WorldWideScience

Sample records for colour vision deficiencies

  1. Colour Vision Deficiency and Physics Teaching

    Science.gov (United States)

    Maule, Louise; Featonby, David

    2016-01-01

    1 in 12 males suffer from some form of colour vision deficiency (CVD) which in the present colour dominated world of education presentation can be a severe disadvantage. Although aware of "colourblindness" most teachers make little or no adjustment for these pupils for whom tasks may be more difficult. This article examines colour vision…

  2. [Historical Development of the Wool and Colour Plate Tests for Screening for Colour Vision Deficiencies in German Speaking Countries].

    Science.gov (United States)

    Kuchenbecker, J

    2017-07-01

    Colour vision is a complex visual function that can be affected by congenital and/or acquired disorders. The frequency of congenital colour vision deficiencies has been investigated in rail and navy staff since the 1870s. Various test methods have been developed. Wool tests, flor contrast tests and colour plate tests have been used. A published colour plate test, based on Stilling's pseudo-isochromatic plates in combination with a flor contrast test, has been a common screening method for colour vision testing in German-speaking countries. This test is intended to detect congenital and acquired colour vision deficiencies in a simple and safe manner. More modern options, such as Internet and tablet PC have technical limitations, but will increasingly be used for screening for colour vision deficiencies. Georg Thieme Verlag KG Stuttgart · New York.

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

    Science.gov (United States)

    Torrents, Aurora; Bofill, Francesc; Cardona, Genis

    2011-01-01

    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…

  4. Visual contents adaptation for colour vision deficiency using customised ICC profile.

    Science.gov (United States)

    Jang, Young Gun; Choi, Hoon Il; Hong, Kyoung Soon

    2010-07-01

    Approximately, 1 of 12 persons in the world has colour vision deficiency (CVD), named colour blindness. While the amount of graphic information in digital contents is continuing to increase dramatically, assistive tools for colour vision deficiencies remain scarce. We developed a method to generate customised International Colour Consortium (ICC) colour profiles for patients suffering from CVD, which could adjust graphic contents according to individual needs. Compensation rules for the pale or dark range of red and green colours were established, and an ICC profile was generated using this set of rules. The passing rate for Ishihara test was 99.5% when the generated profile was applied to 10 Ishihara plates and tested on individuals suffering from red deficiency, and green deficiency (5, and 15 participants, respectively). The time used to generate the compensation profile was 12.9 min on average, including the time taken to explain the test to the participants. Reliable results were achieved with a relatively low effort in comparison with methods currently utilised in professional clinics, and does not need expensive instruments.

  5. Colour, vision and ergonomics.

    Science.gov (United States)

    Pinheiro, Cristina; da Silva, Fernando Moreira

    2012-01-01

    This paper is based on a research project - Visual Communication and Inclusive Design-Colour, Legibility and Aged Vision, developed at the Faculty of Architecture of Lisbon. The research has the aim of determining specific design principles to be applied to visual communication design (printed) objects, in order to be easily read and perceived by all. This study target group was composed by a selection of socially active individuals, between 55 and 80 years, and we used cultural events posters as objects of study and observation. The main objective is to overlap the study of areas such as colour, vision, older people's colour vision, ergonomics, chromatic contrasts, typography and legibility. In the end we will produce a manual with guidelines and information to apply scientific knowledge into the communication design projectual practice. Within the normal aging process, visual functions gradually decline; the quality of vision worsens, colour vision and contrast sensitivity are also affected. As people's needs change along with age, design should help people and communities, and improve life quality in the present. Applying principles of visually accessible design and ergonomics, the printed design objects, (or interior spaces, urban environments, products, signage and all kinds of visually information) will be effective, easier on everyone's eyes not only for visually impaired people but also for all of us as we age.

  6. Colour discrimination of dental professionals and colour deficient laypersons.

    Science.gov (United States)

    Poljak-Guberina, Renata; Celebic, Asja; Powers, John M; Paravina, Rade D

    2011-12-01

    The aim of the present study was to compare results of non-dental (conventional) and dental colour discrimination tests (customized, shade guide test), to evaluate influence of profession, gender and age of colour normal dentists and laboratory technicians on colour discrimination results and to evaluate results of colour deficient laypersons. A total of 36 colour normal dental professionals, all volunteers were divided into two groups consisting of 18 participants each: dentists (DDS) and laboratory technicians (CDT). In addition, a group 15 colour deficient males also volunteered (CDP). Colour discrimination was examined using Farnsworth-Munsell 100 Hue Test and total error scores (TES) were calculated. Participants performed a dentistry related colour discrimination test by matching 26 pairs of shade tabs. Shade guide scores (3DS) were calculated. These tests were performed under the controlled conditions of a viewing booth. Mean values and standard deviations were determined. ANOVA, Mann-Whitney test, t-test and Pearson's correlation coefficient (r) were used for result analysis. TES and 3DS were correlated for colour normal observers, r = 0.47 (p gender and age were recorded. TES of 159 (83) and 3DS of 6.7 (2.7) were recorded for colour deficient laypersons. Based on TES, 33% of colour deficient laypersons had average discrimination, whilst 67% had low discrimination. Within the limitation of this study, it was concluded that results of non-dental and dental colour discrimination tests were correlated, and that profession (DDS/CDT), gender and age gender did not influence colour discrimination of colour normal participants. Although colour and appearance of dental restorations are of paramount importance for the aesthetic outcome, colour vision of dental professionals is not routinely tested. This paper validates and recommends the usage of dental shade guides for a simple, affordable and understandable testing of colour vision, either as a sole test or

  7. Colour vision and computer-generated images

    International Nuclear Information System (INIS)

    Ramek, Michael

    2010-01-01

    Colour vision deficiencies affect approximately 8% of the male and approximately 0.4% of the female population. In this work, it is demonstrated that computer generated images oftentimes pose unnecessary problems for colour deficient viewers. Three examples, the visualization of molecular structures, graphs of mathematical functions, and colour coded images from numerical data are used to identify problematic colour combinations: red/black, green/black, red/yellow, yellow/white, fuchsia/white, and aqua/white. Alternatives for these combinations are discussed.

  8. Colour vision experimental studies in teaching of optometry

    Science.gov (United States)

    Ozolinsh, Maris; Ikaunieks, Gatis; Fomins, Sergejs

    2005-10-01

    Following aspects related to human colour vision are included in experimental lessons for optometry students of University of Latvia. Characteristics of coloured stimuli (emitting and reflective), determination their coordinates in different colour spaces. Objective characteristics of transmitting of colour stimuli through the optical system of eye together with various types of appliances (lenses, prisms, Fresnel prisms). Psychophysical determination of mono- and polychromatic stimuli perception taking into account physiology of eye, retinal colour photoreceptor topography and spectral sensitivity, spatial and temporal characteristics of retinal receptive fields. Ergonomics of visual perception, influence of illumination and glare effects, testing of colour vision deficiencies.

  9. Specifying colours for colour vision testing using computer graphics.

    Science.gov (United States)

    Toufeeq, A

    2004-10-01

    This paper describes a novel test of colour vision using a standard personal computer, which is simple and reliable to perform. Twenty healthy individuals with normal colour vision and 10 healthy individuals with a red/green colour defect were tested binocularly at 13 selected points in the CIE (Commission International d'Eclairage, 1931) chromaticity triangle, representing the gamut of a computer monitor, where the x, y coordinates of the primary colour phosphors were known. The mean results from individuals with normal colour vision were compared to those with defective colour vision. Of the 13 points tested, five demonstrated consistently high sensitivity in detecting colour defects. The test may provide a convenient method for classifying colour vision abnormalities.

  10. The handicap of abnormal colour vision.

    Science.gov (United States)

    Cole, Barry L

    2004-07-01

    All people with abnormal colour vision, except for a few mildly affected deuteranomals, report that they experience problems with colour in everyday life and at work. Contemporary society presents them with increasing problems because colour is now so widely used in printed materials and in computer displays. Equal opportunity law gives them protection against unfair discrimination in employment, so a decision to exclude a person from employment on the grounds of abnormal colour vision must now be well supported by good evidence and sound argument. This paper reviews the investigations that have contributed to understanding the nature and consequences of the problems they have. All those with abnormal colour vision are at a disadvantage with comparative colour tasks that involve precise matching of colours or discrimination of fine colour differences either because of their loss of colour discrimination or anomalous perception of metamers. The majority have problems when colour is used to code information, in man-made colour codes and in naturally occurring colour codes that signal ripeness of fruit, freshness of meat or illness. They can be denied the benefit of colour to mark out objects and organise complex visual displays. They may be unreliable when a colour name is used as an identifier. They are slower and less successful in search when colour is an attribute of the target object or is used to organise the visual display. Because those with the more severe forms of abnormal colour vision perceive a very limited gamut of colours, they are at a disadvantage in the pursuit and appreciation of those forms of art that use colour.

  11. Limits of colour vision in dim light.

    Science.gov (United States)

    Kelber, Almut; Lind, Olle

    2010-09-01

    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. © 2010 The Authors, Ophthalmic and Physiological Optics © 2010 The College of Optometrists.

  12. Red-Green Colour Deficiencies and the Study of Science, Computer ...

    African Journals Online (AJOL)

    Colour blindness is the inability to perceive differences between some or all colours that other people can distinguish. It is most often of genetic nature but may also occur because of eye, nerve or brain damage or due to exposure to some chemicals. The most common type of colour vision deficiency is red-green colour ...

  13. Colour Vision Impairment in Young Alcohol Consumers.

    Directory of Open Access Journals (Sweden)

    Alódia Brasil

    Full Text Available Alcohol consumption among young adults is widely accepted in modern society and may be the starting point for abusive use of alcohol at later stages of life. Chronic alcohol exposure can lead to visual function impairment. In the present study, we investigated the spatial luminance contrast sensitivity, colour arrangement ability, and colour discrimination thresholds on young adults that weekly consume alcoholic beverages without clinical concerns. Twenty-four young adults were evaluated by an ophthalmologist and performed three psychophysical tests to evaluate their vision functions. We estimated the spatial luminance contrast sensitivity function at 11 spatial frequencies ranging from 0.1 to 30 cycles/degree. No difference in contrast sensitivity was observed comparing alcohol consumers and control subjects. For the evaluation of colour vision, we used the Farnsworth-Munsell 100 hue test (FM 100 test to test subject's ability to perform a colour arrangement task and the Mollon-Reffin test (MR test to measure subject's colour discrimination thresholds. Alcohol consumers made more mistakes than controls in the FM100 test, and their mistakes were diffusely distributed in the FM colour space without any colour axis preference. Alcohol consumers also performed worse than controls in the MR test and had higher colour discrimination thresholds compared to controls around three different reference points of a perceptually homogeneous colour space, the CIE 1976 chromaticity diagram. There was no colour axis preference in the threshold elevation observed among alcoholic subjects. Young adult weekly alcohol consumers showed subclinical colour vision losses with preservation of spatial luminance contrast sensitivity. Adolescence and young adult age are periods of important neurological development and alcohol exposure during this period of life might be responsible for deficits in visual functions, especially colour vision that is very sensitive to

  14. Colour-grapheme synaesthesia affects binocular vision

    Directory of Open Access Journals (Sweden)

    Chris L.E. Paffen

    2011-11-01

    Full Text Available In colour-grapheme synaesthesia, non-coloured graphemes are perceived as being inherently coloured. In recent years, it has become evident that synaesthesia-inducing graphemes can affect visual processing in a manner comparable to real, physical colours. Here, we exploit the phenomenon of binocular rivalry in which incompatible images presented dichoptically compete for conscious expression. Importantly, the competition only arises if the two images are sufficiently different; if the difference between the images is small, the images will fuse into a single mixed percept. We show that achromatic graphemes that induce synaesthetic colour percepts evoke binocular rivalry, while without the synaesthetic percept, they do not. That is, compared to achromatically perceived graphemes, synaesthesia-inducing graphemes increase the predominance of binocular rivalry over binocular fusion. This finding shows that the synaesthetic colour experience can provide the conditions for evoking binocular rivalry, much like stimulus features that induce rivalry in normal vision.

  15. Coevolution of coloration and colour vision?

    Science.gov (United States)

    Lind, Olle; Henze, Miriam J; Kelber, Almut; Osorio, Daniel

    2017-07-05

    The evolutionary relationship between signals and animal senses has broad significance, with potential consequences for speciation, and for the efficacy and honesty of biological communication. Here we outline current understanding of the diversity of colour vision in two contrasting groups: the phylogenetically conservative birds, and the more variable butterflies. Evidence for coevolution of colour signals and vision exists in both groups, but is limited to observations of phenotypic differences between visual systems, which might be correlated with coloration. Here, to illustrate how one might interpret the evolutionary significance of such differences, we used colour vision modelling based on an avian eye to evaluate the effects of variation in three key characters: photoreceptor spectral sensitivity, oil droplet pigmentation and the proportions of different photoreceptor types. The models predict that physiologically realistic changes in any one character will have little effect, but complementary shifts in all three can substantially affect discriminability of three types of natural spectra. These observations about the adaptive landscape of colour vision may help to explain the general conservatism of photoreceptor spectral sensitivities in birds. This approach can be extended to other types of eye and spectra to inform future work on coevolution of coloration and colour vision.This article is part of the themed issue 'Animal coloration: production, perception, function and application'. © 2017 The Author(s).

  16. From spectral information to animal colour vision: experiments and concepts

    OpenAIRE

    Kelber, Almut; Osorio, Daniel

    2010-01-01

    Many animals use the spectral distribution of light to guide behaviour, but whether they have colour vision has been debated for over a century. Our strong subjective experience of colour and the fact that human vision is the paradigm for colour science inevitably raises the question of how we compare with other species. This article outlines four grades of ‘colour vision’ that can be related to the behavioural uses of spectral information, and perhaps to the underlying mechanisms. In the fir...

  17. From spectral information to animal colour vision: experiments and concepts.

    Science.gov (United States)

    Kelber, Almut; Osorio, Daniel

    2010-06-07

    Many animals use the spectral distribution of light to guide behaviour, but whether they have colour vision has been debated for over a century. Our strong subjective experience of colour and the fact that human vision is the paradigm for colour science inevitably raises the question of how we compare with other species. This article outlines four grades of 'colour vision' that can be related to the behavioural uses of spectral information, and perhaps to the underlying mechanisms. In the first, even without an (image-forming) eye, simple organisms can compare photoreceptor signals to locate a desired light environment. At the next grade, chromatic mechanisms along with spatial vision guide innate preferences for objects such as food or mates; this is sometimes described as wavelength-specific behaviour. Here, we compare the capabilities of di- and trichromatic vision, and ask why some animals have more than three spectral types of receptors. Behaviours guided by innate preferences are then distinguished from a grade that allows learning, in part because the ability to learn an arbitrary colour is evidence for a neural representation of colour. The fourth grade concerns colour appearance rather than colour difference: for instance, the distinction between hue and saturation, and colour categorization. These higher-level phenomena are essential to human colour perception but poorly known in animals, and we suggest how they can be studied. Finally, we observe that awareness of colour and colour qualia cannot be easily tested in animals.

  18. Thresholds and noise limitations of colour vision in dim light.

    Science.gov (United States)

    Kelber, Almut; Yovanovich, Carola; Olsson, Peter

    2017-04-05

    Colour discrimination is based on opponent photoreceptor interactions, and limited by receptor noise. In dim light, photon shot noise impairs colour vision, and in vertebrates, the absolute threshold of colour vision is set by dark noise in cones. Nocturnal insects (e.g. moths and nocturnal bees) and vertebrates lacking rods (geckos) have adaptations to reduce receptor noise and use chromatic vision even in very dim light. In contrast, vertebrates with duplex retinae use colour-blind rod vision when noisy cone signals become unreliable, and their transition from cone- to rod-based vision is marked by the Purkinje shift. Rod-cone interactions have not been shown to improve colour vision in dim light, but may contribute to colour vision in mesopic light intensities. Frogs and toads that have two types of rods use opponent signals from these rods to control phototaxis even at their visual threshold. However, for tasks such as prey or mate choice, their colour discrimination abilities fail at brighter light intensities, similar to other vertebrates, probably limited by the dark noise in cones.This article is part of the themed issue 'Vision in dim light'. © 2017 The Author(s).

  19. Behavioural evidence for colour vision in an elasmobranch.

    Science.gov (United States)

    Van-Eyk, Sarah M; Siebeck, Ulrike E; Champ, Connor M; Marshall, Justin; Hart, Nathan S

    2011-12-15

    Little is known about the sensory abilities of elasmobranchs (sharks, skates and rays) compared with other fishes. Despite their role as apex predators in most marine and some freshwater habitats, interspecific variations in visual function are especially poorly studied. Of particular interest is whether they possess colour vision and, if so, the role(s) that colour may play in elasmobranch visual ecology. The recent discovery of three spectrally distinct cone types in three different species of ray suggests that at least some elasmobranchs have the potential for functional trichromatic colour vision. However, in order to confirm that these species possess colour vision, behavioural experiments are required. Here, we present evidence for the presence of colour vision in the giant shovelnose ray (Glaucostegus typus) through the use of a series of behavioural experiments based on visual discrimination tasks. Our results show that these rays are capable of discriminating coloured reward stimuli from other coloured (unrewarded) distracter stimuli of variable brightness with a success rate significantly different from chance. This study represents the first behavioural evidence for colour vision in any elasmobranch, using a paradigm that incorporates extensive controls for relative stimulus brightness. The ability to discriminate colours may have a strong selective advantage for animals living in an aquatic ecosystem, such as rays, as a means of filtering out surface-wave-induced flicker.

  20. The absolute threshold of colour vision in the horse.

    Directory of Open Access Journals (Sweden)

    Lina S V Roth

    Full Text Available 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.

  1. Genetics Home Reference: color vision deficiency

    Science.gov (United States)

    ... my area? Other Names for This Condition color blindness color vision defects defective color vision vision defect, color ... Perception KidsHealth from the Nemours Foundation MalaCards: color blindness MalaCards: color vision deficiency Orphanet: Blue cone monochromatism Orphanet: NON ...

  2. Parallel inputs to memory in bee colour vision.

    Science.gov (United States)

    Horridge, Adrian

    2016-03-01

    In the 19(th) century, it was found that attraction of bees to light was controlled by light intensity irrespective of colour, and a few critical entomologists inferred that vision of bees foraging on flowers was unlike human colour vision. Therefore, quite justly, Professor Carl von Hess concluded in his book on the Comparative Physiology of Vision (1912) that bees do not distinguish colours in the way that humans enjoy. Immediately, Karl von Frisch, an assistant in the Zoology Department of the same University of Münich, set to work to show that indeed bees have colour vision like humans, thereby initiating a new research tradition, and setting off a decade of controversy that ended only at the death of Hess in 1923. Until 1939, several researchers continued the tradition of trying to untangle the mechanism of bee vision by repeatedly testing trained bees, but made little progress, partly because von Frisch and his legacy dominated the scene. The theory of trichromatic colour vision further developed after three types of receptors sensitive to green, blue, and ultraviolet (UV), were demonstrated in 1964 in the bee. Then, until the end of the century, all data was interpreted in terms of trichromatic colour space. Anomalies were nothing new, but eventually after 1996 they led to the discovery that bees have a previously unknown type of colour vision based on a monochromatic measure and distribution of blue and measures of modulation in green and blue receptor pathways. Meanwhile, in the 20(th) century, search for a suitable rationalization, and explorations of sterile culs-de-sac had filled the literature of bee colour vision, but were based on the wrong theory.

  3. Colour vision and response bias in a coral reef fish.

    Science.gov (United States)

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

    2013-08-01

    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.

  4. iPad colour vision apps for dyschromatopsia screening.

    Science.gov (United States)

    Campbell, Thomas Gordon; Lehn, Alexander; Blum, Stefan; Airey, Caroline; Brown, Helen

    2016-07-01

    Optic neuritis (ON) is a common and important cause of vision loss or vision disturbances in the community, particularly amongst the young, and it is often associated with a persistent dyschromatopsia. Traditionally screening for dyschromatopsia has been carried out using pseudo-isochromatic Ishihara plates. These colour plates were originally developed for testing of colour blindness, and indeed have only more recently been applied to ON. As the Ishihara plate books used for testing are expensive, unwieldy, and are not commonly available in many clinics or wards, many neurologists and ophthalmologists have taken to using untested and unstudied downloadable software packages on portable electronic devices for testing. This study compared the efficacy of printed and iPad (Apple, Cupertino, CA, USA) versions of the Ishihara plates in screening for dyschromatopsia in patients who were suspected of having ON. The main finding was that dyschromatopsia testing using a commercially available application on an iPad was comparable to using the current pragmatic clinical benchmark, the pseudo-isochromatic plates of Ishihara. These findings provide support for the increasingly common practice of screening for dyschromatopsia using the iPad. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Spotting Fruit versus Picking Fruit as the Selective Advantage of Human Colour Vision

    Directory of Open Access Journals (Sweden)

    Aline Bompas

    2013-04-01

    Full Text Available 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.

  6. Quantum photoelectron effects in the eye retina and development of colour vision theory

    International Nuclear Information System (INIS)

    Kremkov, M.V.

    2011-01-01

    The quantum semiconductor mechanism of the colour vision of mans is created. The mechanism is based on quantum effects under influence of light waves exciting valence electrons in different microelement's atoms (Zn, Cu, Fe, Co, P, Br, Se, et al.) that are presented in the photoreceptor's cells of the eye retina (columns and retorts) with the quasi-periodical disks structure. The microelement concentrations correspond to the impurity atom amount in semiconductors, and the photoelectron's current passes out its signal to the vision nerve. The mechanism explains existence of the man colour-blindness, degradation of the vision sensitivity with the man's age and other peculiarities of the colour vision. (authors)

  7. Blue-yellow colour vision impairment and cognitive deficits in occasional and dependent stimulant users.

    Science.gov (United States)

    Hulka, Lea M; Wagner, Michael; Preller, Katrin H; Jenni, Daniela; Quednow, Boris B

    2013-04-01

    Specific blue-yellow colour vision impairment has been reported in dependent cocaine users and it was postulated that drug-induced changes in retinal dopamine neurotransmission are responsible. However, it is unclear whether these changes are confined to chronic cocaine users, whether they are specific for dopaminergic stimulants such as cocaine and amphetamine and whether they are related to cognitive functions such as working memory, encoding and consolidation. In 47 occasional and 29 dependent cocaine users, 23 MDMA (commonly known as 'ecstasy') users and 47 stimulant-naive controls, colour vision discrimination was measured with the Lanthony Desaturated Panel D-15 Test and memory performance with the Auditory Verbal Learning Test. Both occasional and dependent cocaine users showed higher colour confusion indices than controls. Users of the serotonergic stimulant MDMA (26%), occasional (30%) and dependent cocaine users (34%) exhibited more frequent blue-yellow colour vision disorders compared to controls (9%). Inferior performance of MDMA users was caused by a subgroup with high amphetamine co-use (55%), while MDMA use alone was not associated with decreased blue-yellow discrimination (0%). Cognitive performance was worse in cocaine users with colour vision disorder compared to users and controls with intact colour vision and both colour vision impairment and cognitive deficits were related to cocaine use. Occasional cocaine and amphetamine use might induce blue-yellow colour vision impairment, whereas the serotonergic stimulant MDMA does not impair colour vision. The association between colour vision impairment and cognitive deficits in cocaine users may reflect that retinal and cerebral dopamine alterations are linked to a certain degree.

  8. An example of applied colour vision research: the conspicuity of airplane colour

    NARCIS (Netherlands)

    Lucassen, M.P.

    2002-01-01

    This paper describes the application of the combined knowledge on colorimetry, colour imaging (visualization) and colour perception in an aviation related research project. It involves the optimisation of the conspicuity of the colour scheme of an airplane, with the purpose of minimizing the changes

  9. A review of the evolution of animal colour vision and visual communication signals.

    Science.gov (United States)

    Osorio, D; Vorobyev, M

    2008-09-01

    The visual displays of animals and plants are often colourful, and colour vision allows animals to respond to these signals as they forage for food, choose mates and so-forth. This article discusses the evolutionary relationship between photoreceptor spectral sensitivities of four groups of land animals--birds, butterflies, primates and hymenopteran insects (bees and wasps)--, the colour signals that are relevant to them, and how understanding is informed by models of spectral coding and colour vision. Although the spectral sensitivities of photoreceptors are known to vary adaptively under natural selection there is little evidence that those of hymenopterans, birds and primates are specifically adapted to the reflectance spectra of food plants or animal visual signals. On the other hand, the colours of fruit, flowers and feathers may have evolved to be more discriminable for the colour vision of their natural receivers than for other groups of animals. Butterflies are unusual in that they have enjoyed a major radiation in receptor numbers and spectral sensitivities. The reasons for the radiation and diversity of butterfly colour vision remain unknown, but may include their need to find food plants and to select mates.

  10. A study of normal and defective colour vision

    NARCIS (Netherlands)

    Bouman, M.A.; Walraven, P.L.

    1957-01-01

    MEASUREMENTS were made of saturation discrimination of normal and colour defective subjects with illuminant A as reference colour. The colorimeter used in the experiments was of a special design developed for easy use by untrained persons. The results for normals are not quite in agreement with the

  11. Impaired colour vision in workers exposed to organic solvents: A systematic review.

    Science.gov (United States)

    Betancur-Sánchez, A M; Vásquez-Trespalacios, E M; Sardi-Correa, C

    2017-01-01

    To evaluate recent evidence concerning the relationship between the exposure to organic solvents and the impairment of colour vision. A bibliographic search was conducted for scientific papers published in the last 15 years, in the LILACS, PubMed, Science Direct, EBSCO, and Cochrane databases that included observational studies assessing the relationship between impairment in colour vision and exposure to organic solvents. Eleven studies were selected that were performed on an economically active population and used the Lanthony D-15 desaturated test (D-15d), measured the exposure to organic solvents, and included unexposed controls. It was found that there is a statistically significant relationship between the exposure to organic solvents and the presence of an impairment in colour vision. The results support the hypothesis that exposure to organic solvents could induce acquired dyschromatopsia. The evaluation of colour vision with the D-15d test is simple and sensitive for diagnosis. More studies need to be conducted on this subject in order to better understand the relationship between impaired colour vision and more severe side effects caused by this exposure. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

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

    Science.gov (United States)

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

    2014-11-01

    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. © 2014. Published by The Company of Biologists Ltd.

  13. An automatic colour-based computer vision algorithm for tracking the position of piglets

    Energy Technology Data Exchange (ETDEWEB)

    Navarro-Jover, J. M.; Alcaniz-Raya, M.; Gomez, V.; Balasch, S.; Moreno, J. R.; Grau-Colomer, V.; Torres, A.

    2009-07-01

    Artificial vision is a powerful observation tool for research in the field of livestock production. So, based on the search and recognition of colour spots in images, a digital image processing system which permits the detection of the position of piglets in a farrowing pen, was developed. To this end, 24,000 images were captured over five takes (days), with a five-second interval between every other image. The nine piglets in a litter were marked on their backs and sides with different coloured spray paints each one, placed at a considerable distance on the RGB space. The programme requires the user to introduce the colour patterns to be found, and the output is an ASCII file with the positions (column X, lineY) for each of these marks within the image analysed. This information may be extremely useful for further applications in the study of animal behaviour and welfare parameters (huddling, activity, suckling, etc.). The software programme initially segments the image in the RGB colour space to separate the colour marks from the rest of the image, and then recognises the colour patterns, using another colour space [B/(R+G+B), (G-R), (B-G)] more suitable for this purpose. This additional colour space was obtained testing different colour combinations derived from R, G and B. The statistical evaluation of the programmes performance revealed an overall 72.5% in piglet detection, 89.1% of this total being correctly detected. (Author) 33 refs.

  14. Characterisation of flotation froth colour and structure by machine vision

    Science.gov (United States)

    Bonifazi, Giuseppe; Serranti, Silvia; Volpe, Fabio; Zuco, Riccardo

    2001-11-01

    It is well known and well recognised that flotation is a process that is complex to monitor and study if a classical approach based on the evaluation of the signals resulting from sensors is adopted. Sensors are usually strategically positioned in the bank cells and detect global process variables such as pH, reagent addition, froth level, on-stream chemical analysis, particle size distribution, etc. In the last ten years several studies have been carried out with the main goal to utilise imaging techniques to detect froth bubbles characteristics and to evaluate the flotation process performance. In this paper an approach of this type is described. More specifically, image processing techniques to automatically measure the colour and the structure of the froth bubbles are presented and the results are discussed. All the investigations are carried out on digital sample images collected in an industrial flotation plant operating in steady-state conditions. The colour analysis is performed on the whole surface of the froth images considering different colour reference systems (RGB, HSV, HSI); the morphological measurements are obtained after the application of selected enhancement and segmentation techniques, necessary to consider the bubbles as separate domains. The multiple correlation analysis performed between froth mineral concentrations (Cu, MgO, Zn and Pb content) and the extracted colour and structure parameters are good in most situations.

  15. Prevalence of color vision deficiency among arc welders.

    Science.gov (United States)

    Heydarian, Samira; Mahjoob, Monireh; Gholami, Ahmad; Veysi, Sajjad; Mohammadi, Morteza

    This study was performed to investigate whether occupationally related color vision deficiency can occur from welding. A total of 50 male welders, who had been working as welders for at least 4 years, were randomly selected as case group, and 50 age matched non-welder men, who lived in the same area, were regarded as control group. Color vision was assessed using the Lanthony desatured panel D-15 test. The test was performed under the daylight fluorescent lamp with a spectral distribution of energy with a color temperature of 6500K and a color rendering index of 94 that provided 1000lx on the work plane. The test was carried out monocularly and no time limit was imposed. All data analysis were performed using SPSS, version 22. The prevalence of dyschromatopsia among welders was 15% which was statistically higher than that of nonwelder group (2%) (p=0.001). Among welders with dyschromatopsia, color vision deficiency in 72.7% of cases was monocular. There was positive relationship between the employment length and color vision loss (p=0.04). Similarly, a significant correlation was found between the prevalence of color vision deficiency and average working hours of welding a day (p=0.025). Chronic exposure to welding light may cause color vision deficiency. The damage depends on the exposure duration and the length of their employment as welders. Copyright © 2016 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

  16. Dichromatic colour vision in wallabies as characterised by three behavioural paradigms.

    Directory of Open Access Journals (Sweden)

    Wiebke Ebeling

    Full Text Available Despite lacking genetic evidence of a third cone opsin in the retina of any Australian marsupial, most species tested so far appear to be trichromatic. In the light of this, we have re-examined colour vision of the tammar wallaby which had previously been identified as a dichromat. Three different psychophysical tests, based on an operant conditioning paradigm, were used to confirm that colour perception in the wallaby can be predicted and conclusively explained by the existence of only two cone types. Firstly, colour-mixing experiments revealed a Confusion Point between the three primary colours of a LCD monitor that can be predicted by the cone excitation ratio of the short- and middle-wavelength sensitive cones. Secondly, the wavelength discrimination ability in the wallaby, when tested with monochromatic stimuli, was found to be limited to a narrow range between 440 nm and 500 nm. Lastly, an experiment designed to test the wallaby's ability to discriminate monochromatic lights from a white light provided clear evidence for a Neutral Point around 485 nm where discrimination consistently failed. Relative colour discrimination seemed clearly preferred but it was possible to train a wallaby to perform absolute colour discriminations. The results confirm the tammar wallaby as a dichromat, and so far the only behaviourally confirmed dichromat among the Australian marsupials.

  17. Binary pressure-sensitive paint measurements using miniaturised, colour, machine vision cameras

    Science.gov (United States)

    Quinn, Mark Kenneth

    2018-05-01

    Recent advances in machine vision technology and capability have led to machine vision cameras becoming applicable for scientific imaging. This study aims to demonstrate the applicability of machine vision colour cameras for the measurement of dual-component pressure-sensitive paint (PSP). The presence of a second luminophore component in the PSP mixture significantly reduces its inherent temperature sensitivity, increasing its applicability at low speeds. All of the devices tested are smaller than the cooled CCD cameras traditionally used and most are of significantly lower cost, thereby increasing the accessibility of such technology and techniques. Comparisons between three machine vision cameras, a three CCD camera, and a commercially available specialist PSP camera are made on a range of parameters, and a detailed PSP calibration is conducted in a static calibration chamber. The findings demonstrate that colour machine vision cameras can be used for quantitative, dual-component, pressure measurements. These results give rise to the possibility of performing on-board dual-component PSP measurements in wind tunnels or on real flight/road vehicles.

  18. Colour vision abnormality as the only manifestation of normal pressure hydrocephalus.

    Science.gov (United States)

    Asensio-Sánchez, V M; Martín-Prieto, A

    2018-01-01

    The case is presented of a 73-year-old male patient who referred to having black and white vision. Computed tomography showed normal pressure hydrocephalus (NPH). Magnetic resonance imaging was not performed because the patient refused to undergo further examinations. Achromatopsia may be the first or only NPH symptom. It may be prudent to ask patients with NPH regarding colour vision. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  19. Molecular logic behind the three-way stochastic choices that expand butterfly colour vision.

    Science.gov (United States)

    Perry, Michael; Kinoshita, Michiyo; Saldi, Giuseppe; Huo, Lucy; Arikawa, Kentaro; Desplan, Claude

    2016-07-14

    Butterflies rely extensively on colour vision to adapt to the natural world. Most species express a broad range of colour-sensitive Rhodopsin proteins in three types of ommatidia (unit eyes), which are distributed stochastically across the retina. The retinas of Drosophila melanogaster use just two main types, in which fate is controlled by the binary stochastic decision to express the transcription factor Spineless in R7 photoreceptors. We investigated how butterflies instead generate three stochastically distributed ommatidial types, resulting in a more diverse retinal mosaic that provides the basis for additional colour comparisons and an expanded range of colour vision. We show that the Japanese yellow swallowtail (Papilio xuthus, Papilionidae) and the painted lady (Vanessa cardui, Nymphalidae) butterflies have a second R7-like photoreceptor in each ommatidium. Independent stochastic expression of Spineless in each R7-like cell results in expression of a blue-sensitive (Spineless(ON)) or an ultraviolet (UV)-sensitive (Spineless(OFF)) Rhodopsin. In P. xuthus these choices of blue/blue, blue/UV or UV/UV sensitivity in the two R7 cells are coordinated with expression of additional Rhodopsin proteins in the remaining photoreceptors, and together define the three types of ommatidia. Knocking out spineless using CRISPR/Cas9 (refs 5, 6) leads to the loss of the blue-sensitive fate in R7-like cells and transforms retinas into homogeneous fields of UV/UV-type ommatidia, with corresponding changes in other coordinated features of ommatidial type. Hence, the three possible outcomes of Spineless expression define the three ommatidial types in butterflies. This developmental strategy allowed the deployment of an additional red-sensitive Rhodopsin in P. xuthus, allowing for the evolution of expanded colour vision with a greater variety of receptors. This surprisingly simple mechanism that makes use of two binary stochastic decisions coupled with local coordination may prove

  20. Visual Colour-Impulse Stimulation Treatment of Hyperactivity with Deficiency of Attention at Children

    Directory of Open Access Journals (Sweden)

    I.E. Рoverennova

    2009-06-01

    Full Text Available The causes of occurrence and development of the syndrome of hyperactivity with deficiency of attention at children аre considered. The diagnostic complex for application at patients with the given syndrome in conditions of polyclinic is under the study. The new technique in complex treatment of hyperactivity with deficiency of attention with application of visual colour-impulse stimulation for easing emotional tension (“ASIR” is proposed.

  1. Highly polymorphic colour vision in a New World monkey with red facial skin, the bald uakari (Cacajao calvus).

    Science.gov (United States)

    Corso, Josmael; Bowler, Mark; Heymann, Eckhard W; Roos, Christian; Mundy, Nicholas I

    2016-04-13

    Colour vision is highly variable in New World monkeys (NWMs). Evidence for the adaptive basis of colour vision in this group has largely centred on environmental features such as foraging benefits for differently coloured foods or predator detection, whereas selection on colour vision for sociosexual communication is an alternative hypothesis that has received little attention. The colour vision of uakaris (Cacajao) is of particular interest because these monkeys have the most dramatic red facial skin of any primate, as well as a unique fission/fusion social system and a specialist diet of seeds. Here, we investigate colour vision in a wild population of the bald uakari,C. calvus, by genotyping the X-linked opsin locus. We document the presence of a polymorphic colour vision system with an unprecedented number of functional alleles (six), including a novel allele with a predicted maximum spectral sensitivity of 555 nm. This supports the presence of strong balancing selection on different alleles at this locus. We consider different hypotheses to explain this selection. One possibility is that trichromacy functions in sexual selection, enabling females to choose high-quality males on the basis of red facial coloration. In support of this, there is some evidence that health affects facial coloration in uakaris, as well as a high prevalence of blood-borne parasitism in wild uakari populations. Alternatively, the low proportion of heterozygous female trichromats in the population may indicate selection on different dichromatic phenotypes, which might be related to cryptic food coloration. We have uncovered unexpected diversity in the last major lineage of NWMs to be assayed for colour vision, which will provide an interesting system to dissect adaptation of polymorphic trichromacy. © 2016 The Author(s).

  2. Computer vision system approach in colour measurements of foods: Part II. validation of methodology with real foods

    Directory of Open Access Journals (Sweden)

    Fatih TARLAK

    2016-01-01

    Full Text Available Abstract The colour of food is one of the most important factors affecting consumers’ purchasing decision. Although there are many colour spaces, the most widely used colour space in the food industry is L*a*b* colour space. Conventionally, the colour of foods is analysed with a colorimeter that measures small and non-representative areas of the food and the measurements usually vary depending on the point where the measurement is taken. This leads to the development of alternative colour analysis techniques. In this work, a simple and alternative method to measure the colour of foods known as “computer vision system” is presented and justified. With the aid of the computer vision system, foods that are homogenous and uniform in colour and shape could be classified with regard to their colours in a fast, inexpensive and simple way. This system could also be used to distinguish the defectives from the non-defectives. Quality parameters of meat and dairy products could be monitored without any physical contact, which causes contamination during sampling.

  3. Pseudoisochromatic test plate colour representation dependence on printing technology

    International Nuclear Information System (INIS)

    Luse, K; Ozolinsh, M; Fomins, S

    2012-01-01

    The aim of the study is to determine best printing technology for creation of colour vision deficiency tests. Valid tests for protanopia and deuteranopia were created from perceived colour matching experiments from printed colour samples by colour deficient individuals. Calibrated EpsonStylus Pro 7800 printer for ink prints and Noritsu HD 3701 digital printer for photographic prints were used. Multispectral imagery (by tunable liquid crystal filters system CRI Nuance Vis 07) data analysis show that in case of ink prints, the measured pixel colour coordinate dispersion (in the CIExy colour diagram) of similar colour arrays is smaller than in case of photographic printing. The print quality in terms of colour coordinate dispersion for printing methods used is much higher than in case of commercially available colour vision deficiency tests.

  4. Application of Computer Vision for quality control in frozen mixed berries production: colour calibration issues

    Directory of Open Access Journals (Sweden)

    D. Ricauda Aimonino

    2013-09-01

    Full Text Available Computer vision is becoming increasingly important in quality control of many food processes. The appearance properties of food products (colour, texture, shape and size are, in fact, correlated with organoleptic characteristics and/or the presence of defects. Quality control based on image processing eliminates the subjectivity of human visual inspection, allowing rapid and non-destructive analysis. However, most food matrices show a wide variability in appearance features, therefore robust and customized image elaboration algorithms have to be implemented for each specific product. For this reason, quality control by visual inspection is still rather diffused in several food processes. The case study inspiring this paper concerns the production of frozen mixed berries. Once frozen, different kinds of berries are mixed together, in different amounts, according to a recipe. The correct quantity of each kind of fruit, within a certain tolerance, has to be ensured by producers. Quality control relies on bringing few samples for each production lot (samples of the same weight and, manually, counting the amount of each species. This operation is tedious, subject to errors, and time consuming, while a computer vision system (CVS could determine the amount of each kind of berries in a few seconds. This paper discusses the problem of colour calibration of the CVS used for frozen berries mixture evaluation. Images are acquired by a digital camera coupled with a dome lighting system, which gives a homogeneous illumination on the entire visible surface of the berries, and a flat bed scanner. RBG device dependent data are then mapped onto CIELab colorimetric colour space using different transformation operators. The obtained results show that the proposed calibration procedure leads to colour discrepancies comparable or even below the human eyes sensibility.

  5. 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.

    Science.gov (United States)

    Abu Bakar, Nurul Farhana; Chen, Ai-Hong

    2014-02-01

    Children with learning disabilities might have difficulties to communicate effectively and give reliable responses as required in various visual function testing procedures. 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. 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. 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 learning disabilities. Modifications of vision testing procedures are essential for children with learning disabilities.

  6. Colour cues for leaf food selection by long-tailed macaques (Macaca fascicularis) with a new suggestion for the evolution of trichromatic colour vision.

    Science.gov (United States)

    Lucas, P W; Darvell, B W; Lee, P K; Yuen, T D; Choong, M F

    1998-01-01

    Leaf colour, size and toughness were investigated in five plant species important in the diet of Macaca fascicularis in Singapore. Leaf colour and size were examined as potential visual cues for food selection, whereas toughness mirrored fibre content, the inverse of food quality. As leaves matured, they changed colour and toughened. Leaf lightness and yellowness were strongly negatively correlated with toughness, but variation in both the red-green axis of the CIE Lab colour space and leaf size were not. Leaves selected as food by the macaques were distinguished by being very light, yellow to slightly green. Some leaves were dappled with red. The literature suggests that these leaves are relatively rich in protein without being tough and therefore would be sought after by primates. We argue that leaf colour is an important indicator of the nutritive value of leaves. Trichromatic vision is an important advantage in finding those palatable leaves that are dappled red. These would appear dark to dichromatic primates and be deceptive by making leaves look older (lower in quality) than they actually are. This would decrease the perceived window of feeding opportunity for such primates who would be at a disadvantage in trying to find these leaves. It is possible that trichromatic vision in catarrhine primates may have originally evolved for the detection of red coloration in the leaves of shade-tolerant tropical plants, enabling the better exploitation of a food resource.

  7. The effect of tinted spectacle lenses on contrast sensitivity and colour vision

    Directory of Open Access Journals (Sweden)

    M. Shaik

    2013-12-01

    The greater enhancement was for low spatial frequencies (LSF and least for high spatial frequencies (HSF. With all tints Grade C had the least enhancement for very HSF. Many subjects showed no change in CV with any of the lensesused. The grey tint showed greater enhancement of CV as the density increases. Blue and brown tints showed a similar trend with grade B enhancing CV the most while grade C resulted in theleast reduction of CV. Conclusion: Grade A, B, and C of blue, brown and grey tinted spectacle lenses do not alter colour vision significantly but for the selected levels of transmission of the tints used, contrast sensitivity can be improved to some extent.

  8. Memory colours affect colour appearance.

    Science.gov (United States)

    Witzel, Christoph; Olkkonen, Maria; Gegenfurtner, Karl R

    2016-01-01

    Memory colour effects show that colour perception is affected by memory and prior knowledge and hence by cognition. None of Firestone & Scholl's (F&S's) potential pitfalls apply to our work on memory colours. We present a Bayesian model of colour appearance to illustrate that an interaction between perception and memory is plausible from the perspective of vision science.

  9. A randomised comparison between an inexpensive, general-purpose headlight and a purpose-built surgical headlight on users' visual acuity and colour vision.

