mutation in valosin-containing protein (VCP) with typical onset of symptoms in the 30s. APOE [Latin Small Letter Open E]4 is a major risk factor for late-onset Alzheimer disease, a progressive neurodegenerative disorder that affects memory, thinking, behavior, and emotion as a result of the excessive buildup and decreased clearance of ?-amyloid proteins resulting in the appearance of neuritic plaques and neurofibrillary tangles. In conclusion, we report a unique patient with an APOE [Latin Small Letter Open E]4/APOE [Latin Small Letter Open E]4 genotype and atypical VCP disease associated with early Alzheimer disease and severe vision impairment. Future studies will elucidate the interaction of VCP mutations and APOE [Latin Small Letter Open E]4 alleles in understanding common mechanisms in AD and VCP disease. PMID:23715207

Shamirian, Sharis; Nalbandian, Angèle; Khare, Manaswitha; Castellani, Rudolph; Kim, Ronald; Kimonis, Virginia E

2013-05-24

156

Hyperbolic geometry for colour metrics.  

PubMed

It is well established from both colour difference and colour order perpectives that the colour space cannot be Euclidean. In spite of this, most colour spaces still in use today are Euclidean, and the best Euclidean colour metrics are performing comparably to state-of-the-art non-Euclidean metrics. In this paper, it is shown that a transformation from Euclidean to hyperbolic geometry (i.e., constant negative curvature) for the chromatic plane can significantly improve the performance of Euclidean colour metrics to the point where they are statistically significantly better than state-of-the-art non-Euclidean metrics on standard data sets. The resulting hyperbolic geometry nicely models both qualitatively and quantitatively the hue super-importance phenomenon observed in colour order systems. PMID:24921355

Farup, Ivar

2014-05-19

157

Leading Vision  

ERIC Educational Resources Information Center

The current educational landscape makes it imperative that a vision statement become more than a fine-sounding statement that is laminated, hung on the wall, and quickly forgotten. If educators do not have a clear image of the future they wish to create, then someone will be ready to create it for them. But with a clear vision of the future, a…

Fawcett, Gay

2004-01-01

158

The secret world of shrimps: polarisation vision at its best  

E-print Network

Animal vision spans a great range of complexity, with systems evolving to detect variations in optical intensity, distribution, colour, and polarisation. Polarisation vision systems studied to date detect one to four channels of linear polarisation, combining them in opponent pairs to provide intensity-independent operation. Circular polarisation vision has never been seen, and is widely believed to play no part in animal vision. Polarisation is fully measured via Stokes' parameters--obtained by combined linear and circular polarisation measurements. Optimal polarisation vision is the ability to see Stokes' parameters: here we show that the crustacean \\emph{Gonodactylus smithii} measures the exact components required. This vision provides optimal contrast-enhancement, and precise determination of polarisation with no confusion-states or neutral-points--significant advantages. We emphasise that linear and circular polarisation vision are not different modalities--both are necessary for optimal polarisation vision, regardless of the presence of strongly linear or circularly polarised features in the animal's environment.

Sonja Kleinlogel; Andrew G. White

2008-04-14

159

Local and Global Factors in Spatially- contingent Coloured Aftereffects  

Microsoft Academic Search

Dodwell and O'Shea's 1(1987) Vision Research, 27, 569-5801 conclusions that contingent coloured aftereffects (CAEs) depend on gobal pattern organization were investigated in four experiments. In Expt 1, we replicated findings that CAEs can be induced with complex patterns (concentric circles; radial spokes) under conditions of systematic eye movements. Contrary to Dodwell and O'Shea's argument that eye movements should uniformly cancel

JACK BROERSE; ROBERT P. O'SHEAt

1995-01-01

160

Assessing Functional Vision Using Microcomputers.  

ERIC Educational Resources Information Center

The paper describes a software system which uses microcomputers to aid in the assessment of functional vision in visually impaired students. The software also aims to be visually stimulating and to develop hand-eye coordination, visual memory, and cognitive abilities. (DB)

Spencer, Simon; Ross, Malcolm

1989-01-01

161

Colour cues proved to be more informative for dogs than brightness  

PubMed Central

The results of early studies on colour vision in dogs led to the conclusion that chromatic cues are unimportant for dogs during their normal activities. Nevertheless, the canine retina possesses two cone types which provide at least the potential for colour vision. Recently, experiments controlling for the brightness information in visual stimuli demonstrated that dogs have the ability to perform chromatic discrimination. Here, we show that for eight previously untrained dogs colour proved to be more informative than brightness when choosing between visual stimuli differing both in brightness and chromaticity. Although brightness could have been used by the dogs in our experiments (unlike previous studies), it was not. Our results demonstrate that under natural photopic lighting conditions colour information may be predominant even for animals that possess only two spectral types of cone photoreceptors. PMID:23864600

Kasparson, Anna A.; Badridze, Jason; Maximov, Vadim V.

2013-01-01

162

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. PMID:24335074

Dagnelie, Gislin

2013-01-01

163

Specifying colour and maintaining colour accuracy for 3D printing  

Microsoft Academic Search

Advances in rapid prototyping technologies have led to the emergence of three-dimensional printers which can fabricate physical artefacts, including the application of surface colours. In light of these developments, this paper asserts that the need to print colour accurately is just as important for designers using three-dimensional colour printing as it is for two-dimensional inkjet printing. Parallels can be made

Carinna Parraman; Peter Walters; Brendan Reid; David Huson

2008-01-01

164

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

165

The colours of the Sun  

NASA Astrophysics Data System (ADS)

We compile a sample of Sun-like stars with accurate effective temperatures, metallicities and colours (from the ultraviolet to the near-infrared). A crucial improvement is that the effective temperature scale of the stars has recently been established as both accurate and precise through direct measurement of angular diameters obtained with stellar interferometers. We fit the colours as a function of effective temperature and metallicity, and derive colour estimates for the Sun in the Johnson-Cousins, Tycho, Strömgren, 2MASS and SDSS photometric systems. For (B-V)solar, we favour the `red' colour 0.64 versus the `blue' colour 0.62 of other recent papers, but both values are consistent within the errors; we ascribe the difference to the selection of Sun-like stars versus interpolation of wider colour-Teff-metallicity relations.

Holmberg, Johan; Flynn, Chris; Portinari, Laura

2006-04-01

166

The colours of the Sun  

E-print Network

We compile a sample of Sun-like stars with accurate effective temperatures, metallicities and colours (from the UV to the near-IR). A crucial improvement is that the effective temperature scale of the stars has recently been established as both accurate and precise through direct measurement of angular diameters obtained with stellar interferometers. We fit the colours as a function of effective temperature and metallicity, and derive colour estimates for the Sun in the Johnson/Cousins, Tycho, Stromgren, 2MASS and SDSS photometric systems. For (B-V)_Sun, we favour the ``red'' colour 0.64 versus the ``blue'' colour 0.62 of other recent papers, but both values are consistent within the errors; we ascribe the difference to the selection of Sun-like stars versus interpolation of wider colour-Teff-metallicity relations.

Johan Holmberg; Chris Flynn; Laura Portinari

2005-11-06

167

Novel coloured flowers.  

PubMed

The floricultural industry has focused its attention primarily on the development of novel coloured and longer living cut flowers. The basis for this was laid down some years ago through the isolation of 'blue' genes and ethylene biosynthesis genes. Recently, a novel 'blue' gene has been discovered and yellow pigments were produced in petunias by addition of a new branch to the phenylpropanoid pathway. More insight was obtained into the sequestration of anthocyanin pigments into storage vacuoles. Significant progress has been achieved in the commercialisation of genetically modified flower varieties. PMID:10209139

Mol, J; Cornish, E; Mason, J; Koes, R

1999-04-01

168

The colour of bubbles  

NASA Astrophysics Data System (ADS)

Students of General Physics often complain that the course is too abstract and remote from daily life. As teachers, we emphasize that the abstract concepts of physics are indispensable for understanding our daily experiences, and we try to give the impression that quantitative descriptions can be achieved by adopting concrete mathematical expressions. Thus the abstract formulation is not to make physics more difficult, but to make it easier to grasp. We expect the students to learn to describe phenomena qualitatively using the concepts of physics, and to provide a quantitative description by manipulating the mathematical formulation. Here we supply one such example to calculate the colour of bubble films.

Huang, Ding-wei; Huang, Wei-neng; Tseng, Hsiang-chi

2005-11-01

169

The Need for a Uniform Method of Recording and Reporting Functional Vision Assessments  

ERIC Educational Resources Information Center

The use of functional vision by school-age students who have visual impairments, including those with additional disabilities, is typically reported by teachers of students with visual impairments. Functional vision assessments determine how well a student uses his or her vision to perform tasks throughout the school day. The information that is…

Shaw, Rona; Russotti, Joanne; Strauss-Schwartz, Judy; Vail, Helen; Kahn, Ronda

2009-01-01

170

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. PMID:24573847

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

2014-01-01

171

Vision Memo  

E-print Network

This Memo proposes a set of systems programs for vision work. Please comment immediately as we should start on it at once. Values stored outside an array range should have no effect, but set an overflow flag: values read ...

Minsky, Marvin

1967-02-01

172

Vision Utilities  

E-print Network

This paper documents a collection of Lisp utilities which I have written while doing vision programming on a Symbolics Lisp machine. Many of these functions are useful both as interactive commands invoked from the Lisp ...

Voorhees, Harry

173

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

174

Vision Symptoms  

MedlinePLUS

... Torn Retina Diabetic Retinopathy Dry Eye Floaters & Flashes Glaucoma Hyperopia (Farsightedness) Low Vision Myopia (Nearsightedness) Pink Eye ( ... Remedies for Simple Eye Problems Medical Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports Using Eye ...

175

Colour invariant target recognition in multiple camera CCTV surveillance  

NASA Astrophysics Data System (ADS)

People tracking in crowded scene have been a popular, and at the same time a very difficult topic in computer vision. It is mainly because of the difficulty for the acquisition of intrinsic signatures of targets from a single view of the scene. Many factors, such as variable illumination conditions and viewing angles, will induce illusive modification of intrinsic signatures of targets. The objective of this paper is to verify if colour constancy (CC) approach really helps people tracking in CCTV network system. We have testified a number of CC algorithms together with various colour descriptors, to assess the efficiencies of people recognitions from multi-camera i-LIDS data set via receiver operation characteristics (ROC). It is found that when CC is applied together with some form of colour restoration mechanisms such as colour transfer, it does improve people recognition by at least a factor of 2. An elementary luminance based CC coupled with a pixel based colour transfer algorithm have been developed and it is reported in this paper.

Soori, Umair; Yuen, P. W. T.; Ibrahim, I.; Han, J.; Tsitiridis, A.; Hong, K.; Chen, T.; Jackman, J.; James, D.; Richardson, M.

2011-11-01

176

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. PMID:22163628

Blanco, Edward; Mazo, Manuel; Bergasa, Luis; Palazuelos, Sira; Rodríguez, Jose; Losada, Cristina; Martín, Jose

2010-01-01

177

Class separation improvements in pixel classification using colour injection.  

PubMed

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 (YC(1)C(2)) 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. PMID:22163628

Blanco, Edward; Mazo, Manuel; Bergasa, Luis; Palazuelos, Sira; Rodríguez, Jose; Losada, Cristina; Martín, Jose

2010-01-01

178

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

2012-03-01

179

Computational Production of Colour Harmony. Part 1: A Prototype Colour  

E-print Network

with the human expression of personal taste. Our Colour Harmoniser is a research tool that is meant to explore 5 July 2011; accepted 24 August 2011 Abstract: Although web page and computer interface devel- opers the possibility of automatically producing har- monious and usable user interface colour schemes by modeling

Marsland, Stephen

180

Rapid mixing for lattice colourings with fewer colours  

Microsoft Academic Search

We provide an optimally mixing Markov chain for 6-colourings of the square lattice on rectangular regions with free, fixed, or toroidal boundary conditions. This implies that the uniform distribution on the set of such colourings has strong spatial mixing, so the six-state Potts antiferromagnet has a finite correlation length and a unique Gibbs measure at zero temperature. Four and five

Dimitris Achlioptas; Mike Molloy; Cristopher Moore; Frank Van Bussel

2005-01-01

181

Improper Colourings of Unit Disk Graphs  

Microsoft Academic Search

Abstract: Motivated by a satellite communications problem, we consider a generalised colouring problem on unit disk graphs. A colouring is k-improper if no vertex receives the same colour as k+1 of its neighbours. The k-improper chromatic number ´, for unit interval graphs. Key-words: improper colouring, defective colouring, unit disk graph, interval graph, triangular

Frédéric Havet; Ross J. Kang; Jean-sébastien Sereni

2005-01-01

182

Disruptive Colouration and Perceptual Grouping  

PubMed Central

Camouflage is the primary defence of many animals and includes multiple strategies that interfere with figure-ground segmentation and object recognition. While matching background colours and textures is widespread and conceptually straightforward, less well explored are the optical ‘tricks’, collectively called disruptive colouration, that exploit perceptual grouping mechanisms. Adjacent high contrast colours create false edges, but this is not sufficient for an object’s shape to be broken up; some colours must blend with the background. We test the novel hypothesis that this will be particularly effective when the colour patches on the animal appear to belong to, not merely different background colours, but different background objects. We used computer-based experiments where human participants had to find cryptic targets on artificial backgrounds. Creating what appeared to be bi-coloured foreground objects on bi-coloured backgrounds, we generated colour boundaries that had identical local contrast but either lay within or between (illusory) objects. As predicted, error rates for targets matching what appeared to be different background objects were higher than for targets which had otherwise identical local contrast to the background but appeared to belong to single background objects. This provides evidence for disruptive colouration interfering with higher-level feature integration in addition to previously demonstrated low-level effects involving contour detection. In addition, detection was impeded in treatments where targets were on or in close proximity to multiple background colour or tone boundaries. This is consistent with other studies which show a deleterious influence of visual ‘clutter’ or background complexity on search. PMID:24466337

Espinosa, Irene; Cuthill, Innes C.

2014-01-01

183

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

184

Reversible colour change in Arthropoda.  

PubMed

The mechanisms and functions of reversible colour change in arthropods are highly diverse despite, or perhaps due to, the presence of an exoskeleton. Physiological colour changes, which have been recorded in 90 arthropod species, are rapid and are the result of changes in the positioning of microstructures or pigments, or in the refractive index of layers in the integument. By contrast, morphological colour changes, documented in 31 species, involve the anabolism or catabolism of components (e.g. pigments) directly related to the observable colour. In this review we highlight the diversity of mechanisms by which reversible colour change occurs and the evolutionary context and diversity of arthropod taxa in which it has been observed. Further, we discuss the functions of reversible colour change so far proposed, review the limited behavioural and ecological data, and argue that the field requires phylogenetically controlled approaches to understanding the evolution of reversible colour change. Finally, we encourage biologists to explore new model systems for colour change and to engage scientists from other disciplines; continued cross-disciplinary collaboration is the most promising approach to this nexus of biology, physics, and chemistry. PMID:24495279

Umbers, Kate D L; Fabricant, Scott A; Gawryszewski, Felipe M; Seago, Ainsley E; Herberstein, Marie E

2014-11-01

185

Light Filters of Coloured `Perspex'  

Microsoft Academic Search

LIGHT filters of coloured glass and gelatin are in common use for visual and photoelectric photometers. They are satisfactory, on the whole; but the glass filters are easily broken, and those of gelatin require to be mounted between glass to protect them from water. The transparent polymethyl methacrylate `Perspex' is now obtainable in several colours and in sheets. This material

E. J. King; S. Ventura

1951-01-01

186

Associating Colours with Musical Genres  

Microsoft Academic Search

To study visualizations for music, we arranged a set of online questionnaires on how people map various visual properties to certain musical attributes. This paper presents the results of a questionnaire that concentrated on how people map colours to musical genres. The participants were shown 12 colours one at a time, and asked which of listed 18 genres they associated

Jukka Holm; Antti Aaltonen; Harri Siirtola

2009-01-01

187

The Four-Colour Problem  

Microsoft Academic Search

THE correctness of the statement that any plane map may always be tinted with four colours in such a way that two areas meeting on the same boundary never have the same colour has always been admitted since Möbius mentioned it in 1840, although no mathematical proof of this theorem has yet been firmly established. I think I have found

S. M. de Backer

1944-01-01

188

VISION INSURANCE VISION SERVICE PLAN (VSP)  

E-print Network

- 38 - VISION INSURANCE VISION SERVICE PLAN (VSP) Premium Payments Vision coverage is voluntary and premiums are entirely paid by the Employee. To assist in reducing your insurance premium costs, your vision. How VSP Works: STEP ONE: To obtain vision care services, call your VSP doctor. To locate a VSP network

189

Improved data association and occlusion handling for vision-based people tracking by mobile robots  

Microsoft Academic Search

This paper presents an approach for tracking multiple persons using a combination of colour and thermal vision sensors on a mobile robot. First, an adaptive colour model is incorporated into the measurement model of the tracker. Second, a new approach for detecting occlusions is introduced, using a machine learning classifier for pairwise comparison of persons (classifying which one is in

Grzegorz Cielniak; Tom Duckett; Achim J. Lilienthal

2007-01-01

190

Low Vision FAQs  

MedlinePLUS

... at NEI Education Programs Training and Jobs Healthy Vision Diabetes Diabetes Home How Much Do You Know? ... los Ojos Cómo hablarle a su oculista Low Vision FAQs Listen What is low vision? Low vision ...

191

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

192

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

193

Training Visions  

ERIC Educational Resources Information Center

In this article, "Training" asks the 2011 winners to give their predictions for what training--either in general or specifically at their companies--will look like in the next five to 10 years. Perhaps their "training visions" will spark some ideas in one's organization--or at least help prepare for what might be coming in the next decade or so.

Training, 2011

2011-01-01

194

Agrarian Visions.  

ERIC Educational Resources Information Center

A new feature in "Country Teacher,""Agrarian Visions" reminds rural teachers that they can do something about rural decline. Like to populism of the 1890s, the "new populism" advocates rural living. Current attempts to address rural decline are contrary to agrarianism because: (1) telecommunications experts seek to solve problems of rural…

Theobald, Paul

195

Visions 2001.  

ERIC Educational Resources Information Center

Reports on the views of 18 educational leaders regarding their vision on the future of education in an information age. Topics include people's diverse needs; relationships between morality, ethics, values, and technology; leadership; parental involvement; online courses from multiple higher education institutions; teachers' role; technology…

Rivero, Victor; Norman, Michele

2001-01-01

196

Colour Spaces for Colour Transfer Erik Reinhard and Tania Pouli  

E-print Network

, Correlation 1 Introduction Colour is one of the main image attributes used in art, photography and visuali of the L, M and S cones in the human retina (the letters stand for Long, Medium and Short wavelength

Reinhard, Erik

197

Linguistic Determinants of Word Colouring in Grapheme-Colour Synaesthesia  

Microsoft Academic Search

Previous studies of grapheme-colour synaesthesia have suggested that words tend to be coloured by their initial letter or initial vowel (e.g., Baron-Cohen et al., 1993; Ward et al., 2005). We examine this assumption in two ways. First, we show that letter position and syllable stress have been confounded, such that the initial letters of a word are often in stressed

Julia Simner; Louise Glover; Alice Mowat

2006-01-01

198

The visually impaired patient.  

PubMed

Blindness or low vision affects more than 3 million Americans 40 years and older, and this number is projected to reach 5.5 million by 2020. In addition to treating a patient's vision loss and comorbid medical issues, physicians must be aware of the physical limitations and social issues associated with vision loss to optimize health and independent living for the visually impaired patient. In the United States, the four most prevalent etiologies of vision loss in persons 40 years and older are age-related macular degeneration, cataracts, glaucoma, and diabetic retinopathy. Exudative macular degeneration is treated with laser therapy, and progression of nonexudative macular degeneration in its advanced stages may be slowed with high-dose antioxidant and zinc regimens. The value of screening for glaucoma is uncertain; management of this condition relies on topical ocular medications. Cataract symptoms include decreased visual acuity, decreased color perception, decreased contrast sensitivity, and glare disability. Lifestyle and environmental interventions can improve function in patients with cataracts, but surgery is commonly performed if the condition worsens. Diabetic retinopathy responds to tight glucose control, and severe cases marked by macular edema are treated with laser photocoagulation. Vision-enhancing devices can help magnify objects, and nonoptical interventions include special filters and enhanced lighting. PMID:18533377

Rosenberg, Eric A; Sperazza, Laura C

2008-05-15

199

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

200

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

201

Ophthalmology. Screening and treatment of age-related and pathologic vision changes.  