    Science.gov (United States)

    Street, I; Sayles, M; Nistor, M; McRae, A R

    2014-02-01

    To determine if there are any differences in near visual acuity and colour vision between an inexpensive general-purpose light emitting diode (LED) headlight and a purpose-built surgical LED headlight. A prospective study was conducted sequentially comparing near visual acuity and colour vision, the headlights being tested in random order, in a testing room with a constant minimal amount of background light. The participants were NHS employee volunteers, with self-declared normal (or corrected) vision, working in occupations requiring full literacy. For visual acuity, outcome was measured by recording the smallest font legible when using each headlight when the subject read a near visual acuity test card. For colour vision, the outcome was passing or failing the Ishihara test. There was no statistically significant difference between the general-purpose and the purpose-built headlights in users' near visual acuity or colour vision.

  10. Colour vision in ADHD: part 1--testing the retinal dopaminergic hypothesis.

    Science.gov (United States)

    Kim, Soyeon; Al-Haj, Mohamed; Chen, Samantha; Fuller, Stuart; Jain, Umesh; Carrasco, Marisa; Tannock, Rosemary

    2014-10-24

    To test the retinal dopaminergic hypothesis, which posits deficient blue color perception in ADHD, resulting from hypofunctioning CNS and retinal dopamine, to which blue cones are exquisitely sensitive. Also, purported sex differences in red color perception were explored. 30 young adults diagnosed with ADHD and 30 healthy young adults, matched on age and gender, performed a psychophysical task to measure blue and red color saturation and contrast discrimination ability. Visual function measures, such as the Visual Activities Questionnaire (VAQ) and Farnsworth-Munsell 100 hue test (FMT), were also administered. Females with ADHD were less accurate in discriminating blue and red color saturation relative to controls but did not differ in contrast sensitivity. Female control participants were better at discriminating red saturation than males, but no sex difference was present within the ADHD group. Poorer discrimination of red as well as blue color saturation in the female ADHD group may be partly attributable to a hypo-dopaminergic state in the retina, given that color perception (blue-yellow and red-green) is based on input from S-cones (short wavelength cone system) early in the visual pathway. The origin of female superiority in red perception may be rooted in sex-specific functional specialization in hunter-gather societies. The absence of this sexual dimorphism for red colour perception in ADHD females warrants further investigation.

  11. Screening for Congenital Color Vision Deficiency in Primary ...

    African Journals Online (AJOL)

    Methods: The teachers were randomly selected from 13 schools in Port Harcourt City (PHC) and given a six hours training workshop on vision disorders in children and congenital color vision screening. They were given a self administered pre and post test questionnaires before and after training respectively. Subsequently ...

  12. Hypoxia, color vision deficiencies, and blood oxygen saturation.

    Science.gov (United States)

    2013-11-01

    Chromatic thresholds were measured using the Cambridge Color Test (CCT), Color Assessment and Diagnosis : (CAD) test, and Cone Specific Contrast Test at ground and 3780 m (12,400 ft) for subjects with normal color : vision and red-green color vision ...

  13. Colour vision and light sensitivity in tunnel workers previously exposed to acrylamide and N-methylolacrylamide containing grouting agents.

    Science.gov (United States)

    Goffeng, Lars Ole; Kjuus, Helge; Heier, Mona Skard; Alvestrand, Monica; Ulvestad, Bente; Skaug, Vidar

    2008-01-01

    The aim of the study was to examine possible persisting visual system effects in tunnel workers previously exposed to acrylamide and N-methylolacrylamide during grouting work. Visual field light sensitivity threshold and colour vision has been examined among 44 tunnel workers 2-10 years after exposure to acrylamide and N-methylolacrylamide containing grouting agents. Forty-four tunnel workers not involved in grouting operations served as control group. Information on exposure and background variables was obtained for all participants from a questionnaire. Visual light sensitivity threshold was measured using Humphrey Visual Field Static Perimeter 740, program 30-2 Fastpack, with red stimuli on white background, and colour vision, using Lanthony D-15 Desaturated Color test. Based on D-15d test results, colour confusion index (CCI), and a severity index (C-index) was calculated. The exposed group had a significantly higher threshold for detecting single stimuli in all parts of the inner 30 degrees of the visual field compared to the control group. The foveal threshold group difference was 1.4 dB (p=0.002) (mean value, both eyes). On the Lanthony 15 Hue Desaturated test, the exposed subjects made more errors in sorting blue colours, and a statistically significant increase in C-index was observed. Surrogate measures for duration and intensity of exposure gave no further improvement of the model. The results indicate slightly reduced light sensitivity and reduced colour discrimination among the exposed subjects compared to the controls. The findings may be due to previous exposure to acrylamide containing grouts among the tunnel workers.

  14. Hypoxia, Color Vision Deficiencies, and Blood Oxygen Saturation

    Science.gov (United States)

    2013-11-01

    using the Dvorine Pseudoisochromatic Plate Test (2nd edition, Psychological Corporation, Baltimore, MD) illuminated by True Daylight Illuminator T8...Plant, G.T. (1994). Insights into the different exploits of colour in the visual cortex. Proc Biol Sci, 258 (1353), 327-334. Barbur, J.L...Aviat Space Environ Med, 80, 933-940. Crow, T.J.,& Kelman, G.R.(1973). Psychological effects of mild acute hypoxia. Br J Anaesth, 45, 335-337

  15. Color Functionality Used in Visual Display for Occupational and Environmental Safety and Managing Color Vision Deficiency.

    Science.gov (United States)

    Ochiai, Nobuhisa; Kondo, Hiroyuki

    2017-01-01

    The effects of color perception are utilized in visual displays for the purpose of safety in the workplace and in daily life. These effects, generally known as color functionality, are divided into four classifications: visibility, legibility, conspicuity and discriminability. This article focuses on the relationship between the color functionality of color schemes used in visual displays for occupational and environmental safety and color vision deficiency (particularly congenital red-green color deficiency), a critical issue in ophthalmology, and examines the effects of color functionality on the perception of the color red in individuals with protan defects. Due to abrupt system reforms, current Japanese clinical ophthalmology finds itself in a situation where it is insufficiently prepared to handle congenital red-green color deficiencies. Indeed, occupational problems caused by color vision deficiencies have been almost completely neglected, and are an occupational safety and health concern that will need to be solved in the future. This report will present the guidelines for the color vision testing established by the British Health and Safety Executive (HSE), a pioneering example of a model meant to solve these problems. Issues relating to the creation of guidelines adapted to Japanese clinical ophthalmology will also be examined, and we will discuss ways to utilize color functionality used in visual displays for occupational and environmental safety to help manage color vision deficiency.

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

    Science.gov (United States)

    Adams, Rachel C; Chambers, Christopher D

    2012-03-01

    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. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Fast Segmentation of Colour Apple Image under All-Weather Natural Conditions for Vision Recognition of Picking Robots

    Directory of Open Access Journals (Sweden)

    Wei Ji

    2016-02-01

    Full Text Available In order to resolve the poor real-time performance problem of the normalized cut (Ncut method in apple vision recognition of picking robots, a fast segmentation method of colour apple images based on the adaptive mean-shift and Ncut methods is proposed in this paper. Firstly, the traditional Ncut method based on pixels is changed into the Ncut method based on regions by the adaptive mean-shift initial segmenting. In this way, the number of peaks and edges in the image is dramatically reduced and the computation speed is improved. Secondly, the image is divided into regional maps by extracting the R-B colour feature, which not only reduces the quantity of regions, but also to some extent overcomes the effect on illumination. On this basis, every region map is expressed by a region point, so the undirected graph of the R-B colour grey-level feature is attained. Finally, regarding the undirected graph as the input of Ncut, we construct the weight matrix W by region points and determine the number of clusters based on the decision-theoretic rough set. The adaptive clustering segmentation can be implemented by an Ncut algorithm. Experimental results show that the maximum segmentation error is 3% and the average recognition time is less than 0.7s, which can meet the requirements of a real-time picking robot.

  18. [The influence of IOL implantation on visual acuity, contrast sensitivity and colour vision 2 and 4 months after cataract surgery].

    Science.gov (United States)

    Ventruba, J

    2006-04-01

    To assess the change in visual acuity, contrast sensitivity and colour vision in relation to the time after cataract surgery and to the type of implanted IOL, and to compare visual functions by patients with one and two pseudophakic eyes. 45 cataract patients were examined before and then 2 and 4 month after the cataract surgery. Visual acuity (VA) was tested on logMAR optotype chart with Landolt rings, contrast sensitivity (CS) was tested on the Pelli-Robson chart and the SWCT chart. For colour vision (CV) testing, the standard Farnsworth D-15 test and the desaturated Lanthony D-15 test were used. The patients were divided into two groups--a group with one pseudophakic eye and a group with two pseudophakic eyes, and also according to the type of IOL--PMMA or hydrophobic acrylate that had been implanted. Control group was composed of phakic subjects with no ocular pathology. After the cataract surgery, in both groups there was a significant improvement in monocular and binocular VA (p test (p test (p tested by means of psychophysical methods of VA, CS and CV significantly improve and are stable 2 month after the surgery. The second eye surgery improves binocular visual functions the level of which doesn't differ from that of normal phakic subjects. There was no influence of the type of IOL on final state of VA, CS or CV.

  19. Color Vision Deficiency and Color Blindness: An Introduction to the Problem.

    Science.gov (United States)

    Olsen, Mary Margaret; Harris, Kenneth R.

    The paper examines issues concerned with the education and employment of individuals, primarily males, with color vision deficiency. After a brief introduction, the first chapter looks at adult problems such as employment areas in which the disability presents problems. The next chapter considers problems of children, noting the heavy use of color…

  20. Universal Design: Supporting Students with Color Vision Deficiency (CVD) in Medical Education

    Science.gov (United States)

    Meeks, Lisa M.; Jain, Neera R.; Herzer, Kurt R.

    2016-01-01

    Color Vision Deficiency (CVD) is a commonly occurring condition in the general population. For medical students, it has the potential to create unique challenges in the classroom and clinical environments. Few studies have provided medical educators with comprehensive recommendations to assist students with CVD. This article presents a focused…

  1. Transforming 3D Coloured Pixels into Musical Instrument Notes for Vision Substitution Applications

    Directory of Open Access Journals (Sweden)

    Deville Benoît

    2007-01-01

    Full Text Available The goal of the See ColOr project is to achieve a noninvasive mobility aid for blind users that will use the auditory pathway to represent in real-time frontal image scenes. We present and discuss here two image processing methods that were experimented in this work: image simplification by means of segmentation, and guiding the focus of attention through the computation of visual saliency. A mean shift segmentation technique gave the best results, but for real-time constraints we simply implemented an image quantification method based on the HSL colour system. More particularly, we have developed two prototypes which transform HSL coloured pixels into spatialised classical instrument sounds lasting for 300 ms. Hue is sonified by the timbre of a musical instrument, saturation is one of four possible notes, and luminosity is represented by bass when luminosity is rather dark and singing voice when it is relatively bright. The first prototype is devoted to static images on the computer screen, while the second has been built up on a stereoscopic camera which estimates depth by triangulation. In the audio encoding, distance to objects was quantified into four duration levels. Six participants with their eyes covered by a dark tissue were trained to associate colours with musical instruments and then asked to determine on several pictures, objects with specific shapes and colours. In order to simplify the protocol of experiments, we used a tactile tablet, which took the place of the camera. Overall, colour was helpful for the interpretation of image scenes. Moreover, preliminary results with the second prototype consisting in the recognition of coloured balloons were very encouraging. Image processing techniques such as saliency could accelerate in the future the interpretation of sonified image scenes.

  2. Transforming 3D Coloured Pixels into Musical Instrument Notes for Vision Substitution Applications

    Directory of Open Access Journals (Sweden)

    Guido Bologna

    2007-08-01

    Full Text Available The goal of the See ColOr project is to achieve a noninvasive mobility aid for blind users that will use the auditory pathway to represent in real-time frontal image scenes. We present and discuss here two image processing methods that were experimented in this work: image simplification by means of segmentation, and guiding the focus of attention through the computation of visual saliency. A mean shift segmentation technique gave the best results, but for real-time constraints we simply implemented an image quantification method based on the HSL colour system. More particularly, we have developed two prototypes which transform HSL coloured pixels into spatialised classical instrument sounds lasting for 300 ms. Hue is sonified by the timbre of a musical instrument, saturation is one of four possible notes, and luminosity is represented by bass when luminosity is rather dark and singing voice when it is relatively bright. The first prototype is devoted to static images on the computer screen, while the second has been built up on a stereoscopic camera which estimates depth by triangulation. In the audio encoding, distance to objects was quantified into four duration levels. Six participants with their eyes covered by a dark tissue were trained to associate colours with musical instruments and then asked to determine on several pictures, objects with specific shapes and colours. In order to simplify the protocol of experiments, we used a tactile tablet, which took the place of the camera. Overall, colour was helpful for the interpretation of image scenes. Moreover, preliminary results with the second prototype consisting in the recognition of coloured balloons were very encouraging. Image processing techniques such as saliency could accelerate in the future the interpretation of sonified image scenes.

  3. Is colour cognitive?

    Science.gov (United States)

    Skorupski, Peter; Chittka, Lars

    2011-03-01

    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.

  4. Neuropsychology of colour vision: Studies in patients with acquired brain damage, healthy participants, and cases

    NARCIS (Netherlands)

    Nijboer, T.C.W.

    2007-01-01

    In this thesis, we studied the neuropsychology of low-level sensory and higher-order visual perception in healthy participants, patients with acquired deficits in visual perception, and a man with a selective developmental deficit in colour processing. In neuropsychological literature, sensory

  5. Visual search in the real world: Color vision deficiency affects peripheral guidance, but leaves foveal verification largely unaffected

    Directory of Open Access Journals (Sweden)

    Günter eKugler

    2015-12-01

    Full Text Available Background: People with color vision deficiencies report numerous limitations in daily life. However, they use basic color terms systematically and in a similar manner as people with people with normal color vision. We hypothesize that a possible explanation for this discrepancy between color perception and behavioral consequences might be found in the gaze behavior of people with color vision deficiency.Methods: A group of participants with color vision deficiencies and a control group performed several search tasks in a naturalistic setting on a lawn.Results: Search performance was similar in both groups in a color-unrelated search task as well as in a search for yellow targets. While searching for red targets, color vision deficient participants exhibited a strongly degraded performance. This was closely matched by the number of fixations on red objects shown by the two groups. Importantly, once they fixated a target, participants with color vision deficiencies exhibited only few identification errors. Conclusions: Participants with color vision deficiencies are not able to enhance their search for red targets on a (green lawn by an efficient guiding mechanism. The data indicate that the impaired guiding is the main influence on search performance, while foveal identification (verification largely unaffected.

  6. Controllable liquid colour-changing lenses with microfluidic channels for vision protection, camouflage and optical filtering based on soft lithography fabrication.

    Science.gov (United States)

    Zhang, Min; Li, Songjing

    2016-01-01

    In this work, liquid colour-changing lenses for vision protection, camouflage and optical filtering are developed by circulating colour liquids through microfluidic channels on the lenses manually. Soft lithography technology is applied to fabricate the silicone liquid colour-changing layers with microfluidic channels on the lenses instead of mechanical machining. To increase the hardness and abrasion resistance of the silicone colour-changing layers on the lenses, proper fabrication parameters such as 6:1 (mass ration) mixing proportion and 100 °C curing temperature for 2 h are approved for better soft lithography process of the lenses. Meanwhile, a new surface treatment for the irreversible bonding of silicone colour-changing layer with optical resin (CR39) substrate lens by using 5 % (volume ratio) 3-Aminopropyltriethoxysilane solution is proposed. Vision protection, camouflage and optical filtering functions of the lenses are investigated with different designs of the channels and multi-layer structures. Each application can not only well achieve their functional demands, but also shows the advantages of functional flexibility, rapid prototyping and good controllability compared with traditional ways. Besides optometry, some other designs and applications of the lenses are proposed for potential utility in the future.

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

    Energy Technology Data Exchange (ETDEWEB)

    Sahragard, Nasrolah; Ramli, Abdul Rahman B [Institute of Advanced Technology, Universiti Putra Malaysia 43400 Serdang, Selangor (Malaysia); Marhaban, Mohammad Hamiruce [Department of Electrical and Electronic Engineering, Faculty of Engineering, Universiti Putra Malaysia 43400 Serdang, Selangor (Malaysia); Mansor, Shattri B, E-mail: sahragard@yahoo.com [Department of Civil Engineering, Faculty of Engineering, Universiti Putra Malaysia 43400 Serdang, Selangor (Malaysia)

    2011-02-15

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

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

    Science.gov (United States)

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

    2011-02-01

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

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  10. Individualization of 2D color maps for people with color vision deficiencies

    KAUST Repository

    Waldin, Nicholas; Bernhard, Matthias; Rautek, Peter; Viola, Ivan

    2016-01-01

    2D color maps are often used to visually encode complex data characteristics such as heat or height. The comprehension of color maps in visualization is affected by the display (e.g., a monitor) and the perceptual abilities of the viewer. People with color vision deficiencies, such as red-green blindness, face difficulties when using conventional color maps. We propose a novel method for adapting a color map to an individual person, by having the user sort lines extracted from a given color map.

  11. Individualization of 2D color maps for people with color vision deficiencies

    KAUST Repository

    Waldin, Nicholas

    2016-12-13

    2D color maps are often used to visually encode complex data characteristics such as heat or height. The comprehension of color maps in visualization is affected by the display (e.g., a monitor) and the perceptual abilities of the viewer. People with color vision deficiencies, such as red-green blindness, face difficulties when using conventional color maps. We propose a novel method for adapting a color map to an individual person, by having the user sort lines extracted from a given color map.

  12. Multispectral colour analysis for quantitative evaluation of pseudoisochromatic color deficiency tests

    Science.gov (United States)

    Ozolinsh, Maris; Fomins, Sergejs

    2010-11-01

    Multispectral color analysis was used for spectral scanning of Ishihara and Rabkin color deficiency test book images. It was done using tunable liquid-crystal LC filters built in the Nuance II analyzer. Multispectral analysis keeps both, information on spatial content of tests and on spectral content. Images were taken in the range of 420-720nm with a 10nm step. We calculated retina neural activity charts taking into account cone sensitivity functions, and processed charts in order to find the visibility of latent symbols in color deficiency plates using cross-correlation technique. In such way the quantitative measure is found for each of diagnostics plate for three different color deficiency carrier types - protanopes, deutanopes and tritanopes. Multispectral color analysis allows to determine the CIE xyz color coordinates of pseudoisochromatic plate design elements and to perform statistical analysis of these data to compare the color quality of available color deficiency test books.

  13. A Call for Considering Color Vision Deficiency When Creating Graphics for Psychology Reports.

    Science.gov (United States)

    Frane, Andrew

    2015-01-01

    Although color vision deficiency (CVD) is fairly common, it is often not adequately considered when data is presented in color graphics. This study found that CVD tends to be mentioned neither in the author guidelines of psychology journals nor in the standard publication manuals of the field (e.g., the publication manuals of the American Psychological Association and the American Medical Association). To illustrate the relevance of this problem, a panel of scholars with CVD was used to evaluate the color figures in three respected psychological science journals. Results suggested that a substantial proportion of those figures were needlessly confusing for viewers with CVD and could have been easily improved through simple adjustments. Based on prior literature and on feedback from the panelists, recommendations are made for improving the accessibility of graphics in psychology reports.

  14. Accessible maps for the color vision deficient observers: past and present knowledge and future possibilities

    Science.gov (United States)

    Kvitle, Anne Kristin

    2018-05-01

    Color is part of the visual variables in map, serving an aesthetic part and as a guide of attention. Impaired color vision affects the ability to distinguish colors, which makes the task of decoding the map colors difficult. Map reading is reported as a challenging task for these observers, especially when the size of stimuli is small. The aim of this study is to review existing methods for map design for color vision deficient users. A systematic review of research literature and case studies of map design for CVD observers has been conducted in order to give an overview of current knowledge and future research challenges. In addition, relevant research on simulations of CVD and color image enhancement for these observers from other fields of industry is included. The study identified two main approaches: pre-processing by using accessible colors and post-processing by using enhancement methods. Some of the methods may be applied for maps, but requires tailoring of test images according to map types.

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

    Science.gov (United States)

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

    2014-11-01

    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.

  16. Operational Colour Vision in the Modern Aviation Environment (la Vision des couleurs dans l’environnement aeronautique operationnel d’ aujourd hui)

    Science.gov (United States)

    2001-03-01

    recommended. The Nagel II is no longer in production . Advantages: test has a long and hallowed history that is well respected. Disadvantages: expensive...Illuminator (Catalog No. 1388R) from Richmond Products , 1021 Rogers Circle, Suite 6, Boca Raton FL, 33487-2894. Phones:1-800-448-4538 and 407-994-2112...III Antineoplastics Mercaptopurine II Vincristine II Antirheumatics Ibuprofen II Colours appear faded Indomethacin III Antispasmodics

  17. Colouring outside the lines

    Science.gov (United States)

    Commissariat, Tushna

    2017-10-01

    Walk into a bookshop today, or even a gift shop, and you will most likely come across an entire section of colouring books for adults. Visions of Numberland: a Colouring Journey Through the Mysteries of Maths by Alex Bellos and Edmund Harriss is one such book.

  18. Colour contribution to children's wayfinding in school environments

    Science.gov (United States)

    Helvacıoǧlu, Elif; Olguntürk, Nilgün

    2011-03-01

    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.

  19. Object Knowledge Modulates Colour Appearance

    Directory of Open Access Journals (Sweden)

    Christoph Witzel

    2011-01-01

    Full Text Available 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.

  20. Object knowledge modulates colour appearance

    Science.gov (United States)

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

    2011-01-01

    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

  1. Impairment of Colour Vision in Diabetes with No Retinopathy: Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetics Study (SNDREAMS- II, Report 3.

    Directory of Open Access Journals (Sweden)

    Laxmi Gella

    Full Text Available To assess impairment of colour vision in type 2 diabetics with no diabetic retinopathy and elucidate associated risk factors in a population-based cross-sectional study.This is part of Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular-genetics Study (SN-DREAMS II which was conducted between 2007-2010. FM 100 hue-test was performed in 253 subjects with no clinical evidence of diabetic retinopathy. All subjects underwent detailed ophthalmic evaluation including cataract grading using LOCS III and 45° 4-field stereoscopic fundus photography. Various ocular and systemic risk factors for impairment of colour vision (ICV were assessed in subjects with diabetes but no retinopathy. P value of < 0.05 was considered statistically significant.The mean age of the study sample was 57.08 ± 9.21 (range: 44-86 years. Gender adjusted prevalence of ICV among subjects with diabetes with no retinopathy was 39.5% (CI: 33.5-45.5. The mean total error score in the study sample was 197.77 ± 100 (range: 19-583. The risk factors for ICV in the study were women OR: 1.79 (1.00-3.18, increased resting heart rate OR: 1.04 (1.01-1.07 and increased intraocular pressure OR: 1.12 (1.00-1.24. Significant protective factor was serum high-density lipoprotein OR: 0.96 (0.93-0.99.Acquired ICV is an early indicator of neurodegenerative changes in the retina. ICV found in diabetic subjects without retinopathy may be of non-vascular etiology.

  2. Color vision deficiency compensation for Visual Processing Disorder using Hardy-Rand-Rittler test and color transformation

    Science.gov (United States)

    Balbin, Jessie R.; Pinugu, Jasmine Nadja J.; Bautista, Joshua Ian C.; Nebres, Pauline D.; Rey Hipolito, Cipriano M.; Santella, Jose Anthony A.

    2017-06-01

    Visual processing skill is used to gather visual information from environment however, there are cases that Visual Processing Disorder (VPD) occurs. The so called visual figure-ground discrimination is a type of VPD where color is one of the factors that contributes on this type. In line with this, color plays a vital role in everyday living, but individuals that have limited and inaccurate color perception suffers from Color Vision Deficiency (CVD) and still not aware on their case. To resolve this case, this study focuses on the design of KULAY, a Head-Mounted Display (HMD) device that can assess whether a user has a CVD or not thru the standard Hardy-Rand-Rittler (HRR) test. This test uses pattern recognition in order to evaluate the user. In addition, color vision deficiency simulation and color correction thru color transformation is also a concern of this research. This will enable people with normal color vision to know how color vision deficient perceives and vice-versa. For the accuracy of the simulated HRR assessment, its results were validated thru an actual assessment done by a doctor. Moreover, for the preciseness of color transformation, Structural Similarity Index Method (SSIM) was used to compare the simulated CVD images and the color corrected images to other reference sources. The output of the simulated HRR assessment and color transformation shows very promising results indicating effectiveness and efficiency of the study. Thus, due to its form factor and portability, this device is beneficial in the field of medicine and technology.

  3. Cone photoreceptor structure in patients with x-linked cone dysfunction and red-green color vision deficiency

    DEFF Research Database (Denmark)

    Patterson, Emily J.; Wilk, Melissa; Langlo, Christopher S.

    2016-01-01

    encoded by exon 4, and two with a novel insertion in exon 2. Foveal cone structure and retinal thickness was disrupted to a variable degree, even among related individuals with the same L/M array. CONCLUSIONS. Our findings provide a direct link between disruption of the cone mosaic and L/ M opsin variants......PURPOSE. Mutations in the coding sequence of the L and M opsin genes are often associated with X-linked cone dysfunction (such as Bornholm Eye Disease, BED), though the exact color vision phenotype associated with these disorders is variable. We examined individuals with L/ M opsin gene mutations...... to clarify the link between color vision deficiency and cone dysfunction.  METHODS. We recruited 17 males for imaging. The thickness and integrity of the photoreceptor layers were evaluated using spectral-domain optical coherence tomography. Cone density was measured using high-resolution images of the cone...

  4. A treatable cause of myelopathy and vision loss mimicking neuromyelitis optica spectrum disorder: late-onset biotinidase deficiency.

    Science.gov (United States)

    Yilmaz, Sanem; Serin, Mine; Canda, Ebru; Eraslan, Cenk; Tekin, Hande; Ucar, Sema Kalkan; Gokben, Sarenur; Tekgul, Hasan; Serdaroglu, Gul

    2017-06-01

    Biotinidase deficiency is characterized by severe neurological manifestations as hypotonia, lethargy, ataxia, hearing loss, seizures and developmental retardation in its classical form. Late-onset biotinidase deficiency presents distinctly from the classical form such as limb weakness and vision problems. A 14-year-old boy presented with progressive vision loss and upper limb weakness. The patient was initiated steroid therapy with a preliminary diagnosis of neuromyelitis optica spectrum disorder due to the craniospinal imaging findings demonstrating optic nerve, brainstem and longitudinally extensive spinal cord involvement. Although the patient exhibited partial clinical improvement after pulse steroid therapy, craniocervical imaging performed one month after the initiation of steroid therapy did not show any regression. The CSF IgG index was <0.8 (normal: <0.8), oligoclonal band and aquaporin-4 antibodies were negative. Metabolic investigations revealed a low biotinidase enzyme activity 8% (0.58 nmoL/min/mL; normal range: 4.4 to 12). Genetic testing showed c.98-104delinsTCC and p.V457 M mutations in biotinidase (BTD) gene. At the third month of biotin replacement therapy, control craniospinal MRI demonstrated a complete regression of the lesions. The muscle strength of the case returned to normal. His visual acuity was 7/10 in the left eye and 9/10 in the right. The late-onset form of the biotinidase deficiency should be kept in mind in all patients with myelopathy with or without vision loss, particularly in those with inadequate response to steroid therapy. The family screening is important to identify asymptomatic individuals and timely treatment.

  5. Vision based nutrient deficiency classification in maize plants using multi class support vector machines

    Science.gov (United States)

    Leena, N.; Saju, K. K.

    2018-04-01

    Nutritional deficiencies in plants are a major concern for farmers as it affects productivity and thus profit. The work aims to classify nutritional deficiencies in maize plant in a non-destructive mannerusing image processing and machine learning techniques. The colored images of the leaves are analyzed and classified with multi-class support vector machine (SVM) method. Several images of maize leaves with known deficiencies like nitrogen, phosphorous and potassium (NPK) are used to train the SVM classifier prior to the classification of test images. The results show that the method was able to classify and identify nutritional deficiencies.

  6. Color vision deficiencies and the child's willingness for visual activity: preliminary research

    Science.gov (United States)

    Geniusz, Malwina; Szmigiel, Marta; Geniusz, Maciej

    2017-09-01

    After a few weeks a newborn baby can recognize high contrasts in colors like black and white. They reach full color vision at the age of circa six months. Matching colors is the next milestone. Most children can do it at the age of two. Good color vision is one of the factors which indicate proper development of a child. Presented research shows the correlation between color vision and visual activity. The color vision of a group of children aged 3-8 was examined with saturated Farnsworth D-15. Fransworth test was performed twice - in a standard version and in a magnetic version. The time of completing standard and magnetic tests was measured. Furthermore, parents of subjects answered questions checking the children's visual activity in 1 - 10 scale. Parents stated whether the child willingly watched books, colored coloring books, put puzzles or liked to play with blocks etc. The Fransworth D-15 test designed for color vision testing can be used to test younger children from the age of 3 years. These are preliminary studies which may be a useful tool for further, more accurate examination on a larger group of subjects.

  7. What do colour-blind people really see?

    NARCIS (Netherlands)

    Hogervorst, M.A.; Alferdinck, J.W.A.M.

    2008-01-01

    Problem: colour perception of dichromats (colour-blind persons) Background: Various models have been proposed (e. g. Walraven & Alferdinck, 1997; Brettel et al. , 1997) to model reduced colour vision of colour-blind people. It is clear that colour-blind people cannot distinguish certain object

  8. Restoration of vision in the pde6β-deficient dog, a large animal model of rod-cone dystrophy.

    Science.gov (United States)

    Petit, Lolita; Lhériteau, Elsa; Weber, Michel; Le Meur, Guylène; Deschamps, Jack-Yves; Provost, Nathalie; Mendes-Madeira, Alexandra; Libeau, Lyse; Guihal, Caroline; Colle, Marie-Anne; Moullier, Philippe; Rolling, Fabienne

    2012-11-01

    Defects in the β subunit of rod cGMP phosphodiesterase 6 (PDE6β) are associated with autosomal recessive retinitis pigmentosa (RP), a childhood blinding disease with early retinal degeneration and vision loss. To date, there is no treatment for this pathology. The aim of this preclinical study was to test recombinant adeno-associated virus (AAV)-mediated gene addition therapy in the rod-cone dysplasia type 1 (rcd1) dog, a large animal model of naturally occurring PDE6β deficiency that strongly resembles the human pathology. A total of eight rcd1 dogs were injected subretinally with AAV2/5RK.cpde6β (n = 4) or AAV2/8RK.cpde6β (n = 4). In vivo and post-mortem morphological analysis showed a significant preservation of the retinal structure in transduced areas of both AAV2/5RK.cpde6β- and AAV2/8RK.cpde6β-treated retinas. Moreover, substantial rod-derived electroretinography (ERG) signals were recorded as soon as 1 month postinjection (35% of normal eyes) and remained stable for at least 18 months (the duration of the study) in treated eyes. Rod-responses were undetectable in untreated contralateral eyes. Most importantly, dim-light vision was restored in all treated rcd1 dogs. These results demonstrate for the first time that gene therapy effectively restores long-term retinal function and vision in a large animal model of autosomal recessive rod-cone dystrophy, and provide great promise for human treatment.

  9. [Retinitis pigmentosa and color vision deficiency in Kamigoto island, Nagasaki Prefecture].

    Science.gov (United States)

    Toda, S

    1997-08-01

    I studied two genetic diseases, retinitis pigmentosa (RP) and color vision anomaly, in Kamigoto, one of the off-shore islands in Nagasaki Prefecture. The Prevalance of RP patients in this island was estimated to be one in 473 persons. Among the RP patients observed, familial cases whose disorders are transmitted through successive generations comprised 25.7%. Although it seems that the inheritance mode of RP in these familial cases is autosomal dominant, an autosomal recessive fashion showing quasi-dominance cannot be ruled out, because inbreeding frequently occurs on this island. There were at least two types of RP, one with late onset (40 years of age or later) and the other with early onset, and patients with the latter RP tended to have a poor prognosis. Only a few RP patients had posterior subcapsular cataract, and none had pseudexfoliation in spite of advanced age. Color vision anomalies were found in 3.86% of high-school boys and in 0.41% of girls in this island, and they included protanopia (4.2%), protanomaly (10.4%), deuteranopia (37.5%), and deuteranomaly (47.9%). The prevalence in boys was comparable to that in the general Japanese population, but the prevalence in girls was higher in Kamigoto than in other districts. It is most likely that the unique findings regarding the two disorders reflect geographical and/or social features in Kamigoto island.

  10. Colour simplicity

    OpenAIRE

    du Preez, Warren

    2017-01-01

    This dissertation addresses the metaphysics of conscious experience. I defend a thesis labelled Colour Simplicity, according to which the properties constitutive of what it is like to have visual sensory experiences of colourcolour qualia – are simple, in that they lack more basic constituent properties. I develop a valid argument for Colour Simplicity, drawing on the premises that (P1) ‘colour qualia appear to be simple under introspection’, and (P2) ‘if colour qualia appear to be simp...

  11. Neural correlates of imagined and synaesthetic colours.

    Science.gov (United States)

    Rich, Anina N; Williams, Mark A; Puce, Aina; Syngeniotis, Ari; Howard, Matthew A; McGlone, Francis; Mattingley, Jason B

    2006-01-01

    The experience of colour is a core element of human vision. Colours provide important symbolic and contextual information not conveyed by form alone. Moreover, the experience of colour can arise without external stimulation. For many people, visual memories are rich with colour imagery. In the unusual phenomenon of grapheme-colour synaesthesia, achromatic forms such as letters, words and numbers elicit vivid experiences of colour. Few studies, however, have examined the neural correlates of such internally generated colour experiences. We used functional magnetic resonance imaging (fMRI) to compare patterns of cortical activity for the perception of external coloured stimuli and internally generated colours in a group of grapheme-colour synaesthetes and matched non-synaesthetic controls. In a voluntary colour imagery task, both synaesthetes and non-synaesthetes made colour judgements on objects presented as grey scale photographs. In a synaesthetic colour task, we presented letters that elicited synaesthetic colours, and asked participants to perform a localisation task. We assessed the neural activity underpinning these two different forms of colour experience that occur in the absence of chromatic sensory input. In both synaesthetes and non-synaesthetes, voluntary colour imagery activated the colour-selective area, V4, in the right hemisphere. In contrast, the synaesthetic colour task resulted in unique activity for synaesthetes in the left medial lingual gyrus, an area previously implicated in tasks involving colour knowledge. Our data suggest that internally generated colour experiences recruit brain regions specialised for colour perception, with striking differences between voluntary colour imagery and synaesthetically induced colours.

  12. Measuring colour

    National Research Council Canada - National Science Library

    Hunt, R. W. G; Pointer, Michael, Ph. D

    2011-01-01

    ... industries.Building upon the success of earlier editions, the 4th edition of [start italics]Measuring Colour[end italics] has been updated throughout with new chapters on colour rendering by light sources...

  13. Supervised Object Class Colour Normalisation

    DEFF Research Database (Denmark)

    Riabchenko, Ekatarina; Lankinen, Jukka; Buch, Anders Glent

    2013-01-01

    . In this work, we develop a such colour normalisation technique, where true colours are not important per se but where examples of same classes have photometrically consistent appearance. This is achieved by supervised estimation of a class specic canonical colour space where the examples have minimal variation......Colour is an important cue in many applications of computer vision and image processing, but robust usage often requires estimation of the unknown illuminant colour. Usually, to obtain images invariant to the illumination conditions under which they were taken, color normalisation is used...... in their colours. We demonstrate the effectiveness of our method with qualitative and quantitative examples from the Caltech-101 data set and a real application of 3D pose estimation for robot grasping....

  14. Colour Studies

    African Journals Online (AJOL)

    DR Nneka

    2015-04-14

    Apr 14, 2015 ... failure of the student to differentiate what is of particular concern to him or her, and .... perception of the physical appearance of colour and our ..... Colour is perceived in different modes and dimension and has derivative ..... which pigment colours can effectively depict existing realities, express emotions and.

  15. Development and validation of a questionnaire assessing the quality of life impact of Colour Blindness (CBQoL).

    Science.gov (United States)

    Barry, John A; Mollan, Susan; Burdon, Michael A; Jenkins, Michelle; Denniston, Alastair K

    2017-10-02

    Congenital colour vision deficiency (CVD), commonly called 'colour blindness', affects around 8% of men and 0.4% of women. Although many aspects of health (e.g. change in colour of urine) and healthcare (e.g. coloured medication, colour-coded diagnostic tests), and modern life depend upon colour coding (e.g. graphs, maps, signals), the impact of colour blindness on everyday life is not generally considered a topic of importance. This study is the first to create and validate a questionnaire measuring the quality of life (QoL) impact of being colour blind. This study consisted of two phases. Firstly, the questionnaire design and development phase was led by an expert panel and piloted on a focus group. Secondly, an online sample of 128 men and 291 women filled in the questionnaire, and the psychometric properties of the questionnaire were analysed using principal components analysis (PCA). The scores of colour blind (CB) participants and normal-sighted controls, controlling for age and sex, were compared using matched t-tests. The PCA resulted in a questionnaire with three domains (or subscales): QoL for Health & Lifestyle, QoL for Work, and QoL for Emotions. Controlling for age, there was a significantly greater negative impact on QoL for CB people than normal-sighted controls in regards to confusion over colour in various aspects of their health (p = 5 × 10 -7 ), work (p = 1.3 × 10 -7 ), and emotional life (p = 6 × 10 -5 ). Colour blindness can significantly impact quality of life for health, emotions, and especially careers. The tool developed here could be useful in future clinical studies to measure changes in CBQoL in response to therapy in conditions where colour vision is affected. We also discuss ways in which everyday problems related to colour vision might be reduced, for example, workplaces could avoid colour coding where a non-colour alternative is possible.

  16. Colour Terms Affect Detection of Colour and Colour-Associated Objects Suppressed from Visual Awareness

    Science.gov (United States)

    Forder, Lewis; Taylor, Olivia; Mankin, Helen; Scott, Ryan B.; Franklin, Anna

    2016-01-01

    The idea that language can affect how we see the world continues to create controversy. A potentially important study in this field has shown that when an object is suppressed from visual awareness using continuous flash suppression (a form of binocular rivalry), detection of the object is differently affected by a preceding word prime depending on whether the prime matches or does not match the object. This may suggest that language can affect early stages of vision. We replicated this paradigm and further investigated whether colour terms likewise influence the detection of colours or colour-associated object images suppressed from visual awareness by continuous flash suppression. This method presents rapidly changing visual noise to one eye while the target stimulus is presented to the other. It has been shown to delay conscious perception of a target for up to several minutes. In Experiment 1 we presented greyscale photos of objects. They were either preceded by a congruent object label, an incongruent label, or white noise. Detection sensitivity (d’) and hit rates were significantly poorer for suppressed objects preceded by an incongruent label compared to a congruent label or noise. In Experiment 2, targets were coloured discs preceded by a colour term. Detection sensitivity was significantly worse for suppressed colour patches preceded by an incongruent colour term as compared to a congruent term or white noise. In Experiment 3 targets were suppressed greyscale object images preceded by an auditory presentation of a colour term. On congruent trials the colour term matched the object’s stereotypical colour and on incongruent trials the colour term mismatched. Detection sensitivity was significantly poorer on incongruent trials than congruent trials. Overall, these findings suggest that colour terms affect awareness of coloured stimuli and colour- associated objects, and provide new evidence for language-perception interaction in the brain. PMID:27023274

  17. Colour Terms Affect Detection of Colour and Colour-Associated Objects Suppressed from Visual Awareness.

    Science.gov (United States)

    Forder, Lewis; Taylor, Olivia; Mankin, Helen; Scott, Ryan B; Franklin, Anna

    2016-01-01

    The idea that language can affect how we see the world continues to create controversy. A potentially important study in this field has shown that when an object is suppressed from visual awareness using continuous flash suppression (a form of binocular rivalry), detection of the object is differently affected by a preceding word prime depending on whether the prime matches or does not match the object. This may suggest that language can affect early stages of vision. We replicated this paradigm and further investigated whether colour terms likewise influence the detection of colours or colour-associated object images suppressed from visual awareness by continuous flash suppression. This method presents rapidly changing visual noise to one eye while the target stimulus is presented to the other. It has been shown to delay conscious perception of a target for up to several minutes. In Experiment 1 we presented greyscale photos of objects. They were either preceded by a congruent object label, an incongruent label, or white noise. Detection sensitivity (d') and hit rates were significantly poorer for suppressed objects preceded by an incongruent label compared to a congruent label or noise. In Experiment 2, targets were coloured discs preceded by a colour term. Detection sensitivity was significantly worse for suppressed colour patches preceded by an incongruent colour term as compared to a congruent term or white noise. In Experiment 3 targets were suppressed greyscale object images preceded by an auditory presentation of a colour term. On congruent trials the colour term matched the object's stereotypical colour and on incongruent trials the colour term mismatched. Detection sensitivity was significantly poorer on incongruent trials than congruent trials. Overall, these findings suggest that colour terms affect awareness of coloured stimuli and colour- associated objects, and provide new evidence for language-perception interaction in the brain.

  18. Colour Terms Affect Detection of Colour and Colour-Associated Objects Suppressed from Visual Awareness.

    Directory of Open Access Journals (Sweden)

    Lewis Forder

    Full Text Available The idea that language can affect how we see the world continues to create controversy. A potentially important study in this field has shown that when an object is suppressed from visual awareness using continuous flash suppression (a form of binocular rivalry, detection of the object is differently affected by a preceding word prime depending on whether the prime matches or does not match the object. This may suggest that language can affect early stages of vision. We replicated this paradigm and further investigated whether colour terms likewise influence the detection of colours or colour-associated object images suppressed from visual awareness by continuous flash suppression. This method presents rapidly changing visual noise to one eye while the target stimulus is presented to the other. It has been shown to delay conscious perception of a target for up to several minutes. In Experiment 1 we presented greyscale photos of objects. They were either preceded by a congruent object label, an incongruent label, or white noise. Detection sensitivity (d' and hit rates were significantly poorer for suppressed objects preceded by an incongruent label compared to a congruent label or noise. In Experiment 2, targets were coloured discs preceded by a colour term. Detection sensitivity was significantly worse for suppressed colour patches preceded by an incongruent colour term as compared to a congruent term or white noise. In Experiment 3 targets were suppressed greyscale object images preceded by an auditory presentation of a colour term. On congruent trials the colour term matched the object's stereotypical colour and on incongruent trials the colour term mismatched. Detection sensitivity was significantly poorer on incongruent trials than congruent trials. Overall, these findings suggest that colour terms affect awareness of coloured stimuli and colour- associated objects, and provide new evidence for language-perception interaction in the brain.

  19. Measuring Colour

    CERN Document Server

    Hunt, R W G

    2011-01-01

    The classic authority on colour measurement now fully revised and updated with the latest CIE recommendations The measurement of colour is of major importance in many commercial applications, such as the textile, paint, and foodstuff industries; as well as having a significant role in the lighting, paper, printing, cosmetic, plastics, glass, chemical, photographic, television, transport, and communication industries. Building upon the success of earlier editions, the 4th edition of Measuring Colour has been updated throughout with new chapters on colour rendering by light sources; colorimetry

  20. Assessing the colour quality of LED sources

    DEFF Research Database (Denmark)

    Jost-Boissard, S.; Avouac, P.; Fontoynont, Marc

    2015-01-01

    The CIE General Colour Rendering Index is currently the criterion used to describe and measure the colour-rendering properties of light sources. But over the past years, there has been increasing evidence of its limitations particularly its ability to predict the perceived colour quality of light...... sources and especially some LEDs. In this paper, several aspects of perceived colour quality are investigated using a side-by-side paired comparison method, and the following criteria: naturalness of fruits and vegetables, colourfulness of the Macbeth Color Checker chart, visual appreciation...... (attractiveness/ preference) and colour difference estimations for both visual scenes. Forty-five observers with normal colour vision evaluated nine light sources at 3000 K, and 36 observers evaluated eight light sources at 4000 K. Our results indicate that perceived colour differences are better dealt...

  1. Do dichromats see colours in this way? Assessing simulation tools without colorimetric measurements.

    Science.gov (United States)

    Lillo Jover, Julio A; Álvaro Llorente, Leticia; Moreira Villegas, Humberto; Melnikova, Anna

    2016-11-01

    Simulcheck evaluates Colour Simulation Tools (CSTs, they transform colours to mimic those seen by colour vision deficients). Two CSTs (Variantor and Coblis) were used to know if the standard Simulcheck version (direct measurement based, DMB) can be substituted by another (RGB values based) not requiring sophisticated measurement instruments. Ten normal trichromats performed the two psychophysical tasks included in the Simulcheck method. The Pseudoachromatic Stimuli Identification task provided the h uv (hue angle) values of the pseudoachromatic stimuli: colours seen as red or green by normal trichromats but as grey by colour deficient people. The Minimum Achromatic Contrast task was used to compute the L R (relative luminance) values of the pseudoachromatic stimuli. Simulcheck DMB version showed that Variantor was accurate to simulate protanopia but neither Variantor nor Coblis were accurate to simulate deuteranopia. Simulcheck RGB version provided accurate h uv values, so this variable can be adequately estimated when lacking a colorimeter —an expensive and unusual apparatus—. Contrary, the inaccuracy of the L R estimations provided by Simulcheck RGB version makes it advisable to compute this variable from the measurements performed with a photometer, a cheap and easy to find apparatus.

  2. Colour Perception in Ancient World

    Science.gov (United States)

    Nesterov, D. I.; Fedorova, M. Yu

    2017-11-01

    How did the human thought form the surrounding color information into the persistent semantic images of a mythological, pseudoscientific and religious nature? The concepts associated with colour perception are suggested. The existence of colour environment does not depend on the human consciousness. The colour culture formation is directly related to the level of the human consciousness development and the possibility to influence the worldview and culture. The colour perception of a person goes through the stages similar to the development of colour vision in a child. Like any development, the colour consciousness has undergone stages of growth and decline, evolution and stagnation. The way of life and difficult conditions for existence made their own adjustments to the development of the human perception of the surrounding world. Wars have been both a powerful engine of progress in all spheres of life and a great destructive force demolishing the already created and preserved heritage. The surrounding world has always been interesting for humans, evoked images and fantasies in the consciousness of ancient people. Unusual and inexplicable natural phenomena spawned numerous legends and myths which was reflected in the ancient art and architecture and, accordingly, in a certain manifestation of colour in the human society. The colour perception of the ancient man, his pragmatic, utilitarian attitude to colour is considered as well as the influence of dependence on external conditions of existence and their reflection in the colour culture of antiquity. “Natural Science” conducts research in the field of the colour nature and their authorial interpretation of the Hellenic period. Several authorial concepts of the ancient world have been considered.

  3. Colour schemes

    DEFF Research Database (Denmark)

    van Leeuwen, Theo

    2013-01-01

    This chapter presents a framework for analysing colour schemes based on a parametric approach that includes not only hue, value and saturation, but also purity, transparency, luminosity, luminescence, lustre, modulation and differentiation.......This chapter presents a framework for analysing colour schemes based on a parametric approach that includes not only hue, value and saturation, but also purity, transparency, luminosity, luminescence, lustre, modulation and differentiation....

  4. An Urban Colour Space in the Context of Culture

    Directory of Open Access Journals (Sweden)

    Olga Zheleznyak

    2015-08-01

    Full Text Available A colour space is seen as an actual discourse when discussing problems of formation and inhabitation of the modern city environment. The key aspect of such understanding is an activity-cultural interpretation of the urban environment colouristics proposed by the author, which allows building of an integral sphere of colour existence. This model of working with colour includes basic components and structures a colour space, while matching up all the elements (basic paradigms that provide proper functioning and development of the colour space; mechanisms of formation of colour paradigms; processes of formation and transformation of cultural norms and stereotypes; the culture of colour as a holistic unit that penetrates the variety of colour space forms, as well as the reality of colour establishment in the framework of human culture; the urban colouristics as a material and virtual, artificial and natural, organized and spontaneously appearing colour reality together with professional and conventional visions of it, etc..

  5. Fundamentals of colour awareness: a literature review

    OpenAIRE

    A. Rubin

    2005-01-01

    A description of some of the basic or funda-mental aspects of the colour sensory mechanism will be provided here, based on modern ideas and literature, with reference specifically to the likely origins and evolution of colour vision.  The mo-lecular basis for colour awareness and the human colour pathway will also be considered in some detail. This paper intends to provide the theoreti-cal and philosophical basis for further papers that will introduce a modern and original computer- based  met...

  6. Colour chemistry

    International Nuclear Information System (INIS)

    Hong-Mo, C.

    1978-10-01

    Colour is now popularly believed to be the basis of strong interactions and as evidence for such a fundamental new degree of freedom one should expect an entirely new class of phenomena qualitatively different from those in a colourless world. One place to seek such manifestations is in spectroscopy, where a new degree of freedom should lead to a richer spectrum. this approach is here discussed with especial reference to the case of diquoniums. The very existence of M-diquoniums, whose spectrum has been calculated and is shown, would be a verification of colour. (U.K.)

  7. Colour perception in ADHD

    NARCIS (Netherlands)

    Banaschewski, T.; Ruppert, S; Tannock, R.; Albrecht, B.; Becker, A.; Uebel, H.; Sergeant, J.A.; Rothenberger, A.

    2006-01-01

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

  8. Automated Field-of-View, Illumination, and Recognition Algorithm Design of a Vision System for Pick-and-Place Considering Colour Information in Illumination and Images.

    Science.gov (United States)

    Chen, Yibing; Ogata, Taiki; Ueyama, Tsuyoshi; Takada, Toshiyuki; Ota, Jun

    2018-05-22

    Machine vision is playing an increasingly important role in industrial applications, and the automated design of image recognition systems has been a subject of intense research. This study has proposed a system for automatically designing the field-of-view (FOV) of a camera, the illumination strength and the parameters in a recognition algorithm. We formulated the design problem as an optimisation problem and used an experiment based on a hierarchical algorithm to solve it. The evaluation experiments using translucent plastics objects showed that the use of the proposed system resulted in an effective solution with a wide FOV, recognition of all objects and 0.32 mm and 0.4° maximal positional and angular errors when all the RGB (red, green and blue) for illumination and R channel image for recognition were used. Though all the RGB illumination and grey scale images also provided recognition of all the objects, only a narrow FOV was selected. Moreover, full recognition was not achieved by using only G illumination and a grey-scale image. The results showed that the proposed method can automatically design the FOV, illumination and parameters in the recognition algorithm and that tuning all the RGB illumination is desirable even when single-channel or grey-scale images are used for recognition.

  9. Vitamin D deficiency intensifies deterioration of risk factors, such as male sex and absence of vision, leading to increased postural body sway.

    Science.gov (United States)

    Krause, Matthias; Anschütz, Wilma; Vettorazzi, Eik; Breer, Stefan; Amling, Michael; Barvencik, Florian

    2014-01-01

    Due to inconsistent findings, the influence of vitamin D on postural body sway (PBS) is currently under debate. This study evaluated the impact of vitamin D on PBS with regards to different foot positions and eye opening states in community-dwelling older individuals. In a cross-sectional study, we assessed PBS in 342 older individuals (264 females [average age (± SD): 68.3 ± 9.0 years], 78 males [65.7 ± 9.6 years]). A detailed medical history and vitamin D level were obtained for each individual. Fall risk was evaluated using the New York-Presbyterian Fall Risk Assessment Tool (NY PFRA). PBS parameters (area, distance, velocity, frequency) were evaluated on a pressure plate with feet in closed stance (CS) or hip-width stance (HWS), open eyes and closed eyes. Statistical analysis included logarithmic mixed models for repeated measures with the MIXED model procedure to test the influence of vitamin D (categorized in 30 μg/l), foot position, eye opening state, age, sex and frequency of physical activity on PBS. Vitamin D was not an independent risk factor for falls experienced in the last 12 months. Nonetheless, PBS was higher in patients with vitamin D deficiency (risk factors for increased PBS like male sex and absence of vision are additionally compromised by vitamin D deficiency. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Colour application on mammography image segmentation

    Science.gov (United States)

    Embong, R.; Aziz, N. M. Nik Ab.; Karim, A. H. Abd; Ibrahim, M. R.

    2017-09-01

    The segmentation process is one of the most important steps in image processing and computer vision since it is vital in the initial stage of image analysis. Segmentation of medical images involves complex structures and it requires precise segmentation result which is necessary for clinical diagnosis such as the detection of tumour, oedema, and necrotic tissues. Since mammography images are grayscale, researchers are looking at the effect of colour in the segmentation process of medical images. Colour is known to play a significant role in the perception of object boundaries in non-medical colour images. Processing colour images require handling more data, hence providing a richer description of objects in the scene. Colour images contain ten percent (10%) additional edge information as compared to their grayscale counterparts. Nevertheless, edge detection in colour image is more challenging than grayscale image as colour space is considered as a vector space. In this study, we implemented red, green, yellow, and blue colour maps to grayscale mammography images with the purpose of testing the effect of colours on the segmentation of abnormality regions in the mammography images. We applied the segmentation process using the Fuzzy C-means algorithm and evaluated the percentage of average relative error of area for each colour type. The results showed that all segmentation with the colour map can be done successfully even for blurred and noisy images. Also the size of the area of the abnormality region is reduced when compare to the segmentation area without the colour map. The green colour map segmentation produced the smallest percentage of average relative error (10.009%) while yellow colour map segmentation gave the largest percentage of relative error (11.367%).

  11. Colorimetry and prime colours--a theorem.

    Science.gov (United States)

    Hornaes, Hans Petter; Wold, Jan Henrik; Farup, Ivar

    2005-08-01

    Human colour vision is the result of a complex process involving topics ranging from physics of light to perception. Whereas the diversity of light entering the eye in principle span an infinite-dimensional vector space in terms of the spectral power distributions, the space of human colour perceptions is three dimensional. One important consequence of this is that a variety of colours can be visually matched by a mixture of only three adequately chosen reference lights. It has been observed that there exists one particular set of monochromatic reference lights that, according to a certain definition, is optimal for producing colour matches. These reference lights are commonly denoted prime colours. In the present paper, we intend to rigorously show that the existence of prime colours is not particular to the human visual system as sometimes stated, but rather an algebraic consequence of the manner in which a kind of colorimetric functions called colour-matching functions are defined and transformed. The solution is based on maximisation of a determinant determining the gamut size of the colour space spanned by the prime colours. Cramer's rule for solving a set of linear equations is an essential part of the proof. By means of examples, it is shown that mathematically the optimal set of reference lights is not unique in general, and that the existence of a maximum determinant is not a necessary condition for the existence of prime colours.

  12. Exploring the functional nature of synaesthetic colour: Dissociations from colour perception and imagery.

    Science.gov (United States)

    Chiou, Rocco; Rich, Anina N; Rogers, Sebastian; Pearson, Joel

    2018-08-01

    Individuals with grapheme-colour synaesthesia experience anomalous colours when reading achromatic text. These unusual experiences have been said to resemble 'normal' colour perception or colour imagery, but studying the nature of synaesthesia remains difficult. In the present study, we report novel evidence that synaesthetic colour impacts conscious vision in a way that is different from both colour perception and imagery. Presenting 'normal' colour prior to binocular rivalry induces a location-dependent suppressive bias reflecting local habituation. By contrast, a grapheme that evokes synaesthetic colour induces a facilitatory bias reflecting priming that is not constrained to the inducing grapheme's location. This priming does not occur in non-synaesthetes and does not result from response bias. It is sensitive to diversion of visual attention away from the grapheme, but resistant to sensory perturbation, reflecting a reliance on cognitive rather than sensory mechanisms. Whereas colour imagery in non-synaesthetes causes local priming that relies on the locus of imagined colour, imagery in synaesthetes caused global priming not dependent on the locus of imagery. These data suggest a unique psychophysical profile of high-level colour processing in synaesthetes. Our novel findings and method will be critical to testing theories of synaesthesia and visual awareness. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Forbidden Structures for Planar Perfect Consecutively Colourable Graphs

    Directory of Open Access Journals (Sweden)

    Borowiecka-Olszewska Marta

    2017-05-01

    Full Text Available A consecutive colouring of a graph is a proper edge colouring with posi- tive integers in which the colours of edges incident with each vertex form an interval of integers. The idea of this colouring was introduced in 1987 by Asratian and Kamalian under the name of interval colouring. Sevast- janov showed that the corresponding decision problem is NP-complete even restricted to the class of bipartite graphs. We focus our attention on the class of consecutively colourable graphs whose all induced subgraphs are consecutively colourable, too. We call elements of this class perfect consecutively colourable to emphasise the conceptual similarity to perfect graphs. Obviously, the class of perfect consecutively colourable graphs is induced hereditary, so it can be characterized by the family of induced forbidden graphs. In this work we give a necessary and sufficient conditions that must be satisfied by the generalized Sevastjanov rosette to be an induced forbid- den graph for the class of perfect consecutively colourable graphs. Along the way, we show the exact values of the deficiency of all generalized Sevastjanov rosettes, which improves the earlier known estimating result. It should be mentioned that the deficiency of a graph measures its closeness to the class of consecutively colourable graphs. We motivate the investigation of graphs considered here by showing their connection to the class of planar perfect consecutively colourable graphs.

  14. Machine Vision Handbook

    CERN Document Server

    2012-01-01

    The automation of visual inspection is becoming more and more important in modern industry as a consistent, reliable means of judging the quality of raw materials and manufactured goods . The Machine Vision Handbook  equips the reader with the practical details required to engineer integrated mechanical-optical-electronic-software systems. Machine vision is first set in the context of basic information on light, natural vision, colour sensing and optics. The physical apparatus required for mechanized image capture – lenses, cameras, scanners and light sources – are discussed followed by detailed treatment of various image-processing methods including an introduction to the QT image processing system. QT is unique to this book, and provides an example of a practical machine vision system along with extensive libraries of useful commands, functions and images which can be implemented by the reader. The main text of the book is completed by studies of a wide variety of applications of machine vision in insp...

  15. Light Vision Color

    Science.gov (United States)

    Valberg, Arne

    2005-04-01

    Light Vision Color takes a well-balanced, interdisciplinary approach to our most important sensory system. The book successfully combines basics in vision sciences with recent developments from different areas such as neuroscience, biophysics, sensory psychology and philosophy. Originally published in 1998 this edition has been extensively revised and updated to include new chapters on clinical problems and eye diseases, low vision rehabilitation and the basic molecular biology and genetics of colour vision. Takes a broad interdisciplinary approach combining basics in vision sciences with the most recent developments in the area Includes an extensive list of technical terms and explanations to encourage student understanding Successfully brings together the most important areas of the subject in to one volume

  16. Developmental colour agnosia.

    Science.gov (United States)

    van Zandvoort, Martine J E; Nijboer, Tanja C W; de Haan, Edward

    2007-08-01

    Colour agnosia concerns the inability to recognise colours despite intact colour perception, semantic memory for colour information, and colour naming. Patients with selective colour agnosia have been described and the deficit is associated with left hemisphere damage. Here we report a case study of a 43-year-old man who was referred to us with a stroke in his right cerebellar hemisphere. During the standard assessment it transpired that he was unable to name coloured patches. Detailed assessment of his colour processing showed that he suffers from a selective colour agnosia. As he claimed to have had this problem all his life, and the fact that the infratentorial infarct that he had incurred was in an area far away from the brain structures that are known to be involved in colour processing, we suggest that he is the first reported case of developmental colour agnosia.

  17. Colour is more than hue: preferences for compiled colour traits in the stingless bees Melipona mondury and M. quadrifasciata.

    Science.gov (United States)

    Koethe, Sebastian; Bossems, Jessica; Dyer, Adrian G; Lunau, Klaus

    2016-10-01

    The colour vision of bees has been extensively analysed in honeybees and bumblebees, but few studies consider the visual perception of stingless bees (Meliponini). In a five-stage experiment the preference for colour intensity and purity, and the preference for the dominant wavelength were tested by presenting four colour stimuli in each test to freely flying experienced workers of two stingless bee species, Melipona mondury and Melipona quadrifasciata. The results with bee-blue, bee-UV-blue and bee-green colours offered in four combinations of varying colour intensity and purity suggest a complex interaction between these colour traits for the determination of colour choice. Specifically, M. mondury preferred bee-UV-blue colours over bee-green, bee-blue and bee-blue-green colours while M. quadrifasciata preferred bee-green colour stimuli. Moreover in M. mondury the preferences were different if the background colour was changed from grey to green. There was a significant difference between species where M. mondury preferred UV-reflecting over UV-absorbing bee-blue-green colour stimuli, whereas M. quadrifasciata showed an opposite preference. The different colour preferences of the free flying bees in identical conditions may be caused by the bees' experience with natural flowers precedent to the choice tests, suggesting reward partitioning between species.

  18. Fundamentals of colour awareness: a literature review

    Directory of Open Access Journals (Sweden)

    A. Rubin

    2005-12-01

    Full Text Available A description of some of the basic or funda-mental aspects of the colour sensory mechanism will be provided here, based on modern ideas and literature, with reference specifically to the likely origins and evolution of colour vision.  The mo-lecular basis for colour awareness and the human colour pathway will also be considered in some detail. This paper intends to provide the theoreti-cal and philosophical basis for further papers that will introduce a modern and original computer- based  method  for  more  comprehensive  colour vision  assessment.    This  new  approach,  to  be fully described in later manuscripts, may contrib-ute towards improvements in understanding and knowledge of human colour perception and its measurement, still perhaps a relatively under-ex-plored or neglected field of study within optom-etry and ophthalmology.

  19. Spectral sensitivity of a colour changing spider.

    Science.gov (United States)

    Defrize, Jérémy; Lazzari, Claudio R; Warrant, Eric J; Casas, Jérôme

    2011-04-01

    Vision plays a paramount role in some spider families such as the Salticidae, Lycosidae and Thomisidae, as it is involved in prey hunting, orientation or choice of substrate. In the thomisid Misumena vatia, for which the substrate colour affects the body colour, vision seems to mediate morphological colour changes. However, nothing is known about which component of visual signals from the substrate might be perceived, nor whether M. vatia possesses the physiological basis for colour vision. The aim of this study is thus to investigate the vision of this spider species by measuring the spectral sensitivities of the different pairs of eyes using electrophysiological methods. Extra- and intracellular electrophysiological recordings combined with selective adaptation revealed the presence of two classes of photoreceptor cells, one sensitive in the UV region of the spectrum (around 340 nm) and one sensitive in the green (around 520 nm) regions in the four pairs of eyes. We conclude that M. vatia possesses the physiological potential to perceive both chromatic and achromatic components of the environment. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Colour Perception in ADHD

    Science.gov (United States)

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

    2006-01-01

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

  1. Colour perception in ADHD

    OpenAIRE

    Banaschewski, T.; Ruppert, S; Tannock, R.; Albrecht, B.; Becker, A.; Uebel, H.; Sergeant, J.A.; Rothenberger, A.

    2006-01-01

    Attention-deficit/hyperactivity disorder (ADHD) is associated with unexplained impairments on speeded naming of coloured stimuli. These deficits may reflect hypofunctioning retinal dopaminergic mechanisms impairing particularly blue-yellow colour discrimination. Colour perception and rapid colour naming ability were investigated in 14 children with ADHD and 13 healthy peers matched for age, gender, and IQ, using the Farnsworth-Munsell 100 Hue Test (FMT) and the Stroop-Colour-Word test. Childr...

  2. Rethinking Colour Constancy.

    Science.gov (United States)

    Logvinenko, Alexander D; Funt, Brian; Mirzaei, Hamidreza; Tokunaga, Rumi

    2015-01-01

    Colour constancy needs to be reconsidered in light of the limits imposed by metamer mismatching. Metamer mismatching refers to the fact that two objects reflecting metameric light under one illumination may reflect non-metameric light under a second; so two objects appearing as having the same colour under one illuminant can appear as having different colours under a second. Yet since Helmholtz, object colour has generally been believed to remain relatively constant. The deviations from colour constancy registered in experiments are usually thought to be small enough that they do not contradict the notion of colour constancy. However, it is important to determine how the deviations from colour constancy relate to the limits metamer mismatching imposes on constancy. Hence, we calculated metamer mismatching's effect for the 20 Munsell papers and 8 pairs of illuminants employed in the colour constancy study by Logvinenko and Tokunaga and found it to be so extensive that the two notions-metamer mismatching and colour constancy-must be mutually exclusive. In particular, the notion of colour constancy leads to some paradoxical phenomena such as the possibility of 20 objects having the same colour under chromatic light dispersing into a hue circle of colours under neutral light. Thus, colour constancy refers to a phenomenon, which because of metamer mismatching, simply cannot exist. Moreover, it obscures the really important visual phenomenon; namely, the alteration of object colours induced by illumination change. We show that colour is not an independent, intrinsic attribute of an object, but rather an attribute of an object/light pair, and then define a concept of material colour in terms of equivalence classes of such object/light pairs. We suggest that studying the shift in material colour under a change in illuminant will be more fruitful than pursuing colour constancy's false premise that colour is an intrinsic attribute of an object.

  3. Rethinking Colour Constancy.

    Directory of Open Access Journals (Sweden)

    Alexander D Logvinenko

    Full Text Available Colour constancy needs to be reconsidered in light of the limits imposed by metamer mismatching. Metamer mismatching refers to the fact that two objects reflecting metameric light under one illumination may reflect non-metameric light under a second; so two objects appearing as having the same colour under one illuminant can appear as having different colours under a second. Yet since Helmholtz, object colour has generally been believed to remain relatively constant. The deviations from colour constancy registered in experiments are usually thought to be small enough that they do not contradict the notion of colour constancy. However, it is important to determine how the deviations from colour constancy relate to the limits metamer mismatching imposes on constancy. Hence, we calculated metamer mismatching's effect for the 20 Munsell papers and 8 pairs of illuminants employed in the colour constancy study by Logvinenko and Tokunaga and found it to be so extensive that the two notions-metamer mismatching and colour constancy-must be mutually exclusive. In particular, the notion of colour constancy leads to some paradoxical phenomena such as the possibility of 20 objects having the same colour under chromatic light dispersing into a hue circle of colours under neutral light. Thus, colour constancy refers to a phenomenon, which because of metamer mismatching, simply cannot exist. Moreover, it obscures the really important visual phenomenon; namely, the alteration of object colours induced by illumination change. We show that colour is not an independent, intrinsic attribute of an object, but rather an attribute of an object/light pair, and then define a concept of material colour in terms of equivalence classes of such object/light pairs. We suggest that studying the shift in material colour under a change in illuminant will be more fruitful than pursuing colour constancy's false premise that colour is an intrinsic attribute of an object.

  4. Low Vision Devices and Training

    Directory of Open Access Journals (Sweden)

    Imran Azam Butt

    2004-01-01

    Full Text Available Vision is the ability to see with a clear perception of detail, colour and contrast, and to distinguish objects visually. Like any other sense, vision tends to deteriorate or diminish naturally with age. In most cases, reduction in visual capability can be corrected with glasses, medicine or surgery. However, if the visual changes occur because of an incurable eye disease, condition or injury, vision loss can be permanent. Many people around the world with permanent visual impairment have some residual vision which can be used with the help of low vision services, materials and devices. This paper describes different options for the enhancement of residual vision including optical and non-optical devices and providing training for the low vision client.

  5. Recolouring-resistant colourings

    DEFF Research Database (Denmark)

    Pedersen, A. S.; Rautenbach, D.

    2011-01-01

    We study colourings of graphs with the property that the number of used colours cannot be reduced by applying some recolouring operation. A well-studied example of such colourings are b-colourings, which were introduced by Irving and Manlove [R.W. Irving, D.F. Manlove, The la-chromatic number...... of a graph, Discrete Appl. Math. 91 (1999) 127-141]. Given a graph and a colouring, a recolouring operation specifies a set of vertices of the graph on which the colouring can be changed. We consider two such operations: One which allows the recolouring of all vertices within some given distance of some...... colour class, and another which allows the recolouring of all vertices that belong to one of a given number of colour classes. Our results extend known results concerning b-colourings and the associated b-chromatic number. (C) 2011 Elsevier B.V. All rights reserved....

  6. The brightness of colour.

    Directory of Open Access Journals (Sweden)

    David Corney

    Full Text Available The perception of brightness depends on spatial context: the same stimulus can appear light or dark depending on what surrounds it. A less well-known but equally important contextual phenomenon is that the colour of a stimulus can also alter its brightness. Specifically, stimuli that are more saturated (i.e. purer in colour appear brighter than stimuli that are less saturated at the same luminance. Similarly, stimuli that are red or blue appear brighter than equiluminant yellow and green stimuli. This non-linear relationship between stimulus intensity and brightness, called the Helmholtz-Kohlrausch (HK effect, was first described in the nineteenth century but has never been explained. Here, we take advantage of the relative simplicity of this 'illusion' to explain it and contextual effects more generally, by using a simple Bayesian ideal observer model of the human visual ecology. We also use fMRI brain scans to identify the neural correlates of brightness without changing the spatial context of the stimulus, which has complicated the interpretation of related fMRI studies.Rather than modelling human vision directly, we use a Bayesian ideal observer to model human visual ecology. We show that the HK effect is a result of encoding the non-linear statistical relationship between retinal images and natural scenes that would have been experienced by the human visual system in the past. We further show that the complexity of this relationship is due to the response functions of the cone photoreceptors, which themselves are thought to represent an efficient solution to encoding the statistics of images. Finally, we show that the locus of the response to the relationship between images and scenes lies in the primary visual cortex (V1, if not earlier in the visual system, since the brightness of colours (as opposed to their luminance accords with activity in V1 as measured with fMRI.The data suggest that perceptions of brightness represent a robust

  7. Repeatability indices for the Adams D-15 test for colour-normal and colour-defective adults.

    Science.gov (United States)

    Hovis, Jeffery K; Ramaswamy, Shankaran; Anderson, Matthew

    2004-07-01

    The Adams desaturated D-15 test was administered to individuals with normal colour vision or with congenital red-green colour vision defects to establish the repeatability of the test. One hundred subjects with normal colour vision and 64 subjects with defective colour vision participated in the study. Results were analysed from two different sessions to determine the repeatability of the test for different pass/fail criteria. The test was scored using both visual inspection of the score sheet and the modified Colour Difference Vector analysis (CDV) program. For both subject groups, the repeatability was lowest when a perfect arrangement was required for a pass and improved as more errors were allowed. The improvement in repeatability was greatest as the failure criterion changed from 'any mistake' to 'more than two crossings'. The kappa coefficient for the reliability of the defect classification was 0.38 for visual inspection and 0.59 for the CDV analysis. All the protans who failed the test at both sessions were classified correctly. Approximately 98 per cent of the colour-normals and 82 per cent of the colour-defectives would have the same pass/fail outcome on the Adams D-15 test conducted several days apart when the failure criterion was either one or more or two or more crossings. Individuals who make less than four crossings on the Adams D-15 should repeat the test to ensure confidence in the pass/fail result.

  8. Effects of memory colour on colour constancy for unknown coloured objects

    OpenAIRE

    Granzier, Jeroen J M; Gegenfurtner, Karl R

    2012-01-01

    The perception of an object's colour remains constant despite large variations in the chromaticity of the illumination—colour constancy. Hering suggested that memory colours, the typical colours of objects, could help in estimating the illuminant's colour and therefore be an important factor in establishing colour constancy. Here we test whether the presence of objects with diagnostical colours (fruits, vegetables, etc) within a scene influence colour constancy for unknown coloured objects in...

  9. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... and Strategic Vision Leadership Scientific Divisions Operations and Administration Advisory Committees Budget and Legislative Information Jobs and ... may recommend you eat heart-healthy foods or control other conditions that can cause iron-deficiency anemia. ...

  10. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... and Strategic Vision Leadership Scientific Divisions Operations and Administration Advisory Committees Budget and Legislative Information Jobs and ... blood cells. Iron-deficiency anemia usually develops over time because your body’s intake of iron is too ...

  11. Colour Blocking: Disregarding Traditional Artistic Colour Harmonies ...

    African Journals Online (AJOL)

    A development in the world of design – costume, fashion, graphics, architecture and general decor whereby traditional colour harmonies are reengineered to suite the taste of the time engages the attention of the paper. The trending phenomenon popularly referred to as 'colour blocking' involves the use of bright ...

  12. Colour and magnetic monopoles

    International Nuclear Information System (INIS)

    Corrigan, E.; Olive, D.

    1976-01-01

    If the exact gauge symmetry of nature consists of the U(1)sub(EM) generated by the electric charge operator Q and the colour group K, with Q a colour singlet, then, if g is a possible magnetic charge, exp(4πigQ) must equal an element of the colour group. For colour singlet particles this reduces to Dirac's condition eg = n/2. In general, possible monopoles correspond to points of intersection of the colour and electromagnetic groups. If the colour group is semi-simple and compact, there can at most be a finite number p of such points (p = N if K = SU(N)). The existence of non-trivial (not equal to unity) solutions to our condition means that there must be fractionally charged (with p the fraction) coloured particles and magnetic monopoles emanating colour magnetic flux as well as electromagnetic flux. (Auth.)

  13. Topographical coloured plasmonic coins

    OpenAIRE

    Guay, Jean-Michel; Lesina, Antonino Calà; Côté, Guillaume; Charron, Martin; Ramunno, Lora; Berini, Pierre; Weck, Arnaud

    2016-01-01

    Plasmonic resonances in metallic nanoparticles have been used since antiquity to colour glasses. The use of metal nanostructures for surface colourization has attracted considerable interest following recent developments in plasmonics. However, current top-down colourization methods are not ideally suited to large-scale industrial applications. Here we use a bottom-up approach where picosecond laser pulses can produce a full palette of non-iridescent colours on silver, gold, copper and alumin...

  14. Adaptive Colour Feature Identification in Image for Object Tracking

    Directory of Open Access Journals (Sweden)

    Feng Su

    2012-01-01

    Full Text Available Identification and tracking of a moving object using computer vision techniques is important in robotic surveillance. In this paper, an adaptive colour filtering method is introduced for identifying and tracking a moving object appearing in image sequences. This filter is capable of automatically identifying the most salient colour feature of the moving object in the image and using this for a robot to track the object. The method enables the selected colour feature to adapt to surrounding condition when it is changed. A method of determining the region of interest of the moving target is also developed for the adaptive colour filter to extract colour information. Experimental results show that by using a camera mounted on a robot, the proposed methods can perform robustly in tracking a randomly moving object using adaptively selected colour features in a crowded environment.

  15. Does Colour Preference Have a Role in Colour Term Acquisition?

    Science.gov (United States)

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

    2009-01-01

    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…

  16. The twelve colourful stones

    International Nuclear Information System (INIS)

    Doria, R.M.

    1983-01-01

    A dynamics with twelve colourful stones is created based on the concepts of gauge and colour. It is associated different gauge fields to the same group. A group of gauge invariant Lagrangians is established. A gauge invariant mass term is introduced. The colourful stones physical insight is to be building blocks for quarks and leptons. (Author) [pt

  17. Color vision: introduction by the feature editors.

    Science.gov (United States)

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

    2016-03-01

    This feature issue of the Journal of the Optical Society of America A (JOSA A) reflects the basic and applied research interests of members of the color vision community. Most of the articles stem from presentations at the 23rd Biennial Symposium of the International Colour Vision Society (ICVS).

  18. Colour printing techniques

    OpenAIRE

    Parraman, C.

    2017-01-01

    Invited chapter in the book Colour Design: Theories and Applications. In PART 3 COLOUR, DESIGN AND COLORATION this chapter covers:\\ud - Hardcopy colour: analogue versus digital\\ud - Colour theory in relation to printing\\ud - Overview of halftoning and digital print technologies\\ud - Overview and development of inks\\ud - Inkjet papers and inks\\ud - Recent and future trends in colour, printing inks and hardware.\\ud \\ud This book differs from other existing books in the field, with the aim of an...

  19. Plasmonic colour generation

    DEFF Research Database (Denmark)

    Kristensen, Anders; Yang, Joel K. W.; Bozhevolnyi, Sergey I.

    2016-01-01

    Plasmonic colours are structural colours that emerge from resonant interactions between light and metallic nanostructures. The engineering of plasmonic colours is a promising, rapidly emerging research field that could have a large technological impact. We highlight basic properties of plasmonic...... colours and recent nanofabrication developments, comparing technology-performance indicators for traditional and nanophotonic colour technologies. The structures of interest include diffraction gratings, nanoaperture arrays, thin films, and multilayers and structures that support Mie resonances...... and whispering-gallery modes. We discuss plasmonic colour nanotechnology based on localized surface plasmon resonances, such as gap plasmons and hybridized disk–hole plasmons, which allow for colour printing with sub-diffraction resolution. We also address a range of fabrication approaches that enable large...

  20. Rockpool gobies change colour for camouflage.

    Directory of Open Access Journals (Sweden)

    Martin Stevens

    Full Text Available 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.

  1. Rockpool gobies change colour for camouflage.

    Science.gov (United States)

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

    2014-01-01

    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.

  2. Low Vision

    Science.gov (United States)

    ... USAJobs Home » Statistics and Data » Low Vision Listen Low Vision Low Vision Defined: Low Vision is defined as the best- ... Ethnicity 2010 U.S. Age-Specific Prevalence Rates for Low Vision by Age, and Race/Ethnicity Table for 2010 ...

  3. Colour scheme an exploration of the indeterminate space of colour

    OpenAIRE

    Varga, Tania Elke

    2017-01-01

    Colour Scheme examines the potential for colour to be understood as a relational and therefore, indeterminate space. The CMYK process colour model is reworked to investigate the idea of colour as an indeterminate space. In proposing that process colour can be understood as a fluid and relational system I draw attention to the unquantifiable and qualitative nature of colour. Colour can be understood as a verb, and as such may be thought of as an active substance. This understanding of col...

  4. Validation of a colour rendering index based on memory colours

    OpenAIRE

    Smet, Kevin; Jost-Boissard, Sophie; Ryckaert, Wouter; Deconinck, Geert; Hanselaer, Peter

    2010-01-01

    In this paper the performance of a colour rendering index based on memory colours is investigated in comparison with the current CIE Colour Rendering Index, the NIST Colour Quality Scale and visual appreciation results obtained at CNRS at Lyon University for a set of 3000K and 4000K LED light sources. The Pearson and Spearman correlation coefficients between each colour rendering metric and the two sets of visual results were calculated. It was found that the memory colour based colour render...

  5. Vision Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Vision Lab personnel perform research, development, testing and evaluation of eye protection and vision performance. The lab maintains and continues to develop...

  6. Segmenting memory colours

    OpenAIRE

    Fredembach, Clément; Estrada, Francisco; Süsstrunk, Sabine

    2008-01-01

    Memory colours refer to the colour of specific image classes that have the essential attribute of being perceived in a consistent manner by human observers. In colour correction or rendering tasks, this consistency implies that they have to be faithfully reproduced; their importance, in that respect, is greater than other regions in an image. Before these regions can be properly addressed, one must in general detect them. There are various schemes and attributes to do so, but the preferred me...

  7. The twelve colourful stones

    International Nuclear Information System (INIS)

    Doria, R.M.

    1984-01-01

    The gauge symmetry is extended. It is associated differents matter and gauge fields to the same group. A group of gauge invariant Lagrangians is established. A gauge invariant mass term is introduced. A massive Yang Mills is obtained. A dynamics with twelve colourful stones is created based on the concepts of gauge and colour. Structures identified as quarks and leptons are generated. A discussion about colour meaning is presented. (Author) [pt

  8. Colour and Organization Studies

    DEFF Research Database (Denmark)

    Beyes, Timon

    2017-01-01

    Colour is inescapable. It fills and forms the world, shaping what can be felt and known, desired and expressed. It thus becomes social technology and organizational tool. At the same time, however, colour betrays, undermines and subverts the attempts to manage it. Based on an understanding...... of colour as aesthetic force and medium of transformation, the essay presents a montage of scenes that set up encounters with what colour does: how it affects organization, and how it is affected by organization; how it organizes what is given to perception, knowledge and organization itself, and how...

  9. Colourful FKS subtraction

    CERN Document Server

    Frixione, Stefano

    2011-01-01

    I formulate in a colour-friendly way the FKS method for the computation of QCD cross sections at the next-to-leading order accuracy. This is achieved through the definition of subtraction terms for squared matrix elements, constructed with single colour-dressed or pairs of colour-ordered amplitudes. The latter approach relies on the use of colour flows, is exact to all orders in $N$, and is thus particularly suited to being organized as a systematic expansion in 1/N.

  10. Visual awareness of objects and their colour.

    Science.gov (United States)

    Pilling, Michael; Gellatly, Angus

    2011-10-01

    At any given moment, our awareness of what we 'see' before us seems to be rather limited. If, for instance, a display containing multiple objects is shown (red or green disks), when one object is suddenly covered at random, observers are often little better than chance in reporting about its colour (Wolfe, Reinecke, & Brawn, Visual Cognition, 14, 749-780, 2006). We tested whether, when object attributes (such as colour) are unknown, observers still retain any knowledge of the presence of that object at a display location. Experiments 1-3 involved a task requiring two-alternative (yes/no) responses about the presence or absence of a colour-defined object at a probed location. On this task, if participants knew about the presence of an object at a location, responses indicated that they also knew about its colour. A fourth experiment presented the same displays but required a three-alternative response. This task did result in a data pattern consistent with participants' knowing more about the locations of objects within a display than about their individual colours. However, this location advantage, while highly significant, was rather small in magnitude. Results are compared with those of Huang (Journal of Vision, 10(10, Art. 24), 1-17, 2010), who also reported an advantage for object locations, but under quite different task conditions.

  11. The unsuitability of HTML-based colour charts for estimating animal colours--a comment on Berggren and Merilä (2004).

    Science.gov (United States)

    Stevens, Martin; Cuthill, Innes C

    2005-08-30

    A variety of techniques are used to study the colours of animal signals, including the use of visual matching to colour charts. This paper aims to highlight why they are generally an unsatisfactory tool for the measurement and classification of animal colours and why colour codes based on HTML (really RGB) standards, as advocated in a recent paper, are particularly inappropriate. There are many theoretical arguments against the use of colour charts, not least that human colour vision differs markedly from that of most other animals. However, the focus of this paper is the concern that, even when applied to humans, there is no simple 1:1 mapping from an RGB colour space to the perceived colours in a chart (the results are both printer- and illumination-dependent). We support our criticisms with data from colour matching experiments with humans, involving self-made, printed colour charts. Colour matching experiments with printed charts involving 11 subjects showed that the choices made by individuals were significantly different between charts that had exactly the same RGB values, but were produced from different printers. Furthermore, individual matches tended to vary under different lighting conditions. Spectrophotometry of the colour charts showed that the reflectance spectra of the charts varied greatly between printers and that equal steps in RGB space were often far from equal in terms of reflectance on the printed charts. In addition to outlining theoretical criticisms of the use of colour charts, our empirical results show that: individuals vary in their perception of colours, that different printers produce strikingly different results when reproducing what should be the same chart, and that the characteristics of the light irradiating the surface do affect colour perception. Therefore, we urge great caution in the use of colour charts to study animal colour signals. They should be used only as a last resort and in full knowledge of their limitations, with

  12. The unsuitability of html-based colour charts for estimating animal colours – a comment on Berggren and Merilä (2004

    Directory of Open Access Journals (Sweden)

    Cuthill Innes C

    2005-08-01

    Full Text Available Abstract Background A variety of techniques are used to study the colours of animal signals, including the use of visual matching to colour charts. This paper aims to highlight why they are generally an unsatisfactory tool for the measurement and classification of animal colours and why colour codes based on HTML (really RGB standards, as advocated in a recent paper, are particularly inappropriate. There are many theoretical arguments against the use of colour charts, not least that human colour vision differs markedly from that of most other animals. However, the focus of this paper is the concern that, even when applied to humans, there is no simple 1:1 mapping from an RGB colour space to the perceived colours in a chart (the results are both printer- and illumination-dependent. We support our criticisms with data from colour matching experiments with humans, involving self-made, printed colour charts. Results Colour matching experiments with printed charts involving 11 subjects showed that the choices made by individuals were significantly different between charts that had exactly the same RGB values, but were produced from different printers. Furthermore, individual matches tended to vary under different lighting conditions. Spectrophotometry of the colour charts showed that the reflectance spectra of the charts varied greatly between printers and that equal steps in RGB space were often far from equal in terms of reflectance on the printed charts. Conclusion In addition to outlining theoretical criticisms of the use of colour charts, our empirical results show that: individuals vary in their perception of colours, that different printers produce strikingly different results when reproducing what should be the same chart, and that the characteristics of the light irradiating the surface do affect colour perception. Therefore, we urge great caution in the use of colour charts to study animal colour signals. They should be used only as a last

  13. The colours of CERN

    CERN Multimedia

    Laëtitia Pedroso

    2010-01-01

    Would you move into an office painted in a colour you hate? As we all know, taste in colour is individual. Thanks to the establishment of a new Painting Charter, conflicting opinions will be unified.   The four new paint colours established in the Painting Charter. There were many reasons behind the creation of the Painting Charter by the GS SEM Department. Unlike many companies, CERN has not until now regulated which colours can be used inside buildings. With many nationalities passing through CERN, tastes tend to differ: northern countries usually prefer colder colours, while southern countries seem to prefer warm colours. It’s not hard to imagine how quickly we could make a rainbow! In addition, whenever an office needs to be repainted, it can be difficult to find exactly the same colour. This results in entire walls being repainted, which increases the cost. If – by chance – the original colour is found, it could be out of stock. While ...

  14. Colour: code, mode, modality

    DEFF Research Database (Denmark)

    van Leeuwen, Theo

    2014-01-01

    This article uses a social semiotic approach to discuss the influence of film, video and digital technologies on the way colour is used in audiovisual media......This article uses a social semiotic approach to discuss the influence of film, video and digital technologies on the way colour is used in audiovisual media...

  15. Graph Colouring Algorithms

    DEFF Research Database (Denmark)

    Husfeldt, Thore

    2015-01-01

    This chapter presents an introduction to graph colouring algorithms. The focus is on vertex-colouring algorithms that work for general classes of graphs with worst-case performance guarantees in a sequential model of computation. The presentation aims to demonstrate the breadth of available...

  16. Chemistry of Colours

    Indian Academy of Sciences (India)

    focus on why things have colour and what causes them to change their colour. Light is a form of .... Another pigment found in the leaves of many plants is carotene. Carotene absorbs ... structure of cyanidin changes with pH. The form shown in ...