PubMed

In the older adult, deterioration of normal vision is caused by age-related physiologic and pathologic changes. Vision impairment undermines quality of life by reducing independence, mobility, and the enjoyment that goes with seeing clearly. The most common causes of vision impairment are age-related macular degeneration (AMD), glaucoma, cataract, and diabetic retinopathy. Key to successful management of vision impairment is early detection of signs and symptoms, patient education regarding preventive strategies, and swift medical or surgical intervention for established or emerging conditions. Vision rehabilitation is an important management option. PMID:11766560

Rosenthal, B P

2001-12-01

202

An adaptation of the Cambridge Colour Test for use with animals  

Microsoft Academic Search

Recently, molecular biological techniques have presented new opportunities for addressing questions concerning the neural mechanisms involved in color coding, thereby rousing renewed interest in animal color vision testing. We have modified a computer-based assessment tool, the Cambridge Colour Test, to make it suitable for use with animals. Here, the validity and reliability of the testing method were evaluated using squirrel

KATHERINE MANCUSO; MAUREEN NEITZ; JAY NEITZ

2006-01-01

203

On the Induction of Topological Maps from Sequences of Colour Histograms  

Microsoft Academic Search

This paper presents an appearance-based method to automatically determine places from vision data for topological mapping. The approach exploits the continuity of the visual appearance of consecutive im- ages when a robot traverses the environment. Places are determined by clustering colour histograms, and a probabilistic filtering strategy eliminates spurious places with weak evidence. Further, we discuss steps towards the induction

Felix Werner; Joaquin Sitte; Frédéric Maire

2007-01-01

204

Colour unmasks dark targets in complex displays Frederick A.A. Kingdom *, Reza Kasrai  

E-print Network

Colour unmasks dark targets in complex displays Frederick A.A. Kingdom *, Reza Kasrai McGill Vision Research Unit, Department of Ophthalmology, McGill University, 687 Pine Avenue W, Room H4-14, Montre´al, PQ

Kingdom, Frederick A. A.

205

Communication in coral reef fish: the role of ultraviolet colour patterns in damselfish territorial behaviour  

Microsoft Academic Search

Many coral reef fish possess ultraviolet (UV) colour patterns. The behavioural significance of these patterns is poorly understood and experiments on this issue have not been reported for free-living reef fish in their natural environment. The damselfish Pomacentrus amboinensis has UV facial patterns, and spectroradiometric ocular media measurements show that it has the potential for UV vision. To test the

Ulrike E. Siebeck

2004-01-01

206

Irreversible color vision losses in patients with chronic mercury vapor intoxication.  

PubMed

This longitudinal study addresses the reversibility of color vision losses in subjects who had been occupationally exposed to mercury vapor. Color discrimination was assessed in 20 Hg-exposed patients (mean age = 42.4 +/- 6.5 years; 6 females and 14 males) with exposure to Hg vapor during 10.5 +/- 5.3 years and away from the work place (relative to 2002) for 6.8 +/- 4.2 years. During the Hg exposure or up to one year after ceasing it, mean urinary Hg concentration was 47 +/- 35.4 mug/g creatinine. There was no information on Hg urinary concentration at the time of the first tests, in 2002 (Ventura et al., 2005), but at the time of the follow-up tests, in 2005, this value was 1.4 +/- 1.4 microg/g creatinine for patients compared with 0.5 +/- 0.5 microg/g creatinine for controls (different group from the one in Ventura et al. (2005)). Color vision was monocularly assessed using the Cambridge Colour Test (CCT). Hg-exposed patients had significantly worse color discrimination (p < 0.02) than controls, as evaluated by the size of MacAdam's color discrimination ellipses and color discrimination thresholds along protan, deutan, and tritan confusion axes. There were no significant differences between the results of the study in Ventura et al. (2005) and in the present follow-up measurements, in 2005, except for worsening of the tritan thresholds in the best eye in 2005. Both chromatic systems, blue-yellow and red-green, were affected in the first evaluation (Ventura et al., 2005) and remained impaired in the follow-up testing, in 2005. These findings indicate that following a long-term occupational exposure to Hg vapor, even several years away from the source of intoxication, color vision impairment remains irreversible. PMID:18598423

Feitosa-Santana, Cláudia; Barboni, Mirella T S; Oiwa, Nestor N; Paramei, Galina V; Simões, Ana Luisa A C; Da Costa, Marcelo F; Silveira, Luiz Carlos L; Ventura, Dora F

2008-01-01

207

Plants and colour: Flowers and pollination  

Microsoft Academic Search

While there is a range of colours found in plants the predominant colour is green. Pigments in plants have several roles e.g. photosynthesis and signalling. If colour is to be used as a signal then it must stand out from green. However, one should be aware that there are also coloured compounds where we have not yet fully investigated the

Renee Miller; Simon J. Owens; Bjørn Rørslett

2011-01-01

208

Coloured solutions of equations in finite groups  

Microsoft Academic Search

In this article, we consider the relations between colourings and some equations in finite groups. We will express relations linking the numbers of the differently coloured solutions of an equation that depend only on the cardinality of the colouring and not on the distribution of the colours. This gives a link between Ramsey theory that investigates the existence of monochromatic

Éric Balandraud

2007-01-01

209

Using Synthetic Vision for Autonomous Non-Player Characters in Computer Games  

Microsoft Academic Search

In this paper, we discuss the role and utility of synthetic vision in comput er games. We present an implementation of a synthetic vision module based on two viewports rendered in real-time, one representing static information and the other dynamic, with false colouring being used for object identification, depth information and mo vement representation. We demonstrate the utility of this

Sebastian Enrique; Alan Watt; Steve Maddock; Fabio Policarpo

210

Colouring as a special list-colouring problem with selected lists  

Microsoft Academic Search

Colouring of planar graphs can be treated as a special list-colouring problem with selected lists for near-triangulations. The new idea is to use sublists of a common list of four colours, to enforce a common colour in all lists, and to admit on the bounding cycle at most one vertex with a list of at least two colours. By these

Peter Dörre

211

Improving Web Access for Visually Impaired Users  

Microsoft Academic Search

Technology advances and the continuing convergence of computing and telecommunications have made an unprecedented amount of information available to the public. For many people with disabilities, however, accessibility issues limit the impact of such widespread availability. Of the many types of disabilities-mobility, hearing, and learning impairments, for example-vision impairments are most pervasive in the general population, especially among seniors. The

Simon Liu; Wei Ma; Dale Schalow; Kevin Spruill

2004-01-01

212

Improper colouring of unit disk graphs  

Microsoft Academic Search

Motivated by a satellite communications problem, we consider a generalised colouring problem on unit disk graphs. A colouring is k-improper if no vertex receives the same colour as k+1 of its neighbours. The k-improper chromatic number k(G) the least number of colours needed in a k-improper colouring of a graph G. The main subject of this work is analysing the

Ross J. Kang; Jean-S ebastien Sereni

213

3-facial colouring of plane graphs  

Microsoft Academic Search

A plane graph is l-facially k-colourable if its vertices can be coloured with\\u000ak colours such that any two distinct vertices on a facial segment of length at\\u000amost l are coloured differently. We prove that every plane graph is 3-facially\\u000a11-colourable. As a consequence, we derive that every 2-connected plane graph\\u000awith maximum face-size at most 7 is cyclically

Frédéric Havet; Jean-Sébastien Sereni; Riste Skrekovski

2006-01-01

214

The colour of gender stereotyping.  

PubMed

Despite legislative attempts to eliminate gender stereotyping from society, the propensity to evaluate people on the basis of their sex remains a pernicious social problem. Noting the critical interplay between cultural and cognitive factors in the establishment of stereotypical beliefs, the current investigation explored the extent to which culturally transmitted colour-gender associations (i.e., pink is for girls, blue is for boys) set the stage for the automatic activation and expression of gender stereotypes. Across six experiments, the results demonstrated that (1) consumer choice for children's goods is dominated by gender-stereotyped colours (Experiment 1); (2) colour-based stereotypic associations guide young children's behaviour (Experiment 2); (3) colour-gender associations automatically activate associated stereotypes in adulthood (Experiments 3-5); and (4) colour-based stereotypic associations bias impressions of male and female targets (Experiment 6). These findings indicate that, despite prohibitions against stereotyping, seemingly innocuous societal practices may continue to promote this mode of thought. PMID:21752009

Cunningham, Sheila J; Macrae, C Neil

2011-08-01

215

Are Brazilian Conferences and Internship Arrangements, Involving McLeod's Patent Pending Naturoptic Method for Restoring Healthy Vision, for Visually Impaired Professional Americas' Students, an Effective Mechanism to Teach and Implement Desired Changes?  

NASA Astrophysics Data System (ADS)

We have initiated investigations and procedures that we hope can be applied, perhaps first in Brazil, and also possibly in countries like Chile, Paraguay, Peru and Venezuela, or elsewhere in the Americas, to propagate favorably Naturoptic Vision Improvement methods. Could the countries involved serve as conference locations that would determine whether it is feasible and possible to transfer this applied physics process rapidly, economically and effectively? The methods and the practical theory involved are easily transmitted, as we hope to demonstrate. This approach is easiest of all to use with well- sighted youth or other individuals, and can be extended to them appropriately to maintain fine vision throughout their lives. Perhaps there should be Naturoptic Vision Maintenance conferences, also!

Ataide, Italanei; Ataide, Jade; McLeod, Roger

2006-10-01

216

Ecological genomics in full colour.  

PubMed

Colour patterns in animals have long offered an opportunity to observe adaptive traits in natural populations. Colour plays myriad roles in interactions within and among species, from reproductive signalling to predator avoidance, leading to multiple targets of natural and sexual selection and opportunities for diversification. Understanding the genetic and developmental underpinnings of variation in colour promises a fuller understanding of these evolutionary processes, but the path to unravelling these connections can be arduous. The advent of genomic techniques suitable for nonmodel organisms is now beginning to light the way. Two new studies in this issue of Molecular Ecology use genomic sequencing of laboratory crosses to map colour traits in cichlid fishes, a remarkably diverse group in which coloration has played a major role in diversification. They illustrate how genomic approaches, specifically RAD sequencing, can rapidly identify both simple and more complex genetic variation underlying ecologically important traits. In the first, Henning et al. () detect a single locus that appears to control in a Mendelian fashion the presence of horizontal stripes, a trait that has evolved in numerous cichlid lineages. In the second, Albertson et al. () identify several genes and epistatic interactions affecting multiple colour traits, as well as a novel metric describing integration across colour traits. Albertson et al. () go further, by quantifying differential expression of parental alleles at a candidate locus and by relating differentiation among natural populations at mapped loci to trait divergence. Herein lies the promise of ecological genomics - efficiently integrating genetic mapping of phenotypes with population genomic data to both identify functional genes and unravel their evolutionary history. These studies offer guidance on how genomic techniques can be tailored to a research question or study system, and they also add to the growing body of empirical examples addressing basic questions about how ecologically important traits evolve in natural populations. PMID:25330852

Hohenlohe, Paul A

2014-11-01

217

Rainbow Colouring of Split and Threshold Graphs  

E-print Network

A rainbow colouring of a connected graph is a colouring of the edges of the graph, such that every pair of vertices is connected by at least one path in which no two edges are coloured the same. Such a colouring using minimum possible number of colours is called an optimal rainbow colouring, and the minimum number of colours required is called the rainbow connection number of the graph. In this article, we show the following: 1. The problem of deciding whether a graph can be rainbow coloured using 3 colours remains NP-complete even when restricted to the class of split graphs. However, any split graph can be rainbow coloured in linear time using at most one more colour than the optimum. 2. For every integer k larger than 2, the problem of deciding whether a graph can be rainbow coloured using k colours remains NP-complete even when restricted to the class of chordal graphs. 3. For every positive integer k, threshold graphs with rainbow connection number k can be characterised based on their degree sequence al...

Chandran, L Sunil

2012-01-01

218

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

219

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

220

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

221

The Colour of Butterflies' Wings  

Microsoft Academic Search

IN making some experiments a short time ago, I came across a fact of which I was hitherto ignorant. I wished to test the effect of acid on the colours of the wings of a butterfly or moth, and with this view applied muriatic acid to a dried and set specimen of the Six-spotted Burnet [Zygæna filipendulæ). The red parts

F. E. v

1870-01-01

222

The colours of the sun.  

NASA Astrophysics Data System (ADS)

In this paper, arguments are developed for treating (R-I)C as the most important colour to be derived for the Sun. The solar value of (R-I)C is then found to be 0.335±0.002 mag. This result updates a counterpart given by Taylor in 1992.

Taylor, B. J.

223

Colour Parametrization in a Multiparametric Image Interface  

E-print Network

) and HSV (hue, saturation, lightness), are linked to human colour perception: the former to cone cell types is an image. It, too, uses colour to depict its appearance. Thus, the smallest elements of an image

Oldford, R.W.

224

Low Vision and the Visual Interface for Interactive University of Brighton  

E-print Network

with vision impairments represent a substantial viewing audience, with 94% watching TV on a regular basis [9 with existing television viewing patterns presents barriers to iTV access for people with low vision [8Low Vision and the Visual Interface for Interactive Television Mark Rice University of Brighton

Masthoff, Judith

225

Resources for Adapting Low Vision Training Materials for the Adult with Low Literacy Skills. Practice Report  

ERIC Educational Resources Information Center

Adults with low vision who seek clinical low vision services need to be able to read (that is, to interpret or understand words, numbers, and symbols in print meaningfully). Reading difficulties that adults encounter during low vision therapy may be directly connected to a visual impairment or may be related to other reading problems, such as…

Tucker, Laurel A.

2004-01-01

226

BOTANICAL BRIEFING Structural colour and iridescence in plants: the poorly studied relations of pigment colour  

Microsoft Academic Search

†Background Colour is a consequence of the optical properties of an object and the visual system of the animal perceiving it. Colour is produced through chemical and structural means, but structural colour has been relatively poorly studied in plants. †Scope This Botanical Briefing describes the mechanisms by which structures can produce colour. In plants, as in animals, the most common

Beverley J. Glover; Heather M. Whitney

227

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

228

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

229

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

230

An RGB Approach to Prismatic Colours  

ERIC Educational Resources Information Center

Teaching prismatic colours usually boils down to establishing the take-home message that white light consists of "differently refrangible" coloured rays. This approach explains the classical spectrum of seven colours but has its limitations, e.g. in discussing spectra from setups with higher resolution or in understanding the well…

Theilmann, Florian; Grusche, Sascha

2013-01-01

231

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

232

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 ...

233

International computer vision directory  

SciTech Connect

This book contains information on: computerized automation technologies. State-of-the-art computer vision systems for many areas of industrial use are covered. Other topics discussed include the following automated inspection systems; robot/vision systems; vision process control; cameras (vidicon and solid state); vision peripherals and components; and pattern processor.

Flora, P.C.

1986-01-01

234

American Visions  

NSDL National Science Digital Library

American Visions is the companion site to an eight-week PBS series of the same name that runs from May 28 to June 18, 1997. It "tells the history of America's people and places through its art"; this guided tour is conducted by veteran Time magazine art critic Robert Hughes. The site is highlighted by the Exhibition section, a collection of Shockwave-based interactive photo essays on American art history (images and commentary accompanying the first two episodes are available at this time). Each exhibit contains an overall commentary section, as well as specific commentary or quotes for selected images (visible when the mouse pointer moves over the multi-colored bullets that accompany the images). The pages of each exhibit can be navigated from the bottom frame. There is also a large "art gallery" of over 100 images from the series, a series synopsis, and a "remote control" web tour (a separate pop-up window) of sites related to the series. It is a beautiful, though extremely browser and graphics intensive, site.

235

Chromatic properties of the colour-shading effect Frederick A.A. Kingdom *, Sohil Rangwala, Karim Hammamji  

E-print Network

Chromatic properties of the colour-shading effect Frederick A.A. Kingdom *, Sohil Rangwala, Karim Hammamji Vision Research Unit, McGill University, 687 Pine Av. W. Rm. H4-14, Montreal, PQ, Canada H3A 1A1

Kingdom, Frederick A. A.

236

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

237

Carotenoids need structural colours to shine  

PubMed Central

The bright colours of feathers are among the most striking displays in nature and are frequently used as sexual signals. Feathers can be coloured by pigments or by ordered tissue, and these mechanisms have traditionally been treated as distinct modes of display. Here we show that some yellow plumage colour is created both by reflection of light from white structural tissue and absorption of light by carotenoids. Thus, structural components of feathers contribute substantially to yellow ‘carotenoid’ displays, but the effect of variation in structural components on variation in colour displays is, to our knowledge, unstudied. The presence of structural colour in some carotenoid-based colour displays will have to be considered in studies of colour signalling. PMID:17148144

Shawkey, Matthew D; Hill, Geoffrey E

2005-01-01

238

Colourings and preservatives in food.  

PubMed

Colours and preservatives are only two of the many classes of additives in food but they are of interest because many reported cases of sensitivity involve these two groups of substances. Preservatives present the greatest potential health hazard being, by definition, biologically active. Colours and other additives are required to perform a technological function whilst remaining as biologically inert as possible. Food additives are controlled by the Food and Drugs Act 1955 on the basis of advice from the Food Advisory Committee (FAC). Lists of the permitted preservatives and colourings are available, together with details of restrictions on their uses; this information is continually being updated. Food labelling regulations mean that some information about additives can be determined from the labelling--but even if an additive is not listed on the package, one cannot always assume that it is not present in the product, since additives coming through in the original ingredients need not always be listed. Other exemptions also exist, so there can be no absolute certainty about the presence, or absence, of a specific additive. That information can only be obtained by contacting the manufacturer. PMID:6526689

Denner, W H

1984-12-01

239

Colour and odour drive fruit selection and seed dispersal by mouse lemurs  

PubMed Central

Animals and fruiting plants are involved in a complex set of interactions, with animals relying on fruiting trees as food resources, and fruiting trees relying on animals for seed dispersal. This interdependence shapes fruit signals such as colour and odour, to increase fruit detectability, and animal sensory systems, such as colour vision and olfaction to facilitate food identification and selection. Despite the ecological and evolutionary importance of plant-animal interactions for shaping animal sensory adaptations and plant characteristics, the details of the relationship are poorly understood. Here we examine the role of fruit chromaticity, luminance and odour on seed dispersal by mouse lemurs. We show that both fruit colour and odour significantly predict fruit consumption and seed dispersal by Microcebus ravelobensis and M. murinus. Our study is the first to quantify and examine the role of bimodal fruit signals on seed dispersal in light of the sensory abilities of the disperser. PMID:23939534

Valenta, Kim; Burke, Ryan J.; Styler, Sarah A.; Jackson, Derek A.; Melin, Amanda D.; Lehman, Shawn M.

2013-01-01

240

Cortical Visual Impairment: New Directions  

PubMed Central

Cortical visual impairment is the leading cause of bilateral low vision in children in the U.S., yet very little research is being done to find new diagnostic measures and treatments. Dr. Velma Dobson's pioneering work on visual assessments of developmentally delayed children stands out as highly significant in this field. Future research will assess new diagnostic measures, including advanced imaging techniques. In addition, research will evaluate methods to prevent, treat, and rehabilitate infants and children afflicted with this condition. PMID:19417710

Good, William V.

2009-01-01

241

Velhagen Pflügertrident pseudoisochromatic plates in screening congenital red-green vision defects  

Microsoft Academic Search

Red-green colour vision defects were screened in a group of 425 trade school students using Velhagen Pflügertrident pseudoisochromatic plates. Thereafter, the students were examined with the Nagel anomaloscope. Of the 425 students, 31 (7.3%) were found to be colour defectives. Deuteranomalous defects were found in 4.9% of cases; deuteranopic defects, in 0.2%; and protanomalous defects, in 2.1%. There were no

Maija Mantyjärvi

1991-01-01

242

Selection on quantitative colour variation in Centaurea cyanus: the role of the pollinator's visual system.  