  17. Ultrasonic colour Doppler imaging

    DEFF Research Database (Denmark)

    Evans, David H.; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

    2011-01-01

    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...... 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...

  18. Computational colour science using MATLAB

    CERN Document Server

    Westland, Stephen; Cheung, Vien

    2012-01-01

    Computational Colour Science Using MATLAB 2nd Edition offers a practical, problem-based approach to colour physics. The book focuses on the key issues encountered in modern colour engineering, including efficient representation of colour information, Fourier analysis of reflectance spectra and advanced colorimetric computation. Emphasis is placed on the practical applications rather than the techniques themselves, with material structured around key topics. These topics include colour calibration of visual displays, computer recipe prediction and models for colour-appearance prediction. Each t

  19. Colour for Behavioural Success

    Science.gov (United States)

    Reeves, Adam

    2018-01-01

    Colour information not only helps sustain the survival of animal species by guiding sexual selection and foraging behaviour but also is an important factor in the cultural and technological development of our own species. This is illustrated by examples from the visual arts and from state-of-the-art imaging technology, where the strategic use of colour has become a powerful tool for guiding the planning and execution of interventional procedures. The functional role of colour information in terms of its potential benefits to behavioural success across the species is addressed in the introduction here to clarify why colour perception may have evolved to generate behavioural success. It is argued that evolutionary and environmental pressures influence not only colour trait production in the different species but also their ability to process and exploit colour information for goal-specific purposes. We then leap straight to the human primate with insight from current research on the facilitating role of colour cues on performance training with precision technology for image-guided surgical planning and intervention. It is shown that local colour cues in two-dimensional images generated by a surgical fisheye camera help individuals become more precise rapidly across a limited number of trial sets in simulator training for specific manual gestures with a tool. This facilitating effect of a local colour cue on performance evolution in a video-controlled simulator (pick-and-place) task can be explained in terms of colour-based figure-ground segregation facilitating attention to local image parts when more than two layers of subjective surface depth are present, as in all natural and surgical images. PMID:29770183

  20. Flower colour and cytochromes P450.

    Science.gov (United States)

    Tanaka, Yoshikazu; Brugliera, Filippa

    2013-02-19

    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.

  1. Effects of Memory Colour on Colour Constancy for Unknown Coloured Objects

    Directory of Open Access Journals (Sweden)

    Jeroen J M Granzier

    2012-04-01

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

  2. Effects of memory colour on colour constancy for unknown coloured objects.

    Science.gov (United States)

    Granzier, Jeroen J M; Gegenfurtner, Karl R

    2012-01-01

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

  3. Molluscan shell colour.

    Science.gov (United States)

    Williams, Suzanne T

    2017-05-01

    The phylum Mollusca is highly speciose, and is the largest phylum in the marine realm. The great majority of molluscs are shelled, including nearly all bivalves, most gastropods and some cephalopods. The fabulous and diverse colours and patterns of molluscan shells are widely recognised and have been appreciated for hundreds of years by collectors and scientists alike. They serve taxonomists as characters that can be used to recognise and distinguish species, however their function for the animal is sometimes less clear and has been the focus of many ecological and evolutionary studies. Despite these studies, almost nothing is known about the evolution of colour in molluscan shells. This review summarises for the first time major findings of disparate studies relevant to the evolution of shell colour in Mollusca and discusses the importance of colour, including the effects of visual and non-visual selection, diet and abiotic factors. I also summarise the evidence for the heritability of shell colour in some taxa and recent efforts to understand the molecular mechanisms underpinning synthesis of shell colours. I describe some of the main shell pigments found in Mollusca (carotenoids, melanin and tetrapyrroles, including porphyrins and bile pigments), and their durability in the fossil record. Finally I suggest that pigments appear to be distributed in a phylogenetically relevant manner and that the synthesis of colour is likely to be energetically costly. © 2016 Cambridge Philosophical Society.

  4. Ultrasonic colour Doppler imaging

    DEFF Research Database (Denmark)

    Evans, David H; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

    2011-01-01

    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...

  5. An unconventional colour superconductor

    International Nuclear Information System (INIS)

    Huang Mei

    2007-01-01

    Superfluidity, or superconductivity with mismatched Fermi momenta, appears in many systems such as charge-neutral dense quark matter, asymmetric nuclear matter, and in imbalanced cold atomic gases. The mismatch plays the role of breaking the Cooper pairing, and the pair-breaking state cannot be properly described in the framework of standard BCS theory. I give a brief review on recent theoretical developments in understanding unconventional colour superconductivity, including a gapless colour superconductor, chromomagnetic instabilities and the Higgs instability in the gapless phase. I also introduce a possible new framework for describing an unconventional colour superconductor

  6. Plasmonic colour laser printing

    DEFF Research Database (Denmark)

    Zhu, Xiaolong; Vannahme, Christoph; Højlund-Nielsen, Emil

    2016-01-01

    -beam lithography (EBL) or focused ion beam (FIB), both expensive and not scalable processes that are not suitable for post-processing customization. Here we show a method of colour printing on nanoimprinted plasmonic metasurfaces using laser post-writing. Laser pulses induce transient local heat generation...... that leads to melting and reshaping of the imprinted nanostructures. Depending on the laser pulse energy density, different surface morphologies that support different plasmonic resonances leading to different colour appearances can be created. Using this technique we can print all primary colours...

  7. Game Coloured Petri Nets

    DEFF Research Database (Denmark)

    Westergaard, Michael

    2006-01-01

    This paper introduces the notion of game coloured Petri nets. This allows the modeler to explicitly model what parts of the model comprise the modeled system and what parts are the environment of the modeled system. We give the formal definition of game coloured Petri nets, a means of reachability...... analysis of this net class, and an application of game coloured Petri nets to automatically generate easy-to-understand visualizations of the model by exploiting the knowledge that some parts of the model are not interesting from a visualization perspective (i.e. they are part of the environment...

  8. VISION development

    International Nuclear Information System (INIS)

    Hernandez, J.E.; Sherwood, R.J.; Whitman, S.R.

    1994-01-01

    VISION is a flexible and extensible object-oriented programming environment for prototyping computer-vision and pattern-recognition algorithms. This year's effort focused on three major areas: documentation, graphics, and support for new applications

  9. Colour Mixing Based on Daylight

    Science.gov (United States)

    Meyn, Jan-Peter

    2008-01-01

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

  10. Evaluation of functional color vision requirements and current color vision screening tests for air traffic control specialists.

    Science.gov (United States)

    1990-08-01

    An experiment was conducted to evaluate the relation of type and degree of color vision deficiency and aeromedical color vision screening test scores to performance of color-dependent tasks of Air Traffic Control Specialists. The subjects included 37...

  11. Computational vision

    CERN Document Server

    Wechsler, Harry

    1990-01-01

    The book is suitable for advanced courses in computer vision and image processing. In addition to providing an overall view of computational vision, it contains extensive material on topics that are not usually covered in computer vision texts (including parallel distributed processing and neural networks) and considers many real applications.

  12. About Coloured Cold Asphaltic Mixtures

    Directory of Open Access Journals (Sweden)

    Loredana Judele

    2008-01-01

    Full Text Available The first coloured bitumen was obtained by using bitumen from Peru and then bitumen from the Middle East, with a low content of asphaltenes, also called "colourable" bitumens. The colours obtained by adding iron oxides led nevertheless to dark colours, due to the presence of asphaltenes. Nowadays the coloured asphalt is obtained from synthesis binders with translucent aspect. The colours are obtained by adding inorganic pigments, mainly iron oxide for red, chromic oxide for green, titanic dioxide for white. The properties and behaviour of the coloured bitumen during its lifetime are comparable with the ones of classic bitumen, sometimes even better.

  13. COLOURFUL DIET FOR GOOD HEALTH

    OpenAIRE

    Vandana Gupta

    2017-01-01

    We are surrounded by colour and they can affect us profoundly and in ways that we may not have thought of. It is a known fact, that colours can influence your moods, feelings and emotions. Colours influence your actions and how you respond to people, situations and ideas. Apart from the colour of interiors, exteriors, our clothing and other things, the colour of food and beverage products are also extremely important. Green fruits and vegetables support eye health and may help protect against...

  14. Color Vision in Aniridia.

    Science.gov (United States)

    Pedersen, Hilde R; Hagen, Lene A; Landsend, Erlend C S; Gilson, Stuart J; Utheim, Øygunn A; Utheim, Tor P; Neitz, Maureen; Baraas, Rigmor C

    2018-04-01

    To assess color vision and its association with retinal structure in persons with congenital aniridia. We included 36 persons with congenital aniridia (10-66 years), and 52 healthy, normal trichromatic controls (10-74 years) in the study. Color vision was assessed with Hardy-Rand-Rittler (HRR) pseudo-isochromatic plates (4th ed., 2002); Cambridge Color Test and a low-vision version of the Color Assessment and Diagnosis test (CAD-LV). Cone-opsin genes were analyzed to confirm normal versus congenital color vision deficiencies. Visual acuity and ocular media opacities were assessed. The central 30° of both eyes were imaged with the Heidelberg Spectralis OCT2 to grade the severity of foveal hypoplasia (FH, normal to complete: 0-4). Five participants with aniridia had cone opsin genes conferring deutan color vision deficiency and were excluded from further analysis. Of the 31 with aniridia and normal opsin genes, 11 made two or more red-green (RG) errors on HRR, four of whom also made yellow-blue (YB) errors; one made YB errors only. A total of 19 participants had higher CAD-LV RG thresholds, of which eight also had higher CAD-LV YB thresholds, than normal controls. In aniridia, the thresholds were higher along the RG than the YB axis, and those with a complete FH had significantly higher RG thresholds than those with mild FH (P = 0.038). Additional increase in YB threshold was associated with secondary ocular pathology. Arrested foveal formation and associated alterations in retinal processing are likely to be the primary reason for impaired red-green color vision in aniridia.

  15. Colour preferences of UK garden birds at supplementary seed feeders.

    Directory of Open Access Journals (Sweden)

    Luke Rothery

    Full Text Available Supplementary feeding of garden birds generally has benefits for both bird populations and human wellbeing. Birds have excellent colour vision, and show preferences for food items of particular colours, but research into colour preferences associated with artificial feeders is limited to hummingbirds. Here, we investigated the colour preferences of common UK garden birds foraging at seed-dispensing artificial feeders containing identical food. We presented birds simultaneously with an array of eight differently coloured feeders, and recorded the number of visits made to each colour over 370 30-minute observation periods in the winter of 2014/15. In addition, we surveyed visitors to a garden centre and science festival to determine the colour preferences of likely purchasers of seed feeders. Our results suggest that silver and green feeders were visited by higher numbers of individuals of several common garden bird species, while red and yellow feeders received fewer visits. In contrast, people preferred red, yellow, blue and green feeders. We suggest that green feeders may be simultaneously marketable and attractive to foraging birds.

  16. Legal and Illegal Colours

    DEFF Research Database (Denmark)

    Larsen, John Christian

    2008-01-01

    opinions on food additives, including colours, and on the bioavailability and safety of nutrient sources. The WG ADD consists of several members from the AFC Panel together with selected external experts. The draft opinions go forward to the AFC Panel for discussion and final adoption. The adopted opinions......://www.efsa.europa.eu/EFSA/efsa_locale-1178620753812_1178620761956.htm. Accessed 12.05.08.] this paper only deals with some of the major issues that the Panel has faced in relation to the use of food colours. The three topics to be dealt with are (1) evaluation of illegal colours in food in the EU (EFSA, 2005), (2) re-evaluation of the authorised...... food colours in the EU (ongoing, but one opinion on Red 2G has been published; EFSA, 2007), and (3) evaluation of 'the Southampton study' on hyperactivity in children after intake of food colours (and sodium benzoate) (ongoing at the time of this presentation, but an opinion has now been published...

  17. Cadmium colours: composition and properties

    International Nuclear Information System (INIS)

    Paulus, J.; Knuutinen, U.

    2004-01-01

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

  18. Colour in flux: describing and printing colour in art

    Science.gov (United States)

    Parraman, Carinna

    2008-01-01

    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.

  19. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... NHLBI News NHLBI in the Press Research Features All Events Past Events Upcoming Events About NHLBI About NHLBI Home Mission and Strategic Vision ... deficient Donors: Recovery and Storage Quality. Learn more about ... trial . View all trials from ClinicalTrials.gov . Visit Children and Clinical ...

  20. Color Vision 2018: Introduction by the feature editors.

    Science.gov (United States)

    Buck, Steven L; Baraas, Rigmor; Kremers, Jan; Lindsey, Delwin T; Nascimento, Sérgio M C; Webster, Michael A; Werner, John S

    2018-04-01

    This feature issue of the Journal of the Optical Society of America A (JOSA A) reflects the basic and applied research interests of members of the color vision community. Most of the articles stem from presentations at the 24th Biennial Symposium of the International Colour Vision Society (ICVS).

  1. Coloured phase singularities

    International Nuclear Information System (INIS)

    Berry, M.V.

    2002-01-01

    For illumination with white light, the spectra near a typical isolated phase singularity (nodal point of the component wavelengths) can be described by a universal function of position, up to linear distortion and a weak dependence on the spectrum of the source. The appearance of the singularity when viewed by a human observer is predicted by transforming the spectrum to trichromatic variables and chromaticity coordinates, and then rendering the colours, scaled to constant luminosity, on a computer monitor. The pattern far from the singularity is a white that depends on the source temperature, and the centre of the pattern is flanked by intensely coloured 'eyes', one orange and one blue, separated by red, and one of the eyes is surrounded by a bright white circle. Only a small range of possible colours appears near the singularity; in particular, there is no green. (author)

  2. Flare colours and luminosities

    International Nuclear Information System (INIS)

    Cristaldi, S.; Rodono, M.

    1975-01-01

    Flare colours determined from simultaneous UBV observations made at Catania Observatory and from sequential UBV observations made at McDonald Observatory are presented. They fit fairly well with the theoretical colours computed according to the Gurzadian's (1970) non-thermal model. Only part of the observed flare colours are consistent with the solar type models by Gershberg (1967) and Kunkel (1970). From a B-band patrol of UV Cet-type stars carried out from 1967 to 1972, some quantitative estimates of flare frequencies and luminosities and their average contributions to the stellar radiation are given. The corresponding parameters for the Sun, which were estimated from 'white light' flare activity, are also given for comparison. The Sun and V 1216 Sgr can be regarded as low-activity flare stars of the type found by Kunkel (1973). (Auth.)

  3. Colour pyrometer. Farbpyrometer

    Energy Technology Data Exchange (ETDEWEB)

    Luhleich, H; Suetterlin, L; Borchers, D; Pflaum, P

    1980-12-11

    The colour pyrometer according to the invention, in which two beams of limited wavelength from the incoming beam of light are filtered through a chopper with two colour filters of the same diameter rotating round and axis, and are taken to a photo-electric element, from the output signals of which a quotient proportional to the surface temperature of the object is formed in an electrical network, is characterized by the fact that the colour filters in the cylinder wall are arranged at a right angle to each other in a drum rotating around the cylinder axis transverse to the incoming light beam, and are parallel to the axis of rotation, and that the drum wall has openings in the sides diametrically opposite the filters.

  4. Annotating Coloured Petri Nets

    DEFF Research Database (Denmark)

    Lindstrøm, Bo; Wells, Lisa Marie

    2002-01-01

    Coloured Petri nets (CP-nets) can be used for several fundamentally different purposes like functional analysis, performance analysis, and visualisation. To be able to use the corresponding tool extensions and libraries it is sometimes necessary to include extra auxiliary information in the CP......-net. An example of such auxiliary information is a counter which is associated with a token to be able to do performance analysis. Modifying colour sets and arc inscriptions in a CP-net to support a specific use may lead to creation of several slightly different CP-nets – only to support the different uses...... of the same basic CP-net. One solution to this problem is that the auxiliary information is not integrated into colour sets and arc inscriptions of a CP-net, but is kept separately. This makes it easy to disable this auxiliary information if a CP-net is to be used for another purpose. This paper proposes...

  5. Storage Pool Deficiencies

    Science.gov (United States)

    ... Deficiency Factor V Deficiency Combined FV & FVIII Deficiencies Factor VII Deficiency Factor X Deficiency Factor XI Deficiency Factor ... Deficiency Factor V Deficiency Combined FV & FVIII Deficiencies Factor VII Deficiency Factor X Deficiency Factor XI Deficiency Factor ...

  6. Asymmetric chiral colour

    International Nuclear Information System (INIS)

    Cuypers, F.

    1990-01-01

    Chiral colour is considered in a general framework where the coupling constants associated with each SU(3) component are allowed to be different. To reproduce QCD at low energy, gluons and axigluons cannot then be maximally mixed. Present data form e + e - colliders contrains the axigluon mass to values between 50 GeV and 375 GeV whilst the mixing angle is bounded by 13deg and 45deg. The lower limit of the axigluon mass is a definite bound at 90% C.L., whereas the upper limit only applies if chiral colour is to explain the anomalously high rates of hadron production at TRISTAN. (orig.)

  7. Colour centres in germanosilicate glass and optical fibres

    International Nuclear Information System (INIS)

    Neustruev, V.B.

    1994-01-01

    This review presents the state of the art of the study of germanium-related colour centres in silica glass and silica-based fibres. Most attention is concentrated on the dominant colour centres such as the Ge-related oxygen-deficient centres and paramagnetic Ge(n) centres, all of them having ultraviolet absorption bands. The hypothetical models and formation mechanisms proposed so far for these colour centres are discussed in detail. The origins of the models and formation mechanisms and their weak and strong points are analysed. The origin of the less well studied Ge-related colour centres in the visible spectral range (GeH, GeX, drawing-dependent defects) is also discussed. (author)

  8. Effect of absence of vision on posture

    OpenAIRE

    Alotaibi, Abdullah Z.; Alghadir, Ahmad; Iqbal, Zaheen A.; Anwer, Shahnawaz

    2016-01-01

    [Purpose] The visual system is one of the sensory systems that enables the body to assess and process information about the external environment. In the absence of vision, a blind person loses contact with the outside world and develops faulty motor patterns, which results in postural deficiencies. However, literature regarding the development of such deficiencies is limited. The aim of this study was to discuss the effect of absence of vision on posture, the possible biomechanics behind the ...

  9. Living with vision loss

    Science.gov (United States)

    Diabetes - vision loss; Retinopathy - vision loss; Low vision; Blindness - vision loss ... of visual aids. Some options include: Magnifiers High power reading glasses Devices that make it easier to ...

  10. Fun with Colour

    Science.gov (United States)

    Rennie, Richard

    2015-01-01

    The Australian Curriculum: Science for Year 5 includes "recognising that the colour of an object depends on the properties of the object and the color of the light source". This article shows how much more can be done with color in the science laboratory. Activities include using a prism to explore white light, using a hand lens to…

  11. Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1991-01-01

    This paper describes how Coloured Petri Nets (CP-nets) have been developed — from being a promising theoretical model to being a full-fledged language for the design, specification, simulation, validation and implementation of large software systems (and other systems in which human beings and...

  12. Coloured Petri Nets

    CERN Document Server

    Jensen, Kurt

    2009-01-01

    Coloured Petri Nets (CPN) is a graphical language for modelling and validating concurrent and distributed systems, and other systems in which concurrency plays a major role. This book introduces the constructs of the CPN modelling language and presents the related analysis methods. It provides a comprehensive road map for the practical use of CPN.

  13. Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt; Kristensen, Lars Michael

    Coloured Petri Nets (CPN) is a graphical language for modelling and validating concurrent and distributed systems, and other systems in which concurrency plays a major role. The development of such systems is particularly challenging because of inherent intricacies like possible nondeterminism an...

  14. Colour chemistry in water

    OpenAIRE

    Cardona, Maria

    2015-01-01

    Atmospheric carbon dioxide (CO2) levels have increased dramatically in the last few decades. Famous for causing global warming, CO2 is also resulting in the acidification of seas and oceans. http://www.um.edu.mt/think/colour-chemistry-in-water/

  15. ATLAS Colouring Book

    CERN Multimedia

    Anthony, Katarina

    2016-01-01

    The ATLAS Experiment Colouring Book is a free-to-download educational book, ideal for kids aged 5-9. It aims to introduce children to the field of High-Energy Physics, as well as the work being carried out by the ATLAS Collaboration.

  16. Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1987-01-01

    The author describes a Petri net model, called coloured Petri nets (CP-nets), by means of which it is possible to describe large systems without having to cope with unnecessary details. The author introduces CP-nets and provide a first impression of their modeling power and the suitability...

  17. Micro Vision

    OpenAIRE

    Ohba, Kohtaro; Ohara, Kenichi

    2007-01-01

    In the field of the micro vision, there are few researches compared with macro environment. However, applying to the study result for macro computer vision technique, you can measure and observe the micro environment. Moreover, based on the effects of micro environment, it is possible to discovery the new theories and new techniques.

  18. Human lens colouration, age and cataract

    International Nuclear Information System (INIS)

    Truscott, R.J.W.; Garner, B.; Hood, B.

    1999-01-01

    Full text: The human lens biosynthesises UV filter compounds which effectively remove light in the 300-400nm band. These chemicals are present either as an aid to visual acuity, or to filter out damaging UV radiation. The primate UV filters are 3-hydroxykynurenine analogues derived from the metabolism of tryptophan. We have recently demonstrated that these endogenous UV filters are not innocuous, but are in fact capable of binding to proteins, including the crystalline proteins which make up the bulk of the lens. Thus, over time, the levels of protein - bound UV filters increase and this results in the human lens becoming progressively more yellow as we age. This colouration affects our colour vision and it may also be responsible for the brown colour of lenses which is the hallmark of age-related nuclear cataract. An understanding of the intrinsic instability of the endogenous UV filters, combined with changes in the internal transport of these and other small molecular weight compounds including antioxidants, such as glutathione, is allowing us to gain an insight into the processes responsible for the development of age-related cataract: the major cause of world blindness

  19. On colour categorization of nature

    NARCIS (Netherlands)

    Yendrikhovskij, S.N.

    1998-01-01

    The following research elaborates on some of the 'semantic' and 'algorithmic' aspects of the categorization process for thc colour domain. The structure of colour categories is argued to resemble the structure of Ihe distribution of colours in the perceived world. This distribution can be

  20. COLOUR THEREPY-BOON TO MANKIND

    OpenAIRE

    Dr.Sajan Kurien Mathew

    2017-01-01

    Colour Therapy is a complementary therapy for which there is evidence dating back thousands of years to the ancient cultures of Egypt, China and India. Colour is simply light of varying wavelengths, thus each colour has its own particular wavelength and energy. "Colour affects our life. Colour is physical..........we see it. Colour communicates............we recieve information from the language of colour. Colour is emotional..........it evokes our feeling."1 The energy relating to each of th...

  1. Tunnel Vision in Environmental Management.

    Science.gov (United States)

    Miller, Alan

    1982-01-01

    Discusses problem-solving styles in environmental management and the specific deficiencies in these styles that might be grouped under the label "tunnel vision," a form of selective attention contributing to inadequate problem-formulation, partial solutions to complex problems, and generation of additional problems. Includes educational…

  2. Towards Video Quality Metrics Based on Colour Fractal Geometry

    Directory of Open Access Journals (Sweden)

    Richard Noël

    2010-01-01

    Full Text Available Vision is a complex process that integrates multiple aspects of an image: spatial frequencies, topology and colour. Unfortunately, so far, all these elements were independently took into consideration for the development of image and video quality metrics, therefore we propose an approach that blends together all of them. Our approach allows for the analysis of the complexity of colour images in the RGB colour space, based on the probabilistic algorithm for calculating the fractal dimension and lacunarity. Given that all the existing fractal approaches are defined only for gray-scale images, we extend them to the colour domain. We show how these two colour fractal features capture the multiple aspects that characterize the degradation of the video signal, based on the hypothesis that the quality degradation perceived by the user is directly proportional to the modification of the fractal complexity. We claim that the two colour fractal measures can objectively assess the quality of the video signal and they can be used as metrics for the user-perceived video quality degradation and we validated them through experimental results obtained for an MPEG-4 video streaming application; finally, the results are compared against the ones given by unanimously-accepted metrics and subjective tests.

  3. Hue-specific colour memory impairment in an individual with intact colour perception and colour naming.

    Science.gov (United States)

    Jakobson, L S; Pearson, P M; Robertson, B

    2008-01-15

    Cases of hue-selective dyschomatopsias, together with the results of recent optical imaging studies [Xiao, Y., Casti, A. R. R., Xiao, J., & Kaplan, E. (2006). A spatially organized representation of colour in macaque primary visual cortex. Perception, 35, ECVP Abstract Supplement; Xiao, Y., Wang, Y., & Felleman, D. J. (2003). A spatially organized representation of colour in macaque cortical area V2. Nature, 421, 535-539], have provided support for the idea that different colours are processed in spatially distinct regions of extrastriate cortex. In the present report, we provide evidence suggesting that a similar, but distinct, map may exist for representations of colour in memory. This evidence comes from observations of a young woman (QP) who demonstrates an isolated deficit in colour memory secondary to a concussive episode. Despite having normal colour perception and colour naming skills, and above-average memory skills in other domains, QP's ability to recall visually encoded colour information over short retention intervals is dramatically impaired. Her long-term memory for colour and her colour imagery skills are also abnormal. Surprisingly, however, these impairments are not seen with all hues; specifically, her ability to remember or imagine blue shades is spared. This interesting case contributes to the literature suggesting that colour perception, naming, and memory can be clinically dissociated, and provides insights into the organization of colour information in memory.

  4. Colour isomers in quark material

    International Nuclear Information System (INIS)

    Hoegaasen, H.

    1981-01-01

    Quantum chromodynamics is stated to be analogous to quantum electrodynamics and colour to electric charge. However since there are eight gluon fields and only one photon field, and gluons have colour while photons are electrically neutral, QCD is much more complicated than QED. The concept of colour confine confinement is introduced and the addition rules for colour multiplets are discussed. It is shown that quark colour leads to isomeric meson states. Bubble chamber films from CERN groups have been examined and hyperons and (sup a)Y* resonance particles have been found, which appears to confirm the theory. (JIW)

  5. Comportamiento de la visión de color en pacientes sospechosos de glaucoma y glaucomatosos como daño precoz de las células ganglionares de la retina Colour vision of patients suspected of and diagnosed with glaucoma as an early damage of ganglionary cells of the retina

    Directory of Open Access Journals (Sweden)

    José Alberto Cabrera Martínez

    2007-06-01

    Ophtalmology service of “Dr. Carlos J. Finlay” Military Hospital in the period from 2003 to 2006. The sample covered 30 patients suspected of and 30 patients diagnosed with glaucoma that fulfilled inclusion and exclusion requirements. The first 30 patients of each group seen in that period were selected. Several tests were apppied to evaluate colour vision, as an early damage in ganglionary cells of the retina. Every patient having at least three important risk factors (high blood pressure, age over 40 years, black race and family history of first degree relatives suffering the dissease was considered suspect of having glaucoma. The patients were diagnosed as glaucomatous when they presented with symptoms and signs of the disease and incipient alterations of the visual field (increase of blind stain, nasal step or Seidel scotoma. This study also used a sample of 31 supposedly healthy subjects, who had participated as control group under the same exploratory conditions in a prior research study at “Hermanos Ameijeiras” hospital. The title of that research was “Study of chromatic vision in a healthy population”. The evaluation method consisted of an initial ophthalmological exam where general data, clinical symptoms and signs as well as risk factors were collected. It was observed that healthy subjects did not present alterations in relation to colours and that individuals suspected of and diagnosed with glaucoma did have a significant index

  6. Chiral colour and axigluons

    International Nuclear Information System (INIS)

    Cuypers, F.

    1989-01-01

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

  7. Processing bimodal stimuli: Integrality/separability of colour and orientation

    Directory of Open Access Journals (Sweden)

    David eBimler

    2013-10-01

    Full Text Available We examined how two distinct stimulus features, orientation and colour, interact as contributions to global stimulus dissimilarity. Five subjects rated dissimilarity between pairs of bars (N = 30 varying in colour (four cardinal hues, plus white and orientation (six angles at 30° intervals. An exploratory analysis with individual-differences multidimensional scaling resulted in a 5D solution, with two dimensions required to accommodate the circular sequence of the angular attribute, and red-green, blue-yellow and achromatic axes for the colour attribute. Weights of the orientation subspace relative to the colour subspace varied among the subjects, from a 0.32:0.61 ratio to 0.53:0.44, emphasis shifting between colour and orientation. In addition to Euclidean metric, we modelled the interaction of colour and orientation using Minkowski power metrics across a range of Minkowski exponents p, including the city-block (p = 1, Euclidean (p = 2 and Dominance metric (p à ¥ as special cases. For averaged data, p ~ 1.3 provided the best fit, i.e. intermediate between separable and integral features. For individual subjects, however, the metric exponent varied significantly from p = 0.7 to p = 3.1, indicating a subject-specific rule for combining colour and orientation, as in Tversky and Gati’s variable-weights model. No relationship was apparent between dimensional weights and individual p exponents. Factors affecting dimensional integrality are discussed, including possible underlying neural mechanisms where the interaction of the low-level vision attributes orientation and colour might shift between uncorrelated (p =1 or correlated (p ³ 2 forms.

  8. Daylight Influence on Colour Design : Empirical Study on Perceived Colour and Colour Experience Indoors

    OpenAIRE

    Hårleman, Maud

    2007-01-01

    It is known that one and the same interior colouring will appear different in rooms with windows facing north or facing south, but it is not known how natural daylight from these two compass points affects perceived colour and the ways in which colour is experienced. The objective is to describe the perceived colours to be expected in rooms with sunlight and diffused light, and thus develop a tool for colour design. Two empirical investigations provide the basis for six attached papers. The m...

  9. Colour based fire detection method with temporal intensity variation filtration

    Science.gov (United States)

    Trambitckii, K.; Anding, K.; Musalimov, V.; Linß, G.

    2015-02-01

    Development of video, computing technologies and computer vision gives a possibility of automatic fire detection on video information. Under that project different algorithms was implemented to find more efficient way of fire detection. In that article colour based fire detection algorithm is described. But it is not enough to use only colour information to detect fire properly. The main reason of this is that in the shooting conditions may be a lot of things having colour similar to fire. A temporary intensity variation of pixels is used to separate them from the fire. These variations are averaged over the series of several frames. This algorithm shows robust work and was realised as a computer program by using of the OpenCV library.

  10. Colour based fire detection method with temporal intensity variation filtration

    International Nuclear Information System (INIS)

    Trambitckii, K; Musalimov, V; Anding, K; Linß, G

    2015-01-01

    Development of video, computing technologies and computer vision gives a possibility of automatic fire detection on video information. Under that project different algorithms was implemented to find more efficient way of fire detection. In that article colour based fire detection algorithm is described. But it is not enough to use only colour information to detect fire properly. The main reason of this is that in the shooting conditions may be a lot of things having colour similar to fire. A temporary intensity variation of pixels is used to separate them from the fire. These variations are averaged over the series of several frames. This algorithm shows robust work and was realised as a computer program by using of the OpenCV library

  11. Colour Reproduction on Tablet Devices

    Directory of Open Access Journals (Sweden)

    Vladimir Zorić

    2014-07-01

    Full Text Available With the advent of Internet and mobile devices client services and other print production are migrating more and more to online platforms. In a recent technology changeover it is obvious that there is growing number of printers as well need from the customers for the print service providers to expand their business to online and mobile platforms. With this technological transition there are some open questions regarding the possibilities of using the tablet devices for colour soft proofing and other colour related operations. As a display devices on a hardware level there are large similarities with the desktop display devices but the operating systems which are driving them are not yet colour smart. There have been some initial attempts to characterize the colour reproduction on this type of devices and find a possibility of using them not just for information content but also for colour managed content. In this study we have tested several tablets (Apple iPad2,Asus Transformer TF101, Samsung Galaxy Tab 1 with different display and OS technology and tested a software which is intended for colour managed viewing of the reproduction. We have measured the colour reproduction of the tablets with the digital version of the GretagMacbeth ColorChecker card and have calculated the colour differences between the colour chart data and the displayed data. We have calibrated the Ipad2 with the only existing colour management tool the Spyder Gallery and we have also tested the chart display with and without the colour correction of the software. We have found that there are differences in the colour reproduction of the display technologies and that the possibilities of a real colour managed workflow has yet to be resolved on the OS level of tablet and mobile devices

  12. Colour mixing based on daylight

    International Nuclear Information System (INIS)

    Meyn, Jan-Peter

    2008-01-01

    Colour science is based on the sensation of monochromatic light. In contrast to that, surface colours are caused by reflection of wide sections of the daylight spectrum. Non-spectral colours like magenta and purple appear homologous to colours with spectral hue, if the approach of mixing monochromatic light is abandoned. It is shown that a large region of the colour space can be covered by mixing three primary colours derived from lossless spectral decomposition of daylight. These primaries are specified by hue, saturation and luminosity. Duality of additive and subtractive mixing is formulated quantitatively. Experimental demonstrations of calculated results are suggested. This paper is intended for undergraduate optics courses, and advanced interdisciplinary seminars on arts and physics

  13. Colour reconstruction of underwater images

    OpenAIRE

    Hoth, Julian; Kowalczyk, Wojciech

    2017-01-01

    Objects look very different in the underwater environment compared to their appearance in sunlight. Images with correct colouring simplify the detection of underwater objects and may allow the use of visual SLAM algorithms developed for land-based robots underwater. Hence, image processing is required. Current algorithms focus on the colour reconstruction of scenery at diving depth where different colours can still be distinguished. At greater depth this is not the case. In this study it is i...

  14. Colouring and knot polynomials

    International Nuclear Information System (INIS)

    Welsh, D.J.A.

    1991-01-01

    These lectures will attempt to explain a connection between the recent advances in knot theory using the Jones and related knot polynomials with classical problems in combinatorics and statistical mechanics. The difficulty of some of these problems will be analysed in the context of their computational complexity. In particular we shall discuss colourings and groups valued flows in graphs, knots and the Jones and Kauffman polynomials, the Ising, Potts and percolation problems of statistical physics, computational complexity of the above problems. (author). 20 refs, 9 figs

  15. Theory of colours

    CERN Document Server

    Goethe, Johann Wolfgang von

    2006-01-01

    The wavelength theory of light and color had been firmly established by the time the great German poet published his Theory of Colours in 1810. Nevertheless, Goethe believed that the theory derived from a fundamental error, in which an incidental result was mistaken for a elemental principle. Far from affecting a knowledge of physics, he maintained that such a background would inhibit understanding. The conclusions Goethe draws here rest entirely upon his personal observations.This volume does not have to be studied to be appreciated. The author's subjective theory of colors permits him to spe

  16. The Metric of Colour Space

    DEFF Research Database (Denmark)

    Gravesen, Jens

    2015-01-01

    and found the MacAdam ellipses which are often interpreted as defining the metric tensor at their centres. An important question is whether it is possible to define colour coordinates such that the Euclidean distance in these coordinates correspond to human perception. Using cubic splines to represent......The space of colours is a fascinating space. It is a real vector space, but no matter what inner product you put on the space the resulting Euclidean distance does not correspond to human perception of difference between colours. In 1942 MacAdam performed the first experiments on colour matching...

  17. Industrial vision

    DEFF Research Database (Denmark)

    Knudsen, Ole

    1998-01-01

    This dissertation is concerned with the introduction of vision-based application s in the ship building industry. The industrial research project is divided into a natural seq uence of developments, from basic theoretical projective image generation via CAD and subpixel analysis to a description...... is present ed, and the variability of the parameters is examined and described. The concept of using CAD together with vision information is based on the fact that all items processed at OSS have an associated complete 3D CAD model that is accessible at all production states. This concept gives numerous...... possibilities for using vision in applications which otherwise would be very difficult to automate. The requirement for low tolerances in production is, despite the huge dimensions of the items involved, extreme. This fact makes great demands on the ability to do robust sub pixel estimation. A new method based...

  18. Innate colour preferences of the Australian native stingless bee Tetragonula carbonaria Sm.

    Science.gov (United States)

    Dyer, Adrian G; Boyd-Gerny, Skye; Shrestha, Mani; Lunau, Klaus; Garcia, Jair E; Koethe, Sebastian; Wong, Bob B M

    2016-10-01

    Innate preferences promote the capacity of pollinators to find flowers. Honeybees and bumblebees have strong preferences for 'blue' stimuli, and flowers of this colour typically present higher nectar rewards. Interestingly, flowers from multiple different locations around the world independently have the same distribution in bee colour space. Currently, however, there is a paucity of data on the innate colour preferences of stingless bees that are often implicated as being key pollinators in many parts of the world. In Australia, the endemic stingless bee Tetragonula carbonaria is widely distributed and known to be an efficient pollinator of both native plants and agricultural crops. In controlled laboratory conditions, we tested the innate colour responses of naïve bees using standard broadband reflectance stimuli representative of common flower colours. Colorimetric analyses considering hymenopteran vision and a hexagon colour space revealed a difference between test colonies, and a significant effect of green contrast and an interaction effect of green contrast with spectral purity on bee choices. We also observed colour preferences for stimuli from the blue and blue-green categorical regions of colour space. Our results are discussed in relation to the similar distribution of flower colours observed from bee pollination around the world.

  19. EFFECTS OF FATLIQURING PROCESS ON LEATHERS COLOURED WITH IR REFLECTIVE DYES AND PIGMENTS

    OpenAIRE

    MUTLU Mehmet Mete; ORK Nilay; YAKUT Fatih

    2017-01-01

    Black coloured materials and consumer goods are known to be heating up more, because they absorb sun radiation more than light colours. This heating is a problem for the users for black automotive or motorcycle leathers and also for dark shoes and boots which are exposed to sun heat. Human vision system can distinguish visible colours between the wavelengths of 390-700 nm. So reflecting the sun radiation in the infrared area of radiation spectrum higher than 700nm, is a solution for heating p...

  20. Subjective estimates of colour attributes for surface colours

    NARCIS (Netherlands)

    Ishak, I.G.H.; Bouma, H.; van Bussel, H.J.J.

    1970-01-01

    Subjective estimates of hue, saturation, and lightness are reported for sixty coloured Munsell samples, shown against seven backgrounds (black, grey, white, red, yellow, green, and blue) as judged by two observers. The results show the adequacy of this method for studies on colour appearance. The

  1. Across light: through colour

    Science.gov (United States)

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

    2012-03-01

    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.

  2. A colourful clock.

    Directory of Open Access Journals (Sweden)

    Hester C van Diepen

    2015-05-01

    Full Text Available Circadian rhythms are an essential property of life on Earth. In mammals, these rhythms are coordinated by a small set of neurons, located in the suprachiasmatic nuclei (SCN. The environmental light/dark cycle synchronizes (entrains the SCN via a distinct pathway, originating in a subset of photosensitive retinal ganglion cells (pRGCs that utilize the photopigment melanopsin (OPN4. The pRGCs are also innervated by rods and cones and, so, are both endogenously and exogenously light sensitive. Accumulating evidence has shown that the circadian system is sensitive to ultraviolet (UV, blue, and green wavelengths of light. However, it was unclear whether colour perception itself can help entrain the SCN. By utilizing both behavioural and electrophysiological recording techniques, Walmsley and colleagues show that multiple photic channels interact and enhance the capacity of the SCN to synchronize to the environmental cycle. Thus, entrainment of the circadian system combines both environmental irradiance and colour information to ensure that internal and external time are appropriately aligned.

  3. Color Vision Changes and Effects of High Contrast Visor Use at Simulated Cabin Altitudes

    Science.gov (United States)

    2016-06-08

    Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person...Morris DS, Kalson NS, Wright AD, Imray CHE, et al. Changes to colour vision on exposure to high altitude. J R Army Med Corps. 2011; 157(1):107-109...4. Richalet JP, Duval-Arnould G, Darnaud B, Keromes A, Rutgers V. Modification of colour vision in the green/red axis in acute and chronic

  4. Disruptive colouration and perceptual grouping.

    Science.gov (United States)

    Espinosa, Irene; Cuthill, Innes C

    2014-01-01

    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.

  5. Disruptive colouration and perceptual grouping.

    Directory of Open Access Journals (Sweden)

    Irene Espinosa

    Full Text Available 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.

  6. Agrarian Visions.

    Science.gov (United States)

    Theobald, Paul

    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…

  7. Fractured Visions

    DEFF Research Database (Denmark)

    Bonde, Inger Ellekilde

    2016-01-01

    In the post-war period a heterogeneous group of photographers articulate a new photographic approach to the city as motive in a photographic language that combines intense formalism with subjective vision. This paper analyses the photobook Fragments of a City published in 1960 by Danish photograp...

  8. Embodied Visions

    DEFF Research Database (Denmark)

    Grodal, Torben Kragh

    Embodied Visions presents a groundbreaking analysis of film through the lens of bioculturalism, revealing how human biology as well as human culture determine how films are made and experienced. Throughout the book the author uses the breakthroughs of modern brain science to explain general featu...

  9. Vision Screening

    Science.gov (United States)

    ... an efficient and cost-effective method to identify children with visual impairment or eye conditions that are likely to lead ... main goal of vision screening is to identify children who have or are at ... visual impairment unless treated in early childhood. Other problems that ...

  10. Ultrasonographic elastography of thyroid nodules: Is adding strain ratio to colour mapping better?

    International Nuclear Information System (INIS)

    Chong, Y.; Shin, J.H.; Ko, E.S.; Han, B.-K.

    2013-01-01

    Aim: To determine the diagnostic performance of colour mapping and strain ratio for characterizing malignant thyroid nodules on ultrasonographic (US) elastography. Materials and methods: The study was approved by the institutional review board and written informed consent was obtained. One hundred and thirty-one patients with 142 thyroid nodules >0.5 cm were prospectively enrolled between July 2010 and January 2011. Seven radiologists performed US elastography (iU22 Vision 2010; Philips, Seattle, WA, USA) using colour mapping and strain ratio for thyroid nodules blinded to the cytopathological results. Diagnostic performances of colour mapping alone, strain ratio alone, colour mapping and strain ratio, and colour mapping or strain ratio were compared using receiver operating characteristic (ROC) curve analysis. Results: Of the 142 nodules, 69 (48.6%) were benign and 73 (51.4%) were malignant. Colour mapping of elastography showed a more frequent blue colour in malignant nodules than in benign nodules (65.8% versus 24.6%, p < 0.0001). A higher ratio than 1.21 as the best cut-off value was found in 65.8% of malignant nodules and 46.4% of benign nodules (p = 0.030). Area under the ROC curve (AUC) of colour mapping alone was significantly greater than that of colour mapping or strain ratio (AUC = 0.706 versus AUC = 0.63, p = 0.0195) and similar to that of colour mapping and strain ratio (AUC = 0.673, p = 0.1364). Conclusion: US elastography is helpful to predict malignant thyroid nodules. However, adding strain ratio to colour mapping does not improve performance compared to colour mapping alone

  11. SVM Pixel Classification on Colour Image Segmentation

    Science.gov (United States)

    Barui, Subhrajit; Latha, S.; Samiappan, Dhanalakshmi; Muthu, P.

    2018-04-01

    The aim of image segmentation is to simplify the representation of an image with the help of cluster pixels into something meaningful to analyze. Segmentation is typically used to locate boundaries and curves in an image, precisely to label every pixel in an image to give each pixel an independent identity. SVM pixel classification on colour image segmentation is the topic highlighted in this paper. It holds useful application in the field of concept based image retrieval, machine vision, medical imaging and object detection. The process is accomplished step by step. At first we need to recognize the type of colour and the texture used as an input to the SVM classifier. These inputs are extracted via local spatial similarity measure model and Steerable filter also known as Gabon Filter. It is then trained by using FCM (Fuzzy C-Means). Both the pixel level information of the image and the ability of the SVM Classifier undergoes some sophisticated algorithm to form the final image. The method has a well developed segmented image and efficiency with respect to increased quality and faster processing of the segmented image compared with the other segmentation methods proposed earlier. One of the latest application result is the Light L16 camera.

  12. Complementary Colours for a Physicist

    Science.gov (United States)

    Babic, Vitomir; Cepic, Mojca

    2009-01-01

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

  13. Edge colouring by total labellings

    DEFF Research Database (Denmark)

    Brandt, Stephan; Rautenbach, D.; Stiebitz, M.

    2010-01-01

    We introduce the concept of an edge-colouring total k-labelling. This is a labelling of the vertices and the edges of a graph G with labels 1, 2, ..., k such that the weights of the edges define a proper edge colouring of G. Here the weight of an edge is the sum of its label and the labels of its...

  14. Colouring our view of safety

    International Nuclear Information System (INIS)

    Spare, P.

    2000-01-01

    The public have great difficulty interpreting numerical risk data, and particularly the relative importance of the hazards presented by advanced technologies compared with everyday activities. A form of presentation is proposed, utilizing a decade-based seven colour spectrum. The colours are directly connected to the auditable statistics and provide a qualitative measure of the risk to the non-specialist. (author)

  15. Phenomenology of colour exotic fermions

    International Nuclear Information System (INIS)

    Luest, D.

    1986-01-01

    The authors discuss the phenomenological consequences of a dynamical scenario according to which the electroweak symmetry breaking and generation of fermion masses is due to fermions that transform under high colour representations. Particular emphasis is given to the predictions for rare processes and to the spectrum of high colour boundstates. (Auth.)

  16. Colour Sonar: Multi-Frequency Sidescan Sonar Images of the Seabed in the Inner Sound of the Pentland Firth, Scotland

    Directory of Open Access Journals (Sweden)

    Duncan Tamsett

    2016-03-01

    Full Text Available The backscatter response of a seabed to an incident sonar signal is dependent on the carrier wave frequency: i.e., the seabed is acoustically colourful. Colour is implemented in a prototype three-frequency sidescan sonar system deployed in the Pentland Firth, north Scotland. Sonar amplitude data as a function of frequency are processed to render them an unconfounded effect of the seabed normalized to the response at a reference inclination angle, for colour to be a meaningful property of the seabed. Methods for mapping data at sonar frequencies to optical primary colours for human visualisation are explored. We recommend methods that in our opinion generate colour characteristics harmonious with human vision in which: shadow is white; saturation black; colour shade darkness is proportional to backscatter strength; and shades of red, green and blue are seen in proportion to the backscatter amplitudes of the low-, mid- and high-frequency sonar data. Frequency equalisation is applied to achieve a balance in colour responses in images. The seabed in the survey area is acoustically colourful. Using the “negative BGR” colour mapping method: a weakly backscattering sand dune in the north of the survey area appears as shades of light blue and purple; a strongly backscattering halo of cobbles around the dune appears as shades of hazel brown; a strongly backscattering gravel ridge across the south of the survey area appears as shades of royal blue; and exposed rock as textures ranging in colour from light brown to light blue/green. There is evidence for colour anisotropy (a dependence of colour on the direction of ensonification. Similarities between anthropic colour sonar and the natural sonar of Microchiropteran bats are noted. Bats’ sonar satisfies the information criteria for acoustic colour, and it is hypothesized that it informs a colourfully-perceived world view.

  17. Iodine Deficiency

    Science.gov (United States)

    ... Fax/Phone Home » Iodine Deficiency Leer en Español Iodine Deficiency Iodine is an element that is needed ... world’s population remains at risk for iodine deficiency. Iodine Deficiency FAQs WHAT IS THE THYROID GLAND? The ...

  18. Skin Colour Analysis of Iraqi Kurdish Population

    OpenAIRE

    Zardawi, Faraedon M; Xiao, Kaida; Yates, Julian M

    2015-01-01

    Objective: Skin colour measurement and analysis was performed for Iraqi Kurdish population in sulaimani city. The purpose of this study was to produce a dedicated skin shade guide for precise colour reproduction and colour matching of maxillofacial prostheses with the patient’s original skin colour. Methodology: A skin colour measurement was undertaken for 140 subjects (73 female and 67 male). A method of capturing their (L* a* b*) colour values from nine body parts was performed using a Mi...

  19. Natural Blue Food Colour

    DEFF Research Database (Denmark)

    Roda-Serrat, Maria Cinta

    In recent years, there has been a growing tendency to avoid the use of artificial colorants and additives in food products, especially after some studies linked their consumption with behavioural changes in children. However, the incorporation of colorants from natural origin remains a challenge...... for food technologists, as these are typically less vivid and less stable than their synthetic alternatives. Regarding blue colorants, phycocyanins from cyanobacteria are currently in the spotlight as promising new natural blue colorants. Phycocyanins are proteins which blue colour results from...... the presence of the chromophore phycocyanobilin (PCB), a covalently attached linear tetrapyrrole. The applications of phycocyanins as food colorants are however limited, as they show poor stability in certain conditions of pH, light and temperature. Cleavage of PCB from the protein followed by careful product...

  20. Connected Colourings of Complete Graphs and Hypergraphs

    OpenAIRE

    Leader, Imre; Tan, Ta Sheng

    2014-01-01

    Gallai's colouring theorem states that if the edges of a complete graph are 3-coloured, with each colour class forming a connected (spanning) subgraph, then there is a triangle that has all 3 colours. What happens for more colours: if we $k$-colour the edges of the complete graph, with each colour class connected, how many of the $\\binom{k}{3}$ triples of colours must appear as triangles? In this note we show that the `obvious' conjecture, namely that there are always at least $\\binom{k-1}{2}...

  1. Visions and visioning in foresight activities

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard; Grosu, Dan

    2007-01-01

    The paper discusses the roles of visioning processes and visions in foresight activities and in societal discourses and changes parallel to or following foresight activities. The overall topic can be characterised as the dynamics and mechanisms that make visions and visioning processes work...... or not work. The theoretical part of the paper presents an actor-network theory approach to the analyses of visions and visioning processes, where the shaping of the visions and the visioning and what has made them work or not work is analysed. The empirical part is based on analyses of the roles of visions...... and visioning processes in a number of foresight processes from different societal contexts. The analyses have been carried out as part of the work in the COST A22 network on foresight. A vision is here understood as a description of a desirable or preferable future, compared to a scenario which is understood...

  2. Pleiades Visions

    Science.gov (United States)

    Whitehouse, M.

    2016-01-01

    Pleiades Visions (2012) is my new musical composition for organ that takes inspiration from traditional lore and music associated with the Pleiades (Seven Sisters) star cluster from Australian Aboriginal, Native American, and Native Hawaiian cultures. It is based on my doctoral dissertation research incorporating techniques from the fields of ethnomusicology and cultural astronomy; this research likely represents a new area of inquiry for both fields. This large-scale work employs the organ's vast sonic resources to evoke the majesty of the night sky and the expansive landscapes of the homelands of the above-mentioned peoples. Other important themes in Pleiades Visions are those of place, origins, cosmology, and the creation of the world.

  3. Optoelectronic vision

    Science.gov (United States)

    Ren, Chunye; Parel, Jean-Marie A.

    1993-06-01

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

  4. Lambda Vision

    Science.gov (United States)

    Czajkowski, Michael

    2014-06-01

    There is an explosion in the quantity and quality of IMINT data being captured in Intelligence Surveillance and Reconnaissance (ISR) today. While automated exploitation techniques involving computer vision are arriving, only a few architectures can manage both the storage and bandwidth of large volumes of IMINT data and also present results to analysts quickly. Lockheed Martin Advanced Technology Laboratories (ATL) has been actively researching in the area of applying Big Data cloud computing techniques to computer vision applications. This paper presents the results of this work in adopting a Lambda Architecture to process and disseminate IMINT data using computer vision algorithms. The approach embodies an end-to-end solution by processing IMINT data from sensors to serving information products quickly to analysts, independent of the size of the data. The solution lies in dividing up the architecture into a speed layer for low-latent processing and a batch layer for higher quality answers at the expense of time, but in a robust and fault-tolerant way. This approach was evaluated using a large corpus of IMINT data collected by a C-130 Shadow Harvest sensor over Afghanistan from 2010 through 2012. The evaluation data corpus included full motion video from both narrow and wide area field-of-views. The evaluation was done on a scaled-out cloud infrastructure that is similar in composition to those found in the Intelligence Community. The paper shows experimental results to prove the scalability of the architecture and precision of its results using a computer vision algorithm designed to identify man-made objects in sparse data terrain.

  5. Virtual Vision

    Science.gov (United States)

    Terzopoulos, Demetri; Qureshi, Faisal Z.

    Computer vision and sensor networks researchers are increasingly motivated to investigate complex multi-camera sensing and control issues that arise in the automatic visual surveillance of extensive, highly populated public spaces such as airports and train stations. However, they often encounter serious impediments to deploying and experimenting with large-scale physical camera networks in such real-world environments. We propose an alternative approach called "Virtual Vision", which facilitates this type of research through the virtual reality simulation of populated urban spaces, camera sensor networks, and computer vision on commodity computers. We demonstrate the usefulness of our approach by developing two highly automated surveillance systems comprising passive and active pan/tilt/zoom cameras that are deployed in a virtual train station environment populated by autonomous, lifelike virtual pedestrians. The easily reconfigurable virtual cameras distributed in this environment generate synthetic video feeds that emulate those acquired by real surveillance cameras monitoring public spaces. The novel multi-camera control strategies that we describe enable the cameras to collaborate in persistently observing pedestrians of interest and in acquiring close-up videos of pedestrians in designated areas.

  6. Producing colour pictures from SCAN

    International Nuclear Information System (INIS)

    Robichaud, K.

    1982-01-01

    The computer code SCAN.TSK has been written for use on the Interdata 7/32 minicomputer which will convert the pictures produced by the SCAN program into colour pictures on a colour graphics VDU. These colour pictures are a more powerful aid to detecting errors in the MONK input data than the normal lineprinter pictures. This report is intended as a user manual for using the program on the Interdata 7/32, and describes the method used to produce the pictures and gives examples of JCL, input data and of the pictures that can be produced. (U.K.)

  7. Colour reconnection in WW events

    CERN Document Server

    D'Hondt, J

    2003-01-01

    Preliminary results are presented for a measurement of the kappa parameter used in the JETSET SK-I model of colour reconnection in W /sup +/W/sup -/ to qq'qq' events at LEP2. An update on the investigation of colour reconnection effects in hadronic decays of W pairs, using the particle flow in DELPHI is presented. A second method is based on the observation that two different m/sub W/ estimators have different sensitivity to the parametrised colour reconnection effect. Hence the difference between them is an observable with information content about kappa. (6 refs).

  8. The dual rod system of amphibians supports colour discrimination at the absolute visual threshold.

    Science.gov (United States)

    Yovanovich, Carola A M; Koskela, Sanna M; Nevala, Noora; Kondrashev, Sergei L; Kelber, Almut; Donner, Kristian

    2017-04-05

    The presence of two spectrally different kinds of rod photoreceptors in amphibians has been hypothesized to enable purely rod-based colour vision at very low light levels. The hypothesis has never been properly tested, so we performed three behavioural experiments at different light intensities with toads ( Bufo ) and frogs ( Rana ) to determine the thresholds for colour discrimination. The thresholds of toads were different in mate choice and prey-catching tasks, suggesting that the differential sensitivities of different spectral cone types as well as task-specific factors set limits for the use of colour in these behavioural contexts. In neither task was there any indication of rod-based colour discrimination. By contrast, frogs performing phototactic jumping were able to distinguish blue from green light down to the absolute visual threshold, where vision relies only on rod signals. The remarkable sensitivity of this mechanism comparing signals from the two spectrally different rod types approaches theoretical limits set by photon fluctuations and intrinsic noise. Together, the results indicate that different pathways are involved in processing colour cues depending on the ecological relevance of this information for each task.This article is part of the themed issue 'Vision in dim light'. © 2017 The Authors.

  9. Optimal colour quality of LED clusters based on memory colours.

    Science.gov (United States)

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

    2011-03-28

    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.

  10. Colour Separation and Aversion

    Directory of Open Access Journals (Sweden)

    Sarah M Haigh

    2012-05-01

    Full Text Available Aversion to achromatic patterns is well documented but relatively little is known about discomfort from chromatic patterns. Large colour differences are uncommon in the natural environment and deviation from natural statistics makes images uncomfortable (Fernandez and Wilkins 2008, Perception, 37(7, 1098–113; Juricevic et al 2010, Perception, 39(7, 884–899. We report twelve studies documenting a linear increase in aversion to chromatic square-wave gratings as a function of the separation in UCS chromaticity between the component bars, independent of their luminance contrast. Two possible explanations for the aversion were investigated: (1 accommodative response, or (2 cortical metabolic demand. We found no correlation between chromaticity separation and accommodative lag or variance in lag, measured using an open-field autorefractor. However, near infrared spectroscopy of the occipital cortex revealed a larger oxyhaemoglobin response to patterns with large chromaticity separation. The aversion may be cortical in origin and does not appear to be due to accommodation.

  11. String Formation Beyond Leading Colour

    CERN Document Server

    Christiansen, Jesper R.

    2015-08-03

    We present a new model for the hadronisation of multi-parton systems, in which colour correlations beyond leading $N_C$ are allowed to influence the formation of confining potentials (strings). The multiplet structure of $SU(3)$ is combined with a minimisation of the string potential energy, to decide between which partons strings should form, allowing also for "baryonic" configurations (e.g., two colours can combine coherently to form an anticolour). In $e^+e^-$collisions, modifications to the leading-colour picture are small, suppressed by both colour and kinematics factors. But in $pp$ collisions, multi-parton interactions increase the number of possible subleading connections, counteracting their naive $1/N_C^2$ suppression. Moreover, those that reduce the overall string lengths are kinematically favoured. The model, which we have implemented in the PYTHIA 8 generator, is capable of reaching agreement not only with the important $\\left(n_\\mathrm{charged})$ distribution but also with measured rates (and ra...

  12. Health Deficiencies

    Data.gov (United States)

    U.S. Department of Health & Human Services — A list of all health deficiencies currently listed on Nursing Home Compare, including the nursing home that received the deficiency, the associated inspection date,...

  13. A new universal colour image fidelity metric

    NARCIS (Netherlands)

    Toet, A.; Lucassen, M.P.

    2003-01-01

    We extend a recently introduced universal grayscale image quality index to a newly developed perceptually decorrelated colour space. The resulting colour image fidelity metric quantifies the distortion of a processed colour image relative to its original version. We evaluated the new colour image

  14. What Colour Is a Shadow?

    Science.gov (United States)

    Hughes, S. W.

    2009-01-01

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

  15. Colour Day: an innovative project

    CERN Multimedia

    Staff Association

    2016-01-01

    This year, the Children’s Day-Care Centre (EVE) and School works on the theme of colours. Every class has their own project revolving around this common theme. The class of Claire, Sandrine and Nadia, introduced a monthly “Colour Day”. The objective of this day is to offer children different activities (arts and crafts, baking, etc.) designed around a specific colour. The children get a chance to decorate their classroom and learn in many different ways inspired by the colours blue, red, and many others. The parents are also called to contribute and invited to dress their children in the colour of the day. In September, we discovered the colour blue, in October it was time for red, and in mid-November yellow will brighten up our structure. Everyone plays along, making this a very festive day for us all. On Tuesday, 20 September, we saw the whole School turn blue! We were all dressed in blue and we made blue paintings, too! We made beautiful artwork inspired by artists like Ma...

  16. Poor vision, refractive errors and barriers to treatment among ...

    African Journals Online (AJOL)

    Poor vision, refractive errors and barriers to treatment among commercial vehicle drivers in the Cape Coast municipality. ... were also administered to the participants to collect demographic data, history of driving and RTAs and utilization of eye care services as well as identification of the colours of the traffic light. Results: A ...

  17. Colour in a larger perspective: the rebirth of Gestalt psychology.

    Science.gov (United States)

    Spillmann, L

    1997-01-01

    This overview takes the reader from the classical contrast and assimilation studies of the past to today's colour research, in a broad sense, with its renewed emphasis on the phenomenological qualities of visual perception. It shows how the shift in paradigm from local to global effects in single-unit recordings prompted a reappraisal of appearance in visual experiments, not just in colour, but in the perception of motion, texture, and depth as well. Gestalt ideas placed in the context of modern concepts are shown to inspire psychophysicists, neurophysiologists, and computational vision scientists alike. Feedforward, horizontal interactions, and feedback are discussed as potential neuronal mechanisms to account for phenomena such as uniform surfaces, filling-in, and grouping arising from processes beyond the classical receptive field. A look forward towards future developments in the field of figure-ground segregation (Gestalt formation) concludes the article.

  18. Influence of colour in working environment

    OpenAIRE

    Gabrovšek, Barbara

    2014-01-01

    Anton Trstenjak wrote: »Our life is practically sinking in the sea of light and colours.« Different colours create different psycho-physiological responses. That is why colours have various impacts on human experiences and arrangements of our attention. When we know how control the colours in our environment, we can influence human psychological and physiological well-being and attention in the space. In my thesis, I explore how colours affect our feelings, our body and attention. Knowing all...

  19. Low Vision FAQs

    Science.gov (United States)

    ... de los Ojos Cómo hablarle a su oculista Low Vision FAQs What is low vision? Low vision is a visual impairment, not correctable ... person’s ability to perform everyday activities. What causes low vision? Low vision can result from a variety of ...

  20. Pediatric Low Vision

    Science.gov (United States)

    ... Asked Questions Español Condiciones Chinese Conditions Pediatric Low Vision What is Low Vision? Partial vision loss that cannot be corrected causes ... and play. What are the signs of Low Vision? Some signs of low vision include difficulty recognizing ...

  1. Vision Screening

    Science.gov (United States)

    1993-01-01

    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.

  2. Robot vision

    International Nuclear Information System (INIS)

    Hall, E.L.

    1984-01-01

    Almost all industrial robots use internal sensors such as shaft encoders which measure rotary position, or tachometers which measure velocity, to control their motions. Most controllers also provide interface capabilities so that signals from conveyors, machine tools, and the robot itself may be used to accomplish a task. However, advanced external sensors, such as visual sensors, can provide a much greater degree of adaptability for robot control as well as add automatic inspection capabilities to the industrial robot. Visual and other sensors are now being used in fundamental operations such as material processing with immediate inspection, material handling with adaption, arc welding, and complex assembly tasks. A new industry of robot vision has emerged. The application of these systems is an area of great potential

  3. High-speed Fourier transform profilometry for reconstructing objects having arbitrary surface colours

    International Nuclear Information System (INIS)

    Chen, Liang-Chia; Nguyen, Xuan Loc; Zhang, Fu-Hao; Lin, Tzeng-Yow

    2010-01-01

    In this paper, Fourier transform profilometry (FTP) using a colour fringe selection technique for accurate phase map reconstruction is newly proposed to overcome the limitation of FTP in measuring objects having arbitrary surface colours. The sinusoidal colour fringe pattern is encoded to form a unique colour pattern for projecting onto the object's surface, and its reflected deformed fringe image is taken using a triple-colour CCD camera and rapidly processed by the developed FTP method employing a novel band-pass filter. A new 3D vision system is capable of measuring objects with a high speed of up to 60 frames s −1 . To reconstruct the 3D profile of an object having arbitrary surface colours, an innovative strategy is developed to identify the colour channel of the detected fringe pattern with the best modulation transfer function (MTF) for retrieving accurate phase maps. The experimental results demonstrate that the system has the capability to acquire 3D maps at a high speed while the measurement accuracy of the developed method is substantially better than that of the traditional FTP method. By measuring the standard step heights in a repeatability test, it is confirmed that a maximum measured error can be controlled to less than 2.8% of the overall measuring depth range

  4. Color vision test

    Science.gov (United States)

    ... present from birth) color vision problems: Achromatopsia -- complete color blindness , seeing only shades of gray Deuteranopia -- difficulty telling ... Vision test - color; Ishihara color vision test Images Color blindness tests References Bowling B. Hereditary fundus dystrophies. In: ...

  5. Impairments to Vision

    Science.gov (United States)

    ... 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 ...

  6. Effect of absence of vision on posture.

    Science.gov (United States)

    Alotaibi, Abdullah Z; Alghadir, Ahmad; Iqbal, Zaheen A; Anwer, Shahnawaz

    2016-04-01

    [Purpose] The visual system is one of the sensory systems that enables the body to assess and process information about the external environment. In the absence of vision, a blind person loses contact with the outside world and develops faulty motor patterns, which results in postural deficiencies. However, literature regarding the development of such deficiencies is limited. The aim of this study was to discuss the effect of absence of vision on posture, the possible biomechanics behind the resulting postural deficiencies, and strategies to correct and prevent them. [Subjects and Methods] Various electronic databases including PubMed, Medline, and Google scholar were examined using the words "body", "posture", "blind" and "absence of vision". References in the retrieved articles were also examined for cross-references. The search was limited to articles in the English language. [Results] A total of 74 papers were shortlisted for this review, most of which dated back to the 1950s and 60s. [Conclusion] Blind people exhibit consistent musculoskeletal deformities. Absence of vision leads to numerous abnormal sensory and motor interactions that often limit blind people in isolation. Rehabilitation of the blind is a multidisciplinary task. Specialists from different fields need to diagnose and treat the deficiencies of the blind together as a team. Before restoring the normal mechanics of posture and gait, the missing link with the external world should be reestablished.

  7. The colour of gender stereotyping.

    Science.gov (United States)

    Cunningham, Sheila J; Macrae, C Neil

    2011-08-01

    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. ©2011 The British Psychological Society.

  8. The secret world of shrimps: polarisation vision at its best.

    Directory of Open Access Journals (Sweden)

    Sonja Kleinlogel

    Full Text Available BACKGROUND: Animal vision spans a great range of complexity, with systems evolving to detect variations in light 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. METHODOLOGY/PRINCIPAL FINDINGS: 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 Gonodactylus smithii measures the exact components required. CONCLUSIONS/SIGNIFICANCE: This vision provides optimal contrast-enhancement and precise determination of polarisation with no confusion states or neutral points--significant advantages. Linear and circular polarisation each give partial information about the polarisation of light--but the combination of the two, as we will show here, results in optimal polarisation vision. We suggest that linear and circular polarisation vision not be regarded as different modalities, since both are necessary for optimal polarisation vision; their combination renders polarisation vision independent of strongly linearly or circularly polarised features in the animal's environment.

  9. The colour of an avifauna: A quantitative analysis of the colour of Australian birds

    Science.gov (United States)

    Delhey, Kaspar

    2015-01-01

    Animal coloration is a poorly-understood aspect of phenotypic variability. Here I expand initial studies of the colour gamut of birds by providing the first quantitative description of the colour variation of an entire avifauna: Australian landbirds (555 species). The colour of Australian birds occupies a small fraction (19%) of the entire possible colour space and colour variation is extremely uneven. Most colours are unsaturated, concentrated in the centre of colour space and based on the deposition of melanins. Other mechanisms of colour production are less common but account for larger portions of colour space and for most saturated colours. Male colours occupy 45–25% more colour space than female colours, indicating that sexual dichromatism translates into a broader range of male colours. Male-exclusive colours are often saturated, at the edge of chromatic space, and have most likely evolved for signalling. While most clades of birds occupy expected or lower-than-expected colour volumes, parrots and cockatoos (Order Psittaciformes) occupy a much larger volume than expected. This uneven distribution of colour variation across mechanisms of colour production, sexes and clades is probably shared by avifaunas in other parts of the world, but this remains to be tested with comparable data. PMID:26679370

  10. Filtering and polychromatic vision in mantis shrimps: themes in visible and ultraviolet vision.

    Science.gov (United States)

    Cronin, Thomas W; Bok, Michael J; Marshall, N Justin; Caldwell, Roy L

    2014-01-01

    Stomatopod crustaceans have the most complex and diverse assortment of retinal photoreceptors of any animals, with 16 functional classes. The receptor classes are subdivided into sets responsible for ultraviolet vision, spatial vision, colour vision and polarization vision. Many of these receptor classes are spectrally tuned by filtering pigments located in photoreceptors or overlying optical elements. At visible wavelengths, carotenoproteins or similar substances are packed into vesicles used either as serial, intrarhabdomal filters or lateral filters. A single retina may contain a diversity of these filtering pigments paired with specific photoreceptors, and the pigments used vary between and within species both taxonomically and ecologically. Ultraviolet-filtering pigments in the crystalline cones serve to tune ultraviolet vision in these animals as well, and some ultraviolet receptors themselves act as birefringent filters to enable circular polarization vision. Stomatopods have reached an evolutionary extreme in their use of filter mechanisms to tune photoreception to habitat and behaviour, allowing them to extend the spectral range of their vision both deeper into the ultraviolet and further into the red.

  11. Incorporating Colour Information for Computer-Aided Diagnosis of Melanoma from Dermoscopy Images: A Retrospective Survey and Critical Analysis

    Directory of Open Access Journals (Sweden)

    Ali Madooei

    2016-01-01

    Full Text Available Cutaneous melanoma is the most life-threatening form of skin cancer. Although advanced melanoma is often considered as incurable, if detected and excised early, the prognosis is promising. Today, clinicians use computer vision in an increasing number of applications to aid early detection of melanoma through dermatological image analysis (dermoscopy images, in particular. Colour assessment is essential for the clinical diagnosis of skin cancers. Due to this diagnostic importance, many studies have either focused on or employed colour features as a constituent part of their skin lesion analysis systems. These studies range from using low-level colour features, such as simple statistical measures of colours occurring in the lesion, to availing themselves of high-level semantic features such as the presence of blue-white veil, globules, or colour variegation in the lesion. This paper provides a retrospective survey and critical analysis of contributions in this research direction.

  12. Color Vision Defects in School Going Children

    Directory of Open Access Journals (Sweden)

    R K Shrestha

    2010-12-01

    Full Text Available Introduction: Color Vision defect can be observed in various diseases of optic nerve and retina and also a significant number of people suffer from the inherited condition of red and green color defect. Methods: A cross-sectional descritptive study was designed with purposive sampling of students from various schools of Kathmandu Valley. All children were subjected to color vision evaluation using Ishihara Isochromatic color plates along with other examination to rule out any other causes of color deficiency. Results: A total of 2001 students were examined, 1050 male students and 951 females with mean age of 10.35 (±2.75 and 10.54 (±2.72 respectively. Among the total students examined, 2.1% had some form of color vision defects. Of the male population , 3.9% had color vision defects while none of the female was found with the deficiency. Conclusions: The prelevance of color vision defect in Nepal is significant and comparable with the prelevance quoted in the studies from different countries. Keywords:color vision; congenital red green color effect; Nepal; prevalence.

  13. Hypersensitivity reactions to food colours with special reference to the natural colour annatto extract (butter colour).

    Science.gov (United States)

    Mikkelsen, H; Larsen, J C; Tarding, F

    1978-01-01

    It is well known that synthetic food colours especially some azo dyes can provoke hypersensitivity reactions such as urticaria, angioneurotic oedema, and astma (Michaëlsson and Juhlin, 1973, Granholt and Thune, 1975). Natural food colours are scarcely investigated with respect to potential allergic properties. Annatto extract, a commonly used food colour in edible fats e.g. butter, has been tested in patients. Among 61 consecutive patients suffereing from chornic urticaria and/or angioneurotic oedema 56 patients were orally provoked by annatto extract during elimination diet. Challenge was performed with a dose equivalent to the amount used in 25 grammes of butter. Twentysix per cent of the patients reacted to this colour 4 hours (SD: 2,6) after intake. Similar challenges with synthetic dyes showed the following results: Tartrazine 11%, Sunset Yellow FCF 17%, Food Red 17 16%, Amaranth 9%, Ponceau 4 R 15%, Erythrosine 12% and Brillant Blue FCF 14%. The present study indicates that natural food colours may induce hypersensitivity reactions as frequent as synthetic dyes.

  14. Background colour matching by a crab spider in the field: a community sensory ecology perspective.

    Science.gov (United States)

    Defrize, Jérémy; Théry, Marc; Casas, Jérôme

    2010-05-01

    The question of whether a species matches the colour of its natural background in the perspective of the correct receiver is complex to address for several reasons; however, the answer to this question may provide invaluable support for functional interpretations of colour. In most cases, little is known about the identity and visual sensory abilities of the correct receiver and the precise location at which interactions take place in the field, in particular for mimetic systems. In this study, we focused on Misumena vatia, a crab spider meeting the criteria for assessing crypsis better than many other models, and claimed to use colour changes for both aggressive and protective crypsis. We carried out a systematic field survey to quantitatively assess the exactness of background colour matching in M. vatia with respect to the visual system of many of its receivers within the community. We applied physiological models of bird, bee and blowfly colour vision, using flower and spider spectral reflectances measured with a spectroradiometer. We observed that crypsis at long distance is systematically achieved, exclusively through achromatic contrast, in both bee and bird visions. At short distance, M. vatia is mostly chromatically detectable, whatever the substrate, for bees and birds. However, spiders can be either poorly discriminable or quite visible depending on the substrate for bees. Spiders are always chromatically undetectable for blowflies. We discuss the biological relevance of these results in both defensive and aggressive contexts of crypsis within a community sensory perspective.

  15. Colour and inclusivity: a visual communication design project with older people.

    Science.gov (United States)

    da Silva, Fernando Moreira

    2012-01-01

    In an ideal world, inclusive products and services would be the standard and not the exception. This paper presents a systematic approach to an overlap between Visual Communication Design, Printed Colour and Inclusive Design, for older people, with the aim to develop of a set of research-based ageing and ergonomics-centred communication design guidelines and recommendations for printed material (analogical displays). The approach included an initial extensive literature review in the area of colour, older people and ergonomics issues and vision common diseases, communication design. The second phase was the implementation of an experiment to measure the different colour experiences of the participants in two sample groups (one in UK and another one in Portugal), using printed material, to find out the colours one should use in analogical communication material, being aware of the colour contrast importance (foreground versus background) and the difficulties experienced by older people to read and understand lettering, signs. As main contribution of this research project, we developed a set of guidelines and recommendations based on the reviewed literature and the sample groups' findings, trying to demonstrate the importance of these guidelines when conceiving a new communicational design project in a way this project will achieve vision comfort and understandability, especially for older people, in an inclusive design perspective.

  16. A Fast Vision System for Soccer Robot

    Directory of Open Access Journals (Sweden)

    Tianwu Yang

    2012-01-01

    Full Text Available This paper proposes a fast colour-based object recognition and localization for soccer robots. The traditional HSL colour model is modified for better colour segmentation and edge detection in a colour coded environment. The object recognition is based on only the edge pixels to speed up the computation. The edge pixels are detected by intelligently scanning a small part of whole image pixels which is distributed over the image. A fast method for line and circle centre detection is also discussed. For object localization, 26 key points are defined on the soccer field. While two or more key points can be seen from the robot camera view, the three rotation angles are adjusted to achieve a precise localization of robots and other objects. If no key point is detected, the robot position is estimated according to the history of robot movement and the feedback from the motors and sensors. The experiments on NAO and RoboErectus teen-size humanoid robots show that the proposed vision system is robust and accurate under different lighting conditions and can effectively and precisely locate robots and other objects.

  17. Synaesthetic Colours Can Behave More like Recalled Colours, as Opposed to Physical Colours that Can Be Seen

    OpenAIRE

    Derek H. Arnold; Signy V. Wegener; Francesca Brown; Jason B. Mattingley

    2011-01-01

    Grapheme-color synaesthesia is an atypical condition characterized by coloured sensations when reading achromatic text. Different forms have been characterized, but this is somewhat controversial. In associative grapheme-colour synaesthesia, written graphemes can automatically trigger a sensation of colour in the ?mind's eye?, but hearing the name of a grapheme does not. This allowed us explore the precision with which synaesthetes match triggered synaesthetic colours across separate presenta...

  18. Iodine Deficiency

    NARCIS (Netherlands)

    Zimmermann, M.B.

    2009-01-01

    Iodine deficiency has multiple adverse effects in humans, termed iodine deficiency disorders, due to inadequate thyroid hormone production. Globally, it is estimated that 2 billion individuals have an insufficient iodine intake, and South Asia and sub-Saharan Africa are particularly affected.

  19. Biomimetic superwettable materials with structural colours.

    Science.gov (United States)

    Wang, Zelinlan; Guo, Zhiguang

    2017-12-05

    Structural colours and superwettability are of great interest due to their unique characteristics. However, the application of materials with either structural colours or superwettability is limited. Moreover, materials possessing both structural colours and superwettability are crucial for many practical applications. The combination of structural colours and superwettability can result in materials for use various applications, such as in sensors, detectors, bioassays, anti-counterfeiting, and liquid actuators, by controlling surfaces to repel or absorb liquids. Regarding superwettability and structural colours, surface texture and chemical composition are two factors for the construction of materials with superwettable structural colours. This review aims at offering a comprehensive elaboration of the mechanism, recent biomimetic research, and applications of biomimetic superwettable materials with structural colours. Furthermore, this review provides significant insight into the design, fabrication, and application of biomimetic superwettable materials with structural colours.

  20. Special Section on Coloured Petri Nets

    DEFF Research Database (Denmark)

    1998-01-01

    Special section on coloured Petri nets, their basic concepts, analysis methods, tool support and industrial applications.......Special section on coloured Petri nets, their basic concepts, analysis methods, tool support and industrial applications....

  1. What Is Low Vision?

    Science.gov (United States)

    ... Your Rights Training Resources Workplace Technology CareerConnect Stories Working as a Senior with Vision Loss For Seniors Age-Related Vision ... Changes Health and Aging Retirement Living Continuing to Work as a Senior with Vision Loss Get Connected About VisionAware Join ...

  2. String formation beyond leading colour

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, Jesper R. [Department of Astronomy and Theoretical Physics, Lund University,Sölvegatan 14, Lund (Sweden); Theoretical Physics, CERN,CH-1211, Geneva 23 (Switzerland); Skands, Peter Z. [Theoretical Physics, CERN,CH-1211, Geneva 23 (Switzerland); School of Physics and Astronomy, Monash University,VIC-3800 (Australia)

    2015-08-03

    We present a new model for the hadronisation of multi-parton systems, in which colour correlations beyond leading N{sub C} are allowed to influence the formation of confining potentials (strings). The multiplet structure of SU(3) is combined with a minimisation of the string potential energy, to decide between which partons strings should form, allowing also for “baryonic” configurations (e.g., two colours can combine coherently to form an anticolour). In e{sup +}e{sup −}collisions, modifications to the leading-colour picture are small, suppressed by both colour and kinematics factors. But in pp collisions, multi-parton interactions increase the number of possible subleading connections, counteracting their naive 1/N{sub C}{sup 2} suppression. Moreover, those that reduce the overall string lengths are kinematically favoured. The model, which we have implemented in the PYTHIA 8 generator, is capable of reaching agreement not only with the important 〈p{sub ⊥}〉(n{sub charged}) distribution but also with measured rates (and ratios) of kaons and hyperons, in both ee and pp collisions. Nonetheless, the shape of their p{sub ⊥} spectra remains challenging to explain.

  3. COLOUR LEARNING IN RETARDED CHILDREN*

    African Journals Online (AJOL)

    COLOUR LEARNING IN RETARDED CHILDREN* !\\'fRS E. K~SEBOOM, Principal, ADS. LEVIN, M.B., M.R.C.P., D.C.H., Hon. Medical Officer, Hamlet B School for. Retarded Children, Johannesburg. '... silly children, with no understanding .. -'. Jeremiah 4:22. Tt has been observed' that mentally retarded children have.

  4. The discovery of coloured kaons

    International Nuclear Information System (INIS)

    Feldman, G.

    1976-01-01

    The recently discovered M(1.86) mesons may be coloured kaons and a weak interaction in Han-Nambu theory is proposed which has the required general properties and forces the charged M particle to decay into the observed exotic state. (Auth.)

  5. Colour reconnection at LEP2

    CERN Document Server

    Abreu, P

    2002-01-01

    The preliminary results on the search of colour reconnection effects (CR) from the four experiments at LEP, ALEPH, DELPHI, L3 and OPAL, are reviewed. Extreme models are excluded by studies of standard variables, and on going studies of a method first suggested by L3, the particle flow method (D. Duchesneau, (2001)), are yet inconclusive. (22 refs).

  6. Thirteen-colour photometry of Be stars

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, M; Schuster, W J [Universidad Nacional Autonoma de Mexico, Mexico City. Inst. de Astronomia

    1981-01-01

    Thirteen-colour photometry made at the San Pedro Martir Observatory in Baja California, for a number of spectroscopically variable Be and shell stars is presented. Several of these stars also show photometric variability in the ultraviolet and/or infrared over a time base of two to three years. We analyze the more interesting stars in terms of colour-colour diagrams, colour excesses, spectral characteristics and changes in their energy distributions. Prospects for future research are discussed.

  7. Thirteen-colour photometry of Be stars

    International Nuclear Information System (INIS)

    Alvarez, M.; Schuster, W.J.

    1981-01-01

    Thirteen-colour photometry made at the San Pedro Martir Observatory in Baja California, for a number of spectroscopically variable Be and shell stars is presented. Several of these stars also show photometric variability in the ultraviolet and/or infrared over a time base of two to three years. We analyze the more interesting stars in terms of colour-colour diagrams, colour excesses, spectral characteristics and changes in their energy distributions. Prospects for future research are discussed. (author)

  8. Colour as a signal for entraining the mammalian circadian clock.

    Directory of Open Access Journals (Sweden)

    Lauren Walmsley

    2015-04-01

    Full Text Available Twilight is characterised by changes in both quantity ("irradiance" and quality ("colour" of light. Animals use the variation in irradiance to adjust their internal circadian clocks, aligning their behaviour and physiology with the solar cycle. However, it is currently unknown whether changes in colour also contribute to this entrainment process. Using environmental measurements, we show here that mammalian blue-yellow colour discrimination provides a more reliable method of tracking twilight progression than simply measuring irradiance. We next use electrophysiological recordings to demonstrate that neurons in the mouse suprachiasmatic circadian clock display the cone-dependent spectral opponency required to make use of this information. Thus, our data show that some clock neurons are highly sensitive to changes in spectral composition occurring over twilight and that this input dictates their response to changes in irradiance. Finally, using mice housed under photoperiods with simulated dawn/dusk transitions, we confirm that spectral changes occurring during twilight are required for appropriate circadian alignment under natural conditions. Together, these data reveal a new sensory mechanism for telling time of day that would be available to any mammalian species capable of chromatic vision.

  9. The "Human Colour" Crayon: Investigating the Attitudes and Perceptions of Learners Regarding Race and Skin Colour

    Science.gov (United States)

    Alexander, Neeske; Costandius, Elmarie

    2017-01-01

    Some coloured and black learners in South Africa use a light orange or pink crayon to represent themselves in art. Many learners name this colour "human colour" or "skin colour". This is troublesome, because it could reflect exclusionary ways of representing race in images and language. This case study, conducted with two…

  10. Search for Colour Singlet and Colour Reconnection Effects in Hadronic Z Decays at LEP

    CERN Document Server

    Achard, P; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Anderhub, H; Andreev, V P; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, G; Baksay, L; Baldew, S V; Banerjee, S; Banerjee, Sw; Barczyk, A; Barillère, R; Bartalini, P; Basile, M; Batalova, N; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Biasini, M; Biglietti, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böhm, A; Boldizsar, L; Borgia, B; Bottai, S; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brochu, F; Burger, J D; Burger, W J; Cai, X D; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada, M; Chamizo-Llatas, M; Chang, Y H; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Clare, I; Clare, R; Coignet, G; Colino, N; Costantini, S; de la Cruz, B; Cucciarelli, S; van Dalen, J A; De Asmundis, R; Déglon, P L; Debreczeni, J; Degré, A; Dehmelt, K; Deiters, K; Della Volpe, D; Delmeire, E; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Dierckxsens, M; Dionisi, C; Dittmar, M; Doria, A; Dova, M T; Duchesneau, D; Duda, M; Echenard, B; Eline, A; El-Hage, A; El-Mamouni, H; Engler, A; Eppling, F J; Extermann, P; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, M; Ferguson, T; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, F; Fisher, P H; Fisher, W; Fisk, I; Forconi, G; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gentile, S; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hirschfelder, J; Hofer, H; Hohlmann, M; Holzner, G; Hou, S R; Hu, Y; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Käfer, D; Kaur, M; Kienzle-Focacci, M N; Kim, J K; Kirkby, Jasper; Kittel, E W; Klimentov, A; König, A C; Kopal, M; Koutsenko, V F; Kräber, M H; Krämer, R W; Krüger, A; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Le Goff, J M; Leiste, R; Levtchenko, M; Levchenko, P M; Li, C; Likhoded, S; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Luci, C; Luminari, L; Lustermann, W; Ma Wen Gan; Malgeri, L; Malinin, A; Maña, C; Mans, J; Martin, J P; Marzano, F; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Muanza, G S; Muijs, A J M; Musicar, B; Musy, M; Nagy, S; Natale, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Nisati, A; Novák, T; Nowak, H; Ofierzynski, R A; Organtini, G; Pal, I; Palomares, C; Paolucci, P; Paramatti, R; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pioppi, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Pothier, J; Prokofev, D; Prokofiev, D O; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Ranieri, R; Raspereza, A V; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Riemann, S; Riles, K; Roe, B P; Romero, L; Rosca, A; Rosier-Lees, S; Roth, S; Rosenbleck, C; Rubio, J A; Ruggiero, G; Rykaczewski, H; Sakharov, A; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Schäfer, C; Shchegelskii, V; Schopper, Herwig Franz; Schotanus, D J; Sciacca, C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A V; Son, D; Souga, C; Spillantini, P; Steuer, M; Stickland, D P; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Sushkov, S; Suter, H; Swain, J D; Szillási, Z; Tang, X W; Tarjan, P; Tauscher, Ludwig; Taylor, L; Tellili, B; Teyssier, D; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Ulbricht, J; Valente, E; Van de Walle, R T; Vásquez, R; Veszpremi, V; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Wadhwa, M; Wang, Q; Wang, X L; Wang, Z M; Weber, M; Wienemann, P; Wilkens, H; Wynhoff, S; Xia, L; Xu, Z Z; Yamamoto, J; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Yeh, S C; Zalite, A; Zalite, Yu; Zhang, Z P; Zhao, J; Zhu, G Y; Zhu, R Y; Zhuang, H L; Zichichi, A; Zimmermann, B; Zöller, M

    2004-01-01

    A search is performed in symmetric 3-jet hadronic Z decay events for evidence of colour singlet production or colour reconnection effects. Asymmetries in the angular separation of particles are found to be sensitive indicators of such effects. Upper limits on the level of colour singlet production and colour reconnection effects are established for a variety of models.