PubMed

Even though the importance of selection for trait evolution is well established, we still lack a functional understanding of the mechanisms underlying phenotypic selection. Because animals necessarily use their sensory system to perceive phenotypic traits, the model of sensory bias assumes that sensory systems are the main determinant of signal evolution. Yet, it has remained poorly known how sensory systems contribute to shaping the fitness surface of selected individuals. In a greenhouse experiment, we quantified the strength and direction of selection on floral coloration in a population of cornflowers exposed to bumblebees as unique pollinators during 4 days. We detected significant selection on the chromatic and achromatic (brightness) components of floral coloration. We then studied whether these patterns of selection are explicable by accounting for the visual system of the pollinators. Using data on bumblebee colour vision, we first showed that bumblebees should discriminate among quantitative colour variants. The observed selection was then compared to the selection predicted by psychophysical models of bumblebee colour vision. The achromatic but not the chromatic channel of the bumblebee's visual system could explain the observed pattern of selection. These results highlight that (i) pollinators can select quantitative variation in floral coloration and could thus account for a gradual evolution of flower coloration, and (ii) stimulation of the visual system represents, at least partly, a functional mechanism potentially explaining pollinators' selection on floral colour variants. PMID:24070120

Renoult, J P; Thomann, M; Schaefer, H M; Cheptou, P-O

2013-11-01

243

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. PMID:21957131

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

2012-01-01

244

The Social Lives of Canadian Youths with Visual Impairments  

ERIC Educational Resources Information Center

This survey of the social and leisure experiences of Canadian youths with visual impairments found that, in general, youths with low vision experienced more social challenges than did their peers who were blind. Levels of social support were not found to differ on the basis of level of vision, sex, or age. (Contains 1 figure and 1 table.)

Gold, Deborah; Shaw, Alexander; Wolffe, Karen

2010-01-01

245

Epidemiology, aetiology and management of visual impairment in children.  

PubMed

An estimated 19 million of the world's children are visually impaired, while 1.4 million are blind. Using the UK as a model for high income countries, from a population-based incidence study, the annual cumulative incidence of severe visual impairment/blindness (SVL/BL) is estimated to be 6/10 000 by age 15 years, with the incidence being highest in the first year of life. The population of visually impaired children within high, middle and lower income countries differ considerably between and within countries. The numerous and mainly uncommon disorders which can cause impaired vision result in heterogeneous population which includes a substantial proportion (for SVI/BL, the majority) of children with additional systemic disorders or impairments whose needs differ substantially from those with isolated vision impairment. Paediatricians and other paediatric professionals have a key role in early detection and multidisciplinary management to minimise the impact of visual impairment (VI) in childhood. PMID:24148891

Solebo, Ameenat Lola; Rahi, Jugnoo

2014-04-01

246

"GenotypeColour™": colour visualisation of SNPs and CNVs  

PubMed Central

Background The volume of data available on genetic variations has increased considerably with the recent development of high-density, single-nucleotide polymorphism (SNP) arrays. Several software programs have been developed to assist researchers in the analysis of this huge amount of data, but few can rely upon a whole genome variability visualisation system that could help data interpretation. Results We have developed GenotypeColour™ as a rapid user-friendly tool able to upload, visualise and compare the huge amounts of data produced by Affymetrix Human Mapping GeneChips without losing the overall view of the data. Some features of GenotypeColour™ include visualising the entire genome variability in a single screenshot for one or more samples, the simultaneous display of the genotype and Copy Number state for thousands of SNPs, and the comparison of large amounts of samples by producing "consensus" images displaying regions of complete or partial identity. The software is also useful for genotype analysis of trios and to show regions of potential uniparental disomy (UPD). All information can then be exported in a tabular format for analysis with dedicated software. At present, the software can handle data from 10 K, 100 K, 250 K, 5.0 and 6.0 Affymetrix chips. Conclusion We have created a software that offers a new way of displaying and comparing SNP and CNV genomic data. The software is available free at and is especially useful for the analysis of multiple samples. PMID:19193232

Barlati, Sergio; Chiesa, Sergio; Magri, Chiara

2009-01-01

247

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. PMID:18990672

Thery, Marc; Casas, Jerome

2008-01-01

248

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

PubMed

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. PMID:18990672

Théry, Marc; Casas, Jérôme

2009-02-27

249

Adapted list colouring of planar graphs  

Microsoft Academic Search

Given a (possibly improper) edge-colouring F of a graph G, a vertex colour- ing of G is adapted to F if no colour appears at the same time on an edge and on its two endpoints. If for some integer k, a graph G is such that given any list assignment L to the vertices of G, with jL(v)j ‚

Louis Esperet; Mickael Montassiery Xuding Zhuz

250

Computer vision on tap  

E-print Network

We demonstrate a concept of computer vision as a secure, live service on the Internet. We show a platform to distribute a real time vision algorithm using simple widely available Web technologies, such as Adobe Flash. We ...

Chiu, Kevin Geeyoung

251

Color vision test  

MedlinePLUS

... test checks your ability to distinguish between different colors. ... Eye test - color; Vision test - color; Ishihara color vision test ... be asked to determine the intensity of a color, especially in one eye compared to the other. This is often tested ...

252

Vision Loss, Sudden  

MedlinePLUS

... light that can look like lightning, spots, or stars (photopsias) that occur repeatedly Loss of vision that ... light that can look like lightning, spots, or stars (photopsias) that occur repeatedly Loss of vision that ...

253

Hearing Impairment  

MedlinePLUS

... Impaired? For people who lose their hearing after learning to speak and hear, it can be difficult to adjust because hearing has been an essential aspect of their communication and relationships. The good news ...

254

Myopia and iris colour: a possible connection?  

PubMed

Myopia is a common ocular disease in the world. Its prevalence has increased rapidly worldwide, especially in some East-Asian countries. Genetic factors and environmental factors both affect myopia's onset and its progress. Iris colour is an important characteristic of a person. It is a possible risk factor for myopia by affecting the amount and the colour of light entering eyes. The study of iris colour may contribute to the understanding of myopia mechanism and provide good suggestive evidence for studies on other eye diseases. In this article, the possible connection between myopia and iris colour is proposed. Approaches to dissect any link are suggested. PMID:22465466

Meng, Weihua; Butterworth, Jacqueline; Calvas, Patrick; Malecaze, Francois

2012-06-01

255

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

256

Artificial Vision Image Registration  

E-print Network

Artificial Vision Image Registration Dr. Christian Micheloni Department of Computer Science Vision Compensation of the Induced Motion Klagenfurt 6-11 April Image Compensation I(x,t)xT Change Christian Università Degli Studi di Udine Artificial Vision Image Registration · The image registration

257

Computer Vision Bildverarbeitung  

E-print Network

1 1 Computer Vision Bildverarbeitung Bernd Neumann WS 2007 2 IMAGE PROCESSING FOR MULTIMEDIA, Analysis and Machine Vision (3. Ed.) M. Sonka, V. Hlavac, R. Boyle, Thomson 2008 Grundlagen der Bildverarbeitung K.D. Tönnies, Pearson Studium, 2005 Computer Vision - A Modern Approach D.A. Forsyth, J. Ponce

Hamburg,.Universität

258

Artificial Vision INTRODUCTION  

E-print Network

Artificial Vision INTRODUCTION Dr. Christian Micheloni Department of Computer Science University of Udine, ITALY #12;2011 Prof. Micheloni Christian Università Degli Studi di Udine Artificial Vision The origins of vision · People of the ancient world have tried to understand the nature of the light

259

Pregnancy and Your Vision  

MedlinePLUS

Pregnancy and your vision Pregnancy brings an increase in hormones that may cause changes in vision. In most cases, these are temporary eye conditions ... an expectant mother, you should: be aware of vision changes during pregnancy and know what symptoms indicate ...

260

Low Vision Simulations  

MedlinePLUS

Low Vision Simulations Normal Vision A cataract is a clouding of the lens of the eye and light that passes through the lens to the ... Contrast sensitivity decreases, visual acuity drops somewhat, and vision in low light levels suffers. Home , Contact Us ...

261

Vision Based Fire Detection  

Microsoft Academic Search

Vision based fire detection is potentially a useful technique. With the increase in the number of surveillance cameras being installed, a vision based fire detection capability can be incorporated in existing surveillance systems at rela- tively low additional cost. Vision based fire detection of- fers advantages over the traditional methods. It will thus complement the existing devices. In this paper,

Che-bin Liu; Narendra Ahuja

2004-01-01

262

Vision based fire detection  

Microsoft Academic Search

Vision based fire detection is potentially a useful technique. With the increase in the number of surveillance cameras being installed, a vision based fire detection capability can be incorporated in existing surveillance systems at relatively low additional cost. Vision based fire detection offers advantages over the traditional methods. It will thus complement the existing devices. In this paper, we present

Che-Bin Liu; Narendra Ahuja

2004-01-01

263

Feature Extraction and Simplification from colour images based on Colour Image Segmentation and Skeletonization  

E-print Network

application for completely automated or semi-automated processing of (satellite) imagery and scanned maps, as well as heating or pollution monitoring and dense forest mapping among others. Keywords: colour imageFeature Extraction and Simplification from colour images based on Colour Image Segmentation

264

Positive emotion can protect against source memory impairment.  

PubMed

Despite widespread belief that memory is enhanced by emotion, evidence also suggests that emotion can impair memory. Here we test predictions inspired by object-based binding theory, which states that memory enhancement or impairment depends on the nature of the information to be retrieved. We investigated emotional memory in the context of source retrieval, using images of scenes that were negative, neutral or positive in valence. At study each scene was paired with a colour and during retrieval participants reported the source colour for recognised scenes. Critically, we isolated effects of valence by equating stimulus arousal across conditions. In Experiment 1 colour borders surrounded scenes at study: memory impairment was found for both negative and positive scenes. Experiment 2 used colours superimposed over scenes at study: valence affected source retrieval, with memory impairment for negative scenes only. These findings challenge current theories of emotional memory by showing that emotion can impair memory for both intrinsic and extrinsic source information, even when arousal is equated between emotional and neutral stimuli, and by dissociating the effects of positive and negative emotion on episodic memory retrieval. PMID:24784151

MacKenzie, Graham; Powell, Tim F; Donaldson, David I

2015-02-01

265

Computational approaches to vision  

NASA Technical Reports Server (NTRS)

Vision is examined in terms of a computational process, and the competence, structure, and control of computer vision systems are analyzed. Theoretical and experimental data on the formation of a computer vision system are discussed. Consideration is given to early vision, the recovery of intrinsic surface characteristics, higher levels of interpretation, and system integration and control. A computational visual processing model is proposed and its architecture and operation are described. Examples of state-of-the-art vision systems, which include some of the levels of representation and processing mechanisms, are presented.

Barrow, H. G.; Tenenbaum, J. M.

1986-01-01

266

Spelling Performance of Visually Impaired Adults  

ERIC Educational Resources Information Center

Visual processes undoubtedly play an important role in print reading as well as in spelling. In the present study we intend to compare the spelling performance of visually impaired individuals (both individuals who are blind and individuals with low vision) with that of their fully sighted peers. An analysis of errors (misspelled words and…

Papadopoulos, Konstantinos S.; Arvaniti, Evmorfia K.; Dimitriadi, Despina I.; Gkoutsioudi, Vasiliki G.; Zantali, Christina I.

2009-01-01

267

Factors Affecting the Reading Media Used by Visually Impaired Adults  

ERIC Educational Resources Information Center

The aim of this study was to examine reading media (braille, cassettes, screen-reader, screen-magnifier, large print, low vision aids, CCTV) used by visually impaired adults. This article reports the results of a research project involving 100 people with visual impairment. The participants were interviewed and asked to fill in a questionnaire to…

Goudiras, Dimitrios B.; Papadopoulos, Konstantinos S.; Koutsoklenis, Athanasios Ch.; Papageorgiou, Virginia E.; Stergiou, Maria S.

2009-01-01

268

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

269

3D Computer Vision and Video Computing 3D Vision3D Vision  

E-print Network

1 3D Computer Vision and Video Computing 3D Vision3D Vision Topic 1 of Part II Camera Models CSC I6716 Spring2011 Zhigang Zhu, City College of New York zhu@cs.ccny.cuny.edu 3D Computer Vision and Video Computing 3D Vision3D Vision Closely Related Disciplines Image Processing ­ images to mages Computer

Zhu, Zhigang

270

3D Computer Vision and Video Computing 3D Vision3D Vision  

E-print Network

3D Computer Vision and Video Computing 3D Vision3D Vision CSC I6716 Fall 2010 Topic 1 of Part II Camera Models Zhigang Zhu, City College of New York zhu@cs.ccny.cuny.edu #12;3D Computer Vision and Video Computing 3D Vision3D Vision Closely Related Disciplines Image Processing ­ images to mages Computer

Zhu, Zhigang

271

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

272

Pigment chemistry and colour of Pelargonium flowers  

Microsoft Academic Search

The major factors responsible for colour variation in a range of Pelargonium species and cultivars were shown to be the types and relative levels of pigments present. Variations in pH and copigment levels were not found to contribute significantly. Flowers with colours ranging from cream and pink through to deep purple, including salmon, orange and red, were studied. While either

Kevin A. Mitchell; Kenneth R. Markham; Murray R. Boase

1998-01-01

273

Mineralization in Rust-coloured Acarospora  

Microsoft Academic Search

The upper cortex and extracellular hyphal wall matrix are mineralized in both rust-coloured Acarospora sinopica and the paler A. smaragdula ‘f. subochracea’ in the form of microgranular or microbotryoidal phases. Analysis confirmed the distinctive colours are not simply due to hydrated iron oxides, as previously believed, and suggests mixed sulphide and oxide phases with little crystallinity, as well as other

O. William Purvis; Anton Kearsley; Gordon Cressey; Anna T. Crewe; Mats Wedin

2008-01-01

274

Visual Star Colours from Instrumental Photometry  

NASA Astrophysics Data System (ADS)

In order to display graphically the visual colours of stars and other astronomical objects, photometric broadband R, V, B colours are used to proxy for the r, g, b colours of the three visual sensors of the eye. From photometric Johnson B-V and V-R colour indices, R, V, and B magnitudes (V = 0) are calculated, and from these the respective brightnesses (r, v = 1 = g, and b) are calculated. After suitable normalization these are then placed in a ternary diagram having r, g, and b as the vertices. All B-V and V-R are adjusted so that the Sun falls in the same place as a blackbody at 5800 K. The resulting ternary plot shows all of its objects (stars, planets) in their visual colours at their relative positions in the ternary diagram. The star colours displayed on a computer monitor screen or as a print with a colour printer are more vivid than the usual visual impressions of isolated stars, undoubtedly because of properties of the dark-adapted eye, but double-star pairs with contrasting colours correspond nicely to telescopic visual impressions.

Kohman, Truman P.

2005-06-01

275

An incomplete Kochen-Specker colouring  

Microsoft Academic Search

A particular incomplete Kochen-Specker colouring, suggested by Appleby in dimension three, is generalized to arbitrary dimension. We investigate its effectivity as a function of dimension, using two different measures. A limit is derived for the fraction of the sphere that can be coloured using the generalized Appleby construction as the number of dimensions approaches infinity. The second, and physically more

Helena Granstrom

276

Vertex Colouring and Forbidden Subgraphs - A Survey  

Microsoft Academic Search

There is a great variety of colouring concepts and results in the literature. Here our focus is to survey results on vertex colourings of graphs defined in terms of forbidden induced subgraph conditions. Thus, one who wishes to obtain useful results from a graph coloring formulation of his problem must do more than just show that the problem is equivalent

Bert Randerath; Ingo Schiermeyer

2004-01-01

277

Generalized Colourings (Matrix Partitions) of Cographs  

Microsoft Academic Search

Ordinary colourings of cographs are well understood; we focus on more general colourings, known as matrix partitions. We show that all matrix partition problems for cographs admit polynomial time algorithms and forbidden induced subgraph characterizations, even for the list version of the problems. Cographs are the largest natural class of graphs that have been shown to have this property. We

Tomás Feder; Pavol Hell; Winfried Hochstättler

278

DIFFRACTION: QCD EFFECTS IN COLOUR SINGLET EXCHANGE  

E-print Network

DIFFRACTION: QCD EFFECTS IN COLOUR SINGLET EXCHANGE Anthony T. Doyle \\Lambda Department of Physics and the Tevatron are reviewed. A short introduction to the theoretical background is presented where colour singlet and the four­momentum transfer at the proton vertex, given by t = (P \\Gamma P 0 ) 2 . Fig. 1. Kinematic

Glasgow, University of

279

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

280

Colour polymorphism in birds: causes and functions  

Microsoft Academic Search

We studied polymorphism in all species of birds that are presently known to show intraspecific variation in plumage colour. At least three main mecha- nisms have been put forward to explain the maintenance of polymorphism: apostatic, disruptive and sexual selection. All of them make partly different predictions. Our aims were to investigate evolutionary causes and adaptive functions of colour polymorphism

P. Galeotti; D. Rubolini; P. O. Dunn; M. Fasola

2003-01-01

281

Brilliant Colours from a White Snow Cover  

ERIC Educational Resources Information Center

Surprisingly colourful views are possible from sparkling white snow. It is well known that similarly colourful features can exist in the sky whenever appropriate ice crystals are around. However, the transition of light reflection and refraction from ice crystals in the air to reflection and refraction from those in snow on the ground is not…

Vollmer, Michael; Shaw, Joseph A

2013-01-01

282

Interdisciplinary allied health education in treating older adults with low vision.  

PubMed

In 2000, the number of elderly citizens in the United States was 35 million, an increase of 3.7 million (11%) since 1990. Of these older adults, approximately 1.3 million (4%) have a low vision impairment. Older adults make up two-thirds of those diagnosed with a visual impairment. Low vision impairment, which is different from the typical vision changes associated with aging, occurs because of a chronic visual disorder that cannot be corrected medically, surgically, or with conventional eyeglasses, most often resulting in disability. The leading causes of low vision impairment are diabetic retinopathy, cataract, glaucoma, and age-related macular degeneration. Combined with the other physical changes associated with aging, the development of a low vision impairment further challenges the functional performance and safety of those 65 and older. Furthermore, the psychological impact from the physical changes accompanying aging is compounded for those with a low vision impairment. In response to the health needs of all age groups, Healthy People 2010 has established overarching goals to increase quality and years of healthy life and eliminate health disparities. An interdisciplinary course for allied health students was developed to support future health care providers in improving quality of life for older adults with low vision and help decrease health disparities in this population. This paper reports on the pilot experience with this course. PMID:19759992

Newsham Beckley, Margaret; Teaford, Margaret H; Kegelmeyer, Deborah; Balaswamy, Shantha; Flom, Roanne; Raasch, Thomas

2007-01-01

283

Colour in insect thermoregulation: empirical and theoretical tests in the colour-changing grasshopper, Kosciuscola tristis.  

PubMed

Body colours can result in different internal body temperatures, but evidence for the biological significance of colour-induced temperature differences is inconsistent. We investigated the relationship between body colour and temperature in a model insect species that rapidly changes colour. We used an empirical approach and constructed a heat budget model to quantify whether a colour change from black to turquoise has a role in thermoregulation for the chameleon grasshopper (Kosciuscola tristis). Our study shows that colour change in K. tristis provides relatively small temperature differences that vary greatly with wind speed (0.55 °C at ms(-1) to 0.05 °C at 10 ms(-1)). The biological significance of this difference is unclear and we discuss the requirement for more studies that directly test hypotheses regarding the fitness effects of colour in manipulating body temperature. PMID:23108152

Umbers, K D L; Herberstein, M E; Madin, J S

2013-01-01

284

Composition of a Vision Screen for Servicemembers With Traumatic Brain Injury: Consensus Using a Modified Nominal Group Technique  

PubMed Central

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

Finkelstein, Marsha; Llanos, Imelda; Scheiman, Mitchell; Wagener, Sharon Gowdy

2014-01-01

285

Genetics of colour traits in common vetch ( Vicia sativa L.)  

Microsoft Academic Search

Five parents of common vetch (Vicia sativa L.) having orange\\/beige cotyledon colour, brown\\/white testa colour, purple\\/green seedling colour and purple\\/white flower colour were crossed as a full diallele set. The inheritance patterns of cotyledon, testa or seed coat colour, flower and seedling colour, were studied by analyzing their F1, F2, BC1 and BC2 generations. The segregation pattern in F2, BC1

Doza M. S. Chowdhury; Jane M. Rathjen; Max E. Tate; Glenn McDonald

2004-01-01

286

Impaired Driving  

MedlinePLUS

Impaired driving is dangerous. It's the cause of more than half of all car crashes. It means operating a motor vehicle while you are affected by Alcohol Legal or illegal drugs Sleepiness Distractions, such as using a cell phone or texting Having a medical condition which affects your driving For ...

287

Group Vision Care Policy Vision Care for Life  

E-print Network

Group Vision Care Policy Vision Care for Life EVIDENCE OF COVERAGE Provided by: VISION SERVICE PLAN ADMINISTRATOR: ADDRESS: Benefits are furnished under a vision care Policy purchased by the Group and provided by VISION SERVICE PLAN INSURANCE COMPANY(VSP) under which VSP is financially responsible for the payment

New Mexico, University of

288

Real-time people tracking for mobile robots using thermal vision  

Microsoft Academic Search

This paper presents a vision-based approach for tracking people on a mobile robot using thermal images. The approach combines a particle filter with two al- ternative measurement models that are suitable for real-time tracking. With this approach a person can be detected independently from current light conditions and in situations where no skin colour is visible. In addition, the paper

André Treptow; Grzegorz Cielniak; Tom Duckett

2006-01-01

289

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

290

Biological components of colour preference in infancy.  

PubMed

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 4-5-month-olds may be analysed in the same way. We recorded infants' eye-movements in response to pairwise presentations of eight colour stimuli varying only in hue. Infants looked longest at reddish and shortest at greenish hues. Analyses revealed that the L-M and S-(L+M) contrast between stimulus colour and background explained around half of the variation in infant preference across the hue spectrum. Unlike adult colour preference patterns, there was no evidence for sex differences in the weights on either of the cone-opponent contrast components. The findings provide a quantitative model of infant colour preference that summarizes variation in infant preference across hues. PMID:20136931

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

2010-03-01

291

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

292

Colouration and Colour Changes of the Fiddler Crab, Uca capricornis: A Descriptive Study  

PubMed Central

Colour changes in animals may be triggered by a variety of social and environmental factors and may occur over a matter of seconds or months. Crustaceans, like fiddler crabs (genus Uca), are particularly adept at changing their colour and have been the focus of numerous studies. However, few of these studies have attempted to quantitatively describe the individual variation in colour and pattern or their adaptive significance. This paper quantitatively describes the colour patterns of the fiddler crab Uca capricornis and their ability to change on a socially significant timescale. The most dramatic changes in colour pattern are associated with moulting. These ontogenetic changes result in a general reduction of the colour pattern with increasing size, although females are more colourful and variable than similarly-sized males. Uca capricornis are also capable of rapid colour changes in response to stress, but show no endogenous rhythms associated with the semilunar and tidal cycles commonly reported in other fiddler crabs. The extreme colour polymorphism and the relative stability of the colour patterns in Uca capricornis are consistent with their use in visually mediated mate recognition. PMID:18286186

Detto, Tanya; Hemmi, Jan M.; Backwell, Patricia R. Y.

2008-01-01

293

3D Computer Vision and Video Computing 3D Vision3D Vision  

E-print Network

1 3D Computer Vision and Video Computing 3D Vision3D Vision CSc I6716 Spring 2011 Topic 3 of Part II Stereo Vision p g Zhigang Zhu, City College of New York zhu@cs.ccny.cuny.edu 3D Computer Vision and Video Computing Stereo VisionStereo Vision Problem Infer 3D structure of a scene from two or more images

Zhu, Zhigang

294

3D Computer Vision and Video Computing 3D Vision3D Vision  

E-print Network

1 3D Computer Vision and Video Computing 3D Vision3D Vision CSc I6716 Fall 2010 Topic 3 of Part II Stereo Vision Zhigang Zhu, City College of New York zhu@cs.ccny.cuny.edu 3D Computer Vision and Video Computing Stereo VisionStereo Vision Problem Infer 3D structure of a scene from two or more images taken

Zhu, Zhigang

295

The colour wheels of art, perception, science and physiology  

NASA Astrophysics Data System (ADS)

Colour is not the domain of any one discipline be it art, philosophy, psychology or science. Each discipline has its own colour wheel and this presentation examines the origins and philosophies behind the colour circles of Art, Perception, Science and Physiology (after image) with reference to Aristotle, Robert Boyle, Leonardo da Vinci, Goethe, Ewald Hering and Albert Munsell. The paper analyses and discusses the differences between the four colour wheels using the Natural Colour System® notation as the reference for hue (the position of colours within each of the colour wheels). Examination of the colour wheels shows the dominance of blue in the wheels of art, science and physiology particularly at the expense of green. This paper does not consider the three-dimensionality of colour space its goal was to review the hue of a colour with regard to its position on the respective colour wheels.

Harkness, Nick

2006-06-01

296

Vision specific quality of life in children with optic pathway gliomas.  

PubMed

Children with optic pathway gliomas (OPGs) frequently experience vision loss from their tumors. Most pediatric OPG research has focused on radiographic and visual outcomes, yet the impact of vision loss on quality of life (QOL) in children with OPGs has not been studied. The present study prospectively recruited children ? 10 years of age with sporadic or neurofibromatosis type 1 (NF1)-related OPGs. Vision specific QOL was assessed by parent proxy using the Children's Visual Function Questionnaire (CVFQ), and scores were analyzed according to magnitude of visual acuity (VA) loss and presence of visual field (VF) loss. Thirty-six subjects completed the study (53 % female) with median age of 4.6 years. Children with mild, moderate and severe vision loss have lower CVFQ subscale scores, indicating a lower vision specific QOL, compared to those with normal vision. Lower Competence scores were noted in participants with more profound vision loss (p < 0.05), reflecting a decreased ability to complete activities of daily living (e.g., feeding, grooming). Children with two visually impaired eyes were rated as having greater difficulty with social interactions and pleasurable activities (Personality subscale, p = 0.039) compared to those with only one impaired eye. In summary, our findings demonstrate that children with vision loss secondary to their OPG have a decreased vision specific QOL compared to those with normal vision. Measuring vision specific QOL may be considered a meaningful secondary outcome measure for pediatric OPG clinical trials. PMID:24197987

Avery, Robert A; Hardy, Kristina K

2014-01-01

297

Prevalence of Low Vision in Elderly Patients Admitted to an Acute Geriatric Unit in Liverpool: Elderly People Who Fall Are More Likely to Have Low Vision  

Microsoft Academic Search

The prevalence of visual impairment among elderly patients admitted to hospital is unknown. This group of patients may be particularly at risk from poor vision which could jeopardise their independence. A prospective study of visual impairment and its aetiology in acute geriatric admissions assessed after the acute illness had settled was performed. Subjects were all patients aged 65 years or

C. I. A. Jack; T. Smith; C. Neoh; M. Lye; J. N. McGalliard

1995-01-01

298

The History and Future of Low Vision Services in the United States  

ERIC Educational Resources Information Center

This article discusses the history of low vision services in the United States. The field began to gain momentum as the term "low vision" was conceptualized and coined, and this momentum is rapidly increasing with changes in the demographics of visual impairment.

Mogk, Lylas; Goodrich, Gregory

2004-01-01

299

Blending of animal colour patterns by hybridization  

PubMed Central

Biologists have long been fascinated by the amazing diversity of animal colour patterns. Despite much interest, the underlying evolutionary and developmental mechanisms contributing to their rich variety remain largely unknown, especially the vivid and complex colour patterns seen in vertebrates. Here, we show that complex and camouflaged animal markings can be formed by the 'blending' of simple colour patterns. A mathematical model predicts that crossing between animals having inverted spot patterns (for example, 'light spots on a dark background' and 'dark spots on a light background') will necessarily result in hybrid offspring that have camouflaged labyrinthine patterns as 'blended' intermediate phenotypes. We confirmed the broad applicability of the model prediction by empirical examination of natural and artificial hybrids of salmonid fish. Our results suggest an unexplored evolutionary process by means of 'pattern blending', as one of the possible mechanisms underlying colour pattern diversity and hybrid speciation. PMID:20842190

Miyazawa, Seita; Okamoto, Michitoshi; Kondo, Shigeru

2010-01-01

300

Tracking colour objects using adaptive mixture models  

Microsoft Academic Search

Abstract The use of adaptive Gaussian mixtures to model the colour distributions of objects is described. These models are used to perform robust, real-time tracking under varying illumination, viewing geometry and camera parameters. Observed log-likelihood measurements were used to perform selective adaptation. q,1999 Elsevier Science B.V. All rights reserved. Keywords: Real-time tracking; Colour model; Gaussian mixture model; Adaptive learning

Stephen J. Mckenna; Yogesh Raja; Shaogang Gong

1999-01-01

301

Plants and colour: Flowers and pollination  

NASA Astrophysics Data System (ADS)

While there is a range of colours found in plants the predominant colour is green. Pigments in plants have several roles e.g. photosynthesis and signalling. If colour is to be used as a signal then it must stand out from green. However, one should be aware that there are also coloured compounds where we have not yet fully investigated the role of colour in their functions—they may have roles in, for example, defence or heat exchange. In this paper, we will describe the basic chemistry of the major pigments found in plants and especially floral pigments. We will then discuss their locations in parts of the flower (such as sepals, petals, pollen and nectar), the cells in which they are found and their sub-cellular locations. Floral pigments have a large role to play in pollination of flowers by animals. They can and are modified in many ways during the development of flowers in nature, for example, at emergence and post-pollination. There are a range of biochemical mechanisms of colour change both within flowers and in isolated pigments. Some of the factors influencing colour are temperature, co-pigments, pH, metals, sugars, anthocyanin stacking and cell shape. There is a renewed interest in analysing floral pigments and how they are modified partly because of advances in recombinant DNA technologies, but also because of pollinators and their significance to biodiversity and for evolutionary studies. There is continued strong interest from the horticultural industry for the introduction of new colours e.g. the blue rose and for the exploitation of natural dyes. Funding in this area may impact future research in a potentially beneficial way but it must not deflect us from science-based conservation.

Miller, Renee; Owens, Simon J.; Rørslett, Bjørn

2011-03-01

302

Contextual service loading by dependency graph colouring  

Microsoft Academic Search

While installing applications on mobiles devices, we may face issues due to the limit of the device resources. In this paper, we propose AxSeL: A conteXtual Service Loader that considers services-oriented applications and loads them from a distant repository. Services dependencies are represented in a graph that is coloured considering the devices and services constraints. The graph colouring aims to

Amira Ben Hamida; Frédéric Le Mouël; Stéphane Frénot; Mohamed Ben Ahmed

2008-01-01

303

Colour Reagent for Paper Chromatography of Steroids  

Microsoft Academic Search

FOR the paper chromatography of steroids several colour reagents are used, such as 2,4-dinitrophenyl-hydrazine, Zimmermann's reagent, phosphomolybdic acid, antimony trichloride, etc. Their common defect is that the reagent gives some colour with the paper itself, and so the contrast between spot and paper is too small. We have found that acid aniline phthalate in alcoholic solution-the reagent Partridge used for

A. Bodánszky; J. Kollonitsch

1955-01-01

304

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

305

Partitioning Based Algorithms for Some Colouring Problems  

Microsoft Academic Search

We discuss four variants of the graph colouring problem, and present algorithms for solving them. The problems are k-Colourability, Max Ind k-COL, Max Val k-COL, and, finally, Max k-COL, which is the unweighted case of the Max k-Cut problem. The algorithms are based on the idea of partitioning the domain of the problems into disjoint subsets, and then considering all

Ola Angelsmark; Johan Thapper

2005-01-01

306

Colour television image analysis of carious lesions  

Microsoft Academic Search

The new technique of colour television image analysis has been used to produce seven-colour contour maps of the radiodensity\\u000a of micro-radiographs of enamel caries. This method permits the detailed measurement of the mineral content of enamel carious\\u000a lesions to a sensitivity of ±3% of the level of complete mineralisation. By selection of appropriate aluminium step-wedges,\\u000a exposed simultaneously with the tooth

J. C. Rodda; K. V. Mortimer; E. D. Williams

1975-01-01

307

Physicochemical and physiological basis of dichromatic colour  

Microsoft Academic Search

Out of three perceptual characteristics of the colour of any substance, the hue depends mostly on the spectral properties\\u000a of a substance, while the brightness and saturation depend also on the concentration of a substance and its thickness. Here,\\u000a we report that evident change of the hue of the colour (i.e., from green to red) is due to a change

Samo Kreft; Marko Kreft

2007-01-01

308

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. PMID:23378925

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

2013-01-01

309

Vision Texture for Annotation  

Microsoft Academic Search

This paper demonstrates a new application ofcomputer vision to digital libraries -- the use oftexture for annotation, the description of content.Vision-based annotation assists the userin attaching descriptions to large sets of imagesand video. If a user labels a piece of an imageas "water," a texture model can be used topropagate this label to other "visually similar"regions. However, a serious problem

Rosalind W. Picard; Thomas P. Minka

1995-01-01

310

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

311

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

312

Salience of Primary and Secondary Colours in Infancy  

ERIC Educational Resources Information Center

Primary colour terms ("black", "white", "red", "green", "yellow", and "blue") are more fundamental in colour language than secondary colour terms ("pink", "purple", "orange", "brown", and "grey"). Here, we assess whether this distinction exists in the absence of language, by investigating whether primary colours attract and sustain preverbal…

Franklin, Anna; Pitchford, Nicola; Hart, Lynsey; Davies, Ian R. L.; Clausse, Samantha; Jennings, Siobhan

2008-01-01

313

Canvas: An Intelligent Colour Selection Tool For VDU Images  

Microsoft Academic Search

CANVAS is a palette-driven system for colour selection in the density slicing of single-band imagery. By incorporating intelligence on the visual distinction and ordering of colours, the system can operate in several modes. Colours can be selected individually from the palettes or by the system, which maximises the apparent distinction between them. Colour series with unipolar, repeating unipolar and bipolar

G. A. Gill; A. D. Trigg

1988-01-01

314

Facial parity edge colouring of plane pseudographs Jlius Czapa  

E-print Network

is presently known as the Four Colour Theorem (4CT). From the 4CT the following result follows, see [1510, 05C15 1. Introduction The famous Four Colour Problem has served as a motivation for many equivalent colour- ing problems, see e.g. the book of Saaty and Kainen [15]. The Four Colour Problem

Paris-Sud XI, Université de

315

Fano colourings of cubic graphs and the Fulkerson Conjecture  

Microsoft Academic Search

A Fano colouring is a colouring of the edges of a cubic graph by points of the Fano plane such that the colours of any three mutually adjacent edges form a line of the Fano plane. It has recently been shown by Holroyd and Skoviera (J. Combin. Theory Ser. B, to appear) that a cubic graph has a Fano colouring

Edita Mácajová; Martin Skoviera

2005-01-01

316

Flower colour adaptation in a mimetic orchid  

PubMed Central

Although the tremendous variability in floral colour among angiosperms is often attributed to divergent selection by pollinators, it is usually difficult to preclude the possibility that floral colour shifts were driven by non-pollinator processes. Here, we examine the adaptive significance of flower colour in Disa ferruginea, a non-rewarding orchid that is thought to attract its butterfly pollinator by mimicking the flowers of sympatric nectar-producing species. Disa ferruginea has red flowers in the western part of its range and orange flowers in the eastern part—a colour shift that we hypothesized to be the outcome of selection for resemblance to different local nectar-producing plants. Using reciprocal translocations of red and orange phenotypes as well as arrays of artificial flowers, we found that the butterfly Aeropetes tulbaghia, the only pollinator of the orchid, preferred both the red phenotype and red artificial flowers in the west where its main nectar plant also has red flowers, and both the orange phenotype and orange artificial flowers in the east, where its main nectar plant has orange flowers. This phenotype by environment interaction demonstrates that the flower colour shift in D. ferruginea is adaptive and driven by local colour preference in its pollinator. PMID:22298842

Newman, Ethan; Anderson, Bruce; Johnson, Steven D.

2012-01-01

317

Flesh colour dominates consumer preference for chicken.  

PubMed

Existing research investigating interactions between visual and oral sensory cues has tended to use model food systems. In contrast, this study compared product quality assessments of corn-fed and wheat-fed chicken products among persons recruited in Northern Ireland. Three approaches have been adopted to investigate the effect of colour upon consumer choice of chicken: sensory assessment under normal lighting; focus group discussion; and sensory assessment under controlled lighting conditions. Initial consumer sensory assessment indicated that wheat-fed chicken was perceived to be tenderer and to have a more intense flavour than that which was corn-fed. Qualitative enquiry discerned that this was because consumers perceived the yellow colour of corn-fed chicken negatively. Yellow-coloured corn-fed chicken was therefore again compared with wheat-fed chicken in terms of flavour, texture and overall liking with the flesh colour disguised by means of controlled lighting. Quality ratings for corn-fed chicken were more positive when the yellow flesh colour was disguised, with corn-fed chicken judged to be tenderer than wheat-fed chicken and more flavoursome. This study illustrates the importance of using a combination of methods to gain insight into interactions between different sensory modalities in consumer quality judgements and adds to previous research on the importance of colour upon consumer choice of real foods. PMID:15808892

Kennedy, Orla B; Stewart-Knox, Barbara J; Mitchell, Peter C; Thurnham, David I

2005-04-01

318

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. PMID:20926430

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

2011-01-01

319

“We Are Multiculturalism”: A Self-study of Faculty of Colour With Pre-service Teachers of Colour  

Microsoft Academic Search

This paper reports a self-study of three faculty of colour engaged in teaching a special summer session geared to recruiting people of colour to teaching. Given our past experiences in institutions of higher education, we recognised the unique situation and potential of faculty of colour teaching a class made up almost exclusively of students of colour. We analysed our own

Patricia Prado-Olmos; Francisco Ríos; Lillian Vega Castañeda

2007-01-01

320

A Handheld LED Coloured-Light Mixer for Students to Learn Collaboratively the Primary Colours of Light  

ERIC Educational Resources Information Center

To overcome students' inaccurate prior knowledge on primary additive colours, a coloured-light mixer has been constructed to enable students to observe directly the colours produced and reach the conclusion by themselves that the three primary colours of light are red, green, and blue (NOT red, yellow, and blue). Three closely packed tiny…

Nopparatjamjomras, Suchai; Chitaree, Ratchapak; Panijpan, Bhinyo

2009-01-01

321

Development of pattern vision following early and extended blindness  

E-print Network

| sight restoration | visual impairment | childhood blindness Early visual experience is crucial as occurring before 1 y of age. We define "extended" blindness as lasting at least until early childhood, whenDevelopment of pattern vision following early and extended blindness Amy Kaliaa,1,2 , Luis Andres

Sinha, Pawan

322

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

323

Environmental and Personal Safety: No Vision Required. Practice Report  

ERIC Educational Resources Information Center

Personal safety is an important issue for all people, regardless of their physical capabilities. For people with visual impairments (that is, those who are blind or have low vision), real concerns exist regarding their vulnerability to crime and their greater risk of attack. With a nationwide increase in crime in the United States, "Three out of…

Bozeman, Laura A.

2004-01-01

324

Machine vision is not computer vision  

NASA Astrophysics Data System (ADS)

The identity of Machine Vision as an academic and practical subject of study is asserted. In particular, the distinction between Machine Vision on the one hand and Computer Vision, Digital Image Processing, Pattern Recognition and Artificial Intelligence on the other is emphasized. The article demonstrates through four cases studies that the active involvement of a person who is sensitive to the broad aspects of vision system design can avoid disaster and can often achieve a successful machine that would not otherwise have been possible. This article is a transcript of the key- note address presented at the conference. Since the proceedings are prepared and printed before the conference, it is not possible to include a record of the response to this paper made by the delegates during the round-table discussion. It is hoped to collate and disseminate these via the World Wide Web after the event. (A link will be provided at http://bruce.cs.cf.ac.uk/bruce/index.html.).

Batchelor, Bruce G.; Charlier, Jean-Ray

1998-10-01

325

Total-colouring of plane graphs with maximum degree nine  

Microsoft Academic Search

The central problem of the total-colourings is the Total-Colouring Conjecture, which asserts that every graph of maximum degree admits a ( + 2)-total-colouring. Similarly to edge-colourings—with Vizing's edge-colouring conjecture—this bound can be decreased by one for plane graphs of higher maximum degree. More precisely, it is known that if 10 then every plane graph of maximum degree is (

Lukasz Kowalik; Jean-Sebastien Sereni

326

Innovative modelling techniques in computer vision  

NASA Astrophysics Data System (ADS)

The paper is concerned with two of main research activities currently carried on at the Computer Science and Artificial Intelligence lab of DIE. The first part deals with hybrid artificial vision models, intended to provide object recognition and classification capabilities to an autonomous intelligen system. In this framework, a system recovering 3-D shape information from grey-level images of a scene, building a geometric representation of the scene in terms of superquadrics at the geometric level, and reasoning about the scene at the symbolic level is described. In the second part, attention is focused on automatic indexing of image databases. JACOB, a prototypal system allowing for the automatic extraction from images of salient features like colour and texture, and for content-based browsing and querying in image and video databases is briefly described.