  11. SPECTRAL AND SPATIAL SELECTIVITY OF LUMINANCE VISION IN REEF FISH

    Directory of Open Access Journals (Sweden)

    Ulrike E Siebeck

    2014-09-01

    Full Text Available Luminance vision has high spatial resolution and is used for form vision and texture discrimination. In humans, birds and bees luminance channel is spectrally selective – it depends on the signals of the long-wavelength sensitive photoreceptors (bees or on the sum of long- and middle- wavelength sensitive cones (humans, but not on the signal of the short-wavelength sensitive (blue photoreceptors. The reasons of such selectivity are not fully understood. The aim of this study is to reveal the inputs of cone signals to high resolution luminance vision in reef fish. 16 freshly caught damselfish, Pomacentrus amboinensis, were trained to discriminate stimuli differing either in their colour or in their fine patterns (stripes vs. cheques. Three colours (‘bright green’, ‘dark green’ and ‘blue’ were used to create two sets of colour and two sets of pattern stimuli. The ‘bright green’ and ‘dark green’ were similar in their chromatic properties for fish, but differed in their lightness; the ‘dark green’ differed from ‘blue’ in the signal for the blue cone, but yielded similar signals in the long-wavelength and middle-wavelength cones. Fish easily learned to discriminate ‘bright green’ from ‘dark green’ and ‘dark green’ from ‘blue’ stimuli. Fish also could discriminate the fine patterns created from ‘dark green’ and ‘bright green’. However, fish failed to discriminate fine patterns created from ‘blue’ and ‘dark green’ colours, i.e. the colours that provided contrast for the blue-sensitive photoreceptor, but not for the long-wavelength sensitive one. High resolution luminance vision in damselfish, Pomacentrus amboinensis, does not have input from the blue-sensitive cone, which may indicate that the spectral selectivity of luminance channel is a general feature of visual processing in both aquatic and terrestrial animals.

  12. An RGB Approach to Prismatic Colours

    Science.gov (United States)

    Theilmann, Florian; Grusche, Sascha

    2013-01-01

    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…

  13. Biological Components of Colour Preference in Infancy

    Science.gov (United States)

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

    2010-01-01

    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…

  14. Mixed colour states in QCD confining vacuum

    OpenAIRE

    Buividovich, P. V.; Kuvshinov, V. I.

    2005-01-01

    We show that confinement of spinless heavy quarks in fundamental representation of $SU(N_{c})$ gauge group can be treated as decoherence of pure colour state into a white mixture of states. Decoherence rate is found to be proportional to the tension of QCD string and the distance between colour charges. The purity of colour states is calculated.

  15. Kac's ring: The case of four colours

    Indian Academy of Sciences (India)

    2017-03-15

    Mar 15, 2017 ... generalize the discussion to more than two colours. Although the generalization seems nearly trivial, it will be shown that there appear interesting, unanticipated technical difficulties or surprises when we consider four colours. In this work, we consider the Kac's ring with balls of four colours, calling them red ...

  16. Improper colouring of (random) unit disk graphs

    NARCIS (Netherlands)

    Kang, R.J.; Müller, T.; Sereni, J.S.

    2008-01-01

    For any graph G, the k-improper chromatic number ¿k(G) is the smallest number of colours used in a colouring of G such that each colour class induces a subgraph of maximum degree k. We investigate ¿k for unit disk graphs and random unit disk graphs to generalise results of McDiarmid and Reed

  17. Colour development in the apple orchard

    NARCIS (Netherlands)

    Tijskens, L.M.M.; Unuk, T.; Stanislav Tojnko, S.; Hribar, J.; Simcic, M.

    2011-01-01

    Colour is traditionally one of the important appearance features of all fruit for consumers in deciding to buy them. Colour is therefore important in the postharvest supply chain. But where does that colour of fruit come from? Clearly the period of growing and the circumstances during growth are

  18. Synchronization analysis of coloured delayed networks under ...

    Indian Academy of Sciences (India)

    This paper investigates synchronization of coloured delayed networks under decentralized pinning intermittent control. To begin with, the time delays are taken into account in the coloured networks. In addition, we propose a decentralized pinning intermittent control for coloured delayed networks, which is different from that ...

  19. Detection of coloured tracks of heavy ion particles using photographic colour film

    International Nuclear Information System (INIS)

    Kuge, K.; Yasuda, N.; Kumagai, H.; Nakazawa, K.; Kobayashi, T.; Aoki, N.; Hasegawa, A.

    2001-01-01

    A photographic colour film, which was exposed to heavy ions, reveals a coloured dye image of the ion tracks. Since the colour film consists of several layers and different colours appear on each layer, three-dimensional information on the tracks in the layers can be obtained by the colour image. Previously, we have reported the method for which the tracks in different colours represented differences of track depth and we also discussed the disadvantages of using commercial colour films. Here we present the procedure for a self-made photographic coating and the development formula which can overcome the disadvantages

  20. Synaesthetic Colours Can Behave More like Recalled Colours, as Opposed to Physical Colours that Can Be Seen

    Directory of Open Access Journals (Sweden)

    Derek H. Arnold

    2011-05-01

    Full Text Available Grapheme-color synaesthesia is an atypical condition characterized by coloured sensations when reading achromatic text. Different forms have been characterized, but this is somewhat controversial. In associative grapheme-colour synaesthesia, written graphemes can automatically trigger a sensation of colour in the ‘mind's eye’, but hearing the name of a grapheme does not. This allowed us explore the precision with which synaesthetes match triggered synaesthetic colours across separate presentations, versus the precision for recalled experiences cued by spoken graphemes. We recorded CIE coordinates, and found that matches for triggered sensations were equally variable relative to recalled experiences. To ensure this was not due to insensitivity of our apparatus, we next had synaesthetes and age-matched controls either match the colour of a circular patch while they could see it, or from memory after it had disappeared. Both synaesthetes and controls were more variable when matching from memory, and synaesthetes were more precise when matching colour hue, but not brightness. Interestingly, the variance of synaesthetes' recalled matches in this experiment matched that associated with synaesthetic colours in the first experiment. Overall, our data suggests that, for associative grapheme-colour synaesthetes, synaesthetic colours behave more like recalled colours, as opposed to physical colours that can be seen.

  1. EFFECTS OF FATLIQURING PROCESS ON LEATHERS COLOURED WITH IR REFLECTIVE DYES AND PIGMENTS

    Directory of Open Access Journals (Sweden)

    MUTLU Mehmet Mete

    2017-05-01

    Full Text Available Black coloured materials and consumer goods are known to be heating up more, because they absorb sun radiation more than light colours. This heating is a problem for the users for black automotive or motorcycle leathers and also for dark shoes and boots which are exposed to sun heat. Human vision system can distinguish visible colours between the wavelengths of 390-700 nm. So reflecting the sun radiation in the infrared area of radiation spectrum higher than 700nm, is a solution for heating problem without affecting the visible colour. For this reason IR reflective dyes and pigments are designed. A leading Leather Chemical Company has developed an IR reflecting dyeing system for leather keeping the dark coloured leathers cooler under sun radiation. Additionally in theory, fat and water content of leather affects its heating properties. In this study, effect of natural, synthetic and waterproof fatliquoring systems on heating properties of leathers coloured with IR reflective dyes and pigments are investigated.

  2. Measurements and modelling of the influence of dentine colour and enamel on tooth colour.

    Science.gov (United States)

    Battersby, Paul D; Battersby, Stephen J

    2015-03-01

    We provide a quantitative predictive model for the extent to which coloured dentine, visible through the enamel, contributes to tooth colour. Our model uses (L(*),a(*),b(*)) measurements rather than spectral measurements. We have used a model system, composed of a slice of bovine enamel placed on top of coloured paper. We have measured the colour of the enamel-paper combination, as an analogue for a tooth, and have related this to the colour of the paper, as an analogue for dentine. By changing the paper colour, we have been able to explore how the colour of dentine determines tooth colour, according to our model system. We have also compared hydrated and desiccated samples. In qualitative terms, superimposing the enamel on top of the paper increases the "lightness" for all colours tested except white while simultaneously reducing the chromaticity, a measure of the extent to which the colour differs from grey. Desiccated enamel is much more effective at increasing the lightness and reducing the chromaticity than hydrated enamel. Quantitatively, our measurements are reproduced by the mathematical model we have developed to within 2% in "lightness" and about 8% in chromaticity. We are able to predict the colour of an analogue for a tooth, composed of bovine enamel and coloured paper, from the colour of an analogue for the dentine, the coloured paper alone, with good accuracy. This understanding provides insights into the role of dentine colour in determining tooth colour. Our work helps quantify the importance of dentine colour, compared to other, extrinsic causes of colour, such as staining, in determining the visible colour of teeth. Our predicted colours represent a baseline to which extrinsic sources will add. Copyright © 2015. Published by Elsevier Ltd.

  3. Colour annealing - a toy model of colour reconnections

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  4. Colour annealing - a toy model of colour reconnections

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-12-01

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

  5. Put on that colour, it fits your emotion: Colour appropriateness as a function of expressed emotion.

    Science.gov (United States)

    Dael, Nele; Perseguers, Marie-Noëlle; Marchand, Cynthia; Antonietti, Jean-Philippe; Mohr, Christine

    2016-01-01

    People associate affective meaning with colour, and this may influence decisions about colours. Hue is traditionally considered the most salient descriptor of colour and colour-affect associations, although colour brightness and saturation seem to have particularly strong affective connotations. To test whether colour choices can be driven by emotion, we investigated whether and how colour hue, brightness, and saturation are systematically associated with bodily expressions of positive (joy) and negative (fear) emotions. Twenty-five non-colour-blind participants viewed videos of these expressions and selected for each video the most appropriate colour using colour sliders providing values for hue, brightness, and saturation. The overall colour choices were congruent with the expressed emotion--that is, participants selected brighter and more saturated colours for joy expressions than for fear expressions. Also, colours along the red-yellow spectrum were deemed more appropriate for joy expressions and cyan-bluish hues for fear expressions. The current study adds further support to the role of emotion in colour choices by (a) showing that emotional information is spontaneously used in an unconstrained choice setting, (b) extending to ecologically valid stimuli occurring in everyday encounters (dressed bodies), and (c) suggesting that all colour parameters are likely to be important when processing affective nonverbal person information, though not independently from each other.

  6. Colour dependence of zodiacal light models

    Science.gov (United States)

    Giese, R. H.; Hanner, M. S.; Leinert, C.

    1973-01-01

    Colour models of the zodiacal light in the ecliptic have been calculated for both dielectric and metallic particles in the sub-micron and micron size range. Two colour ratios were computed, a blue ratio and a red ratio. The models with a size distribution proportional to s to the -2.5 power ds (where s is the particle radius) generally show a colour close to the solar colour and almost independent of elongation. Especially in the blue colour ratio there is generally no significant dependence on the lower cutoff size (0.1-1 micron). The main feature of absorbing particles is a reddening at small elongations. The models for size distributions proportional to s to the -4 power ds show larger departures from solar colour and more variation with model parameters. Colour measurements, including red and near infra-red, therefore are useful to distinguish between flat and steep size spectra and to verify the presence of slightly absorbing particles.

  7. Colour singlets in perturbative QCD

    International Nuclear Information System (INIS)

    Bassetto, A.

    1979-01-01

    In the axial gauge and at the leading log level, a definite and consistent picture seems to emerge of a parton decay into states in which many partons are found just before confinement should take place. They are grouped into colourless clusters in a number sufficient to exhaust the ''final'' state, still possessing a finite average mass. This result is peculiar of QCD, in particular of its non-abelian nature. Large transverse momenta or more generally average invariant quantities of partons are mainly due to the multiplicities involved in the branching processes. If eventually confinement would convert these clusters into hadrons (and this is of course the main issue which has still to be proven) without a large rearrangement of the colour lines, the picture we have found for colour singlets could apply to the real hadronic world. (author)

  8. Studying colours with a smartphone

    Science.gov (United States)

    Rosi, T.; Malgieri, M.; Onorato, P.; De Ambrosis, , A.; Oss, S.

    2017-03-01

    We show how a low-cost spectrometer, based on the use of inexpensive diffraction transmission gratings coupled with a smartphone photo camera, can be assembled and employed to obtain quantitative measurements of spectra from different sources. The analysis of spectra emitted by different light sources (incandescent bulb, fluorescent lamp, gas lamps, LEDs) helps students understand the different physical mechanisms which govern the production of light. Measurements of emission and transmission spectra allow students to focus on the differences between additive and subtractive models of colour formation. For this purpose the spectra of RGB colours emitted from an LCD screen and the transmission spectra of CMY pigments of a laser printer have been studied, using our low-cost spectroscope. A sequence of experimental activities was designed, and proposed to undergraduate students and secondary school teachers in order to study the feasibility and educational potential.

  9. Quark interactions and colour chemistry

    International Nuclear Information System (INIS)

    Hong-Mo, C.

    1982-01-01

    The interaction between quarks, according to the current theory of quantum chromodynamics, is similar to the electromagnetic interaction between electrons and nucleons, both being governed by locally gauge-invariant field theories. It is tempting therefore to discuss the spectroscopy of hadrons, which are quark composites bound by colour forces, in the same language as the spectroscopy of atoms and molecules which are bound states of electrons and nucleons held together by e.m. forces. Because of the difference in gauge groups, however, the dynamics are very different. Nonetheless, it appears likely that metastable multiquark hadron states can exist which are analogous to atoms and molecules in QED. In these lectures, tentative steps are taken in developing the rudiments of a new colour chemistry' of these 'atoms' and 'molecules'. (author)

  10. Portrait of a colour octet

    CERN Document Server

    Aguilar-Saavedra, J A

    2014-01-01

    New colour octets stand out among the new physics proposals to explain the anomalous forward-backward asymmetry measured in $t \\bar t$ production by the CDF experiment at the Tevatron. We perform a fit to $t \\bar t$ observables at the Tevatron and the LHC, including total cross sections, various asymmetries and the top polarisation and spin correlations, to find the most likely parameters of a light colour octet to be consistent with data. In particular, an octet coupling only to right-handed quarks gives a good fit to all measurements. The implications from the general fit are drawn in terms of predictions for top polarisation observables whose measurements are yet not very precise, and observables which simply have not been measured.

  11. Colour reconnections and rapidity gaps

    International Nuclear Information System (INIS)

    Loennblad, Leif

    1996-01-01

    I argue that the success of recently proposed models describing events with large rapidity gaps in DIS at HERA in terms of non-perturbative colour exchange is heavily reliant on suppression of perturbative gluon emission in the proton direction. There is little or no physical motivation for such suppression and I show that a model without this suppression cannot describe the rapidity gap events at HERA. (author)

  12. Colour Reconnection at LEP2

    CERN Document Server

    Nandakumar, Raja

    2001-01-01

    Colour reconnection is the final state interaction between quarks from different sources. It is not yet fully understood and is a source of systematic error for W-boson mass and width measurements in hadronic \\WW decays at LEP2. The methods of measuring this effect and the results of the 4 LEP experiments at $183\\gev\\leq\\rts\\leq 202\\gev$ will be presented.

  13. Colour categories are reflected in sensory stages of colour perception when stimulus issues are resolved

    Science.gov (United States)

    He, Xun; Franklin, Anna

    2017-01-01

    Debate exists about the time course of the effect of colour categories on visual processing. We investigated the effect of colour categories for two groups who differed in whether they categorised a blue-green boundary colour as the same- or different-category to a reliably-named blue colour and a reliably-named green colour. Colour differences were equated in just-noticeable differences to be equally discriminable. We analysed event-related potentials for these colours elicited on a passive visual oddball task and investigated the time course of categorical effects on colour processing. Support for category effects was found 100 ms after stimulus onset, and over frontal sites around 250 ms, suggesting that colour naming affects both early sensory and later stages of chromatic processing. PMID:28542426

  14. Colours sometimes count: awareness and bidirectionality in grapheme-colour synaesthesia.

    Science.gov (United States)

    Johnson, Addie; Jepma, Marieke; de Jong, Ritske

    2007-10-01

    Three experiments were conducted with 10 grapheme-colour synaesthetes and 10 matched controls to investigate (a) whether awareness of the inducer grapheme is necessary for synaesthetic colour induction and (b) whether grapheme-colour synaesthesia may be bidirectional in the sense that not only do graphemes induce colours, but that colours influence the processing of graphemes. Using attentional blink and Stroop paradigms with digit targets, we found that some synaesthetes did report "seeing" synaesthetic colours even when they were not able to report the inducing digit. Moreover, congruency effects (effects of matching the colour of digit presentation with the synaesthetic colour associated with that digit) suggested that grapheme-colour synaesthesia can be bidirectional, at least for some synaesthetes.

  15. The Attentional Capture of Colour in Visual Interface Design

    DEFF Research Database (Denmark)

    Andersen, Emil; Maier, Anja

    2017-01-01

    The use of colour is an integral component in visual interface design for creating separation between objects and for conveying meaning. It has previously been established that colours can be separated in a hierarchy of primary colours and secondary colours, and that colours are consistently...... in a controlled environment, in which 11 participants scanned a 20 item display for a coloured target amongst coloured distractors. We found evidence to support that primary colours capture attention significantly more than secondary colours, and inconclusive evidence that colours convey their meaning...... at a sufficiently early level of processing to influence attention. We end by discussing implications of our results for design practice and research in psychology....

  16. Developments in medical image processing and computational vision

    CERN Document Server

    Jorge, Renato

    2015-01-01

    This book presents novel and advanced topics in Medical Image Processing and Computational Vision in order to solidify knowledge in the related fields and define their key stakeholders. It contains extended versions of selected papers presented in VipIMAGE 2013 – IV International ECCOMAS Thematic Conference on Computational Vision and Medical Image, which took place in Funchal, Madeira, Portugal, 14-16 October 2013.  The twenty-two chapters were written by invited experts of international recognition and address important issues in medical image processing and computational vision, including: 3D vision, 3D visualization, colour quantisation, continuum mechanics, data fusion, data mining, face recognition, GPU parallelisation, image acquisition and reconstruction, image and video analysis, image clustering, image registration, image restoring, image segmentation, machine learning, modelling and simulation, object detection, object recognition, object tracking, optical flow, pattern recognition, pose estimat...

  17. Low Vision Tips

    Science.gov (United States)

    ... this page: https://medlineplus.gov/lowvision.html MedlinePlus: Low Vision Tips We are sorry. MedlinePlus no longer maintains the For Low Vision Users page. You will still find health resources ...

  18. Chemicals Industry Vision

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1996-12-01

    Chemical industry leaders articulated a long-term vision for the industry, its markets, and its technology in the groundbreaking 1996 document Technology Vision 2020 - The U.S. Chemical Industry. (PDF 310 KB).

  19. The original colours of fossil beetles.

    Science.gov (United States)

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

    2012-03-22

    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.

  20. How Bees Discriminate a Pattern of Two Colours from Its Mirror Image

    Science.gov (United States)

    Horridge, Adrian

    2015-01-01

    A century ago, in his study of colour vision in the honeybee (Apis mellifera), Karl von Frisch showed that bees distinguish between a disc that is half yellow, half blue, and a mirror image of the same. Although his inference of colour vision in this example has been accepted, some discrepancies have prompted a new investigation of the detection of polarity in coloured patterns. In new experiments, bees restricted to their blue and green receptors by exclusion of ultraviolet could learn patterns of this type if they displayed a difference in green contrast between the two colours. Patterns with no green contrast required an additional vertical black line as a landmark. Tests of the trained bees revealed that they had learned two inputs; a measure and the retinotopic position of blue with large field tonic detectors, and the measure and position of a vertical edge or line with small-field phasic green detectors. The angle between these two was measured. This simple combination was detected wherever it occurred in many patterns, fitting the definition of an algorithm, which is defined as a method of processing data. As long as they excited blue receptors, colours could be any colour to human eyes, even white. The blue area cue could be separated from the green receptor modulation by as much as 50°. When some blue content was not available, the bees learned two measures of the modulation of the green receptors at widely separated vertical edges, and the angle between them. There was no evidence that the bees reconstructed the lay-out of the pattern or detected a tonic input to the green receptors. PMID:25617892

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

    Science.gov (United States)

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

    2010-06-01

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

  2. Robot Vision Library

    Science.gov (United States)

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

    2009-01-01

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

  3. What colour is the car? Implicit memory for colour information in children.

    Science.gov (United States)

    Mecklenbräuker, S; Hupbach, A; Wippich, W

    2001-11-01

    Three experiments were conducted to examine age-related differences in colour memory. In Experiment 1, preschool age and elementary school age children were given a conceptual test of implicit colour memory (a colour-choice task). They were presented with the names or achromatic versions of previously studied coloured line drawings and asked to select an appropriate colour. Significant priming could be demonstrated: The children chose the previously seen colours more often than was expected by chance. Equivalent priming was found for both versions (pictorial and verbal) suggesting that colour priming may be conceptually mediated. Moreover, colour priming proved to be age invariant. Experiment 2 replicated and extended this finding by using a wider age group (preschool, elementary school, and young adults) and by giving a perceptual implicit task (picture identification) in addition to a verbal colour-choice task. Colour did not affect priming in the perceptual task. Whereas priming showed no developmental change, age-related improvements were observed on an explicit colour memory task that differed only in the test instructions from the implicit colour-choice task (Experiments 2 and 3). Taken together, the results suggest that implicit colour memory may be mediated by conceptual processes that are age invariant.

  4. The eyes and vision of butterflies.

    Science.gov (United States)

    Arikawa, Kentaro

    2017-08-15

    Butterflies use colour vision when searching for flowers. Unlike the trichromatic retinas of humans (blue, green and red cones; plus rods) and honeybees (ultraviolet, blue and green photoreceptors), butterfly retinas typically have six or more photoreceptor classes with distinct spectral sensitivities. The eyes of the Japanese yellow swallowtail (Papilio xuthus) contain ultraviolet, violet, blue, green, red and broad-band receptors, with each ommatidium housing nine photoreceptor cells in one of three fixed combinations. The Papilio eye is thus a random patchwork of three types of spectrally heterogeneous ommatidia. To determine whether Papilio use all of their receptors to see colours, we measured their ability to discriminate monochromatic lights of slightly different wavelengths. We found that Papilio can detect differences as small as 1-2 nm in three wavelength regions, rivalling human performance. We then used mathematical modelling to infer which photoreceptors are involved in wavelength discrimination. Our simulation indicated that the Papilio vision is tetrachromatic, employing the ultraviolet, blue, green and red receptors. The random array of three ommatidial types is a common feature in butterflies. To address the question of how the spectrally complex eyes of butterflies evolved, we studied their developmental process. We have found that the development of butterfly eyes shares its molecular logic with that of Drosophila: the three-way stochastic expression pattern of the transcription factor Spineless determines the fate of ommatidia, creating the random array in Papilio. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

  5. New particles and breaking the colour symmetry

    International Nuclear Information System (INIS)

    Krolikowski, W.

    1975-01-01

    In the framework of one-gluon-exchange static forces mediated by a colour octet or nonet of vector gluons, we discuss quark binding in coloured-meson states and its connection with breaking the colour symmetry. A possible identification of psi (3.1), psi(3.7) and the broad bump at 4.1 GeV with some coloured bound states of quarks and antiquarks is pointed out. This identification implies the existence of a second bump in the region of 5 GeV. The general conclusion of the paper is that the colour interpretation of the new particles may be true only if the colour symmetry is badly broken (provided the considered forces are relevant). (author)

  6. Colour Consideration for Waiting areas in hospitals

    Science.gov (United States)

    Zraati, Parisa

    2012-08-01

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

  7. Attentional capture by masked colour singletons.

    Science.gov (United States)

    Ansorge, Ulrich; Horstmann, Gernot; Worschech, Franziska

    2010-09-15

    We tested under which conditions a colour singleton of which an observer is unaware captures attention. To prevent visual awareness of the colour singleton, we used backward masking. We find that a masked colour singleton cue captures attention if it matches the observer's goal to search for target colours but not if it is task-irrelevant. This is also reflected in event-related potentials to the visible target: the masked goal-matching cue elicits an attentional potential (N2pc) in a target search task. By contrast, a non-matching but equally strong masked colour singleton cue failed to elicit a capture effect and an N2pc. Results are discussed with regard to currently pertaining conceptions of attentional capture by colour singletons. Copyright 2010 Elsevier Ltd. All rights reserved.

  8. What Are Rare Clotting Factor Deficiencies?

    Science.gov (United States)

    ... Deficiency Factor V Deficiency Combined FV & FVIII Deficiencies Factor VII Deficiency Factor X Deficiency Factor XI Deficiency Factor ... Deficiency Factor V Deficiency Combined FV & FVIII Deficiencies Factor VII Deficiency Factor X Deficiency Factor XI Deficiency Factor ...

  9. Colour-independent partition functions in coloured vertex models

    Energy Technology Data Exchange (ETDEWEB)

    Foda, O., E-mail: omar.foda@unimelb.edu.au [Dept. of Mathematics and Statistics, University of Melbourne, Parkville, VIC 3010 (Australia); Wheeler, M., E-mail: mwheeler@lpthe.jussieu.fr [Laboratoire de Physique Théorique et Hautes Energies, CNRS UMR 7589 (France); Université Pierre et Marie Curie – Paris 6, 4 place Jussieu, 75252 Paris cedex 05 (France)

    2013-06-11

    We study lattice configurations related to S{sub n}, the scalar product of an off-shell state and an on-shell state in rational A{sub n} integrable vertex models, n∈{1,2}. The lattice lines are colourless and oriented. The state variables are n conserved colours that flow along the line orientations, but do not necessarily cover every bond in the lattice. Choosing boundary conditions such that the positions where the colours flow into the lattice are fixed, and where they flow out are summed over, we show that the partition functions of these configurations, with these boundary conditions, are n-independent. Our results extend to trigonometric A{sub n} models, and to all n. This n-independence explains, in vertex-model terms, results from recent studies of S{sub 2} (Caetano and Vieira, 2012, [1], Wheeler, (arXiv:1204.2089), [2]). Namely, 1.S{sub 2}, which depends on two sets of Bethe roots, {b_1} and {b_2}, and cannot (as far as we know) be expressed in single determinant form, degenerates in the limit {b_1}→∞, and/or {b_2}→∞, into a product of determinants, 2. Each of the latter determinants is an A{sub 1} vertex-model partition function.

  10. Colour-independent partition functions in coloured vertex models

    International Nuclear Information System (INIS)

    Foda, O.; Wheeler, M.

    2013-01-01

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

  11. Sgraffito and colour in Alentejo

    Directory of Open Access Journals (Sweden)

    Sofia Salema

    2009-01-01

    Full Text Available This article intends to bring awareness to the architectonic value of sgraffito and summarize its risks, emphasizing the need to change intervention methodologies, promoting its safeguard and material its authenticity. In the last years, hundreds of buildings with sgraffito application in external façades have been discovered in Alentejo. One of the most important results of our research on sgraffito in the Alentejo Region is the fact that the majority of the listed sgraffito ornaments have been painted over so many times, that today we can hardly identify its original aspect, its chromatic values or its textures. Since sgraffito is a decorative technique with external plaster, some of its values, such as the dual colour variation and the aesthetical tension given by different textures and colours, which are intrinsic to the nature of this mural covering, must not be forgotten. Although the current restoration culture assumes as a sine qua non condition the conservation of the substance as a cultural certification, the interventions in sgrafitto, often use criteria deriving from renovation building techniques rather than careful preservation. Unfortunately, a strong unfamiliarity to its particular values and to its specific techniques is usually the case, resulting in inadequate recovering processes. An example is the application of painting layers over those ornaments, causing loss of authenticity, and also loss of aesthetical and historical values of the building. General concept and particular techniques of execution of sgraffito are described, establishing the panorama of sgraffito in Alentejo, illustrated with examples where original colour, texture and surfaces were not modified. Few interventions are shown where an adequate restoration was accomplished, comparing those cases with countless examples where sgraffito technique was completely subverted. Finally, we present a set of recommendations to help changing the quality of

  12. A child's vision.

    Science.gov (United States)

    Nye, Christina

    2014-06-01

    Implementing standard vision screening techniques in the primary care practice is the most effective means to detect children with potential vision problems at an age when the vision loss may be treatable. A critical period of vision development occurs in the first few weeks of life; thus, it is imperative that serious problems are detected at this time. Although it is not possible to quantitate an infant's vision, evaluating ocular health appropriately can mean the difference between sight and blindness and, in the case of retinoblastoma, life or death. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Colour terms in the interior design process

    OpenAIRE

    Attiah, DY; Cheung, TLV; Westland, S; Bromilow, D

    2015-01-01

    Colour is a very important topic that interior designers need to consider. Considerable research has been conducted in the area of colour application in interior design; in this study we are concerned with colour terms in interior design, mainly the terms designers use and know about. Fifteen interior designers with varied professional backgrounds, but based in the Middle East (Saudi Arabia, Dubai, Bahrain, Lebanon, Egypt, and Turkey), were interviewed. Previously we reported that fourteen ou...

  14. Long-range correlations from colour confinement

    International Nuclear Information System (INIS)

    Jurkiewicz, J.; Zenczykowski, P.

    1979-01-01

    A class of independent parton emission models is generalized by the introduction of the colour degrees of freedom. In the proposed models colour confinement extorts strong long-range forward-backward correlations, the rise of one-particle inclusive distribution and the KNO scaling. It leads to the analytically calculable definite asymptotic predictions for the D/ ratio which depends only on the choice of the colour group. Multiplicity distribution develops a remarkably long tail. (author)

  15. Colour in visualisation for computational fluid dynamics

    OpenAIRE

    Kinnear, D; Atherton, MA; Collins, MW; Dokhan, J; Karayiannis, TG

    2006-01-01

    Colour is used in computational fluid dynamic (CFD) simulations in two key ways. First it is used to visualise the geometry and allow the engineers to be confident that the model constructed is a good representation of the engineering situation. Once an analysis has been completed, colour is used in post-processing the data from the simulations to illustrate the complex fluid mechanic phenomena under investigation. This paper describes these two uses of colour and provides some examples to il...

  16. Colour discrimination and categorisation in Williams syndrome

    OpenAIRE

    Farran, E. K.; Cranwell, M. B.; Alvarez, J.; Franklin, A.

    2013-01-01

    Individuals with Williams syndrome (WS) present with impaired functioning of the dorsal visual stream relative to the ventral visual stream. As such, little attention has been given to ventral stream functions in WS. We investigated colour processing, a predominantly ventral stream function, for the first time in nineteen individuals with Williams syndrome. Colour discrimination was assessed using the Farnsworth-Munsell 100 hue test. Colour categorisation was assessed using a match-to-sample ...

  17. Colour Metallography of Cast Iron

    Directory of Open Access Journals (Sweden)

    Zhou Jiyang

    2009-05-01

    Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron.Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron , uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditionalmaterials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour

  18. Shell Colour Polymorphism in Bulla ampulla

    DEFF Research Database (Denmark)

    Cedhagen, Tomas

    1999-01-01

    Colour patterns of Bulla ampulla shells collected from Africa eastward to Pacific Islands were studied. 1\\vo common colour morphs were found. The typical morph is commonest. It is closely and finely mottled or all over with pinkish-gray on a creamy or flesh~tinted ground, with darker clouds......, irregular, V-shaped, or as longitudinal bands. The colouration of the other common morph is more uniform. It is lacking the darker clouds or bands and the colour is more greyish. The entire shell surface is densely mottled all over with small brown spots on a grey or beige background. Both morphs seem...

  19. Colourism: a global adolescent health concern.

    Science.gov (United States)

    Craddock, Nadia; Dlova, Ncoza; Diedrichs, Phillippa C

    2018-05-08

    Colourism, a form of prejudice and discrimination based solely upon skin colour, stands to jeopardize the physical health, wellbeing and life chances of adolescents of colour, globally. Research shows that adolescents can experience colourism at school and college, in the criminal justice system, at work and in the media they consume. It is therefore unsurprising that adolescents of colour often express a desire for lighter skin tones and/or are dissatisfied with their skin tone. Although research is scarce, some studies include older adolescents in their samples of skin-lightening product users. This is significant as the evidence is clear that the unmonitored use of skin-lightening products can be harmful to physical and psychological health, with evidence linking skin-lightening use to skin damage, kidney failure and depression. Although it is evident that colourism is central to the lives of adolescents of colour, more research is needed concerning the use of skin-lightening products among adolescents. Media literacy and critical race theory offer avenues in helping attenuate the harmful impact of colourism for adolescents of colour.

  20. Several ways of breaking the colour symmetry

    International Nuclear Information System (INIS)

    Krolikowski, W.

    1975-01-01

    We discuss some cases of colour-symmetry breaking and its implications for quark binding by one-gluon-exchange forces. We pay special attention to the case, where colour-isospin and colour-hypercharge subsymmetries are preserved. Then, the ω-PHI-like mixing of colour-nonet components 0 and 8 leads to a Zweig-type approximate selection rule for decays of PHI-like meson = antiqsub(B)qsub(B)(qsub(B) is the '' blue'' quark) into ordinary mesons (and photons). (author)

  1. Electrophysiological evidence for colour effects on the naming of colour diagnostic and noncolour diagnostic objects

    OpenAIRE

    Bramão, I.; Francisco, A.; Inácio , F.; Faísca, L.; Reis, A.; Petersson, K.

    2012-01-01

    In this study, we investigated the level of visual processing at which surface colour information improves the naming of colour diagnostic and noncolour diagnostic objects. Continuous electroencephalograms were recorded while participants performed a visual object naming task in which coloured and black-and-white versions of both types of objects were presented. The black-and-white and the colour presentations were compared in two groups of event-related potentials (ERPs): (1) The P1 and N1 c...

  2. The control of attentional target selection in a colour/colour conjunction task

    OpenAIRE

    Berggren, Nick; Eimer, Martin

    2016-01-01

    To investigate the time course of attentional object selection processes in visual search tasks where targets are defined by a combination of features from the same dimension, we measured the N2pc component as an electrophysiological marker of attentional object selection during colour/colour conjunction search. In Experiment 1, participants searched for targets defined by a combination of two colours, while ignoring distractor objects that matched only one of these colours. Reliable N2pc com...

  3. Particular application of methods of AdaBoost and LBP to the problems of computer vision

    OpenAIRE

    Волошин, Микола Володимирович

    2012-01-01

    The application of AdaBoost method and local binary pattern (LBP) method for different spheres of computer vision implementation, such as personality identification and computer iridology, is considered in the article. The goal of the research is to develop error-correcting methods and systems for implements of computer vision and computer iridology, in particular. This article considers the problem of colour spaces, which are used as a filter and as a pre-processing of images. Method of AdaB...

  4. Colours sometimes count : Awareness and bidirectionality in grapheme-colour synaesthesia

    NARCIS (Netherlands)

    Johnson, Addie; Jepma, Marieke; de Jong, Ritske

    2007-01-01

    Three experiments were conducted with 10 grapheme-colour synaesthetes and 10 matched controls to investigate (a) whether awareness of the inducer grapheme is necessary for synaesthetic colour induction and (b) whether grapheme-colour synaesthesia may be bidirectional in the sense that not only do

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

    International Nuclear Information System (INIS)

    Ramachandran, R.

    1979-01-01

    Treating the breaking of colour symmetry via the mixing between the colour gluons and weak bosons (a la Rajasekaran and Roy) it is observed that the colour contribution to the effective weak vertex of a quark at zero momentum transfer is zero upto 0(α). (author)

  6. Can the Farnsworth D15 Color Vision Test Be Defeated through Practice?

    Science.gov (United States)

    Ng, Jason S; Liem, Sophia C

    2018-05-01

    This study suggests that it is possible for some patients with severe red-green color vision deficiency to do perfectly on the Farnsworth D15 test after practicing it. The Farnsworth D15 is a commonly used test to qualify people for certain occupations. For patients with color vision deficiency, there may be high motivation to try to pass the test through practice to gain entry into a particular occupation. There is no evidence in the literature on whether it is possible for patients to learn to pass the D15 test through practice. Ten subjects with inherited red-green color vision deficiency and 15 color-normal subjects enrolled in the study. All subjects had anomaloscope testing, color vision book tests, and a Farnsworth D15 at an initial visit. For the D15, the number of major crossovers was determined for each subject. Failing the D15 was determined as greater than 1 major crossover. Subjects with color vision deficiency practiced the D15 as long as desired to achieve a perfect score and then returned for a second visit for D15 testing. A paired t test was used to analyze the number of major crossovers at visit 1 versus visit 2. Color-normal subjects did not have any major crossovers. Subjects with color vision deficiency had significantly (P color vision deficiency, and this should be considered in certain cases where occupational entry is dependent on D15 testing.

  7. Vision Assessment and Prescription of Low Vision Devices

    OpenAIRE

    Keeffe, Jill

    2004-01-01

    Assessment of vision and prescription of low vision devices are part of a comprehensive low vision service. Other components of the service include training the person affected by low vision in use of vision and other senses, mobility, activities of daily living, and support for education, employment or leisure activities. Specialist vision rehabilitation agencies have services to provide access to information (libraries) and activity centres for groups of people with impaired vision.

  8. Colour As a Signal for Entraining the Mammalian Circadian Clock

    Science.gov (United States)

    Walmsley, Lauren; Hanna, Lydia; Mouland, Josh; Martial, Franck; West, Alexander; Smedley, Andrew R.; Bechtold, David A.; Webb, Ann R.; Lucas, Robert J.; Brown, Timothy M.

    2015-01-01

    Twilight is characterised by changes in both quantity (“irradiance”) and quality (“colour”) of light. Animals use the variation in irradiance to adjust their internal circadian clocks, aligning their behaviour and physiology with the solar cycle. However, it is currently unknown whether changes in colour also contribute to this entrainment process. Using environmental measurements, we show here that mammalian blue–yellow colour discrimination provides a more reliable method of tracking twilight progression than simply measuring irradiance. We next use electrophysiological recordings to demonstrate that neurons in the mouse suprachiasmatic circadian clock display the cone-dependent spectral opponency required to make use of this information. Thus, our data show that some clock neurons are highly sensitive to changes in spectral composition occurring over twilight and that this input dictates their response to changes in irradiance. Finally, using mice housed under photoperiods with simulated dawn/dusk transitions, we confirm that spectral changes occurring during twilight are required for appropriate circadian alignment under natural conditions. Together, these data reveal a new sensory mechanism for telling time of day that would be available to any mammalian species capable of chromatic vision. PMID:25884537

  9. Conspicuous plumage colours are highly variable.

    Science.gov (United States)

    Delhey, Kaspar; Szecsenyi, Beatrice; Nakagawa, Shinichi; Peters, Anne

    2017-01-25

    Elaborate ornamental traits are often under directional selection for greater elaboration, which in theory should deplete underlying genetic variation. Despite this, many ornamental traits appear to remain highly variable and how this essential variation is maintained is a key question in evolutionary biology. One way to address this question is to compare differences in intraspecific variability across different types of traits to determine whether high levels of variation are associated with specific trait characteristics. Here we assess intraspecific variation in more than 100 plumage colours across 55 bird species to test whether colour variability is linked to their level of elaboration (indicated by degree of sexual dichromatism and conspicuousness) or their condition dependence (indicated by mechanism of colour production). Conspicuous colours had the highest levels of variation and conspicuousness was the strongest predictor of variability, with high explanatory power. After accounting for this, there were no significant effects of sexual dichromatism or mechanisms of colour production. Conspicuous colours may entail higher production costs or may be more sensitive to disruptions during production. Alternatively, high variability could also be related to increased perceptual difficulties inherent to discriminating highly elaborate colours. Such psychophysical effects may constrain the exaggeration of animal colours. © 2017 The Author(s).

  10. Colour Mathematics: With Graphs and Numbers

    Science.gov (United States)

    LoPresto, Michael C.

    2009-01-01

    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…

  11. Colour Perception Between Psychology and Art

    OpenAIRE

    Cattaruzza, Serena

    2014-01-01

    The poster refers to important contributions of psychological research on colours. Special emphasis is given to the fundamental classification proposed by David Katz, who strongly influenced subsequent studies; e.g., those by Karl Bühler and Gaetano Kanizsa. In particular, the opposition between diaphanic and epiphanic colours is discussed and applied to two recent paintings of a contemporary experimental artist.

  12. Human colour in mate choice and competition.

    Science.gov (United States)

    Rowland, Hannah M; Burriss, Robert P

    2017-07-05

    The colour of our skin and clothing affects how others perceive us and how we behave. Human skin colour varies conspicuously with genetic ancestry, but even subtle changes in skin colour due to diet, blood oxygenation and hormone levels influence social perceptions. In this review, we describe the theoretical and empirical frameworks in which human colour is researched. We explore how subtle skin colour differences relate to judgements of health and attractiveness. Also, because humans are one of the few organisms able to manipulate their apparent colour, we review how cosmetics and clothing are implicated in courtship and competition, both inside the laboratory and in the real world. Research on human colour is in its infancy compared with human psychophysics and colour research in non-human animals, and hence we present best-practice guidelines for methods and reporting, which we hope will improve the validity and reproducibility of studies on human coloration.This article is part of the themed issue 'Animal coloration: production, perception, function and application'. © 2017 The Author(s).

  13. Colour measurement and white blood cell recognition

    CERN Document Server

    Gelsema, E S

    1972-01-01

    As a part of a collaboration with NEMCH aimed at the automation of the differential white blood cell count, studies have been made of the different possibilities for using colour to help in the recognition process. Results are presented comparing data obtained with a microspectrophotometer and with a simulated three-colour scanner.

  14. Brilliant Colours from a White Snow Cover

    Science.gov (United States)

    Vollmer, Michael; Shaw, Joseph A

    2013-01-01

    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…

  15. Global skin colour prediction from DNA

    NARCIS (Netherlands)

    S. Walsh (Susan); L.C. Chaitanya (Lakshmi); Breslin, K. (Krystal); Muralidharan, C. (Charanya); Bronikowska, A. (Agnieszka); E. Pośpiech (Ewelina); Koller, J. (Julia); L. Kovatsi (Leda); A. Wollstein (Andreas); W. Branicki (Wojciech); F. Liu; M.H. Kayser (Manfred)

    2017-01-01

    textabstractHuman skin colour is highly heritable and externally visible with relevance in medical, forensic, and anthropological genetics. Although eye and hair colour can already be predicted with high accuracies from small sets of carefully selected DNA markers, knowledge about the genetic

  16. Colour Perception on Facial Expression towards Emotion

    Directory of Open Access Journals (Sweden)

    Rubita Sudirman

    2012-12-01

    Full Text Available This study is to investigate human perceptions on pairing of facial expressions of emotion with colours. A group of 27 subjects consisting mainly of younger and Malaysian had participated in this study. For each of the seven faces, which expresses the basic emotions neutral, happiness, surprise, anger, disgust, fear and sadness, a single colour is chosen from the eight basic colours for the match of best visual look to the face accordingly. The different emotions appear well characterized by a single colour. The approaches used in this experiment for analysis are psychology disciplines and colours engineering. These seven emotions are being matched by the subjects with their perceptions and feeling. Then, 12 male and 12 female data are randomly chosen from among the previous data to make a colour perception comparison between genders. The successes or failures in running of this test depend on the possibility of subjects to propose their every single colour for each expression. The result will translate into number and percentage as a guide for colours designers and psychology field.

  17. Coloured Petri Nets and the Invariant Method

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1981-01-01

    processes to be described by a common subnet, without losing the ability to distinguish between them. Our generalization, called coloured Petri nets, is heavily influenced by predicate transition-nets introduced by H.J. Genrich and K. Lautenbach. Moreover our paper shows how the invariant-method, introduced...... for Petri nets by K. Lautenbach, can be generalized to coloured Petri nets....

  18. Is colour modulation an independent factor in human visual photosensitivity?

    NARCIS (Netherlands)

    Parra, J.; Lopes da Silva, F.H.; Stroink, H.; Kalitzin, S.

    2007-01-01

    Considering that the role of colour in photosensitive epilepsy (PSE) remains unclear, we designed a study to determine the potential of different colours, colour combinations and white light to trigger photoparoxysmal responses (PPRs) under stringent controlled conditions. After assessing their

  19. Please pass me the skin coloured crayon!

    DEFF Research Database (Denmark)

    Zimmermann, Martina; Levisen, Carsten; Beck, Thorhalla Gudmundsdottir

    2015-01-01

    worldviews and idealised cognitive models embedded in skin-based colour concepts in contemporary German and Scandi- navian languages. Arguing that colour concepts are linguistic constructs through which speakers have learned to pay attention to their visual worlds, we trace the origin of the skin......This study explores the cultural semantics of colour words in the four urban, European communities of Munich, Berne, Aarhus, and Reykjavik, focussing on hautfarben (German), hutfarb (Bernese Swiss German), hudfarvet (Danish), and húðlitur (Icelandic), all of which can be translated as ‘skin...... coloured’. Unlike in English, where skin coloured has fallen out of use due to its racist semantic profile, these words are still widely present within the four communities. Using evidence from a referential colour naming task and semi-structured interviews, our study seeks to reveal the linguistic...

  20. Voltage-controlled colour-tunable microcavity OLEDs with enhanced colour purity

    International Nuclear Information System (INIS)

    Choy, Wallace C H; Niu, J H; Li, W L; Chui, P C

    2008-01-01

    The emission spectrum of single-unit voltage-controlled colour-tunable organic light emitting devices (OLEDs) has been theoretically and experimentally studied. Our results show that by introducing the microcavity structure, the colour purity of not only the destination colour but also the colour-tunable route can be enhanced, while colour purity is still an issue in typical single-unit voltage-controlled colour-tunable OLEDs. With the consideration of the periodical cycling of resonant wavelength and absorption loss of the metal electrodes, the appropriate change in the thickness of the microcavity structure has been utilized to achieve voltage-controlled red-to-green and red-to-blue colour-tunable OLEDs without adding dyes or other organic materials to the OLEDs

  1. FPGA Vision Data Architecture

    Science.gov (United States)

    Morfopoulos, Arin C.; Pham, Thang D.

    2013-01-01

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

  2. ANALYSES OF ROCK SURFACE COLOUR CHANGES DUE TO WEATHERING

    OpenAIRE

    GOKAY, Mehmet Kemal

    2018-01-01

    Description parameters of rock masses and minerals include their colours as well. Colours appear in daylight for surfaced rock masses are changing slightly due to weathering layers which have been covering its surface gradually. Healthy human eyes can manage to differentiate visible light spectrum to identify colours of substances including rock masses. Then visible blackish colours of magnetite minerals, reddish colours of Terra- Rosa soils, greenish colours of weathered copper ore, pure whi...

  3. ANALYSES OF ROCK SURFACE COLOUR CHANGES DUE TO WEATHERING

    OpenAIRE

    GÖKAY, Mehmet Kemal

    2018-01-01

    Description parameters of rock masses and minerals include their colours as well. Colours appear in daylight for surfaced rock masses are changing slightly due to weathering layers which have been covering its surface gradually. Healthy human eyes can manage to differentiate visible spectrum to identify the colours of substance including rock masses. Then visible blackish colours of magnetite minerals, reddish colours of Terra- Rosa soils, greenish colours of weathered copper ore, pure white ...

  4. Dimensionality of the Consumer Perceived Value of Product Colour

    OpenAIRE

    Kiehelä, Hanna

    2014-01-01

    Consumers’ product assessments are largely based on colour, and a product’s colour can increase consumer satisfaction, awareness and loyalty. However, existing colour research is fragmented and calls for theoretically-enhanced understandings of the role of colour in consumer product perception. The existing colour research mainly focuses on consumers’ immediate reactions when exposed to colours although studies show that consumers evaluate products differently in purchase and in use. There...

  5. A Bayesian Model of the Memory Colour Effect

    OpenAIRE

    Witzel, Christoph; Olkkonen, Maria; Gegenfurtner, Karl R.

    2018-01-01

    According to the memory colour effect, the colour of a colour-diagnostic object is not perceived independently of the object itself. Instead, it has been shown through an achromatic adjustment method that colour-diagnostic objects still appear slightly in their typical colour, even when they are colourimetrically grey. Bayesian models provide a promising approach to capture the effect of prior knowledge on colour perception and to link these effects to more general effects of cue integration....

  6. A Bayesian model of the memory colour effect.

    OpenAIRE

    Witzel, Christoph; Olkkonen, Maria; Gegenfurtner, Karl R.

    2018-01-01

    According to the memory colour effect, the colour of a colour-diagnostic object is not perceived independently of the object itself. Instead, it has been shown through an achromatic adjustment method that colour-diagnostic objects still appear slightly in their typical colour, even when they are colourimetrically grey. Bayesian models provide a promising approach to capture the effect of prior knowledge on colour perception and to link these effects to more general effects of cue integration....

  7. Mutagenesis in naturally coloured cotton

    International Nuclear Information System (INIS)

    Khatod, J.P.; Meshram, L.D.; Jain, P.P.

    2000-01-01

    The seeds of naturally coloured cotton were treated with 15 kR, 20 kR doses of gamma rays and 0.5% Ethyl Methane Sulphonate (EMS) and their combinations. The M 1 and M 2 generations were studied for mutagenic effectiveness and efficiency in inducing the useful mutants, spectrum of mutation and their effects on bract characters. Results obtained revealed that 15 kR and 20 kR doses were more effective in inducing the mutations. In G. hirsutum, significant differences were found for bract size and dry weight of bract was noted in 20 kR dose and low in 0.5% EMS in M 1 . In the M 2 generation increased ratio of bract surface area to lint weight per boll was noted in 20 kR + 0.5% EMS. (author)

  8. Colour isomers in multiquark systems

    International Nuclear Information System (INIS)

    Hoegaasen, H.

    1979-01-01

    If we select configurations where a high angular momentum separates coloured groups of quarks the states can be sufficiently stable to show up as resonances. The kind of states I shall talk about are mesons of the following kind (C=6,7), (C=3 bar,3) and baryons: (C=8,8), (C=6 bar,6). In each state the quarks on each end of the colourelectric flux tube are taken to be in relative s-waves. Models for baryonium and of narrow mesobaryonium states have been proposed on the basis of these configurations. The theoretical input in these models is an extrapolation of what is known about quark-quark interactions from ordinary q anti q and qqq spectroscopy. (author)

  9. Colour screening and quark confinement

    International Nuclear Information System (INIS)

    Mack, G.

    1978-03-01

    It is proposed that in Quantum Chromodynamics the colour charge of gluons and of anything with zero triality is screened by a dynamical Higgs mechanism with Higgs scalars made out of gluons. The center Z 3 of the gauge group SU(3) is left unbroken in this way, and single quarks, which have nonzero triality, cannot be screened. Long range forces between them persist therefore. Given that the Higgs mechanism produces a mass gap, the most favorable configuration of field lines between e.g. quark and antiquark will be in strings analogous to magnetic field lines in a superconductor. The strings confine the quarks. The screening mechanism, on the other hand, produces not only the mass gap (which leads to string formation) but is also responsible for saturation of forces, i.e. absence of bound states of six quarks etc. (orig.) [de

  10. Colour screening and quark confinement

    International Nuclear Information System (INIS)

    Mack, G.

    1978-01-01

    It is proposed that in quantum chromodynamics the colour charge of gluons and of anything with zero triality is screened by a dynamic Higgs mechanism with Higgs scalars made out of gluons, but the center Z 3 of the gauge group SU(3) is left unbroken, and single quarks, which have nonzero triality, are not screened. Long range forces between them persist therefore. Given that the Higgs mechanism produces a mass gap, the most favourable configuration of field lines between e.g., quark and antiquark will be in strings analogous to magnetic field lines in a superconductor. The string confine the quarks. The screening mechanism, on the other hand, produces not only the mass gap (which leads to string formation) but is also responsible for saturation of forces, i.e. absence of bound states of six quarks, etc. (Auth.)

  11. Vision-based interaction

    CERN Document Server

    Turk, Matthew

    2013-01-01

    In its early years, the field of computer vision was largely motivated by researchers seeking computational models of biological vision and solutions to practical problems in manufacturing, defense, and medicine. For the past two decades or so, there has been an increasing interest in computer vision as an input modality in the context of human-computer interaction. Such vision-based interaction can endow interactive systems with visual capabilities similar to those important to human-human interaction, in order to perceive non-verbal cues and incorporate this information in applications such

  12. Colour Terms Affect Detection of Colour and Colour-Associated Objects Suppressed from Visual Awareness

    OpenAIRE

    Forder, Lewis; Taylor, Olivia; Mankin, Helen; Scott, Ryan B.; Franklin, Anna

    2016-01-01

    The idea that language can affect how we see the world continues to create controversy. A potentially important study in this field has shown that when an object is suppressed from visual awareness using continuous flash suppression (a form of binocular rivalry), detection of the object is differently affected by a preceding word prime depending on whether the prime matches or does not match the object. This may suggest that language can affect early stages of vision. We replicated this parad...

  13. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... Research Home / < Back To Health Topics / Iron-Deficiency Anemia Iron-Deficiency Anemia Also known as Leer en español Iron-deficiency ... iron-deficiency anemia. Blood tests to screen for iron-deficiency anemia To screen for iron-deficiency anemia, your doctor ...

  14. Iron deficiency

    DEFF Research Database (Denmark)

    Schou, Morten; Bosselmann, Helle; Gaborit, Freja

    2015-01-01

    BACKGROUND: Both iron deficiency (ID) and cardiovascular biomarkers are associated with a poor outcome in heart failure (HF). The relationship between different cardiovascular biomarkers and ID is unknown, and the true prevalence of ID in an outpatient HF clinic is probably overlooked. OBJECTIVES.......043). CONCLUSION: ID is frequent in an outpatient HF clinic. ID is not associated with cardiovascular biomarkers after adjustment for traditional confounders. Inflammation, but not neurohormonal activation is associated with ID in systolic HF. Further studies are needed to understand iron metabolism in elderly HF...

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

    Science.gov (United States)

    Rohde, Katja; Papiorek, Sarah; Lunau, Klaus

    2013-03-01

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

  16. Most and Least Preferred Colours Differ According to Object Context: New Insights from an Unrestricted Colour Range.

    Science.gov (United States)

    Jonauskaite, Domicele; Mohr, Christine; Antonietti, Jean-Philippe; Spiers, Peter M; Althaus, Betty; Anil, Selin; Dael, Nele

    2016-01-01

    Humans like some colours and dislike others, but which particular colours and why remains to be understood. Empirical studies on colour preferences generally targeted most preferred colours, but rarely least preferred (disliked) colours. In addition, findings are often based on general colour preferences leaving open the question whether results generalise to specific objects. Here, 88 participants selected the colours they preferred most and least for three context conditions (general, interior walls, t-shirt) using a high-precision colour picker. Participants also indicated whether they associated their colour choice to a valenced object or concept. The chosen colours varied widely between individuals and contexts and so did the reasons for their choices. Consistent patterns also emerged, as most preferred colours in general were more chromatic, while for walls they were lighter and for t-shirts they were darker and less chromatic compared to least preferred colours. This meant that general colour preferences could not explain object specific colour preferences. Measures of the selection process further revealed that, compared to most preferred colours, least preferred colours were chosen more quickly and were less often linked to valenced objects or concepts. The high intra- and inter-individual variability in this and previous reports furthers our understanding that colour preferences are determined by subjective experiences and that most and least preferred colours are not processed equally.

  17. Most and Least Preferred Colours Differ According to Object Context: New Insights from an Unrestricted Colour Range.

    Directory of Open Access Journals (Sweden)

    Domicele Jonauskaite

    Full Text Available Humans like some colours and dislike others, but which particular colours and why remains to be understood. Empirical studies on colour preferences generally targeted most preferred colours, but rarely least preferred (disliked colours. In addition, findings are often based on general colour preferences leaving open the question whether results generalise to specific objects. Here, 88 participants selected the colours they preferred most and least for three context conditions (general, interior walls, t-shirt using a high-precision colour picker. Participants also indicated whether they associated their colour choice to a valenced object or concept. The chosen colours varied widely between individuals and contexts and so did the reasons for their choices. Consistent patterns also emerged, as most preferred colours in general were more chromatic, while for walls they were lighter and for t-shirts they were darker and less chromatic compared to least preferred colours. This meant that general colour preferences could not explain object specific colour preferences. Measures of the selection process further revealed that, compared to most preferred colours, least preferred colours were chosen more quickly and were less often linked to valenced objects or concepts. The high intra- and inter-individual variability in this and previous reports furthers our understanding that colour preferences are determined by subjective experiences and that most and least preferred colours are not processed equally.

  18. Most and Least Preferred Colours Differ According to Object Context: New Insights from an Unrestricted Colour Range

    Science.gov (United States)

    Jonauskaite, Domicele; Mohr, Christine; Antonietti, Jean-Philippe; Spiers, Peter M.; Althaus, Betty; Anil, Selin; Dael, Nele

    2016-01-01

    Humans like some colours and dislike others, but which particular colours and why remains to be understood. Empirical studies on colour preferences generally targeted most preferred colours, but rarely least preferred (disliked) colours. In addition, findings are often based on general colour preferences leaving open the question whether results generalise to specific objects. Here, 88 participants selected the colours they preferred most and least for three context conditions (general, interior walls, t-shirt) using a high-precision colour picker. Participants also indicated whether they associated their colour choice to a valenced object or concept. The chosen colours varied widely between individuals and contexts and so did the reasons for their choices. Consistent patterns also emerged, as most preferred colours in general were more chromatic, while for walls they were lighter and for t-shirts they were darker and less chromatic compared to least preferred colours. This meant that general colour preferences could not explain object specific colour preferences. Measures of the selection process further revealed that, compared to most preferred colours, least preferred colours were chosen more quickly and were less often linked to valenced objects or concepts. The high intra- and inter-individual variability in this and previous reports furthers our understanding that colour preferences are determined by subjective experiences and that most and least preferred colours are not processed equally. PMID:27022909

  19. Block colourings of 6-cycle systems

    Directory of Open Access Journals (Sweden)

    Paola Bonacini

    2017-01-01

    Full Text Available Let \\(\\Sigma=(X,\\mathcal{B}\\ be a \\(6\\-cycle system of order \\(v\\, so \\(v\\equiv 1,9\\mod 12\\. A \\(c\\-colouring of type \\(s\\ is a map \\(\\phi\\colon\\mathcal {B}\\rightarrow \\mathcal{C}\\, with \\(C\\ set of colours, such that exactly \\(c\\ colours are used and for every vertex \\(x\\ all the blocks containing \\(x\\ are coloured exactly with \\(s\\ colours. Let \\(\\frac{v-1}{2}=qs+r\\, with \\(q, r\\geq 0\\. \\(\\phi\\ is equitable if for every vertex \\(x\\ the set of the \\(\\frac{v-1}{2}\\ blocks containing \\(x\\ is partitioned in \\(r\\ colour classes of cardinality \\(q+1\\ and \\(s-r\\ colour classes of cardinality \\(q\\. In this paper we study bicolourings and tricolourings, for which, respectively, \\(s=2\\ and \\(s=3\\, distinguishing the cases \\(v=12k+1\\ and \\(v=12k+9\\. In particular, we settle completely the case of \\(s=2\\, while for \\(s=3\\ we determine upper and lower bounds for \\(c\\.

  20. Physicochemical and physiological basis of dichromatic colour

    Science.gov (United States)

    Kreft, Samo; Kreft, Marko

    2007-11-01

    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.

  1. Colour and lighting in hospital design

    Science.gov (United States)

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

    2006-06-01

    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'.

  2. Colour discrimination and categorisation in Williams syndrome.

    Science.gov (United States)

    Farran, Emily K; Cranwell, Matthew B; Alvarez, James; Franklin, Anna

    2013-10-01

    Individuals with Williams syndrome (WS) present with impaired functioning of the dorsal visual stream relative to the ventral visual stream. As such, little attention has been given to ventral stream functions in WS. We investigated colour processing, a predominantly ventral stream function, for the first time in nineteen individuals with Williams syndrome. Colour discrimination was assessed using the Farnsworth-Munsell 100 hue test. Colour categorisation was assessed using a match-to-sample test and a colour naming task. A visual search task was also included as a measure of sensitivity to the size of perceptual colour difference. Results showed that individuals with WS have reduced colour discrimination relative to typically developing participants matched for chronological age; performance was commensurate with a typically developing group matched for non-verbal ability. In contrast, categorisation was typical in WS, although there was some evidence that sensitivity to the size of perceptual colour differences was reduced in this group. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Operational Based Vision Assessment Automated Vision Test Collection User Guide

    Science.gov (United States)

    2017-05-15

    AFRL-SA-WP-SR-2017-0012 Operational Based Vision Assessment Automated Vision Test Collection User Guide Elizabeth Shoda, Alex...June 2015 – May 2017 4. TITLE AND SUBTITLE Operational Based Vision Assessment Automated Vision Test Collection User Guide 5a. CONTRACT NUMBER... automated vision tests , or AVT. Development of the AVT was required to support threshold-level vision testing capability needed to investigate the

  4. Evaluation of Next-Generation Vision Testers for Aeromedical Certification of Aviation Personnel

    Science.gov (United States)

    2009-07-01

    measure distant, intermediate, and near acuity. The slides are essentially abbreviated versions of the Early Treatment for Diabetic Retinopathy Study...over, requiring intermediate vision testing and 12 were color deficient. Analysis was designed to detect statistically significant differences between...Vertical Phoria (Right & Left Hyperphoria) Test scores from each of the vision testers were collated and analyzed. Analysis was designed to detect

  5. The colour wheels of art, perception, science and physiology

    Science.gov (United States)

    Harkness, Nick

    2006-06-01

    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.

  6. Progress in computer vision.

    Science.gov (United States)

    Jain, A. K.; Dorai, C.

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

  7. Jane Addams’ Social Vision

    DEFF Research Database (Denmark)

    Villadsen, Kaspar

    2018-01-01

    resonated with key tenets of social gospel theology, which imbued her texts with an overarching vision of humanity’s progressive history. It is suggested that Addams’ vision of a major transition in industrial society, one involving a BChristian renaissance^ and individuals’ transformation into Bsocialized...

  8. Computer vision for sports

    DEFF Research Database (Denmark)

    Thomas, Graham; Gade, Rikke; Moeslund, Thomas B.

    2017-01-01

    fixed to players or equipment is generally not possible. This provides a rich set of opportunities for the application of computer vision techniques to help the competitors, coaches and audience. This paper discusses a selection of current commercial applications that use computer vision for sports...

  9. Copenhagen Energy Vision

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Lund, Rasmus Søgaard; Connolly, David

    The short-term goal for The City of Copenhagen is a CO2 neutral energy supply by the year 2025, and the long-term vision for Denmark is a 100% renewable energy (RE) supply by the year 2050. In this project, it is concluded that Copenhagen plays a key role in this transition. The long-term vision...

  10. Modeling foveal vision

    NARCIS (Netherlands)

    Florack, L.M.J.; Sgallari, F.; Murli, A.; Paragios, N.

    2007-01-01

    geometric model is proposed for an artificial foveal vision system, and its plausibility in the context of biological vision is explored. The model is based on an isotropic, scale invariant two-form that describes the spatial layout of receptive fields in the the visual sensorium (in the biological

  11. Balancing selection maintains cryptic colour morphs.

    Science.gov (United States)

    Wellenreuther, Maren

    2017-11-01

    Animals display incredibly diverse colour patterns, a testament to evolution's endless innovation in shaping life. In many species, the interplay between males and females in the pursuit of mates has driven the evolution of a myriad of colour forms, from the flashy peacock tail feathers to the tiniest colour markings in damselflies. In others, colour provides crypsis by allowing to blend into the background and to escape the eyes of predators. While the obvious benefits of this dazzling diversity for reproduction and survival seem straightforward, its maintenance is not. Theory predicts that genetic drift and various forms of selection reduce variation over time, making the persistence of colour variants over generations a puzzle. In this issue of Molecular Ecology, Lindtke et al. () study the cryptic colour morphs of Timema cristinae walking sticks to shed light on the genetic architecture and mechanisms that allow colour polymorphism maintenance over long timescales. By combining genome-wide data with phenotyping information from natural populations, they were able to map the green and melanistic colour to one genomic region with highly reduced effective recombination rate between two main chromosomal variants, consistent with an inversion polymorphism. These two main chromosomal variants showed geographically widespread heterozygote excess, and genomic signatures consistent with long-term balancing selection. A younger chromosomal variant was detected for the third morph, the green-striped colour morphs, in the same genomic regions as the melanistic and the green-unstriped morphs. Together, these results suggest that the genetic architecture of cryptic T. cristinae morphs is caused by nonrecombining genomic blocks that have been maintained over extended time periods by balancing selection making this study one of the few available empirical examples documenting that balancing selection of various forms may play an important role in maintaining adaptive genetic

  12. Colour revolutions: criminal-legal aspect

    Directory of Open Access Journals (Sweden)

    Sergey Alekseyevich Gordeychik

    2015-03-01

    Full Text Available Objective basing on the analysis of colour revolution technologies in different countries to formulate propositions for improving criminal legislation aimed at counteraction against this phenomenon. Methods general scientific induction deduction analysis synthesis and specific scientific formaljuridical and comparativelegal. Results using the results of colour revolutionsrsquo research carried out by political scientists the author evaluates the character and level of public danger of colour revolutions. The author states that the colour revolutions threaten the normal existence of the country or several countries. The conclusion is made that the colour revolutions must be counteracted by criminallegal means. The article states the absence of norms in the existing criminal legislation which would impose criminal liability on organizers incendiaries and participants of colour revolutions. It is proposed to supplement the existing criminal law with the norm stipulating the liability for such deeds and to insert this norm into Art. 34 ldquoCrimes against peace and security of humanityrdquo thus equating organization preparation and implementing colour revolutions with planning preparation launching and conducting an aggressive war Art. 353 of the Russian Criminal Code. Scientific novelty basing on the existing legal norms modern politological and juridical scientific literature a conclusion is made that the colour revolutions are based on the abuse of law. This allows the organizers of colour revolutions to legally prepare and implement the subversion of undesirable political regimes. The author formulates proposals for supplementing the criminal legislation. Practical value the materials and conclusions of the article can be used in lawmaking activity when elaborating the drafts of legal acts for changing and supplementing the Russian Criminal Code for research activity when preparing monographs and dissertations tutorials and articles when

  13. Culture of colour in the city

    Directory of Open Access Journals (Sweden)

    Vasiljević-Tomić Dragana

    2009-01-01

    Full Text Available The phenomenon of colour is examined through the evolution of colour and development of culture of colour, which significantly affects the colouristic priorities of people and the colour of the city itself. The terms functional colour and climate of colour are also considered, as some of the most important characteristics of architectural and urban design practice. The quality of the urban public space is directly predicated by cultural identity, and indirectly by appearance of polychromy in urban public space. The need to improve the quality of life in the city represents one of the key motives for operating in urban space, i.e. commencing the process of architectural and urban designing. Historical architectural policrhomy represents the basis for appearance of colour in public space. The complexity of colouristic attributes of the urban public space is conditioned by the basic characteristics: colouristic priorities, harmony of coloured spatial structures and materials in designing the polychrome ambient in the city. The factors that shape the colouristic ambient of the city are: characteristics of nature and climate, interrelations of colour and shape, as well as the experience of the form of the urban public space while preserving its identity. The acquired experiences point to the possibility of redefining the concepts of urban public space in planning and designing practice. The synthesized knowledge is sublimed through examination of the elasticity of its boundaries in accordance to the preservation of the identity of place and the future transformations of the city as well as of its users. The new principles are formed upon which the transformed model of the urban public space as a polychrome ambient is built.

  14. Independent effects of colour on object identification and memory.

    Science.gov (United States)

    Lloyd-Jones, Toby J; Nakabayashi, Kazuyo

    2009-02-01

    We examined the effects of colour on object identification and memory using a study-test priming procedure with a coloured-object decision task at test (i.e., deciding whether an object is correctly coloured). Objects were selected to have a single associated colour and were either correctly or incorrectly coloured. In addition, object shape and colour were either spatially integrated (i.e., colour fell on the object surface) or spatially separated (i.e., colour formed the background to the object). Transforming the colour of an object from study to test (e.g., from a yellow banana to a purple banana) reduced priming of response times, as compared to when the object was untransformed. This utilization of colour information in object memory was not contingent upon colour falling on the object surface or whether the resulting configuration was of a correctly or incorrectly coloured object. In addition, we observed independent effects of colour on response times, whereby coloured-object decisions were more efficient for correctly than for incorrectly coloured objects but only when colour fell on the object surface. These findings provide evidence for two distinct mechanisms of shape-colour binding in object processing.

  15. Panoramic stereo sphere vision

    Science.gov (United States)

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

    2013-01-01

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

  16. Wing scale ultrastructure underlying convergent and divergent iridescent colours in mimetic Heliconius butterflies.

    Science.gov (United States)

    Parnell, Andrew J; Bradford, James E; Curran, Emma V; Washington, Adam L; Adams, Gracie; Brien, Melanie N; Burg, Stephanie L; Morochz, Carlos; Fairclough, J Patrick A; Vukusic, Pete; Martin, Simon J; Doak, Scott; Nadeau, Nicola J

    2018-04-01

    Iridescence is an optical phenomenon whereby colour changes with the illumination and viewing angle. It can be produced by thin film interference or diffraction. Iridescent optical structures are fairly common in nature, but relatively little is known about their production or evolution. Here we describe the structures responsible for producing blue-green iridescent colour in Heliconius butterflies. Overall the wing scale structures of iridescent and non-iridescent Heliconius species are very similar, both having longitudinal ridges joined by cross-ribs. However, iridescent scales have ridges composed of layered lamellae, which act as multilayer reflectors. Differences in brightness between species can be explained by the extent of overlap of the lamellae and their curvature as well as the density of ridges on the scale. Heliconius are well known for their Müllerian mimicry. We find that iridescent structural colour is not closely matched between co-mimetic species. Differences appear less pronounced in models of Heliconius vision than models of avian vision, suggesting that they are not driven by selection to avoid heterospecific courtship by co-mimics. Ridge profiles appear to evolve relatively slowly, being similar between closely related taxa, while ridge density evolves faster and is similar between distantly related co-mimics. © 2018 The Authors.

  17. Innate colour preference, individual learning and memory retention in the ant Camponotus blandus.

    Science.gov (United States)

    Yilmaz, Ayse; Dyer, Adrian G; Rössler, Wolfgang; Spaethe, Johannes

    2017-09-15

    Ants are a well-characterized insect model for the study of visual learning and orientation, but the extent to which colour vision is involved in these tasks remains unknown. We investigated the colour preference, learning and memory retention of Camponotus blandus foragers under controlled laboratory conditions. Our results show that C. blandus foragers exhibit a strong innate preference for ultraviolet (UV, 365 nm) over blue (450 nm) and green (528 nm) wavelengths. The ants can learn to discriminate 365 nm from either 528 nm or 450 nm, independent of intensity changes. However, they fail to discriminate between 450 nm and 528 nm. Modelling of putative colour spaces involving different numbers of photoreceptor types revealed that colour discrimination performance of individual ants is best explained by dichromacy, comprising a short-wavelength (UV) receptor with peak sensitivity at about 360 nm, and a long-wavelength receptor with peak sensitivity between 470 nm and 560 nm. Foragers trained to discriminate blue or green from UV light are able to retain the learned colour information in an early mid-term (e-MTM), late mid-term (l-MTM), early long-term (e-LTM) and late long-term (l-LTM) memory from where it can be retrieved after 1 h, 12 h, 24 h, 3 days and 7 days after training, indicating that colour learning may induce different memory phases in ants. Overall, our results show that ants can use chromatic information in a way that should promote efficient foraging in complex natural environments. © 2017. Published by The Company of Biologists Ltd.

  18. 77 FR 3547 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2012-01-24

    ... restricting him or her to driving in intrastate commerce. To evaluate the effect of these exemptions on safety... the vision deficiency for the past 3 years. Recent driving performance is especially important in evaluating future safety, according to several research studies designed to correlate past and future driving...

  19. 77 FR 38379 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2012-06-27

    ... restricting him or her to driving in intrastate commerce. To evaluate the effect of these exemptions on safety... the vision deficiency for the past 3 years. Recent driving performance is especially important in evaluating future safety, according to several research studies designed to correlate past and future driving...

  20. 76 FR 25763 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2011-05-05

    ... with the vision deficiency: Christopher Kahl, Althea Renita Dowell, Steven DuBois, Steve Campbell... Pulido, Oliver Murphy, Jerome Smalls, Alan Jenkins, Ryan Forsythe, Terry L. Randoll, Edward Joseph... for an exemption. Thomas L. Newingham, Joseph Barlow. The following 2 applicants do not have...

  1. 77 FR 12361 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2012-02-29

    ... Martin C. Baschab Donald Hooper Gregory Chiropolos Ronnie G. Lynn Malinda N. Parks Mark Smith Stephen C... experience driving a CMV with the vision deficiency: Joshua H. Boatright Domingo V. Perez James F. Blush Dean.... Pinson Wayne L. Green Stephen R. Marshall James A. Fassbender The following 6 applicants were denied for...

  2. Trends In Coloured Nursing Education

    Directory of Open Access Journals (Sweden)

    A.M. Venter

    1978-09-01

    Full Text Available Education as a selfgrowth process implies the potential successful adaptation to the world in which one lives; the latter becoming increasingly demanding through the expansion and growth of society as a whole. The Coloured nursing student of today, like all other students, lives in a fantastic era of technological advancement, industrialization, a continual struggle for academic achievement and above all the drive to achieve adjustment within the changing framework of society. The student must therefore be prepared to learn — which is a mental activity by means of which knowledge, skills, attitudes, and ideals are acquired, resulting in the modification of behaviour. The present-day nurse educator, therefore, not only has to be professionally and academically prepared for the educational task in nursing science but has to constantly update knowledge so as to keep abreast of the total interrelated picture of basic human science development. The success or failure of the student when she enters the professional world is an irrevocable reflection of the effectiveness of her teachers.

  3. Optimization of colour quality of LED lighting with reference to memory colours

    OpenAIRE

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

    2012-01-01

    Simulated and real tri- and tetrachromatic light-emitting-diode (LED) clusters were optimized for luminous efficacy of radiation (LER) and the memory colour quality metric developed by the authors. The simulated clusters showed no significant differences in achievable colour quality and LER between the different cluster types investigated. The real clusters (composed of commercially available LEDs) showed substantial differences in achievable colour quality and LER between the different clus...

  4. An evaluation of advanced digital colour technology for colour matching maxillofacial prosthetics.

    OpenAIRE

    Nacher-Garcia, C.

    2016-01-01

    Aim: To evaluate the reliability and reproducibility of the Spectromatch-Pro digital colour system (Spectromatch Ltd. UK) in the reproduction of simulated skin-silicone colour samples; and to determine threshold Delta E (∆E) (CIE L*a*b*) of perceptible and acceptable colour differences for maxillofacial prosthetics. Method: A two phase quantitative research design. Phase 1: tested; (i) the reproducibility of the spectrophotometer for eight subjects (n=48) scans; from four ethnic groups...

  5. A Vision-Based Approach to Fire Detection

    Directory of Open Access Journals (Sweden)

    Pedro Gomes

    2014-09-01

    Full Text Available This paper presents a vision-based method for fire detection from fixed surveillance smart cameras. The method integrates several well-known techniques properly adapted to cope with the challenges related to the actual deployment of the vision system. Concretely, background subtraction is performed with a context-based learning mechanism so as to attain higher accuracy and robustness. The computational cost of a frequency analysis of potential fire regions is reduced by means of focusing its operation with an attentive mechanism. For fast discrimination between fire regions and fire-coloured moving objects, a new colour-based model of fire's appearance and a new wavelet-based model of fire's frequency signature are proposed. To reduce the false alarm rate due to the presence of fire-coloured moving objects, the category and behaviour of each moving object is taken into account in the decision-making. To estimate the expected object's size in the image plane and to generate geo-referenced alarms, the camera-world mapping is approximated with a GPS-based calibration process. Experimental results demonstrate the ability of the proposed method to detect fires with an average success rate of 93.1% at a processing rate of 10 Hz, which is often sufficient for real-life applications.

  6. How to pass higher English colour

    CERN Document Server

    Bridges, Ann

    2009-01-01

    How to Pass is the Number 1 revision series for Scottish qualifications across the three examination levels of Standard Grade, Intermediate and Higher! Second editions of the books present all of the material in full colour for the first time.

  7. Particle creation in colour-electric fields

    International Nuclear Information System (INIS)

    Ambjorn, J.; Hughes, R.J.

    1982-01-01

    The decay of the Yang-Mills vacuum in a uniform colour-electric field is calculated using the method of Bogoliubov transformations. The result does not agree with that obtained by summation of the corresponding perturbation series. (orig.)

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

    Science.gov (United States)

    Cernea, Paul

    2002-01-01

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

  9. Colour Management as a Precondition of Quality

    Directory of Open Access Journals (Sweden)

    Stefan Brues

    2004-12-01

    Full Text Available Colour management technology has reached a high level of maturity. Only ten years after it first appeared on the market, ICC colour profiles have become indispensable in modern premedia. It can be said without exaggeration that colour management has revolutionised digital proof printing. A whole range of newcomers in the print industry supplier community offer an intelligent combination of a PostScript RIP with integral colour management functions. The quality of these low-priced proofing systems has now reached such a high level that even discerning customers accept such digital proofs as contract proofs. Modular proofing solutions are regularly to be found among the leaders in the digital proofer tests.Working with colour profiles and profiled workflows is still a major problem area. It is no mere chance that notably digital proofing is the field in which users work with colour profiles in virtually all systems, since applications here are locally limited.An important step for the widespread use of colour management technology is the now very extensive implementation of ICC mechanisms in application programs such as Adobe Photoshop. Version 7 is regarded as a model of well thought-out ICC-based colour management implementation. As Microsoft has neglected the ICC standard in recent years, Adobe has created its own colour management interface, called ACE. Based on the ICC standard, it is regarded by many experts as a reference implementation. Adobe products, which are so important for the graphic arts industry, now contain a standard colour management platform across all supported operating systems. Incompatibilities at system level can now be virtually ruled out, at least across the Adobe product line, including the important interfaces with PostScript and PDF.Modern prepress technology is set to move ever further away from exclusive print production for standardised offset print. Multiple use of production data is still at an early stage

  10. Salience of Primary and Secondary Colours in Infancy

    Science.gov (United States)

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

    2008-01-01

    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…

  11. Colour Dematerialization in Spiritual Literature and Painting

    OpenAIRE

    Sudrajat, Dadang; Piliang, Yasraf Amir; Sanjaya, Tisna; Kusmara, Andriyanto Rikrik

    2017-01-01

    Colour in variety of art expression can be interpreted differently. This study is aiming at analyzing the colour dematerialization of Javanese spiritual literature “Falsafah Jeroning Warna” by Suprapto Kadis and a painting by Ahmad Sadali entitled “Gunung Mas”. Research was done by employing qualitative research, while data was collected by observation, interview, discussion, and documentation study. The analysis of meanings in the two art works was done in descriptive way by using the theory...

  12. THE COLOUR GLASS CONDENSATE: AN INTRODUCTION

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-08-06

    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.

  13. A gentilionic approach to quark colours

    International Nuclear Information System (INIS)

    Cattani, M.S.D.; Fernandes, N.C.

    1984-01-01

    An extended form of Noether's theorem enable us to identify the colour quantum number with the eigenvalue of the invariant of the algebra of S sup((3)). In the gentilionic approach, the composition of the S sup((3)) colour with the symmetric quark model seems to constitute an exact symmetry of Nature. It is also argued some general properties and the universality of Gentile statistics. (Author) [pt

  14. Modelling colour changes during the caramelisation reaction

    OpenAIRE

    Quintas, Mafalda A.C.; Brandão, Teresa R.S.; Silva, Cristina L.M.

    2007-01-01

    Sucrose solutions, with concentrations near or superior to saturation, present high potentialities for the candy and pastry industries. The development of colour in a neutral and highly concentrated sucrose solution (16.32%(w/w) water content) subjected to isothermal heat treatment (in the 100–160 C range) was investigated. Under such conditions, sucrose degrades through caramelisation and 5- hydroxymethylfurfural (HMF) is formed. Colour development was monitored through lightness/darkening ...

  15. THE COLOUR GLASS CONDENSATE: AN INTRODUCTION

    International Nuclear Information System (INIS)

    Iancu, E.; Leonidov, A.; McLerran, L.

    2001-01-01

    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

  16. Plants and colour: Flowers and pollination

    Science.gov (United States)

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

    2011-03-01

    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.

  17. A gentilion hypothesis for quark colours

    International Nuclear Information System (INIS)

    Cattani, M.S.D.; Fernandes, N.C.

    1984-01-01

    Extendind the Noether's theorem it is possible to identify the colour quantum numbers with the eigenvalue of a S sup((3)) algebra invariant. In the gentilion approximation, the composition of the coloured S sup((3)) with the symmetric quark model seems to constitute in an exact symmetry of the nature. Some general properties related with the observationality in Quantum Mechanics are also approached and the Gentile statistical universality is asserted. (L.C.) [pt

  18. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... To Health Topics / Iron-Deficiency Anemia Iron-Deficiency Anemia Also known as Leer en español Iron-deficiency ... anemia. Blood tests to screen for iron-deficiency anemia To screen for iron-deficiency anemia, your doctor ...

  19. Iron-Deficiency Anemia

    Science.gov (United States)

    ... To Health Topics / Iron-Deficiency Anemia Iron-Deficiency Anemia Also known as Leer en español Iron-deficiency ... anemia. Blood tests to screen for iron-deficiency anemia To screen for iron-deficiency anemia, your doctor ...

  20. Stereo Vision Inside Tire

    Science.gov (United States)

    2015-08-21

    1 Stereo Vision Inside Tire P.S. Els C.M. Becker University of Pretoria W911NF-14-1-0590 Final...Stereo Vision Inside Tire 5a. CONTRACT NUMBER W911NF-14-1-0590 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Prof PS Els CM...on the development of a stereo vision system that can be mounted inside a rolling tire , known as T2-CAM for Tire -Terrain CAMera. The T2-CAM system

  1. Laser-induced plasmonic colours on metals

    Science.gov (United States)

    Guay, Jean-Michel; Calà Lesina, Antonino; Côté, Guillaume; Charron, Martin; Poitras, Daniel; Ramunno, Lora; Berini, Pierre; Weck, Arnaud

    2017-07-01

    Plasmonic resonances in metallic nanoparticles have been used since antiquity to colour glasses. The use of metal nanostructures for surface colourization has attracted considerable interest following recent developments in plasmonics. However, current top-down colourization methods are not ideally suited to large-scale industrial applications. Here we use a bottom-up approach where picosecond laser pulses can produce a full palette of non-iridescent colours on silver, gold, copper and aluminium. We demonstrate the process on silver coins weighing up to 5 kg and bearing large topographic variations (~1.5 cm). We find that colours are related to a single parameter, the total accumulated fluence, making the process suitable for high-throughput industrial applications. Statistical image analyses of laser-irradiated surfaces reveal various nanoparticle size distributions. Large-scale finite-difference time-domain computations based on these nanoparticle distributions reproduce trends seen in reflectance measurements, and demonstrate the key role of plasmonic resonances in colour formation.

  2. Fast polarimetric dehazing method for visibility enhancement in HSI colour space

    Science.gov (United States)

    Zhang, Wenfei; Liang, Jian; Ren, Liyong; Ju, Haijuan; Bai, Zhaofeng; Wu, Zhaoxin

    2017-09-01

    Image haze removal has attracted much attention in optics and computer vision fields in recent years due to its wide applications. In particular, the fast and real-time dehazing methods are of significance. In this paper, we propose a fast dehazing method in hue, saturation and intensity colour space based on the polarimetric imaging technique. We implement the polarimetric dehazing method in the intensity channel, and the colour distortion of the image is corrected using the white patch retinex method. This method not only reserves the detailed information restoration capacity, but also improves the efficiency of the polarimetric dehazing method. Comparison studies with state of the art methods demonstrate that the proposed method obtains equal or better quality results and moreover the implementation is much faster. The proposed method is promising in real-time image haze removal and video haze removal applications.

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

    Science.gov (United States)

    Nopparatjamjomras, Suchai; Chitaree, Ratchapak; Panijpan, Bhinyo

    2009-01-01

    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…

  4. Colours as Non-Verbal Signs on Packages

    OpenAIRE

    Kauppinen, Hannele

    2005-01-01

    Colour is an essential aspect of our daily life, and still, it is a neglected issue within marketing research. The main reason for studying colours is to understand the impact of colours on consumer behaviour, and thus, colours should be studied when it comes to branding, advertising, packages, interiors, and the clothes of the employees, for example. This was an exploratory study about the impact of colours on packages. The focus was on low-involvement purchasing, where the consumer puts...

  5. Colour relations for Mira and Semiregular (SR) type stars

    International Nuclear Information System (INIS)

    Guney, Yavuz; Yesilyaprak, Cahit

    2016-01-01

    In this study, the period-colour relations, the colour-colour relations and the effective temperature were examined for Semiregular (SR) and Mira type variable stars. SR variables show an obvious period-colour relations, especially in infrared (IR). There are differences between SR and Mira type variable stars with respect to their colour relations. It has been thought that these differencies are caused by their mass loss rates and their effective temperatures. (paper)

  6. Scalable, full-colour and controllable chromotropic plasmonic printing

    OpenAIRE

    Xue, Jiancai; Zhou, Zhang-Kai; Wei, Zhiqiang; Su, Rongbin; Lai, Juan; Li, Juntao; Li, Chao; Zhang, Tengwei; Wang, Xue-Hua

    2015-01-01

    Plasmonic colour printing has drawn wide attention as a promising candidate for the next-generation colour-printing technology. However, an efficient approach to realize full colour and scalable fabrication is still lacking, which prevents plasmonic colour printing from practical applications. Here we present a scalable and full-colour plasmonic printing approach by combining conjugate twin-phase modulation with a plasmonic broadband absorber. More importantly, our approach also demonstrates ...

  7. The role of vision processing in prosthetic vision.

    Science.gov (United States)

    Barnes, Nick; He, Xuming; McCarthy, Chris; Horne, Lachlan; Kim, Junae; Scott, Adele; Lieby, Paulette

    2012-01-01

    Prosthetic vision provides vision which is reduced in resolution and dynamic range compared to normal human vision. This comes about both due to residual damage to the visual system from the condition that caused vision loss, and due to limitations of current technology. However, even with limitations, prosthetic vision may still be able to support functional performance which is sufficient for tasks which are key to restoring independent living and quality of life. Here vision processing can play a key role, ensuring that information which is critical to the performance of key tasks is available within the capability of the available prosthetic vision. In this paper, we frame vision processing for prosthetic vision, highlight some key areas which present problems in terms of quality of life, and present examples where vision processing can help achieve better outcomes.

  8. delta-vision

    Data.gov (United States)

    California Natural Resource Agency — Delta Vision is intended to identify a strategy for managing the Sacramento-San Joaquin Delta as a sustainable ecosystem that would continue to support environmental...