Ardizzone, Edoardo; Chella, Antonio

327

Flower colour and cytochromes P450†  

PubMed Central

Cytochromes P450 play important roles in biosynthesis of flavonoids and their coloured class of compounds, anthocyanins, both of which are major floral pigments. The number of hydroxyl groups on the B-ring of anthocyanidins (the chromophores and precursors of anthocyanins) impact the anthocyanin colour, the more the bluer. The hydroxylation pattern is determined by two cytochromes P450, flavonoid 3?-hydroxylase (F3?H) and flavonoid 3?,5?-hydroxylase (F3?5?H) and thus they play a crucial role in the determination of flower colour. F3?H and F3?5?H mostly belong to CYP75B and CYP75A, respectively, except for the F3?5?Hs in Compositae that were derived from gene duplication of CYP75B and neofunctionalization. Roses and carnations lack blue/violet flower colours owing to the deficiency of F3?5?H and therefore lack the B-ring-trihydroxylated anthocyanins based upon delphinidin. Successful redirection of the anthocyanin biosynthesis pathway to delphinidin was achieved by expressing F3?5?H coding regions resulting in carnations and roses with novel blue hues that have been commercialized. Suppression of F3?5?H and F3?H in delphinidin-producing plants reduced the number of hydroxyl groups on the anthocyanidin B-ring resulting in the production of monohydroxylated anthocyanins based on pelargonidin with a shift in flower colour to orange/red. Pelargonidin biosynthesis is enhanced by additional expression of a dihydroflavonol 4-reductase that can use the monohydroxylated dihydrokaempferol (the pelargonidin precursor). Flavone synthase II (FNSII)-catalysing flavone biosynthesis from flavanones is also a P450 (CYP93B) and contributes to flower colour, because flavones act as co-pigments to anthocyanins and can cause blueing and darkening of colour. However, transgenic plants expression of a FNSII gene yielded paler flowers owing to a reduction of anthocyanins because flavanones are precursors of anthocyanins and flavones. PMID:23297355

Tanaka, Yoshikazu; Brugliera, Filippa

2013-01-01

328

Structural colour and iridescence in plants: the poorly studied relations of pigment colour  

PubMed Central

Background Colour is a consequence of the optical properties of an object and the visual system of the animal perceiving it. Colour is produced through chemical and structural means, but structural colour has been relatively poorly studied in plants. Scope This Botanical Briefing describes the mechanisms by which structures can produce colour. In plants, as in animals, the most common mechanisms are multilayers and diffraction gratings. The functions of structural colour are then discussed. In animals, these colours act primarily as signals between members of the same species, although they can also play roles in camouflaging animals from their predators. In plants, multilayers are found predominantly in shade-plant leaves, suggesting a role either in photoprotection or in optimizing capture of photosynthetically active light. Diffraction gratings may be a surprisingly common feature of petals, and recent work has shown that they can be used by bees as cues to identify rewarding flowers. Conclusions Structural colour may be surprisingly frequent in the plant kingdom, playing important roles alongside pigment colour. Much remains to be discovered about its distribution, development and function. PMID:20142263

Glover, Beverley J.; Whitney, Heather M.

2010-01-01

329

[Practising appropriate vision check scheme in eye diseases mass screening works].  

PubMed

Vision check is the first step of mass screening works of most blinding diseases. In recent China, the primary childhood vision check is mainly conducted by hygiene teachers in educational institutions, following the Chinese traditional poor vision classification system, which is based on uncorrected distance visual acuity. However, this classification system does not meet childhood vision developmental mechanism, and may lead to massive unnecessary repetitive screening, diagnosis and treatment of corrected ametropia. In some Chinese communities and villages, the vision check is still based on uncorrected distance visual acuity during eye diseases mass screening procedures in adults. The critical point of preschool children vision impairment screening is then suggested to follow novel Chinese amblyopia diagnostic criteria. Combination of uncorrected, presenting and corrected visual acuity indexes may be used for children' vision check. Collaboration of children health care workers, pediatric ophthalmologists and optometrists in children eye diseases screening projects should be realized as soon as possible. In the adult population, presenting vision is suggested to be used in vision impairment screening works, and appropriate vision check scheme should be adopted in specific eye diseases screening works. PMID:22177120

Zou, Hai-dong; Zhu, Jian-feng

2011-09-01

330

NeatVision: A Development Environment for Machine Vision  

E-print Network

for machine vision engineers. The environment provides high-level access to a wide range of image manipulation Advanced Imaging (JAI) API. (e.g. jai-1_1_X-lib-windows-i586-jre.exe) · NeatVision Standard Edition$ NeatVision: A Development Environment for Machine Vision Engineers By Paul F. Whelan, Robert

Whelan, Paul F.

331

Vision 2020 |LSU Residential Colleges Program Vision 2020  

E-print Network

Vision 2020 |LSU Residential Colleges Program Vision 2020 Residential Colleges Program Department #12;Vision 2020 | LSU Residential Colleges Program 11.24.2011 Page | - 2 - Mission Statement MISSION that promote academic success and personal development in support of Flagship 2020. VISION Be a nationally

Harms, Kyle E.

332

The World Water Vision: From Developing a Vision to Action  

Microsoft Academic Search

The World Water Vision exercise was initiated by the World Water Commission under the auspices of the World Water Council. The goal of the World Water Vision project was to develop a widely shared vision on the actions required to achieve a common set of water-related goals and the necessary commitment to carry out these actions. The Vision should be

S. Gangopadhyay; W. Cosgrove; F. Rijsberman; K. Strzepek

2001-01-01

333

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

334

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. PMID:24759838

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

2014-01-01

335

BINOCULAR VISION Rahul Bhola, MD  

E-print Network

BINOCULAR VISION Rahul Bhola, MD Pediatric Ophthalmology Fellow The University of Iowa Department of Ophthalmology & Visual Sciences posted Jan. 18, 2006, updated Jan. 23, 2006 Binocular vision is one. Binocular Single Vision may be defined as the state of simultaneous vision, which is achieved

Casavant, Tom

336

Computational Architectures for Responsive Vision  

E-print Network

Computational Architectures for Responsive Vision: the Vision Engine James J. Little, Rod Barman, Stewart Kingdon and Jiping Lu Technical Report 91­25 November 1991 Laboratory for Computational Vision email: little@cs.ubc.ca Abstract To respond actively to a dynamic environment, a vision system must

Little, Jim

337

Wavefront Aberrations and Peripheral Vision  

E-print Network

Wavefront Aberrations and Peripheral Vision LINDA LUNDSTRÃ?M Doctoral Thesis Department of Applied with large central visual field loss to better utilize their remaining vision. Central visual field loss means that the person has to rely on peripheral vision since the direct vision is lost, often due

338

Colour preferences in nest-building zebra finches.  

PubMed

Some bird species are selective in the materials they choose for nest building, preferring, for example, materials of one colour to others. However, in many cases the cause of these preferences is not clear. One of those species is the zebra finch, which exhibits strong preferences for particular colours of nest material. In an attempt to determine why these birds strongly prefer one colour of material over another, we compared the preferences of paired male zebra finches for nest material colour with their preferences for food of the same colours. We found that birds did indeed prefer particular colours of nest material (in most cases blue) but that they did not generally prefer food of one colour over the other colours. It appears, then, that a preference for one colour or another of nest material is specific to the nest-building context. This article is part of a Special Issue entitled: insert SI title. PMID:23860278

Muth, Felicity; Steele, Matthew; Healy, Susan D

2013-10-01

339

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. PMID:8981717

Parrish, R K

1996-01-01

340

Vision, Instruction, and Action  

E-print Network

This thesis describes Sonja, a system which uses instructions in the course of visually-guided activity. The thesis explores an integration of research in vision, activity, and natural language pragmatics. Sonja's visual ...

Chapman, David

1990-04-01

341

Ohio's Comprehensive Vision Project  

ERIC Educational Resources Information Center

A vision screening program in seven Ohio counties tested 3,261 preschool children and 44,885 school age children for problems of distance visual acuity, muscle balance, and observable eye problems. (DB)

Bunner, Richard T.

1973-01-01

342

Computer Vision Syndrome  

MedlinePLUS

... pain These symptoms may be caused by: poor lighting glare on the computer screen improper viewing distances ... Computer Vision Syndrome involves taking steps to control lighting and glare on the computer screen, establishing proper ...

343

Eyeglasses for Vision Correction  

MedlinePLUS

... and near vision — in one set of eyeglasses. Progressive lenses function generally the same way as bifocals or ... visible dividing lines. While the invisible transition of progressive lenses may be more aesthetically pleasing, the focal areas ...

344

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

PubMed

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. PMID:24158142

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

2013-12-01

345

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

346

Intelligent vision systems  

NASA Astrophysics Data System (ADS)

NASA's pursuit of reducing the size, weight, and cost of satellite systems, for advanced space systems, is providing a vital thrust to the development of systems-on-a-chip. Novel smart vision systems that incorporate active pixel photo-detectors, MEMs tunable etalons, electro-optical information processors, and applications of the novel smart vision system, including remote sensing, hyperspectral imaging, biomedical imaging and adaptive optics are discussed.

Clark, Natalie; Singh, Upendra N.

2002-09-01

347

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

348

Multi-colour detection of gravitational arcs  

NASA Astrophysics Data System (ADS)

Strong gravitational lensing provides fundamental insights into the understanding of the dark matter distribution in massive galaxies, galaxy clusters, and the background cosmology. Despite their importance, few gravitational arcs have been discovered so far. The urge for more complete, large samples and unbiased methods of selecting candidates increases. Several methods for the automatic detection of arcs have been proposed in the literature, but large amounts of spurious detections retrieved by these methods force observers to visually inspect thousands of candidates per square degree to clean the samples. This approach is largely subjective and requires a huge amount of checking by eye, especially considering the actual and upcoming wide-field surveys, which will cover thousands of square degrees. In this paper we study the statistical properties of the colours of gravitational arcs detected in the 37 deg2 of the CFHTLS-Archive-Research Survey (CARS). Most of them lie in a relatively small region of the (g' - r', r' - i') colour-colour diagram. To explain this property, we provide a model that includes the lensing optical depth expected in a ?CDM cosmology that, in combination with the sources' redshift distribution of a given survey, in our case CARS, peaks for sources at redshift z ~ 1. By furthermore modelling the colours derived from the spectral energy distribution of the galaxies that dominate the population at that redshift, the model reproduces the observed colours well. By taking advantage of the colour selection suggested by both data and model, we automatically detected 24 objects out of 90 detected by eye checking. Compared with the single-band arcfinder, this multi-band filtering returns a sample complete to 83% and a contamination reduced by a factor of ~6.5. New gravitational arc candidates are also proposed.

Maturi, Matteo; Mizera, Sebastian; Seidel, Gregor

2014-07-01

349

Measuring the colour of rendering mortars  

NASA Astrophysics Data System (ADS)

When restoring decorative mortar layers on historic façades, professionals need to determine the colour of these finishes in order to select an appropriate repair mortar. Currently, the appearance of these renders is only assessed from a subjective point of view. To match with the aesthetic aspects of the façade, contractors must constantly adjust their repair mortar composition to avoid a patchwork of different colours, which is detrimental for heritage. This time-consuming (trial-and-error) methodology can be excluded by evaluating `colour' with an objective numerical approach. The challenge of the research was to define and evaluate optimal material dependent boundary conditions for measuring the colour of nonhomogeneous mortars. Four samples with different scale of heterogeneity were measured by two spectrocolorimeters, both with a diffuse illumination geometry. The results were plotted in CIE-L*a*b* colour space. By calculating the colour difference (?E*), the influence of measuring with or without specular component was evaluated. We discovered the minimal number of measuring points depends on the scale of heterogeneity and the aperture area. The less homogeneous the mortar sample is and the smaller the aperture area, the more unique measuring points are required. Therefore, it is recommended to choose an aperture head of 25 mm or more to reduce the number of measurements, making your work time-efficient. However, in order to obtain accurate measurements on site, a portable optical spectrum analyser can be used with a 6 mm-diameter aperture, a viewing angle of 10°, SCI mode, illumination source D65, considering a minimum of 15 unique measuring points.

Govaerts, Yves; Meulebroeck, Wendy; Verdonck, Ann; de Bouw, Michael

2014-05-01

350

Principal components colour display of ERTS imagery  

NASA Technical Reports Server (NTRS)

In the technique presented, colours are not derived from single bands, but rather from independent linear combinations of the bands. Using a simple model of the processing done by the visual system, three informationally independent linear combinations of the four ERTS bands are mapped onto the three visual colour dimensions of brightness, redness-greenness and blueness-yellowness. The technique permits user-specific transformations which enhance particular features, but this is not usually needed, since a single transformation provides a picture which conveys much of the information implicit in the ERTS data. Examples of experimental vector images with matched individual band images are shown.

Taylor, M. M.

1974-01-01

351

Pitfalls in colour photography of choroidal tumours.  

PubMed

Colour imaging of fundus tumours has been transformed by the development of digital and confocal scanning laser photography. These advances provide numerous benefits, such as panoramic images, increased contrast, non-contact wide-angle imaging, non-mydriatic photography, and simultaneous angiography. False tumour colour representation can, however, cause serious diagnostic errors. Large choroidal tumours can be totally invisible on angiography. Pseudogrowth can occur because of artefacts caused by different methods of fundus illumination, movement of reference blood vessels, and flattening of Bruch's membrane and sclera when tumour regression occurs. Awareness of these pitfalls should prevent the clinician from misdiagnosing tumours and wrongfully concluding that a tumour has grown. PMID:23238442

Schalenbourg, A; Zografos, L

2013-02-01

352

Imagery, colour and illness: a review.  

PubMed

This paper reviews research on the role of colour and imagery in relation to illness and examines how this might improve communication between the sufferer and those treating or caring for them. It describes a method by which colour can be related to situations such as an individual's mood and how this might be used to predict response to treatment. Furthermore, it provides evidence that documenting the imagery of an illness might give insight into the patients' fears and concerns about their condition as well as helping non-sufferers to understand what they are going through. PMID:22023001

Carruthers, Helen R

2011-09-01

353

CMSC 426: Image Processing (Computer Vision)  

E-print Network

CMSC 426: Image Processing (Computer Vision) David Jacobs Today's class · What is vision · What is computer vision · Layout of the class #12;Vision · ``to know what is where, by looking.'' (Marr). · Where · What Why is Vision Interesting? · Psychology ­ ~ 50% of cerebral cortex is for vision. ­ Vision is how

Jacobs, David

354

Methods of Reading Information on Labels of Prescription Medications by Persons Who Are Visually Impaired  

ERIC Educational Resources Information Center

The prevalence of visual impairment (that is, blindness and low vision) is increasing in the United States, especially in persons aged 65 and older, with more than half of all people who are blind in this age demographic. It has been estimated that about 6.5 million Americans aged 55 and older report vision loss, and this number is expected to…

McMahon, John M.; Curtis, Amy

2009-01-01

355

How feather colour reflects its carotenoid content  

Microsoft Academic Search

Summary 1. Many birds sequester carotenoid pigments in colourful patches of feathers to advertise or compete for mates. Because carotenoids can be scarce in nature and serve valuable physiological functions, only the highest-quality individuals are thought to acquire or allocate more pigments for use in sexual displays. 2. A critical but rarely tested assumption of carotenoid-based signals is that the

Lauri Saks; Kevin McGraw; Peeter Horak

2003-01-01

356

Odonata colour: more than meets the eye?  

Microsoft Academic Search

Interpretations of behavioural visual cues, based on human perception of colour, may mislead because of the difference in our visual range compared to other animals. Investigations into ultraviolet (UV) reflectance have shown that this can be an important mode of communication in many animals. The present study focused on 10 species of British Odonata. Digital photography was used to capture

Wendy E. Harris; Dan W. Forman; Roy D. Battell; Marie T. R. Battell; Alan K. Nelson; Paul F. Brain

2011-01-01

357

Dietary tannins improve lamb meat colour stability  

Microsoft Academic Search

Fourteen male Comisana lambs were divided into two groups at 45days of age: lambs fed a concentrate diet (C), or lambs fed the same concentrate with the addition of quebracho (Schinopsis lorentzii) tannins (T). Sheep were slaughtered at 105days of age. Lipid oxidation, colour coordinates, haem pigment concentration, and metmyoglobin percentages were measured on minced semimembranosus muscle (SM) over 14days

G. Luciano; F. J. Monahan; V. Vasta; L. Biondi; M. Lanza; A. Priolo

2009-01-01

358

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

359

The cultural origins of colour categories  

E-print Network

? ­ Nativism: genetic makeup. ­ Empiricism: interaction with the environment. ­ Culturalism: culturalThe cultural origins of colour categories Tony Belpaeme Artificial Intelligence Lab Vrije.g. Elman et al., 1996; Yendrikhovskij, 2001) ­ This all happens without the influence of culture

Belpaeme, Tony

360

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

361

Colour-the-INSight: combining a direct view rifle sight with fused intensified and thermal imagery  

NASA Astrophysics Data System (ADS)

We present the design and evaluation of a new demonstrator rifle sight viewing system containing direct view, red aim point and fusion of an (uncooled, LWIR) thermal sensor with a digital image intensifier. Our goal is to create a system that performs well under a wide variety of (weather) conditions during daytime and nighttime and combines the advantages of the various sensor systems. A real-time colour image with salient hot targets is obtained from the night vision sensors by implementing the Colour-the-Night fusion method (Hogervorst & Toet, 2010) on the on-board processor. The prototype system was evaluated in a series of field trials with military observers performing detection and identification tasks. The tests showed that during daytime the addition of a thermal image to direct vision is advantageous, e.g. for the detection of hot targets. At nighttime, the fusion of thermal and image intensified imagery results in increased situational awareness and improved detection of (hot) targets. For identification of small (handheld) objects, the technology needs to be further refined.

Hogervorst, M. A.; Jansen, C.; Toet, A.; Bijl, P.; Bakker, P.; Hiddema, A. C.; van Vliet, S. F.

2012-06-01

362

Testing the AUDI2000 colour-difference formula for solid colours using some visual datasets with usefulness to automotive industry  

NASA Astrophysics Data System (ADS)

Colour-difference formulas are tools employed in colour industries for objective pass/fail decisions of manufactured products. These objective decisions are based on instrumental colour measurements which must reliably predict the subjective colour-difference evaluations performed by observers' panels. In a previous paper we have tested the performance of different colour-difference formulas using the datasets employed at the development of the last CIErecommended colour-difference formula CIEDE2000, and we found that the AUDI2000 colour-difference formula for solid (homogeneous) colours performed reasonably well, despite the colour pairs in these datasets were not similar to those typically employed in the automotive industry (CIE Publication x038:2013, 465-469). Here we have tested again AUDI2000 together with 11 advanced colour-difference formulas (CIELUV, CIELAB, CMC, BFD, CIE94, CIEDE2000, CAM02-UCS, CAM02-SCD, DIN99d, DIN99b, OSA-GP-Euclidean) for three visual datasets we may consider particularly useful to the automotive industry because of different reasons: 1) 828 metallic colour pairs used to develop the highly reliable RIT-DuPont dataset (Color Res. Appl. 35, 274-283, 2010); 2) printed samples conforming 893 colour pairs with threshold colour differences (J. Opt. Soc. Am. A 29, 883-891, 2012); 3) 150 colour pairs in a tolerance dataset proposed by AUDI. To measure the relative merits of the different tested colour-difference formulas, we employed the STRESS index (J. Opt. Soc. Am. A 24, 1823-1829, 2007), assuming a 95% confidence level. For datasets 1) and 2), AUDI2000 was in the group of the best colour-difference formulas with no significant differences with respect to CIE94, CIEDE2000, CAM02-UCS, DIN99b and DIN99d formulas. For dataset 3) AUDI2000 provided the best results, being statistically significantly better than all other tested colour-difference formulas.

Martínez-García, Juan; Melgosa, Manuel; Gómez-Robledo, Luis; Li, Changjun; Huang, Min; Liu, Haoxue; Cui, Guihua; Luo, M. Ronnier; Dauser, Thomas

2013-11-01

363

[Quality system Vision 2000].  

PubMed

A recent document of the Italian Ministry of Health points out that all structures which provide services to the National Health System should implement a Quality System according to the ISO 9000 standards. Vision 2000 is the new version of the ISO standard. Vision 2000 is less bureaucratic than the old version. The specific requests of the Vision 2000 are: a) to identify, to monitor and to analyze the processes of the structure, b) to measure the results of the processes so as to ensure that they are effective, d) to implement actions necessary to achieve the planned results and the continual improvement of these processes, e) to identify customer requests and to measure customer satisfaction. Specific attention should be also dedicated to the competence and training of the personnel involved in the processes. The principles of the Vision 2000 agree with the principles of total quality management. The present article illustrates the Vision 2000 standard and provides practical examples of the implementation of this standard in cardiological departments. PMID:12611210

Pasini, Evasio; Pitocchi, Oreste; de Luca, Italo; Ferrari, Roberto

2002-12-01

364

Perception of colour in unilateral tritanopia.  

PubMed Central

The unilateral tritanope described in the previous paper (Alpern, Kitahara & Krantz, 1983) was able to match every narrow-band light presented to his tritanopic eye with lights from a tristimulus colorimeter viewed in the adjacent field by the normal eye. In two regions of the spectrum (called isochromes) physically identical lights appeared identical to the observer's two eyes. One isochrome was close to 'blue' for the normal eye, the other was in the long-wave spectral region seen by the normal eye predominantly as 'red'. Between these isochromes the normal eye required less than spectral purity to match, dropping to near zero purity at 560-570 nm. A mixture of the two isochromes that appeared purple to the normal eye appeared neutral to the tritanopic eye. Hence dichoptic matches grossly violate Grassmann's additivity law. For the normal eye colour naming conformed to typical normal results. For the tritanopic eye the results were coherent with those found by dichoptic matching: the spectrum was divided into two regions by the achromatic neutral band. To the short-wave side, only the colour names 'blue' and 'white' were ever used. To the long-wave side the predominant colour names were 'red' and 'white' with some 'yellow'. Spectral lights appeared neither 'red-blue' nor greenish. Surrounding the test with an annulus either 430 nm, 650 nm, or a mixture of these, fails to induce any greenish appearance, although the achromatic band shifted in the expected directions. It is concluded that there must be exactly three functionally independent, essentially non-linear central codes for colour perception, and that these codes are different from those suggested in existing theories of colour perception. PMID:6603509

Alpern, M; Kitahara, K; Krantz, D H

1983-01-01

365

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

366

VisionBlocks: A Social Computer Vision Framework  

E-print Network

Vision Blocks (http://visionblocks.org) is an on demand, in-browser, customizable computer vision application publishing platform for masses. It empowers end-users (consumers)to create novel solutions for themselves that ...

Bendale, Abhijit

367

Colour management is a socio-technical problem  

Microsoft Academic Search

This paper describes how achieving consistent colour reproduction across different devices is a complicated matter. Although there is a technological infrastructure for managing colour across devices this is very rarely used as intended. This infrastructure has been created by modelling the problem of colour management as a wholly technical one. In this paper we illustrate the importance of understanding the

Jacki O'neill; David Martin; Tommaso Colombino; Frédéric Roulland; Jutta Willamowski

2008-01-01

368

EXERCISES IN CARTOGRAPHY AND GEOINFORMATICS: TEACHING THE COLOURS Arzu LTEKN  

E-print Network

employ colour as information. In a Remote-Sensing data based forest classification map, the classes production. #12;2. What is Colour 2.1. Definition Colour is light. In other words, it is a side product of the light-spectrum. The light is reflected or absorbed by the objects, and we "see" the reflected ones

�öltekin, Arzu

369

The representation of colours in the cerebral cortex  

Microsoft Academic Search

New insights into how colour is represented in the cerebral cortex and what variables govern the responses of single cortical colour-coded cells have been gained by the discovery of specific visual cortical areas rich in colour-coded cells.

S. Zeki

1980-01-01

370

Skin Blood Perfusion and Oxygenation Colour Affect Perceived Human Health  

Microsoft Academic Search

Skin blood perfusion and oxygenation depends upon cardiovascular, hormonal and circulatory health in humans and provides socio-sexual signals of underlying physiology, dominance and reproductive status in some primates. We allowed participants to manipulate colour calibrated facial photographs along empirically-measured oxygenated and deoxygenated blood colour axes both separately and simultaneously, to optimise healthy appearance. Participants increased skin blood colour, particularly oxygenated,

Ian D. Stephen; Vinet Coetzee; Miriam Law Smith; David I. Perrett; Rebecca Sear

2009-01-01

371

Summing Large-N Towers in Colour Flow Evolution  

E-print Network

We consider soft gluon evolution in the colour flow basis. We give explicit expressions for the colour structure of the (one-loop) soft anomalous dimension matrix for an arbitrary number of partons, and show how the successive exponentiation of classes of large-N contributions can be achieved to provide a systematic expansion of the evolution in terms of colour supressed contributions.

Simon Plätzer

2013-12-09

372

Inheritance of coat colour in the field spaniel dog  

E-print Network

Note Inheritance of coat colour in the field spaniel dog R Robinson St Stephens Nursery, Stephens known as roan. dog genetics / coat colour / field spaniel / breed R�sum� - H�r�dit� de la couleur du for the heredity of coat colour in the dog (Little, 1957; Robinson, 1990), it has become apparent as work

Paris-Sud XI, Université de

373

Colour contribution to children's wayfinding in school environments  

Microsoft Academic Search

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

Nilgün Olguntürk

2011-01-01

374

Towards more adequate colour histograms for in-body images  

Microsoft Academic Search

Although there is a growing number of scientific papers describing classification of in-body images, most of it is based on traditional colour histograms. In this paper we explain why these might not be the most adequate visual features for in-body image classification. Based on a colour dynamic range maximization criterion, we propose a methodology for creating more adequate colour histograms,

A. Sousa; M. Dinis-Ribeiro; M. Areia; M. Correia; M. Coimbra

2008-01-01

375

A NEW PROOF OF THE FOUR-COLOUR THEOREM  

Microsoft Academic Search

The four-colour theorem, that every loopless planar graph admits a vertex-colouring with at most four dierent colours, was proved in 1976 by Appel and Haken, using a computer. Here we announce another proof, still using a computer, but simpler than Appel and Haken's in several respects. For our purposes a graph G consists of a nite set V (G) of

NEIL ROBERTSON; DANIEL P. SANDERS; PAUL SEYMOUR; ROBIN THOMAS

1996-01-01

376

Extending partial 3-colourings in a planar graph  

Microsoft Academic Search

Let D be a disc, and let X be a finite subset of points on the boundary of D. An essential part of the proof of the four colour theorem is the fact that many sets of 4-colourings of X do not arise from the proper 4-colourings of any graph drawn in D. In contrast to this, we show that

Matt Devos; Paul D. Seymour

2003-01-01

377

Four colours suffice: how the map problem was solved  

Microsoft Academic Search

This book contains an account of the history of the Four Colour Problem and its solution. Suppose one wants to assign colours to the countries on a map in such a way that no two neighbouring countries — with a common boundary consisting of more than just isolated points — receive the same colour. (We assume the map is drawn

Robin Wilson; Charles Nash

2003-01-01

378

Rotation sequences and edge-colouring of binary tree pairs  

Microsoft Academic Search

The famous four-colour problem of planar maps is equivalent, by an optimally fast reduction, to the problem of colouring pairs of binary trees (CPBT). Extant proofs of the four colour theorem lack conciseness, are not lucid in their detail and require hours of electronic computation. The search for a more satisfactory proof continues and, in this spirit, we explore one

Alan Gibbons; Paul Sant

2004-01-01

379

The Sylvester-Gallai theorem, colourings and algebra  

Microsoft Academic Search

Our point of departure is the following simple common gen- eralisation of the Sylvester-Gallai theorem and the Motzkin-Rabin the- orem: Let S be a finite set of points in the plane, with each point coloured red or blue or with both colours. Suppose that for any two distinct points A, B 2 S sharing a colour there is a third

Lourens M. Pretorius; Konrad J. Swanepoel

2009-01-01

380

Dependence between colour and individual anthocyanin content in ripening grapes  

Microsoft Academic Search

Three red grape cultivars of different coloration (Flame seedless, Exotic and Monastrell), grown in Murcia (southeast Spain) were analysed during ripening for external colour and individual pigment content. The application of the CIRG colour index, calculated from the coordinates hue angle (h), lightness (L*) and chroma (C*) of the CIELAB colour space, and defined as [(180-h)\\/(L*+C*)], permitted an objective evaluation

José A Fernández-López; Luis Almela; José A Muñoz; Venancio Hidalgo; Juan Carreño

1998-01-01

381

THE EFFECTIVENESS OF COLOUR IN LEARNING FROM EDUCATIONAL TELEVISION  

Microsoft Academic Search

The author reviews recent research comparing both the relative learning gains and relative attitudes of students using colour or monochrome television material. It is concluded that all users of educational television should resist the temptation to spend large sums on colour television equipment merely because colour is now widely preferred by society at large.

Geoffrey Roberts

1978-01-01

382

Visual pattern based colour image compression G. Schaefer+  

E-print Network

& Imaging Institute ++ School of Computing & Mathematics University of Derby, UK ABSTRACT A novel colour of predefined, universal visual patterns in a uniform colour space. Source coding and colour quantisation per pixel) needed to represent a digital image whilst trying to maintain high perceptual image quality

Aickelin, Uwe

383

Assessment of fire damaged concrete using colour image analysis  

Microsoft Academic Search

Assessment of fire damaged concrete structures usually starts with visual observation of colour change, cracking and spalling. On heating, a change in colour from normal to a pink\\/red is often observed and this is useful since it coincides with the onset of significant loss of concrete strength. Optical microscopy combined with colour image analysis has been used to quantify changes

N. R Short; J. A Purkiss; S. E Guise

2001-01-01

384

A Three-Phase Qualitative Study of Dual-Certified Vision Education Professionals in the Southwestern United States  

ERIC Educational Resources Information Center

The purpose of this qualitative study was to develop a comprehensive understanding of the roles and responsibilities of vision education professionals who are dual-certified as teachers of students with visual impairments and orientation and mobility specialists. Through three phases, the study combined interviews and observations of the vision…

Griffin-Shirley, Nora; Pogrund, Rona L.; Smith, Derrick W.; Duemer, Lee

2009-01-01

385

Night Vision Camera  

NASA Technical Reports Server (NTRS)

PixelVision, Inc. developed the Night Video NV652 Back-illuminated CCD Camera, based on the expertise of a former Jet Propulsion Laboratory employee and a former employee of Scientific Imaging Technologies, Inc. The camera operates without an image intensifier, using back-illuminated and thinned CCD technology to achieve extremely low light level imaging performance. The advantages of PixelVision's system over conventional cameras include greater resolution and better target identification under low light conditions, lower cost and a longer lifetime. It is used commercially for research and aviation.

1996-01-01

386

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

387

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

388

Fast and Accurate Robot Vision for Vision Based Motion  

Microsoft Academic Search

This paper describes the vision module from the soccer playing robots of the Dutch Team. Fast vision is necessary to get a close coupling with the motion software in order to allow fast turning and dribbling with the ball without loosing it. Accurate vision is necessary for the determination of the robot's position in the field and the accurate estimation

Pieter P. Jonker; Jurjen Caarls; Wouter Bokhove

2000-01-01

389

The economic impact and cost of visual impairment in Australia  

PubMed Central

Aims To quantify the total economic costs of vision loss in Australia. Methods Prevalence data of visual impairment, unpublished data on indirect costs, and national healthcare cost databases were used. Results Vision disorders cost Australia an estimated A$9.85 billion in 2004. A$4.8 billion is the loss of wellbeing (years of life lost as a result of disability and premature mortality). Vision disorders rank seventh and account for 2.7% of the national loss of wellbeing. Direct health system costs total A$1.8 billion. They have increased by A$1 billion over the last 10?years and will increase a further A$1–2 billion in the next 10?years. Cataract, the largest direct cost, takes 18% of expenditure. The health system costs place vision disorders seventh, ahead of coronary heart disease, diabetes, depression, and stroke. Indirect costs, A$3.2 billion, include carers' costs, low vision aids, lost earnings, and other welfare payments and taxes. Conclusions Even a developed economy such as Australia's cannot afford avoidable vision loss. Priority needs to be given to prevent preventable vision loss; to treat treatable eye diseases; and to increase research into vision loss that can be neither prevented nor treated. PMID:16488942

Taylor, H R; Pezzullo, M L; Keeffe, J E

2006-01-01

390

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

391

Contact Lenses for Vision Correction  

MedlinePLUS

... Eye Health News Consumer Alerts Contact Lenses for Vision Correction Tweet What are contacts? Contact lenses are ... on the surface of the eye. They correct vision like eyeglasses do and are safe when used ...

392

Do You Have Low Vision?  

MedlinePLUS

... at NEI Education Programs Training and Jobs Healthy Vision Diabetes Diabetes Home How Much Do You Know? ... hablarle a su oculista Do You Have Low Vision? Listen There are many signs that can signal ...

393

Near Vision Test for Adults  

MedlinePLUS

... test requires you to print the Near Vision Chart. The appearance of your printed chart may vary depending on the printer you are ... printed copy. Instructions ? Instructions ? Print the Near Vision Chart . Do not take this test if you are ...

394

California State University, Fullerton Vision & Visionaries  

E-print Network

California State University, Fullerton Vision & Visionaries 2014-2015 Call for Nominations Vision. Above all other university accolades, the Vision & Visionaries award is the highest honor that can recommended. November 2014.....................Vision & Visionaries Awardees are announced February 5, 2015

de Lijser, Peter

395

What You Should Know (Low Vision)  

MedlinePLUS

... Disease Low Vision Healthy Eyes Promoting independence through vision rehabilitation. RELATED TOPICS Do You Have Low Vision? What You ... the greater your chances of keeping your remaining vision. next page Imagine How You ... degeneration Links open a new window. ...

396

A National Video Library for Teacher Preparation in Visual Impairments  

ERIC Educational Resources Information Center

This article presents the findings of the first phase of a multiyear funded project whose ultimate purpose is to clearly define and then create a video clip library of 8- to 10-minute video clips that demonstrate exemplary teaching practices for working with students who are visually impaired (that is, those who are blind or have low vision).…

Trief, Ellen; Lengel, Jim; Baecher, Laura

2013-01-01

397

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

398

Hearing-Impaired Students: Options for Far Visual Acuity Screening.  

ERIC Educational Resources Information Center

The comparison of Orthorater vision tester and Snellen chart far visual acuity results for 261 National Technical Institute for the Deaf (NTID) students. Results indicated that a rear illuminated Snellen chart is an acceptable alternative to the Orthorater for screening postsecondary, hearing impaired students' far visual acuity. (Author)

Johnson, Donald D.; Caccamise, Frank

1983-01-01

399

Vision as Adaptive Epistemology  

E-print Network

In the last years the debate on complexity has been developing and developing in transdisciplinary way to meet the need of explanation for highly organized collective behaviors and sophisticated hierarchical arrangements in physical, biological, cognitive and social systems. Unfortunately, no clear definition has been reached, so complexity appears like an anti-reductionist paradigm in search of a theory. In our short survey we aim to suggest a clarification in relation to the notions of computational and intrinsic emergence, and to show how the latter is deeply connected to the new Logical Openness Theory, an original extension of Godel theorems to the model theory. The epistemological scenario we are going to make use of is that of the theory of vision, a particularly instructive one. Vision is an element of our primordial relationship with the world;consequently it comes as no surprise that carefully taking into consideration the processes of visual perception can lead us straight to some significant questions useful to delineate a natural history of knowledge. The common Greek etymological root of theory and vision sounds like a metaphor pointing out the analogy between the modalities of vision and those we use to see and build the world because them both can say us something about the central role of the observer and the semantic complexity of cognitive strategies.

Ignazio Licata

2008-11-30

400

Global Vision Study Abroad  

E-print Network

Finding a Global Vision Study Abroad Students Visit South Africa Philosophy in the Community arts sculpture of South Africa's late pop diva Brenda Fassie. More on Page 4 #12;At every post of issues. Dirk has now returned to his previous position as Head of the Department of Geography

Saskatchewan, University of

401

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

402

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

403

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.

404

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

405

Different effects of alcohol on automatic detection of colour, location and time change: A mismatch negativity study.  

PubMed

The effects of alcohol on pre-attentive processing have been well studied in the past decades. However, the majority of studies focus on pre-attentive auditory processing and only a few studies have examined the effects of alcohol on visual processing. This study investigates the effects of alcohol on automatic pre-attentive processing of visual changes in colour, location and duration. We compared the mean amplitudes and the amplitude decline ratios of visual mismatch negativity (vMMN) responses elicited for small and large changes in image colour, location and duration in 12 individuals under the influence of alcohol and in a placebo condition. The vMMN amplitudes for changes in location and duration significantly decreased in the alcohol condition as compared with the placebo condition, and the magnitude of decrease was not related to the magnitude of change in the deviant stimuli. However, the amplitude of colour vMMN, in the alcohol condition, did not change significantly compared to the placebo condition. These results show that pre-attentive visual processing is impaired by alcohol, and that this impairment may be feature-specific. In addition, this impairment was not related to the magnitude of stimuli change. PMID:25237124

He, Jinbo; Hu, Yue; Pakarinen, Satu; Li, Bingbing; Zhou, Zongkui

2014-12-01

406

Comparison of Reading Performance between Visually Impaired and Normally Sighted Students in Malaysia  

ERIC Educational Resources Information Center

The aim of this study is to compare reading performance between visually impaired and normally sighted school children. Participants (n = 299) were divided into three groups: normal vision (NV, n = 193), visually impaired print reader (PR, n = 52), and Braille reader (BR, n = 54). Reading performance was determined by measuring reading rate and…

Mohammed, Zainora; Omar, Rokiah

2011-01-01

407

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

408

Clinical Trials in Vision Research  

E-print Network

Clinical Trials in Vision Research Information for Volunteers U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Eye Institute #12;Clinical trials in vision Trials in Vision Research 1 Basics of Clinical Trials 3 How a Clinical Trial is Conducted 7 Participating

Bandettini, Peter A.

409

CORRESPONDENCE PROBLEMS IN GEOMETRIC VISION  

E-print Network

- Dimensional Vision, submitted to SIAM Journal on Imaging Sciences ­ Special Issue on Optimization in ImagingCORRESPONDENCE PROBLEMS IN GEOMETRIC VISION OLOF ENQVIST Faculty of Engineering CentreTryck, Lund 2009 #12;Preface This thesis concerns optimal methods for geometric vision problems. Two important

Lunds Universitet

410

Purposive and qualitative active vision  

Microsoft Academic Search

The traditional view of the problem of computer vision as a recovery problem is questioned, and the paradigm of purposive-qualitative vision is offered as an alternative. This paradigm considers vision as a general recognition problem (recognition of objects, patterns or situations). To demonstrate the usefulness of the framework, the design of the Medusa of CVL is described. It is noted

J. Aloimonos

1990-01-01

411

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

412

A Developmental Robot Vision System  

Microsoft Academic Search

This paper presents a robot vision system that is able to develop its vision gradually in its environment, from motion detection, to analysis of static features of objects, to object individuation, to identifying object unity, to tracking objects and finally to understanding some fundamental object relations. Through a developmental approach, our robot vision system is adaptive to environmental changes and

Xing Zhang; M. H. Lee

2006-01-01

413

Robotic Vision Systems: A Survey  

Microsoft Academic Search

This paper is a survey of robotic vision systems. We will cover a wide array of angles of robotic vision systems beginning with an introduction defining the concepts behind these vision systems and a history of these systems in general. We will move on to cover some of the techniques that are used and a few specific examples that show

Keller J. C. McBride; Trent Johnson

414

2013 update Mission, Vision & Identity  

E-print Network

Mission Vision & Identity. 2013 update #12;2 Mission, Vision & Identity Vice. Economic crisis, environmental challenge, the possibilities of new technologies, questions about society, Vision and Identity explains who we are, what values we have and our ideas about where we are going

Martin, Stephen John

415

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

416

Colour-tunable fluorescent multiblock micelles.  

PubMed

Emerging strategies based on the self-assembly of block copolymers have recently enabled the bottom-up fabrication of nanostructured materials with spatially distinct functional regions. Concurrently, a drive for further miniaturization in applications such as optics, electronics and diagnostic technology has led to intense interest in nanomaterials with well-defined patterns of emission colour. Using a series of fluorescent block copolymers and the crystallization-driven living self-assembly approach, we herein describe the synthesis of multicompartment micelles in which the emission of each segment can be controlled to produce colours throughout the visible spectrum. This represents a bottom-up synthetic route to objects analogous to nanoscale pixels, into which complex patterns may be written. Because of their small size and high density of encoded information, these findings could lead to the development of new materials for applications in, for example, biological diagnostics, miniaturized display technology and the preparation of encoded nanomaterials with high data density. PMID:24594554

Hudson, Zachary M; Lunn, David J; Winnik, Mitchell A; Manners, Ian

2014-01-01

417

Colour-tunable fluorescent multiblock micelles  

NASA Astrophysics Data System (ADS)

Emerging strategies based on the self-assembly of block copolymers have recently enabled the bottom-up fabrication of nanostructured materials with spatially distinct functional regions. Concurrently, a drive for further miniaturization in applications such as optics, electronics and diagnostic technology has led to intense interest in nanomaterials with well-defined patterns of emission colour. Using a series of fluorescent block copolymers and the crystallization-driven living self-assembly approach, we herein describe the synthesis of multicompartment micelles in which the emission of each segment can be controlled to produce colours throughout the visible spectrum. This represents a bottom-up synthetic route to objects analogous to nanoscale pixels, into which complex patterns may be written. Because of their small size and high density of encoded information, these findings could lead to the development of new materials for applications in, for example, biological diagnostics, miniaturized display technology and the preparation of encoded nanomaterials with high data density.

Hudson, Zachary M.; Lunn, David J.; Winnik, Mitchell A.; Manners, Ian

2014-03-01

418

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

419

The HS chromaticity diagram and the Lmn colour space  

NASA Astrophysics Data System (ADS)

In this paper a new HS chromaticity diagram for 10-degree observer with more linear colour distribution is presented. Both, the spectral locus and curve of purple colours generate unity circle -the HS diagram. By using the CIE lightness L as the third dimension, the Lrnn colour space is generated. This new colour space is embedded into cylinder radius of 100 (it stands for chroma) and height of 100 (it stands for lightness). If n is plotted against m the points in resulting Lmn-space are not uniquely related to chromaticity because their position depends on the value of L. The colours of all object-colour stimuli fall within this cylinder boundary. The spectrum locus of the monochromatic stimuli is generally well outside the boundary of object-colour stimuli.

Dohnal, Miroslav

2006-03-01

420

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

421

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

422

Evolution of ultraviolet vision in the largest avian radiation - the passerines  

PubMed Central

Background Interspecific variation in avian colour vision falls into two discrete classes: violet sensitive (VS) and ultraviolet sensitive (UVS). They are characterised by the spectral sensitivity of the most shortwave sensitive of the four single cones, the SWS1, which is seemingly under direct control of as little as one amino acid substitution in the cone opsin protein. Changes in spectral sensitivity of the SWS1 are ecologically important, as they affect the abilities of birds to accurately assess potential mates, find food and minimise visibility of social signals to predators. Still, available data have indicated that shifts between classes are rare, with only four to five independent acquisitions of UV sensitivity in avian evolution. Results We have classified a large sample of passeriform species as VS or UVS from genomic DNA and mapped the evolution of this character on a passerine phylogeny inferred from published molecular sequence data. Sequencing a small gene fragment has allowed us to trace the trait changing from one stable state to another through the radiation of the passeriform birds. Their ancestor is hypothesised to be UVS. In the subsequent radiation, colour vision changed between UVS and VS at least eight times. Conclusions The phylogenetic distribution of SWS1 cone opsin types in Passeriformes reveals a much higher degree of complexity in avian colour vision evolution than what was previously indicated from the limited data available. Clades with variation in the colour vision system are nested among clades with a seemingly stable VS or UVS state, providing a rare opportunity to understand how an ecologically important trait under simple genetic control may co-evolve with, and be stabilised by, associated traits in a character complex. PMID:22024316

2011-01-01

423

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

424

Background complexity affects colour preference in bumblebees  

NASA Astrophysics Data System (ADS)

Flowers adapted for hummingbird pollination are typically red. This correlation is usually explained by the assertion that nectar- or pollen-stealing bees are “blind” to red flowers. However, laboratory studies have shown that bees are capable of locating artificial red flowers and often show no innate preference for blue over red. We hypothesised that these findings might be artefacts of the simplified laboratory environment. Using bumblebees ( Bombus impatiens) that had been trained to visit red and blue artificial flowers, we tested whether colour preference was influenced by complexity of the background on which they were foraging. Many bees were indifferent to flower colour when tested using a uniform green background like those commonly used in laboratory studies, but all bees showed strong colour preferences (usually for blue) when flowers were presented against a photograph of real foliage. Overall, preference for blue flowers was significantly greater on the more realistic, complex background. These results support the notion that the red of “hummingbird syndrome” flowers can function to reduce bee visits despite the ability of bees to detect red and highlight the need to consider context when drawing inferences about pollinator preferences from laboratory data.

Forrest, Jessica; Thomson, James D.

2009-08-01

425

Colourful antenna subtraction for gluon scattering  

E-print Network

In this talk I discuss the application and generalization of the antenna subtraction method to processes involving incoherent interferences of partial amplitudes, which are generically present for the sub-leading colour contributions to processes involving more than five partons. The approach makes use of the known infrared (IR) singularity structure of one- and two-loop matrix elements to guide the construction of the subtraction terms. A set of integrated dipoles are defined which can be used to express the poles of one- and two-loop matrix elements in terms of integrated antennae. The unintegrated counterparts of these subtraction terms are then inferred to construct the double real and real-virtual subtraction terms. The method has been tested by computing the NNLO sub-leading colour contribution dijet production via gluon scattering. The double real and real virtual matrix elements for this process can be written purely in terms of incoherent interferences and so the successful removal of all singularities and divergences demonstrates the ability of the antenna subtraction method to handle general sub-leading colour contributions

James Currie

2013-11-24

426

The Machine Vision Toolbox: a MATLAB toolbox for vision and vision-based control  

Microsoft Academic Search

The article described an open-source toolbox for machine vision called Machine Vision Toolbox (MVT). MVT includes more than 60 functions including image file reading and writing, acquisition, display, filtering, blob, point and line feature extraction, mathematical morphology, homographies, visual Jacobians, camera calibration, and color space conversion. MVT can be used for research into machine vision but is also versatile enough

PETER I. CORKE

2005-01-01

427

Vision as Bayesian Inference:Vision as Bayesian Inference: Analysis by Synthesis.Analysis by Synthesis.  

E-print Network

Vision as Bayesian Inference:Vision as Bayesian Inference: Analysis by Synthesis. ·· Videos/Videos/PDFPDF''ss available for download.available for download. #12;Difficulty of VisionDifficulty of Vision ·· Vision is extremely difficult.Vision is extremely difficult. ·· 50% cortex involved in vision

Haykin, Simon

428

Identifying solutions to medication adherence in the visually impaired elderly.  

PubMed

Adults older than 65 years of age with vision impairment are more likely to have difficulty managing medications compared with people having normal vision. This patient population has difficulty reading medication information and may take the wrong medication or incorrect doses of medication, resulting in serious consequences, including overdose or inadequate treatment of health problems. Visually impaired patients report increased anxiety related to medication management and must rely on others to obtain necessary drug information. Pharmacists have a unique opportunity to pursue accurate medication adherence in this special population. This article reviews literature illustrating how severe medication mismanagement can occur in the visually impaired elderly and presents resources and solutions for pharmacists to take a larger role in adherence management in this population. PMID:24513423

Smith, Miranda; Bailey, Trista

2014-02-01

429

The impact of blurred vision on cognitive assessment.  

PubMed

The purpose of this study was to systematically assess the effect of blurred vision on several nonverbal neuropsychological measures commonly used as part of test batteries to assess the cognitive status of different patient populations. A total of 30 highly educated and healthy participants aged between 21 and 33 years were placed in one of three blurred vision groups, defined by their maximal visual acuity (20/20 or control group, 20/40, and 20/60). Blurred vision was simulated using positive diopters at a distance of 40 cm, the same distance as that at which tests were administered. Each participant was then assessed on a predetermined battery of nonverbal and verbal neuropsychological tests demanding different levels of acuity for optimal performance (i.e., tests whose items varied in terms of size and spatial frequency characteristics). In general, blurred vision significantly affected performance on nonverbal tests defined by small-sized/high-spatial-frequency items to a greater extent than on tests defined by larger sized/lower spatial-frequency items. As expected, blurred vision did not affect verbal test performance (Similarities, Information, and Arithmetic WAIS subtests). Our results are a clear indication of how even a "minimal" loss of visual acuity (20/40) can have a significant effect on the performance for certain nonverbal tests. In conclusion, such inferior performance is hypothetically interpretable as reflecting impaired cognitive functioning (i.e., attentional) targeted by a specific task (i.e., visual search) and suggests that the precision of the cognitive assessment and subsequent diagnosis are significantly biased when visuo-sensory abilities are not optimal, particularly for older patient populations where blurred vision resulting from correctable visual impairment is quite common. PMID:17564912

Bertone, Armando; Bettinelli, Line; Faubert, Jocelyn

2007-07-01

430

Vision North Texas  

E-print Network

?business as usual? ?Vision North Texas and the North Texas 2050 document ?Implications for energy conservation ESL-KT-11-11-18 CATEE 2011, Dallas, Texas, Nov. 7 ? 9, 2011 The North Texas Region ESL-KT-11-11-18 CATEE 2011, Dallas, Texas, Nov. 7 ? 9..., 2011 ? ? FW D 16 County Region for Vision North Texas 5.3M people in 2000; 6.5M in 2010; 9.5M in 2030; 11.7M in 2050 ESL-KT-11-11-18 CATEE 2011, Dallas, Texas, Nov. 7 ? 9, 2011 ESL-KT-11-11-18 CATEE 2011, Dallas, Texas, Nov. 7 ? 9, 2011 ESL-KT-11...

Walz, K.

2011-01-01

431

Military personnel recognition system using texture, colour, and SURF features  

NASA Astrophysics Data System (ADS)

This paper presents an automatic, machine vision based, military personnel identification and classification system. Classification is done using a Support Vector Machine (SVM) on sets of Army, Air Force and Navy camouflage uniform personnel datasets. In the proposed system, the arm of service of personnel is recognised by the camouflage of a persons uniform, type of cap and the type of badge/logo. The detailed analysis done include; camouflage cap and plain cap differentiation using gray level co-occurrence matrix (GLCM) texture feature; classification on Army, Air Force and Navy camouflaged uniforms using GLCM texture and colour histogram bin features; plain cap badge classification into Army, Air Force and Navy using Speed Up Robust Feature (SURF). The proposed method recognised camouflage personnel arm of service on sets of data retrieved from google images and selected military websites. Correlation-based Feature Selection (CFS) was used to improve recognition and reduce dimensionality, thereby speeding the classification process. With this method success rates recorded during the analysis include 93.8% for camouflage appearance category, 100%, 90% and 100% rates of plain cap and camouflage cap categories for Army, Air Force and Navy categories, respectively. Accurate recognition was recorded using SURF for the plain cap badge category. Substantial analysis has been carried out and results prove that the proposed method can correctly classify military personnel into various arms of service. We show that the proposed method can be integrated into a face recognition system, which will recognise personnel in addition to determining the arm of service which the personnel belong. Such a system can be used to enhance the security of a military base or facility.

Irhebhude, Martins E.; Edirisinghe, Eran A.

2014-06-01

432

Dynamic monocular machine vision  

Microsoft Academic Search

A new approach to real-time machine vision in dynamic scenes is presented based on special hardware and methods for feature extraction and information processing. Using integral spatio-temporal models, it by-passes the nonunique inversion of the perspective projection by applying recursive least squares filtering. By prediction error feedback methods similar to those used in modern control theory, all spatial state variables

Ernst Dieter Dickmanns; Volker Graefe

1988-01-01

433

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

434

Project Space Vision  

NASA Astrophysics Data System (ADS)

Project Space Vision attempts to document the visions of a new generation of international space professionals for the long-term future of space activities. This voluntary effort was initiated as an independent response from the young space community to an invitation to provide direct input to the Long Term Space Policy Committee of the European Space Agency. By using modern communications tools in the form of the Internet, the World Wide Web and the ISUnet, calls for contributions could reach several thousands of potential contributors within a few weeks time. In return, contributions in the form of survey responses and concise papers were received internationally from young professionals within space agencies, space industry, universities and other organisations. The dominating fundamental reasons for future space activities were found in the areas of services to humankind, scientific progress and exploration. Main perceived barriers were lack of public and political support and high cost of access to space. Other main results include drastic overestimates by the contributors regarding the relative magnitude of spending on space activities. This paper describes the specifics of Project Space Vision and provides an analysis of the fundamental motivations for space activities in our generation as seen by the reached representatives of an emerging space community. The ideas, proposals and suggestions for future space activities are condensed into five specific areas of recommendations followed by general conclusions. Final recommendations are expressed in the form of a space policy in three steps, supported by the general spirit of the contributors.

Edin, P.; Baker, A.; Breitfellner, M.; Debouzy, S.; Fatelnig, P.; Figa, J.; Gilson, P.; Norstrom, J.; Postema, R.; Spiero, F.; Vignelles, A.

1996-01-01

435

Piaget's water-level task: the impact of vision on performance.  

PubMed

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 study. Fourteen sighted individuals participated blindfolded and 14 were able to use their sight. The findings indicate that use of vision can influence the performance in water-level task. However, in the restriction of visual ability (participants with blindfold), individuals with blindness might present better performance than blindfolded sighted participants. PMID:21696918

Papadopoulos, Konstantinos; Koustriava, Eleni

2011-01-01

436

How big does a coloured overlay have to be?  

PubMed

Coloured overlays and coloured lenses can both increase reading speed, but when they do their colour is not necessarily the same, suggesting that the beneficial effects of a coloured filter might depend upon the area of the visual field that it colours. We investigated the effects of overlays on reading speed and varied the size of the overlay and the colour of the surround. Children who had been assessed with coloured overlays were required to read a passage of randomly ordered common words. The words were printed in black ink as a block of text positioned centrally on an A4 page of white paper in landscape orientation. The speed of reading was compared under four conditions: (1) without an overlay; (2) with an overlay of the chosen colour covering the entire page; (3) with the overlay cut so that it just covered the text but left the margin white; (4) with the overlay of the chosen colour covering the text but with the margin coloured a complementary colour, using a second overlay. The children who were using an overlay read more quickly with the overlay; those who were no longer using the overlay did not. Although the block of text covered less than half the page, the colour and nature of the margin did not affect reading speed significantly. These findings suggest that in order to be effective at improving reading speed an overlay needs to cover the text, but not necessarily the remainder of the page, which means that smaller overlays may sometimes be sufficient. PMID:14687202

Waldie, Michelle; Wilkins, Arnold

2004-01-01

437

On the red colour of raspberry ( Rubus idaeus)  

Microsoft Academic Search

Anthocyanins are the ubiquitous water-soluble pigments that are found in flowers and fruits, and are responsible for their impressive red and blue colours. Many examples of the strategies used by nature to obtain colour in plants are based on co-pigmentation, a phenomenon that stabilises and intensifies colours at pH values where the anthocyanin pigment alone is colourless. Several examples of

Maria João Melo; Margarida C Moncada; Fernando Pina

2000-01-01

438

Strong edge-colouring of sparse planar graphs Julien Bensmaila  

E-print Network

is a planar graph then s(G) 4 + 4, for 3. The proof of Theorem 1 uses the Four Colour Theorem. The authorsStrong edge-colouring of sparse planar graphs Julien Bensmaila , Ararat Harutyunyanb , Hervé, LIP, �quipe MC2, 46, allée d'Italie, 69342 Lyon Cedex 07, France Abstract A strong edge-colouring

Paris-Sud XI, Université de

439

Control of shell colour changes in the lobster, Panulirus cygnus.  

PubMed

The transition from juvenile to adult in the Australian western rock lobster, Panulirus cygnus (George), is preceded by a mass migration from inshore nursery reefs to offshore breeding grounds. Associated with this migration is a moult which results in the animals that are due to migrate undergoing characteristic colour change from deep red to pale pink, known as the ;white' phase, which is believed to be triggered by environmental factors. To investigate this phenomenon, the colour change of wild-caught animals was measured over two separate years in response to two important modifiers of crustacean shell colour, dietary carotenoid and background substrate colour. Changes in shell colour during this colour transition period were influenced more greatly by other factors independent of diet or background substrate and no mass colour change was induced during this time. Shell colour measurement and carotenoid quantification confirmed the presence of animals similar to wild-caught ;whites', regardless of the treatment. From these experimental observations we infer that the ;white' phase of the western rock lobster is not triggered by dietary modification or in response to background substrate. We propose that this transition is under the regulation of an ontogenetic program activated at a specific moult, which induces presently unidentified molecular changes linked to shell colour production. This unique colour transition may have evolved to provide protective camouflage during migration, and serves as an excellent model to study the genetic mechanisms underlying crustacean shell colouration. These data also provide insight into the changes in carotenoid levels induced by environmental factors, and the ability to modify crustacean shell colour in aquaculture. PMID:18424686

Wade, Nicholas M; Melville-Smith, Roy; Degnan, Bernard M; Hall, Michael R

2008-05-01

440

Adapting for Impaired Patrons.  

ERIC Educational Resources Information Center

Describes how a library, with an MCI Corporation grant, approached the process of setting up computers for the visually impaired. Discusses preparations, which included hiring a visually-impaired user as a consultant and contacting the VIP (Visually Impaired Persons) group; equipment; problems with the graphical user interface; and training.…

Schuyler, Michael

1999-01-01

441

The Categorisation of Non-Categorical Colours: A Novel Paradigm in Colour Perception  

PubMed Central

In this paper, we investigate a new paradigm for studying the development of the colour ‘signal’ by having observers discriminate and categorize the same set of controlled and calibrated cardinal coloured stimuli. Notably, in both tasks, each observer was free to decide whether two pairs of colors were the same or belonged to the same category. The use of the same stimulus set for both tasks provides, we argue, an incremental behavioural measure of colour processing from detection through discrimination to categorisation. The measured data spaces are different for the two tasks, and furthermore the categorisation data is unique to each observer. In addition, we develop a model which assumes that the principal difference between the tasks is the degree of similarity between the stimuli which has different constraints for the categorisation task compared to the discrimination task. This approach not only makes sense of the current (and associated) data but links the processes of discrimination and categorisation in a novel way and, by implication, expands upon the previous research linking categorisation to other tasks not limited to colour perception. PMID:23536899

Cropper, Simon J.; Kvansakul, Jessica G. S.; Little, Daniel R.

2013-01-01

442

Development of a forensic skin colour predictive test.  

PubMed

There is growing interest in skin colour prediction in the forensic field. However, a lack of consensus approaches for recording skin colour phenotype plus the complicating factors of epistatic effects, environmental influences such as exposure to the sun and unidentified genetic variants, present difficulties for the development of a forensic skin colour predictive test centred on the most strongly associated SNPs. Previous studies have analysed skin colour variation in single unadmixed population groups, including South Asians (Stokowski et al., 2007, Am. J. Hum. Genet, 81: 1119-32) and Europeans (Jacobs et al., 2013, Hum Genet. 132: 147-58). Nevertheless, a major challenge lies in the analysis of skin colour in admixed individuals, where co-ancestry proportions do not necessarily dictate any one person's skin colour. Our study sought to analyse genetic differences between African, European and admixed African-European subjects where direct spectrometric measurements and photographs of skin colour were made in parallel. We identified strong associations to skin colour variation in the subjects studied from a pigmentation SNP discovery panel of 59 markers and developed a forensic online classifier based on naïve Bayes analysis of the SNP profiles made. A skin colour predictive test is described using the ten most strongly associated SNPs in 8 genes linked to skin pigmentation variation. PMID:25082135

Maroñas, Olalla; Phillips, Chris; Söchtig, Jens; Gomez-Tato, Antonio; Cruz, Raquel; Alvarez-Dios, José; de Cal, María Casares; Ruiz, Yarimar; Fondevila, Manuel; Carracedo, Angel; Lareu, María V

2014-11-01

443

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

444

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

445

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. PMID:20015861

Ödeen, Anders; Håstad, Olle; Alström, Per

2010-01-01

446

Visioning: an important management tool.  

PubMed

Visioning is a powerful process that assists us in creating a picture of an ideal future. A vision is a dream, personally created, of how we would like our world to be. In sharing our visions we find common ground and a sense of connection. Today, in an unprecedented way, nurses at all levels are expected to exhibit leadership in setting direction for nursing practice. Assisting nurses to create and share their vision of the future is a mark of transformational leadership. It is an act of empowerment and an expression of caring. PMID:8008119

Tyrrell, R A

1994-01-01

447

Vision Internet Services: Cetacea  

NSDL National Science Digital Library

Hosted by UK-based Vision Internet Services, Cetacea is a comprehensive and artful website providing background information for all known species of dolphin, whale, and porpoise. Site visitors can use the search engine or indices to locate cetacean species by common or scientific name. The information pages for individual species include photos and information regarding Classification, Description, Food & Feeding, and more. The site also provides links to sections on cetacean evolution, human influences on cetaceans, and information on whale watching around the world. Additional features include a Glossary, list of Links, and an FAQ section.

Ward, Heather K.

448

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

449

The development of conceptual colour categories in pre-school children: Influence of perceptual  

E-print Network

structure of developing conceptual colour space during the period in which children acquire basic colourThe development of conceptual colour categories in pre-school children: Influence of perceptual investigates the influence of perceptual colour categorization on the development of conceptual colour space

Mullen, Kathy T.

450

Colour polymorphic prey ( Littorina saxatilis Olivi) and predatory effects of a crab population ( Carcinus maenas L.)  

Microsoft Academic Search

Many marine animal species are genetically polymorphic in colour. Visual selective predation is commonly suggested as a mechanism maintaining colour polymorphism in prey species and may, for example, result in correlations between colour frequencies and the background colour. Such correlations are commonly observed as, for example, in the polymorphic gastropod Littorina saxatilis. On Swedish shores the colour polymorphism of this

Anette Ekendahl

1998-01-01

451

Ratio rule and homomorphic filter for enhancement of digital colour image  

Microsoft Academic Search

Digital colour image enhancement using a homomorphic filter provides good dynamic range compression, but it fails in colour rendition. In this letter, we propose to perform natural colour rendition in a digital colour image that is enhanced by a homomorphic filter. A novel neural network learning algorithm, named Ratio rule, is used to carry out the natural colour rendition process.

Ming-jung Seow; Vijayan K. Asari

2006-01-01

452

Saliency interactions between the 'L-M' and 'S' cardinal colour directions.  

PubMed

Two sub-systems characterize the early stages of human colour vision, the 'L-M' system that differences L and M cone signals and the 'S' system that differences S cone signals from the sum of L and M cone signals. How do they interact at suprathreshold contrast levels? To address this question we employed the method used by Kingdom et al. (2010) to study suprathreshold interactions between luminance and colour contrast. The stimulus employed in one condition was similar to that used by Regan and Mollon (1997) for studying the relative 'organizing power' of the two sub-systems, and consisted of obliquely-oriented red-cyan (to isolate the L-M sub-system) and violet-chartreuse (to isolate the S sub-system) stripes within a lattice of circles. In our experiment there were two conditions, (1) the Separated condition, in which the L-M and S modulations were of opposite orientation and presented separately as a forced-choice pair, and (2) the Combined condition, in which the L-M and S modulations were added. In the Separated condition the task was to indicate the stimulus with the more salient orientation structure, whereas in the Combined condition the task was to indicate the orientation that was more salient. Psychometric functions were used to estimate the ratio of L-M to S contrast at the 'balance-point' i.e. point-of-subjective-equality (PSE) in both conditions. We found that across 20 subjects an average of 8% more S than L-M contrast was needed to achieve a PSE in the Combined compared to Separated condition. We consider possible reasons for this PSE difference and conclude that it is either due to an early-stage interaction between the S and L-M sub-systems, or to a later stage in which new colours that arise from their combination are selectively grouped. PMID:24361603

Kingdom, Frederick A A; Kardous, Natacha; Curran, Laura; Gheorghiu, Elena; Bell, Jason

2014-02-01

453

Combined radio-colour contrast in the examination of ballistic head models.  

PubMed

The conventional analysis of ballistic gelatine is performed by transillumination and scanning of 1-cm-thick slices. Previous research demonstrated the advantages of colour and radio contrast in gelatine for computed tomography (CT). The aim of this study was to determine whether this method could be applied to head models in order to facilitate their examination. Four head models of about 14 cm in diameter were prepared from two acryl hollow spheres and two polypropylene hollow spheres. Acryl paint was mixed with barium meal and sealed in a thin foil bag which was attached to the gelatine-filled sphere which was covered with about 3-mm-thick silicone. The head models were shot at using 9 mm × 19 expanding bullets from 4 m distance. The models were examined via multislice CT. The gelatine core was removed; the bullet track was photographed and cut into consecutive slices which were scanned optically. CT images were processed with Corel Photo-Paint. Optical and radiological images were analysed using the AxioVision software. The disruption of the gelatine within the head model was visualised by extensive distribution of paint up to the end of the finest cracks and fissures and along the whole bullet track. CT imaging with excellent radio contrast in the gelatine cracks caused by the temporary cavity allowed for multiplanar reconstruction. We conclude that the combination of colour contrast in gelatine with contrast material-enhanced CT facilitates accurate measurements in ballistic head models. PMID:22576293

Schyma, C; Greschus, S; Urbach, H; Madea, B

2012-07-01

454

Python and computer vision  

SciTech Connect

This paper discusses the use of Python in a computer vision (CV) project. We begin by providing background information on the specific approach to CV employed by the project. This includes a brief discussion of Constrained Delaunay Triangulation (CDT), the Chordal Axis Transform (CAT), shape feature extraction and syntactic characterization, and normalization of strings representing objects. (The terms 'object' and 'blob' are used interchangeably, both referring to an entity extracted from an image.) The rest of the paper focuses on the use of Python in three critical areas: (1) interactions with a MySQL database, (2) rapid prototyping of algorithms, and (3) gluing together all components of the project including existing C and C++ modules. For (l), we provide a schema definition and discuss how the various tables interact to represent objects in the database as tree structures. (2) focuses on an algorithm to create a hierarchical representation of an object, given its string representation, and an algorithm to match unknown objects against objects in a database. And finally, (3) discusses the use of Boost Python to interact with the pre-existing C and C++ code that creates the CDTs and CATS, performs shape feature extraction and syntactic characterization, and normalizes object strings. The paper concludes with a vision of the future use of Python for the CV project.

Doak, J. E. (Justin E.); Prasad, Lakshman

2002-01-01

455

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

456

Machine Vision Preis Vielseitig, wachstumsstark und zukunftssicher  

E-print Network

Machine Vision Preis Vielseitig, wachstumsstark und zukunftssicher: Sehende Maschinen! Jetzt den richtigen Weg einschlagen, Machine Vision zu deinem Thema machen und die Chance zum Erfolg nutzen beim: Machine Vision, also sehende Systeme, die das menschliche Auge nachahmen, stellen eine moderne

Haller-Dintelmann, Robert

457

Ill-Posed Problems in Early Vision  

E-print Network

The first processing stage in computational vision, also called early vision, consists in decoding 2D images in terms of properties of 3D surfaces. Early vision includes problems such as the recovery of motion and ...

Bertero, Mario

1987-05-01

458

Chapter 116 Signal Functions of Carotenoid Colouration8  

E-print Network

, in relation to other classes of pigments15 and structural colours, has been outlined in Chapter 10. But colour that signals are honest because they are costly to produce [2]. For32 example, the tail of a peacock (Pavo with longer tails should be higher quality35 individuals, because relatively poor quality individuals should

McGraw, Kevin J.

459

they form juxtaposed pointillistic colour centres which, to our  

E-print Network

, the Nireus group that is indigenous to the Afrotropics, concurrently employs a fluorescent pigment fluorescent pigment and colour- producing or colour-controlling nanostructures are so closely tied together and pattern; how larval food plant quality affects male sexual quality indicators; how the forms and relative

Sokolowski, Marla

460

Utilization of new attributes for evaluating a flower colour spectrum  

Microsoft Academic Search

Flower colour spectra were initially used in India to characterize the flora of urban localities (Nagrathna, 1968; Oommachan, 1973), but only on a presence-absence basis. In order to have a quantitative appraisal of the flower colour spectrum of the vegetation at a particular locality, the density of the species and the number of flowers on each plant should be taken

Rajani Varma; R. R. Das

1983-01-01

461

Combination of colour and thermal sensors for enhanced object detection  

Microsoft Academic Search

In uncontrolled environments, with dynamic background and lighting changes, performing efficient and real-time foreground - background segmentation is very challenging. This work is based on the hypothesis that the combination of long wave infrared (LWIR) (8-12 mum) and colour cameras can significantly improve the robustness of moving objects extraction. Pros and cons of colour and thermal imagers in outdoor video

Louis St-Laurent; Xavier Maldague; Donald Prévost

2007-01-01

462

Children's Models about Colours in Nahuatl-Speaking Communities  

NASA Astrophysics Data System (ADS)

This paper presents the development and structure of indigenous children's ideas about mixing colours as well as their ideas about each colour, derived from their traditions. The children were interviewed both at school and outside it, and an educational proposal was implemented. Ideas expressed in the school context were analysed using the partial possible model, which states that the inferences and explanations used to describe a subject consist of constricting ideas, rules of correspondence, and a set of phenomenological inferences about processes. After identifying these components in the children's ideas, we developed models to describe their conceptions about mixing colours. We employed a different approach to analyse children's ideas related to their cultural context. The results showed that children change from a conception that focuses on colours as entities that do not change and as properties of objects (model 1) to the idea that colour represents a quality of substances or objects that can be modified by mixing colours (model 2). Cultural context analysis showed that stories are independent from one another and that they are not connected to colour mixing processes, only to the actions of colour on people. We concluded that students generate independent constructions between school and cultural knowledge.

Gallegos-Cázares, Leticia; Flores-Camacho, Fernando; Calderón-Canales, Elena; Perrusquía-Máximo, Elvia; García-Rivera, Beatriz

2014-10-01

463

Physics-based Segmentation of Colour Images in Spherical Coordinates  

Microsoft Academic Search

We present image segmentation and highlight detection algorithms based on the dichromatic re- flection model. For image segmentation, we use the model prediction that objects of a certain colour produce lines (the matte lines) radiating away from the origin of the RGB colour space. These lines therefore show up as peaks in a 2-dimensional histogram of the angular coordinates of

Allan Hanbury

2004-01-01

464

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. PMID:20484236

McEwen, Jamie R.; Vamosi, Jana C.

2010-01-01

465

Iris colour and relationship of tyrosinase activity to adrenergic innervation  

Microsoft Academic Search

IRIS colour to some degree depends on the sympathetic innervation of the eye. Chance clinical observations of humans and experimental studies in animals have demonstrated consistently a gradual lessening of colour intensity in the iris after interruption of the sympathetic pathways to the eye1,2. Similarly, full iris pigmentation fails to develop when the sympathetic innervation to the eye is absent

Alan M. Laties

1975-01-01

466

Fine colour discrimination requires differential conditioning in bumblebees  

Microsoft Academic Search

Accurate recognition requires that visual systems must be able to discriminate between target and distractor stimuli. Flowers are learned and recognised by bees using visual cues including colour and shape. We investigated whether bees were able to learn to discriminate between colours differently depending upon absolute or differential conditioning. For absolute conditioning bees were rewarded with sucrose solution for visits

Adrian G. Dyer; Lars Chittka

2004-01-01

467

Colour gamuts in polychromatic dielectric elastomer artificial chromatophores  

NASA Astrophysics Data System (ADS)

Chromatophores are the colour changing organelles in the skins of animals including fish and cephalopods. The ability of cephalopods in particular to rapidly change their colouration in response to environmental changes, for example to camouflage against a new background, and in social situations, for example to attract a mate or repel a rival, is extremely attractive for engineering, medical, active clothing and biomimetic robotic applications. The rapid response of these chromatophores is possible by the direct coupling of fast acting muscle and pigmented saccules. In artificial chromatophores we are able to mimic this structure using electroactive polymer artificial muscles. In contrast to prior research which has demonstrated monochromatic artificial chromatophores, here we consider a novel multi-colour, multi-layer, artificial chromatophore structure inspired by the complex dermal chromatophore unit in nature and which exploits dielectric elastomer artificial muscles as the electroactive actuation mechanism. We investigate the optical properties of this chromatophore unit and explore the range of colours and effects that a single unit and a matrix of chromatophores can produce. The colour gamut of the multi-colour chromatophore is analysed and shows its suitability for practical display and camouflage applications. It is demonstrated how, by varying actuator strain and chromatophore base colour, the gamut can be shifted through colour space, thereby tuning the artificial chromatophore to a specific environment or application.

Rossiter, Jonathan; Conn, Andrew; Cerruto, Antonio; Winters, Amy; Roke, Calum

2014-03-01

468

Spectral mouth colour of nestlings changes with carotenoid availability  

Microsoft Academic Search

Summary 1. Despite the proliferation of studies on the role of nestling mouth colour in parent-offspring communication, there has been very little work regarding the proximate mechanism for mouth pigmentation. 2. Carotenoids, a class of phytochemicals important for immune function and gained by birds only through their diet, also serve as pigments for yellow-orange colours. Carotenoids have been shown to

R. Thorogood; R. M. Kilner; F. Karada?; J. G. Ewen

2008-01-01

469

On four-colourings of the rational four-space  

Microsoft Academic Search

Summary LetQ4 denote the graph, obtained from the rational points of the 4-space, by connecting two points iff their Euclidean distance is one. It has been known that its chromatic number is 4. We settle a problem of P. Johnson, showing that in every four-colouring of this graph, every colour class is every-where dense.

Joseph Zaks

1989-01-01

470

Colour mimicry and sexual deception by Tongue orchids ( Cryptostylis)  

NASA Astrophysics Data System (ADS)

Typically, floral colour attracts pollinators by advertising rewards such as nectar, but how does colour function when pollinators are deceived, unrewarded, and may even suffer fitness costs? Sexually deceptive orchids are pollinated only by male insects fooled into mating with orchid flowers and inadvertently transferring orchid pollinia. Over long distances, sexually deceptive orchids lure pollinators with counterfeit insect sex pheromones, but close-range deception with colour mimicry is a tantalising possibility. Here, for the first time, we analyse the colours of four sexually deceptive Cryptostylis orchid species and the female wasp they mimic ( Lissopimpla excelsa, Ichneumonidae), from the perspective of the orchids’ single, shared pollinator, male Lissopimpla excelsa. Despite appearing different to humans, the colours of the orchids and female wasps were effectively identical when mapped into a hymenopteran hexagonal colour space. The orchids and wasps reflected predominantly red-orange wavelengths, but UV was also reflected by raised bumps on two orchid species and by female wasp wings. The orchids’ bright yellow pollinia contrasted significantly with their overall red colour. Orchid deception may therefore involve accurate and species-specific mimicry of wavelengths reflected by female wasps, and potentially, exploitation of insects’ innate attraction to UV and yellow wavelengths. In general, mimicry may be facilitated by exploiting visual vulnerabilities and evolve more readily at the peripheries of sensory perception. Many sexually deceptive orchids are predominantly red, green or white: colours that are all potentially difficult for hymenoptera to detect or distinguish from the background.

Gaskett, A. C.; Herberstein, M. E.

2010-01-01

471

Colour measurements of surfaces to evaluate the restoration materials  

NASA Astrophysics Data System (ADS)

In this paper two case studies on the application of colour measurements for the evaluation of some restoration materials are discussed. The materials related to the research are: watercolours employed in restoration of wall paintings and preservative/consolidants for wood artifacts. Commercial watercolours, supplied by Maimeri, Windsor&Newton and Talens factories have been tested. Colour measurements have been performed by means of a reflectance spectrophotometer (RS) before and after accelerated ageing of watercolours at 92% relative humidity (RH) and in a Solar Box chamber. The experimental results show that watercolours based on natural earths and artificial ultramarine undergo the main colour changes, expressed as L*, a* and b* variations and total colour difference (?E*). In the other cases colour differences depend on both watercolour typology and suppliers. The other example concerns the evaluation of colour change due to surface treatment of Poplar (Populus sp.) and chestnut (Castanea sativa L.) wood samples. The wooden samples have been treated with a novel organic preservative/consolidant product that has been tested also in a real case as comparison. The treated samples have been artificially aged in Solar Box chamber equipped with a 280 nm UV filter. Colour has been measured before and after the artificial ageing by means of a RS. Colour changes have been determined also for the main door of an historical mansion in Viterbo, made of chestnut wood, and exposed outdoors.

Lo Monaco, Angela; Marabelli, Maurizio; Pelosi, Claudia; Picchio, Rodolfo

2011-06-01

472

Visual Impairment, Including Blindness  

MedlinePLUS

... eye, what different parts are called, and what aspect of vision each part is responsible for. http:// ... the particular eye condition a child has; what aspect of the visual system is affected (e.g., ...

473

Mobile assistive technologies for the visually impaired.  

PubMed

There are around 285 million visually impaired people worldwide, and around 370,000 people are registered as blind or partially sighted in the UK. Ongoing advances in information technology (IT) are increasing the scope for IT-based mobile assistive technologies to facilitate the independence, safety, and improved quality of life of the visually impaired. Research is being directed at making mobile phones and other handheld devices accessible via our haptic (touch) and audio sensory channels. We review research and innovation within the field of mobile assistive technology for the visually impaired and, in so doing, highlight the need for successful collaboration between clinical expertise, computer science, and domain users to realize fully the potential benefits of such technologies. We initially reflect on research that has been conducted to make mobile phones more accessible to people with vision loss. We then discuss innovative assistive applications designed for the visually impaired that are either delivered via mainstream devices and can be used while in motion (e.g., mobile phones) or are embedded within an environment that may be in motion (e.g., public transport) or within which the user may be in motion (e.g., smart homes). PMID:24054999

Hakobyan, Lilit; Lumsden, Jo; O'Sullivan, Dympna; Bartlett, Hannah

2013-01-01

474

Vision-Guided Intelligent Robots  

Microsoft Academic Search

We introduce three vision-guided robots that have been designed and built for studying intelligent and adaptive behavior of technical systems in the real world. They are, in the order of commissioning, an autonomous indoor vehicle, a stationary calibration-free manipulator, and a humanoid robot with an omnidirectional wheelbase and two arms. They all use vision as their main sensor modal- ity

Volker Graefe; Rainer Bischoff

1998-01-01

475

Putting the Vision into Practice  

ERIC Educational Resources Information Center

It's almost a year since the revolution--the "Learning Revolution," that is. This was the Government's long-term vision for the development of "informal adult learning", as laid out in the White Paper of March 2009. The vision was expansive, embracing informal learning in the workplace, promoting a "new" culture of involving the arts, broadcasting…

Ravenhall, Mark

2010-01-01

476

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

477

Colour and carotenoid changes of pasteurised orange juice during storage.  

PubMed

The correlation of carotenoid changes with colour degradation of pasteurised single strength orange juice was investigated at 20, 28, 35 and 42°C for a total of 32weeks of storage. Changes in colour were assessed using the CIELAB system and were kinetically described by a zero-order model. L(?), a(?), b(?), ?E(?), Cab(?) and hab were significantly changed during storage (p<0.05). Activation energies for all colour parameters were 64-73kJmol(-1). Several carotenoids showed important changes and appeared to have different susceptibilities to storage. A decrease of ?-cryptoxanthin was observed at higher temperatures, whereas antheraxanthin started to decrease at lower temperatures. Depending on the time and temperature, changes in carotenoids could be due to isomerisation reactions, which may lead to a perceptible colour change. Although the contribution of carotenoids was recognised to some extent, other reactions seem of major importance for colour degradation of orange juice during storage. PMID:25308677

Wibowo, Scheling; Vervoort, Liesbeth; Tomic, Jovana; Santiago, Jihan Santanina; Lemmens, Lien; Panozzo, Agnese; Grauwet, Tara; Hendrickx, Marc; Van Loey, Ann

2015-03-15

478

Implementation and characterization of a fibre-optic colour sensor  

NASA Astrophysics Data System (ADS)

In this paper the implementation of a fibre-optic sensor for colour detection based on reflective colour sensing is proposed. The sensor consists of three plastic optical fibres emitting red, green and blue components and one optical fibre collecting light reflected from the object. Red, green and blue LEDs are excited at different frequencies. In this way detection of the reflected signa