  9. Computer Vision Syndrome.

    Science.gov (United States)

    Randolph, Susan A

    2017-07-01

    With the increased use of electronic devices with visual displays, computer vision syndrome is becoming a major public health issue. Improving the visual status of workers using computers results in greater productivity in the workplace and improved visual comfort.

  10. INSA: Vision and Activities

    International Nuclear Information System (INIS)

    Choe, Kwan-Kyoo

    2013-01-01

    INSA vision: Contribution to the world peace via advanced and excellent nuclear nonproliferation and security education and training; Objectives: Provide practical education and training programs; Raise internationally-recognized experts; Improve awareness about nuclear nonproliferation and security

  11. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... you are diagnosed with iron-deficiency anemia. Risk Factors You may have an increased risk for iron- ... iron-deficiency anemia if you have certain risk factors , including pregnancy. To prevent iron-deficiency anemia, your ...

  12. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... to moderate iron-deficiency anemia, or red blood cell transfusion for severe iron-deficiency anemia. You may ... body needs iron to make healthy red blood cells. Iron-deficiency anemia usually develops over time because ...

  13. Vitamin Deficiency Anemia

    Science.gov (United States)

    ... are unique to specific vitamin deficiencies. Folate-deficiency anemia risk factors include: Undergoing hemodialysis for kidney failure. ... the metabolism of folate. Vitamin B-12 deficiency anemia risk factors include: Lack of intrinsic factor. Most ...

  14. The role of colour in implicit and explicit memory performance.

    Science.gov (United States)

    Vernon, David; Lloyd-Jones, Toby J

    2003-07-01

    We present two experiments that examine the effects of colour transformation between study and test (from black and white to colour and vice versa, of from incorrectly coloured to correctly coloured and vice versa) on implicit and explicit measures of memory for diagnostically coloured natural objects (e.g., yellow banana). For naming and coloured-object decision (i.e., deciding whether an object is correctly coloured), there were shorter response times to correctly coloured-objects than to black-and-white and incorrectly coloured-objects. Repetition priming was equivalent for the different stimulus types. Colour transformation did not influence priming of picture naming, but for coloured-object decision priming was evident only for objects remaining the same from study to test. This was the case for both naming and coloured-object decision as study tasks. When participants were asked to consciously recognize objects that they had named or made coloured-object decisions to previously, whilst ignoring their colour, colour transformation reduced recognition efficiency. We discuss these results in terms of the flexibility of object representations that mediate priming and recognition.

  15. Biofeedback for Better Vision

    Science.gov (United States)

    1990-01-01

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

  16. Minimum Colour Differences Required To Recognise Small Objects On A Colour CRT

    Science.gov (United States)

    Phillips, Peter L.

    1985-05-01

    Data is required to assist in the assessment, evaluation and optimisation of colour and other displays for both military and general use. A general aim is to develop a mathematical technique to aid optimisation and reduce the amount of expensive hardware development and trials necessary when introducing new displays. The present standards and methods available for evaluating colour differences are known not to apply to the perception of typical objects on a display. Data is required for irregular objects viewed at small angular subtense ((1°) and relating the recognition of form rather than colour matching. Therefore laboratory experiments have been carried out using a computer controlled CRT to measure the threshold colour difference that an observer requires between object and background so that he can discriminate a variety of similar objects. Measurements are included for a variety of background and object colourings. The results are presented in the CIE colorimetric system similar to current standards used by the display engineer. Apart from the characteristic small field tritanopia, the results show that larger colour differences are required for object recognition than those assumed from conventional colour discrimination data. A simple relationship to account for object size and background colour is suggested to aid visual performance assessments and modelling.

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

    Science.gov (United States)

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

    2010-12-06

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

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

    DEFF Research Database (Denmark)

    Andersen, Jeppe D.; Johansen, Peter; Harder, Stine

    2013-01-01

    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...... 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......-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...

  19. [Migration and health--from deficiency analysis to diversity vision?].

    Science.gov (United States)

    Weber, A; Hörmann, G

    2011-05-01

    In times of globalization the subjects migration and health are gaining more and more in importance. At the same time, one can observe a discrepancy between published opinions, politically intended messages and scientifically proved evidence. With approximately 15.4 million people with a migration background (this is equivalent to approximately 19% of the German population), migrants perform as an important "customer group" for health care and social security. In 2005, the category migrant background was introduced for the first time by the Federal Statistical Office. This category suggests homogeneity, which in fact is not given. Persons with migration background (including active immigrants, their children and grandchildren, repatriates, foreigners), have to be examined in a differentiated way concerning the consequences that the migration process has on health. Apart from potentially pathogenic influences associated with migration (e. g., ethnicity, national origin, cultural/religious characteristics, migration-related stressors), for example, education, social status, life-style and participation in work and society have to be taken into consideration as important "confounders". In this, a recent sociological approach (sinus migrant milieu) could be useful for socio-medical research and practice. Health-relevant information on migrants results on the one hand from scientific studies primarily designed for this purpose and, on the other hand, from routine data from official health reports. In the interpretation of secondary data, the problem arises that the definition of the target group (migrants) is different in the diverse data sources (for example, Germans, non-Germans, foreigners, migration background) and that important confounders (for example, from socio-cultural milieu) are not included. This may result in, among other things, an under- or overestimation of health risks or even incorrect conclusions. In consideration of these limitations, by means of data sets from official statistics (among others, Federal Statistical Office, social insurance agencies) and recent scientific research the present article analyses chosen aspects of migrant health (for example, health behaviour, morbidity, sickness absence, early retirement, health-care system, rehabilitation and mortality). Finally, possible implications for a more intensive discussion and further development of health care practice are pointed out. © Georg Thieme Verlag KG Stuttgart · New York.

  20. Functional Reflective Polarizer for Augmented Reality and Color Vision Deficiency

    Science.gov (United States)

    2016-03-03

    augment reality system is relatively high as compared to a polarizing beam splitter or a conventional reflective polarizer. Such a functional reflective...brightness of the display [7]. A key component for polarization management is polarizing beam splitter (PBS). Even though the PBS has exceptional...polarizer that can be incorporated into a compact augmented reality system. The design principle of the functional reflective polarizer is explained and

  1. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... Events About NHLBI About NHLBI Home Mission and Strategic Vision Leadership Scientific Divisions Operations and Administration Advisory ... and how patients respond to treatment. The NHLBI Strategic Vision highlights ways we may support research over ...

  2. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... About NHLBI About NHLBI Home Mission and Strategic Vision Leadership Scientific Divisions Operations and Administration Advisory Committees ... how patients respond to treatment. The NHLBI Strategic Vision highlights ways we may support research over the ...

  3. Colour dematerialization in spiritual literature and painting

    Directory of Open Access Journals (Sweden)

    Dadang Sudrajat

    2017-12-01

    Full Text Available Colour in variety of art expression can be interpreted differently. This study is aiming at analyzing the colour dematerialization of Javanese spiritual literature “Falsafah Jeroning Warna” by Suprapto Kadis and a painting by Ahmad Sadali entitled “Gunung Mas”. Research was done by employing qualitative research, while data was collected by observation, interview, discussion, and documentation study. The analysis of meanings in the two art works was done in descriptive way by using the theory and the knowledge of tasawwuf or sufism, the aesthetics, and arts. Results showed that both sufis, Ahmad Sadali and Suprapto Kadis, share similarities in doing dematerialization towards colour. For them, colour was initially taken from nature (the external territory which then experienced dematerialization when it made contact with inspiration that was created from the internal area (mental. On the other hand, the difference between the two art works lies on an understanding that colour in FJW is naturalistic mimesis in nature, meanwhile, the painting of Ahmad Sadali is naturaly abstract.

  4. Sensory evaluation of meat colour using photographs

    Directory of Open Access Journals (Sweden)

    Gianluigi Destefanis

    2010-01-01

    Full Text Available Five m. longissimus thoracis steaks from different breeds, purchased at retail, were cut into samples and simultaneously photographed under standard shooting conditions. The first photo was taken on samples just arrived at the laboratory, the second one on a freshly cut surface after blooming. Two consumer panels evaluated beef colour using respectively photo 1 and photo 2. Each consumer was asked to rank samples in order of preference. Rank sums were evaluated with Fridman’s test. Immediately after taking the photos, colour was measured with a colorimeter. Regarding photo 1, consumers were able to discriminate one sample, the worst, from all the others. Concerning photo 2, consumers discriminated the worst sample, as in photo 1, but also the best one. Therefore a more accurate colour evaluation can be obtained if the assessment is carried out on a fresh cut surface after blooming. In general consumers preferred samples with high lightness and a relatively high yellowness. The sensory evaluation of meat colour using photographs is a promising tool to overcome the difficulties when the meat is directly evaluated. But it is very important to standardize the shooting conditions to obtain a true reproduction of the meat. For this purpose the use of a colour target is useful to check the validity of the adopted parameters.

  5. Scalable, full-colour and controllable chromotropic plasmonic printing

    Science.gov (United States)

    Xue, Jiancai; Zhou, Zhang-Kai; Wei, Zhiqiang; Su, Rongbin; Lai, Juan; Li, Juntao; Li, Chao; Zhang, Tengwei; Wang, Xue-Hua

    2015-01-01

    Plasmonic colour printing has drawn wide attention as a promising candidate for the next-generation colour-printing technology. However, an efficient approach to realize full colour and scalable fabrication is still lacking, which prevents plasmonic colour printing from practical applications. Here we present a scalable and full-colour plasmonic printing approach by combining conjugate twin-phase modulation with a plasmonic broadband absorber. More importantly, our approach also demonstrates controllable chromotropic capability, that is, the ability of reversible colour transformations. This chromotropic capability affords enormous potentials in building functionalized prints for anticounterfeiting, special label, and high-density data encryption storage. With such excellent performances in functional colour applications, this colour-printing approach could pave the way for plasmonic colour printing in real-world commercial utilization. PMID:26567803

  6. Influence of drug colour on perceived drug effects and efficacy.

    Science.gov (United States)

    Tao, Da; Wang, Tieyan; Wang, Tieshan; Qu, Xingda

    2018-02-01

    A drug's physical characteristics, such as colour, could be factors influencing its therapeutic effects. It is not well understood whether people's expectations on drug effects and efficacy are affected by colour, especially among Chinese population. This study was conducted to examine people's expectations on drug effects and efficacy on the basis of drug colour, and to reveal possible gender differences in colour-related drug expectations. Participants (n = 224) were asked to classify seven single-coloured and six two-coloured capsules into one of four categories of drug effects, and to indicate the strength of drug efficacy. It is found that all the coloured capsules yielded non-chance distributions in classifications of drug effects, with six single-coloured and four two-coloured capsules associated with specific drug effects. Colour also conveyed differential strengths of drug efficacy in general and in relation to specific drug effects. There were gender differences in drug expectations for some colours and colour combinations. Practitioner Summary: Drug colour was found to have impacts on perceived drug effects and efficacy. The findings from the present study can be used by ergonomics practitioners to design appropriate drug colours in support of drug differentiation, therapeutic effects and medication adherence.

  7. Optic neuropathy in a patient with pyruvate dehydrogenase deficiency

    Energy Technology Data Exchange (ETDEWEB)

    Small, Juan E. [Massachusetts General Hospital and Harvard Medical School, Department of Radiology, Boston, MA (United States); Gonzalez, Guido E. [Massachusetts Eye and Ear Infirmary and Harvard Medical School, Department of Radiology, Boston, MA (United States); Clinica Alemana de Santiago, Departmento de Imagenes, Santiago (Chile); Nagao, Karina E.; Walton, David S. [Massachusetts Eye and Ear Infirmary and Harvard Medical School, Department of Ophthalmology, Boston, MA (United States); Caruso, Paul A. [Massachusetts Eye and Ear Infirmary and Harvard Medical School, Department of Radiology, Boston, MA (United States)

    2009-10-15

    Pyruvate dehydrogenase (PDH) deficiency is a genetic disorder of mitochondrial metabolism. The clinical manifestations range from severe neonatal lactic acidosis to chronic neurodegeneration. Optic neuropathy is an uncommon clinical sequela and the imaging findings of optic neuropathy in these patients have not previously been described. We present a patient with PDH deficiency with bilateral decreased vision in whom MRI demonstrated bilateral optic neuropathy and chiasmopathy. (orig.)

  8. Optic neuropathy in a patient with pyruvate dehydrogenase deficiency

    International Nuclear Information System (INIS)

    Small, Juan E.; Gonzalez, Guido E.; Nagao, Karina E.; Walton, David S.; Caruso, Paul A.

    2009-01-01

    Pyruvate dehydrogenase (PDH) deficiency is a genetic disorder of mitochondrial metabolism. The clinical manifestations range from severe neonatal lactic acidosis to chronic neurodegeneration. Optic neuropathy is an uncommon clinical sequela and the imaging findings of optic neuropathy in these patients have not previously been described. We present a patient with PDH deficiency with bilateral decreased vision in whom MRI demonstrated bilateral optic neuropathy and chiasmopathy. (orig.)

  9. A Standalone Vision Impairments Simulator for Java Swing Applications

    Science.gov (United States)

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

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

  10. [Quality system Vision 2000].

    Science.gov (United States)

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

    2002-12-01

    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.

  11. IDA's Energy Vision 2050

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Lund, Henrik; Hansen, Kenneth

    IDA’s Energy Vision 2050 provides a Smart Energy System strategy for a 100% renewable Denmark in 2050. The vision presented should not be regarded as the only option in 2050 but as one scenario out of several possibilities. With this vision the Danish Society of Engineers, IDA, presents its third...... contribution for an energy strategy for Denmark. The IDA’s Energy Plan 2030 was prepared in 2006 and IDA’s Climate Plan was prepared in 2009. IDA’s Energy Vision 2050 is developed for IDA by representatives from The Society of Engineers and by a group of researchers at Aalborg University. It is based on state......-of-the-art knowledge about how low cost energy systems can be designed while also focusing on long-term resource efficiency. The Energy Vision 2050 has the ambition to focus on all parts of the energy system rather than single technologies, but to have an approach in which all sectors are integrated. While Denmark...

  12. Induced mutation altering flower colour in Chrysanthemum

    Energy Technology Data Exchange (ETDEWEB)

    Datta, S K [National Botanical Research Institute, Lucknow (India)

    1989-01-01

    Full text: 'Flirt' is a double Korean type, small flowered Chrysanthemum of red colour. Rooted cuttings were treated with 1.5-2.5 krad gamma rays. A chimeral flower colour mutant was detected after 1.5 krad treatment. After purification through repeated cuttings a mutant clone was developed and released as commercial cultivar 'Man Bhawan'. It produces bi-coloured flower-heads: yellow and red at full bloom stage becoming completely yellow later on. By chromatography, 6 pigment spots could be identified in the variety 'Flirt' but only 5 in the mutant, violet (hRf 69.83) being absent. Spectrophotometric analysis of petal extracts showed presence of three peaks in both 'Flirt' and 'Man Bhawan' at full bloom stage but only two in 'Man Bhawan' at fading stage. (author)

  13. A familial factor in the development of colour agnosia.

    Science.gov (United States)

    Nijboer, Tanja C W; van Zandvoort, Martine J E; de Haan, Edward H F

    2007-04-09

    An important aspect of research into the link between genes and behaviour concerns the identification of familial determination. There is evidence for familial factors in selective deficits, such as developmental dyslexia and developmental prosopagnosia. Colour agnosia concerns a selective neuropsychological condition in which colour perception is intact, while the identification and naming of colour is disrupted. We recently demonstrated that this deficit can occur as a developmental deficit. Here, we show that there is a familial factor in the development of colour agnosia by reporting the colour processing abilities of the mother and the daughters of a man with developmental colour agnosia.

  14. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... Iron-Deficiency Anemia Iron-Deficiency Anemia Also known as Leer en español Iron-deficiency anemia is a ... address the cause of your iron deficiency, such as any underlying bleeding. If undiagnosed or untreated, iron- ...

  15. Reading aids for adults with low vision.

    Science.gov (United States)

    Virgili, Gianni; Acosta, Ruthy; Bentley, Sharon A; Giacomelli, Giovanni; Allcock, Claire; Evans, Jennifer R

    2018-04-17

    The purpose of low-vision rehabilitation is to allow people to resume or to continue to perform daily living tasks, with reading being one of the most important. This is achieved by providing appropriate optical devices and special training in the use of residual-vision and low-vision aids, which range from simple optical magnifiers to high-magnification video magnifiers. To assess the effects of different visual reading aids for adults with low vision. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 12); MEDLINE Ovid; Embase Ovid; BIREME LILACS, OpenGrey, the ISRCTN registry; ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). The date of the search was 17 January 2018. This review includes randomised and quasi-randomised trials that compared any device or aid used for reading to another device or aid in people aged 16 or over with low vision as defined by the study investigators. We did not compare low-vision aids with no low-vision aid since it is obviously not possible to measure reading speed, our primary outcome, in people that cannot read ordinary print. We considered reading aids that maximise the person's visual reading capacity, for example by increasing image magnification (optical and electronic magnifiers), augmenting text contrast (coloured filters) or trying to optimise the viewing angle or gaze position (such as prisms). We have not included studies investigating reading aids that allow reading through hearing, such as talking books or screen readers, or through touch, such as Braille-based devices and we did not consider rehabilitation strategies or complex low-vision interventions. We used standard methods expected by Cochrane. At least two authors independently assessed trial quality and extracted data. The primary outcome of the review was reading speed in words per minute. Secondary

  16. Colour intransparency and the cross sections for colour-singlet and colour-octet hadrons in the Low-Nussinov model

    International Nuclear Information System (INIS)

    Dolejsi, J.; Huefner, J.

    1992-01-01

    The dependence of cross sections on the colour state of the colliding hadrons is investigated within the Low-Nussinov model of two-gluon exchange. The total cross sections for colour-octet hadrons are practically constant as functions of the hadronic radii, while they tend to zero when the radii of the colour-singlet hadrons approach zero. The slope parameter of the differential elastic cross sections for small momentum transfers is rather insensitive to the colour structure of the colliding hadrons. The integrated colour exchange cross section is calculated. (orig.)

  17. Colour-Temperature Correspondences: When Reactions to Thermal Stimuli Are Influenced by Colour

    Science.gov (United States)

    Ho, Hsin-Ni; Van Doorn, George H.; Kawabe, Takahiro; Watanabe, Junji; Spence, Charles

    2014-01-01

    In our daily lives, information concerning temperature is often provided by means of colour cues, with red typically being associated with warm/hot, and blue with cold. While such correspondences have been known about for many years, they have primarily been studied using subjective report measures. Here we examined this correspondence using two more objective response measures. First, we used the Implicit Association Test (IAT), a test designed to assess the strength of automatic associations between different concepts in a given individual. Second, we used a priming task that involved speeded target discrimination in order to assess whether priming colour or thermal information could invoke the crossmodal association. The results of the IAT confirmed that the association exists at the level of response selection, thus indicating that a participant’s responses to colour or thermal stimuli are influenced by the colour-temperature correspondence. The results of the priming experiment revealed that priming a colour affected thermal discrimination reaction times (RTs), but thermal cues did not influence colour discrimination responses. These results may therefore provide important clues as to the level of processing at which such colour-temperature correspondences are represented. PMID:24618675

  18. Consumer exposures to anthocyanins from colour additives, colouring foodstuffs and from natural occurrence in foods.

    Science.gov (United States)

    Tennant, David R; Klingenberg, Andreas

    2016-06-01

    Anthocyanins are responsible for the red/blue colour of grapes, currants, and other fruits and vegetables. They may also be extracted for use as colour additives (E163) or concentrated for use as colouring foods. Consumer exposures have been assessed using data on natural occurrence, use levels and frequencies from food manufacturers and European food consumption data. Intakes from natural occurrence can be up to 4 mg kg bw(-1) day(-1) at the mean and up to 17 mg kg bw(-1) day(-1) for children who are high level consumers of red/black berries and small fruits. High-level intakes for children from food colour and colouring food applications lie in the range 0.3-6.3 mg kg bw(-1) day(-1) and for adults at 0.6-2.8 mg kg bw(-1) day(-1). Exposures from food colour use and colouring foods separately or combined are therefore lower than those from natural occurrence in foods.

  19. Organic Colouring Agents in the Pharmaceutical Industry

    Directory of Open Access Journals (Sweden)

    Šuleková M.

    2017-09-01

    Full Text Available Food dyes are largely used in the process of manufacturing pharmaceutical products. The aim of such a procedure is not only to increase the attractiveness of products, but also to help patients distinguish between pharmaceuticals. Various dyes, especially organic colouring agents, may in some cases have a negative impact on the human body. They are incorporated into pharmaceutical products including tablets, hard gelatine capsules or soft gelatine capsules, lozenges, syrups, etc. This article provides an overview of the most widely used colouring agents in pharmaceuticals, their characteristics and the EU legislation which regulates their use.

  20. The colours in Lithuanian and French proverbs

    OpenAIRE

    Kosova, Svetlana; Klanauskaitė, Paula

    2015-01-01

    The aim of the article is a comparison of Lithuanian and French proverbs by choosing the names of colours as the main aspect. This is to some extent a new way of analysing proverbs with colour as the key word. Seven main aspects of proverbs are mentioned in the article supported by an analysis and comparison of proverbs in both languages. Two different dictionaries have been used for the research: K. Grigas, L. Kudirkienė, R. Kašetienė, G. Radvilas ir D. Zaikauskienė Lietuvių P...

  1. The phenomenology of scalar colour octets

    International Nuclear Information System (INIS)

    Krasnikov, N.V.

    1995-01-01

    The phenomenology of color scalar octet particles is discussed. Namely, the discovery potential of scalar octets at LEP, FNAL and LHC is discussed. It appears that new hadrons composed from scalar colour octets are rather longlived (Γ≤O(10) keV). The current experimental data don't contradict to the existence of light (M∼O(1) GeV) scalar octets. Light scalar colour octets give additional contribution to the QCD β-function and allow to improve agreement between deep inelastic and LEP data. 10 refs.; 2 figs

  2. PHILOSOPHIES OF COLOUR: GENDER AND ACCULTURATION

    OpenAIRE

    Andrew, Helen V

    2003-01-01

    Merged with duplicate record 10026.1/658 on 06.20.2017 by CS (TIS) My hypothesis is that 'Colour' as idea acts as a dynamic in the production of meaning and as such is part of what Le Doeuff (1991: 46-49) argues are deeply held epistemes that structure and govern our ways of thinking. I have dealt with the difficulties attendant on the analysis of a phenomenon as insubstantial as colour (as idea and as precept) by assuming Goethe's (1810: 305-323) concept of the enrobement o...

  3. Pitfalls in colour photography of choroidal tumours

    Science.gov (United States)

    Schalenbourg, A; Zografos, L

    2013-01-01

    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

  4. Pitfalls in colour photography of choroidal tumours.

    Science.gov (United States)

    Schalenbourg, A; Zografos, L

    2013-02-01

    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.

  5. Integrating National Space Visions

    Science.gov (United States)

    Sherwood, Brent

    2006-01-01

    This paper examines value proposition assumptions for various models nations may use to justify, shape, and guide their space programs. Nations organize major societal investments like space programs to actualize national visions represented by leaders as investments in the public good. The paper defines nine 'vision drivers' that circumscribe the motivations evidently underpinning national space programs. It then describes 19 fundamental space activity objectives (eight extant and eleven prospective) that nations already do or could in the future use to actualize the visions they select. Finally the paper presents four contrasting models of engagement among nations, and compares these models to assess realistic pounds on the pace of human progress in space over the coming decades. The conclusion is that orthogonal engagement, albeit unlikely because it is unprecedented, would yield the most robust and rapid global progress.

  6. Interoperability Strategic Vision

    Energy Technology Data Exchange (ETDEWEB)

    Widergren, Steven E.; Knight, Mark R.; Melton, Ronald B.; Narang, David; Martin, Maurice; Nordman, Bruce; Khandekar, Aditya; Hardy, Keith S.

    2018-02-28

    The Interoperability Strategic Vision whitepaper aims to promote a common understanding of the meaning and characteristics of interoperability and to provide a strategy to advance the state of interoperability as applied to integration challenges facing grid modernization. This includes addressing the quality of integrating devices and systems and the discipline to improve the process of successfully integrating these components as business models and information technology improve over time. The strategic vision for interoperability described in this document applies throughout the electric energy generation, delivery, and end-use supply chain. Its scope includes interactive technologies and business processes from bulk energy levels to lower voltage level equipment and the millions of appliances that are becoming equipped with processing power and communication interfaces. A transformational aspect of a vision for interoperability in the future electric system is the coordinated operation of intelligent devices and systems at the edges of grid infrastructure. This challenge offers an example for addressing interoperability concerns throughout the electric system.

  7. Representing vision and blindness.

    Science.gov (United States)

    Ray, Patrick L; Cox, Alexander P; Jensen, Mark; Allen, Travis; Duncan, William; Diehl, Alexander D

    2016-01-01

    There have been relatively few attempts to represent vision or blindness ontologically. This is unsurprising as the related phenomena of sight and blindness are difficult to represent ontologically for a variety of reasons. Blindness has escaped ontological capture at least in part because: blindness or the employment of the term 'blindness' seems to vary from context to context, blindness can present in a myriad of types and degrees, and there is no precedent for representing complex phenomena such as blindness. We explore current attempts to represent vision or blindness, and show how these attempts fail at representing subtypes of blindness (viz., color blindness, flash blindness, and inattentional blindness). We examine the results found through a review of current attempts and identify where they have failed. By analyzing our test cases of different types of blindness along with the strengths and weaknesses of previous attempts, we have identified the general features of blindness and vision. We propose an ontological solution to represent vision and blindness, which capitalizes on resources afforded to one who utilizes the Basic Formal Ontology as an upper-level ontology. The solution we propose here involves specifying the trigger conditions of a disposition as well as the processes that realize that disposition. Once these are specified we can characterize vision as a function that is realized by certain (in this case) biological processes under a range of triggering conditions. When the range of conditions under which the processes can be realized are reduced beyond a certain threshold, we are able to say that blindness is present. We characterize vision as a function that is realized as a seeing process and blindness as a reduction in the conditions under which the sight function is realized. This solution is desirable because it leverages current features of a major upper-level ontology, accurately captures the phenomenon of blindness, and can be

  8. Bio-inspired vision

    International Nuclear Information System (INIS)

    Posch, C

    2012-01-01

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

  9. Exposure of Polish children to Southampton food colours.

    Science.gov (United States)

    Gajda-Wyrębek, J; Kuźma, K; Świtka, A; Jarecka, J; Beresińska, M; Postupolski, J

    2017-01-01

    A study published in 2007 showed that the intake of six food colours (the so-called 'Southampton colours') may have an adverse effect on activity and attention in children. The present study set out to assess the exposure of Polish children (3 and 8-9 years old, n = 149) to six of the target colours. Two methods were used to evaluate colour consumption by children: scenario 1 using the maximum permitted levels (MPLs) and actual food consumption data; and scenario 2 using the actual levels in food and actual food consumption data. The data on the actual consumption of food containing the colours was collected using a 7-day questionnaire survey. The results of laboratory analysis of food consumed by children provided data on the actual levels of the colours in food. Consumption of the colours estimated by scenario 1 in any case did not exceed the acceptable daily intakes (ADIs) of the colours in both age groups of children. For more refined colour intake (scenario 2), isolated cases exceeding the ADI were recorded for four colours, but assuming that manufacturers comply with the current legislation on MPL of colours in food, the intake of the colours assessed in scenario 2 should not be a reason for exceeding of ADIs for the target food colours.

  10. Determinants of Colour Constancy and the Blue Bias

    Science.gov (United States)

    Gegenfurtner, Karl

    2017-01-01

    We investigated several sensory and cognitive determinants of colour constancy across 40 illumination hues. In the first experiment, we measured colour naming for the illumination and for the colour induced by the illumination on the colorimetric grey. Results confirmed that the induced colours are approximately complementary to the colour of the illumination. In the second experiment, we measured colour constancy using achromatic adjustments. Average colour constancy was perfect under the blue daylight illumination and decreased in colour directions away from the blue daylight illumination due to undershooting and a strong blue bias. Apart from this blue bias, colour constancy was not related to illumination discrimination and to chromatic detection measured previously with the same setup and stimuli. We also observed a strong negative relationship between the degree of colour constancy and the consensus of naming the illumination colour. Constancy coincided with a low naming consensus, in particular because bluish illumination colours were sometimes seen as achromatic. Blue bias and category consensus alone explained >68%, and all determinants together explained >94% of the variance of achromatic adjustments. These findings suggest that colour constancy is optimised for blue daylight. PMID:29348910

  11. Geographical variation in colour of female threespine stickleback (Gasterosteus aculeatus).

    Science.gov (United States)

    French, Connor M; Ingram, Travis; Bolnick, Daniel I

    2018-01-01

    The ecological multifunctionality of colour often results in multiple selective pressures operating on a single trait. Most research on colour evolution focuses on males because they are the most conspicuous sex in most species. This bias can limit inferences about the ecological drivers of colour evolution. For example, little is known about population divergence in colour of female threespine stickleback ( Gasterosteus aculeatus ), which is among the most intensively-studied model vertebrates in evolution, ecology, and behaviour. In contrast, the evolution and ecology of colour in male stickleback has received considerable attention. One aspect of female colouration that is lacking previous research is non-ornamental body colour. Non-ornamental colour can play defensive and social roles, and indicate other aspects of female stickleback ecology. To remedy this knowledge gap, we measured the colour and brightness of one dorsal and one ventral lateral area on female stickleback from nine lake populations on Vancouver Island. We found that lake populations varied in overall colour brightness and dorso-ventral contrast. In addition, we found that female brightness increased with lake size, indicating potential ecological drivers of these colour differences. Our results demonstrate that there is substantial scope for future research on female colour diversification, which has been overlooked because past researchers focused on dramatic male nuptial colours.

  12. Geographical variation in colour of female threespine stickleback (Gasterosteus aculeatus

    Directory of Open Access Journals (Sweden)

    Connor M. French

    2018-05-01

    Full Text Available The ecological multifunctionality of colour often results in multiple selective pressures operating on a single trait. Most research on colour evolution focuses on males because they are the most conspicuous sex in most species. This bias can limit inferences about the ecological drivers of colour evolution. For example, little is known about population divergence in colour of female threespine stickleback (Gasterosteus aculeatus, which is among the most intensively-studied model vertebrates in evolution, ecology, and behaviour. In contrast, the evolution and ecology of colour in male stickleback has received considerable attention. One aspect of female colouration that is lacking previous research is non-ornamental body colour. Non-ornamental colour can play defensive and social roles, and indicate other aspects of female stickleback ecology. To remedy this knowledge gap, we measured the colour and brightness of one dorsal and one ventral lateral area on female stickleback from nine lake populations on Vancouver Island. We found that lake populations varied in overall colour brightness and dorso-ventral contrast. In addition, we found that female brightness increased with lake size, indicating potential ecological drivers of these colour differences. Our results demonstrate that there is substantial scope for future research on female colour diversification, which has been overlooked because past researchers focused on dramatic male nuptial colours.

  13. Low Vision Enhancement System

    Science.gov (United States)

    1995-01-01

    NASA's Technology Transfer Office at Stennis Space Center worked with the Johns Hopkins Wilmer Eye Institute in Baltimore, Md., to incorporate NASA software originally developed by NASA to process satellite images into the Low Vision Enhancement System (LVES). The LVES, referred to as 'ELVIS' by its users, is a portable image processing system that could make it possible to improve a person's vision by enhancing and altering images to compensate for impaired eyesight. The system consists of two orientation cameras, a zoom camera, and a video projection system. The headset and hand-held control weigh about two pounds each. Pictured is Jacob Webb, the first Mississippian to use the LVES.

  14. En vision for CBS?

    DEFF Research Database (Denmark)

    Thyssen, Ole

    2015-01-01

    Kommentar. CBS’ ry for at være et moderne Business University med forskere fra hele verden og forskningsmæssig dynamik faldt på gulvet. Udfordringen er nu at få samlet CBS forskere om en fælles vision.......Kommentar. CBS’ ry for at være et moderne Business University med forskere fra hele verden og forskningsmæssig dynamik faldt på gulvet. Udfordringen er nu at få samlet CBS forskere om en fælles vision....

  15. Low Cost Night Vision System for Intruder Detection

    Science.gov (United States)

    Ng, Liang S.; Yusoff, Wan Azhar Wan; R, Dhinesh; Sak, J. S.

    2016-02-01

    The growth in production of Android devices has resulted in greater functionalities as well as lower costs. This has made previously more expensive systems such as night vision affordable for more businesses and end users. We designed and implemented robust and low cost night vision systems based on red-green-blue (RGB) colour histogram for a static camera as well as a camera on an unmanned aerial vehicle (UAV), using OpenCV library on Intel compatible notebook computers, running Ubuntu Linux operating system, with less than 8GB of RAM. They were tested against human intruders under low light conditions (indoor, outdoor, night time) and were shown to have successfully detected the intruders.

  16. Automaticity and localisation of concurrents predicts colour area activity in grapheme-colour synaesthesia.

    Science.gov (United States)

    Gould van Praag, Cassandra D; Garfinkel, Sarah; Ward, Jamie; Bor, Daniel; Seth, Anil K

    2016-07-29

    In grapheme-colour synaesthesia (GCS), the presentation of letters or numbers induces an additional 'concurrent' experience of colour. Early functional MRI (fMRI) investigations of GCS reported activation in colour-selective area V4 during the concurrent experience. However, others have failed to replicate this key finding. We reasoned that individual differences in synaesthetic phenomenology might explain this inconsistency in the literature. To test this hypothesis, we examined fMRI BOLD responses in a group of grapheme-colour synaesthetes (n=20) and matched controls (n=20) while characterising the individual phenomenology of the synaesthetes along dimensions of 'automaticity' and 'localisation'. We used an independent functional localiser to identify colour-selective areas in both groups. Activations in these areas were then assessed during achromatic synaesthesia-inducing, and non-inducing conditions; we also explored whole brain activations, where we sought to replicate the existing literature regarding synaesthesia effects. Controls showed no significant activations in the contrast of inducing > non-inducing synaesthetic stimuli, in colour-selective ROIs or at the whole brain level. In the synaesthete group, we correlated activation within colour-selective ROIs with individual differences in phenomenology using the Coloured Letters and Numbers (CLaN) questionnaire which measures, amongst other attributes, the subjective automaticity/attention in synaesthetic concurrents, and their spatial localisation. Supporting our hypothesis, we found significant correlations between individual measures of synaesthetic phenomenology and BOLD responses in colour-selective areas, when contrasting inducing against non-inducing stimuli. Specifically, left-hemisphere colour area responses were stronger for synaesthetes scoring high on phenomenological localisation and automaticity/attention, while right-hemisphere colour area responses showed a relationship with localisation

  17. Achieving Harmonious Colour Relationship in Art/Design: Towards ...

    African Journals Online (AJOL)

    Nneka Umera-Okeke

    2011-12-06

    Dec 6, 2011 ... Phone: +2348033205662. Abstract ... problematic. Therefore, as a panacea, ... usage and achieve harmonious colour relationship. This is ..... Gender and the meaning of colour in interior environments in mobile color matters.

  18. Whorfian effects on colour memory are not reliable.

    Science.gov (United States)

    Wright, Oliver; Davies, Ian R L; Franklin, Anna

    2015-01-01

    The Whorfian hypothesis suggests that differences between languages cause differences in cognitive processes. Support for this idea comes from studies that find that patterns of colour memory errors made by speakers of different languages align with differences in colour lexicons. The current study provides a large-scale investigation of the relationship between colour language and colour memory, adopting a cross-linguistic and developmental approach. Colour memory on a delayed matching-to-sample (XAB) task was investigated in 2 language groups with differing colour lexicons, for 3 developmental stages and 2 regions of colour space. Analyses used a Bayesian technique to provide simultaneous assessment of two competing hypotheses (H1-Whorfian effect present, H0-Whorfian effect absent). Results of the analyses consistently favoured H0. The findings suggest that Whorfian effects on colour memory are not reliable and that the importance of such effects should not be overestimated.

  19. Classical confining solutions of a tensor gauge theory incorporating colour

    International Nuclear Information System (INIS)

    Salam, A.; Strathdee, J.

    1977-04-01

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

  20. Carotenoid-based breast plumage colour, body condition and clutch ...

    African Journals Online (AJOL)

    dependent ornamental trait. In some species of birds, red, orange and yellow feather colouration reflects male quality and advertises the carotenoid concentration of feathers. Such colouration is an important aspect of mate selection by females.

  1. Application of Modern Colour Measurement Dervices in Coloration Industries

    Institute of Scientific and Technical Information of China (English)

    CHUNG Y.S.; XIN John H.; SIN K.M.

    2002-01-01

    In colour measurement ralated industry, reflectance spectrophotometer is the one of the popular measuring machine for measutring colour and quality control. Colour communications is frequently confusing. This is because the colour appearance is subject to the influence of at least three different phenomena: the light source, the object and the visual system. The variation in either the radiant quantity or the spectral distribution of the source can alter the observed colour. Because of this reason,the objective quantitative tool, colour measurement equipment and communication method; become more important in evaluating of the colour. In fact, based on the advanced in computer system and electronic device,the colour measurement becomes more and more accuracy, especiany in spectrophotometer measurement.In this paper, we will focus on the review of modern spectrophotometers in coloration industries.

  2. Study of structural colour of Hebomoia glaucippe butterfly wing scales

    Science.gov (United States)

    Shur, V. Ya; Kuznetsov, D. K.; Pryakhina, V. I.; Kosobokov, M. S.; Zubarev, I. V.; Boymuradova, S. K.; Volchetskaya, K. V.

    2017-10-01

    Structural colours of Hebomoia glaucippe butterfly wing scales have been studied experimentally using high resolution scanning electron microscopy. Visualization of scales structures and computer simulation allowed distinguishing correlation between nanostructures on the scales and their colour.

  3. Selective interference reveals dissociation between memory for location and colour.

    Science.gov (United States)

    Vuontela, V; Rämä, P; Raninen, A; Aronen, H J; Carlson, S

    1999-08-02

    The aim was to study whether there is indication of a dissociation in processing of visuospatial and colour information in working memory in humans. Experimental subjects performed visuospatial and colour n-back tasks with and without visuospatial and colour distractive stimuli presented in the middle of the delay period to specifically affect mnemonic processing of task-related information. In the high memory-load condition, the visuospatial, but not the colour, task was selectively disrupted by visuospatial but not colour distractors. When subvocal rehearsal of the memoranda in the colour task was prevented by articulatory suppression; colour task performance was also selectively disrupted by distractors qualitatively similar to the memoranda. The results support the suggestion that visual working memory for location is processed separate from that for colour.

  4. Floral colour versus phylogeny in structuring subalpine flowering communities.

    Science.gov (United States)

    McEwen, Jamie R; Vamosi, Jana C

    2010-10-07

    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.

  5. Near vision spectacle coverage and barriers to near vision ...

    African Journals Online (AJOL)

    easily help to address this visual disability.7 An average cost of near vision spectacle in Ghana is approximately. $ 5.8 Near-vision spectacle could be dispensed as single vision, bifocal or progressive eye glasses to meet near vi- sion needs.2. Recent evidence suggests that the ageing population in. Ghana is increasing ...

  6. Grounding Our Vision: Brain Research and Strategic Vision

    Science.gov (United States)

    Walker, Mike

    2011-01-01

    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…

  7. Effects of visual skills training, vision coaching and sports vision ...

    African Journals Online (AJOL)

    The purpose of this study was to determine the effectiveness of three different approaches to improving sports performance through improvements in “sports vision:” (1) a visual skills training programme, (2) traditional vision coaching sessions, and (3) a multi-disciplinary approach identified as sports vision dynamics.

  8. Colour thresholding and objective quantification in bioimaging

    Science.gov (United States)

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

    1992-01-01

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

  9. New Evidence for Infant Colour Categories

    Science.gov (United States)

    Franklin, Anna; Davies, Ian R. L.

    2004-01-01

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

  10. Jottings on protective colour in animals

    NARCIS (Netherlands)

    Beaufort, de L.F.

    1964-01-01

    I have often been puzzled about the remarkable change of colour in the roedeer, a species that I can watch almost daily from my house. In the winter the greyish brown coat can hardly be distinguished against the dull, brownish shrubby wood, at the border of which they come to feed. The only visible

  11. Central Limit Theorem for Coloured Hard Dimers

    Directory of Open Access Journals (Sweden)

    Maria Simonetta Bernabei

    2010-01-01

    Full Text Available We study the central limit theorem for a class of coloured graphs. This means that we investigate the limit behavior of certain random variables whose values are combinatorial parameters associated to these graphs. The techniques used at arriving this result comprise combinatorics, generating functions, and conditional expectations.

  12. ATLAS Experiment Colouring Book in Arabic

    CERN Multimedia

    Anthony, Katarina

    2018-01-01

    Language: Arabic - The ATLAS Experiment Colouring Book is a free-to-download educational book, ideal for kids aged 5-9. It aims to introduce children to the field of High-Energy Physics, as well as the work being carried out by the ATLAS Collaboration.

  13. A Brief Introduction to Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1997-01-01

    Coloured Petri Nets (CP-nets or CPN) is a graphical oriented language for design, specification, simulation and verification of systems. It is in particular well- suited for systems in which communication, synchronisation and resource sharing are important. Typical examples of application areas a...

  14. All the colours of the rainbow

    Science.gov (United States)

    Smithson, Hannah E.; Gasper, Giles E. M.; McLeish, Tom C. B.

    2014-08-01

    Our perception of colour has always been a source of fascination, so it's little wonder that studies of the phenomenon date back hundreds of years. What, though, can modern scientists learn from medieval literature -- and how do we go about it?

  15. Kac's ring: The case of four colours

    Indian Academy of Sciences (India)

    We present an instance from nonequilibrium statistical mechanics which combines increase in entropy and finite Poincaré recurrence time. The model we consider is a variation of the well-known Kac's ring where we consider balls of four colours. As is known, Kac introduced this model where balls arranged between lattice ...

  16. Colour connections in e+e- annihilation

    International Nuclear Information System (INIS)

    Friberg, C.; Gustafson, G.; Haekkinen, J.

    1997-01-01

    We have very limited knowledge about how the confinement mechanism works in processes like e + e - →qqg..g, when there are identical colour charges. In this case the partons can be colour connected by a string or a cluster chain in several different ways. We do not know if in such a situation Nature chooses a particular configuration at random, or if some configuration is dynamically favoured. Also in the perturbative parton cascade we have no well-founded recipe for describing the interference effects, which correspond to non-planar diagrams and are caused by identical colour charges. We have studied two different models, and are in particular interested in the possibility that a colour singlet gluon system hadronizes isolated from the remainder of the state. Using double tagged events with heavy cc or bb quarks, it appears to be possible to find a significant signal, if such events appear in Nature. If this type of (re)connected states appear in Z decays it may also be an indication that reconnection might appear between the decay products of two W's in the reaction e + e - →W + W - →q 1 q 2 Q 1 Q 2 at LEP2. This would be important, e.g. for a precision measurement of the W mass. (orig.)

  17. ELECTROCOAGULATION METHOD FOR COLOUR REMOVAL IN ...

    African Journals Online (AJOL)

    Preferred Customer

    is a multi-stage process that requires considerable land area and a continual supply of chemicals ... In view of this, it was necessary to develop and optimize an effective electrochemical method for colour removal using a two-electrode system.

  18. The dark side of galaxy colour

    Science.gov (United States)

    Hearin, Andrew P.; Watson, Douglas F.

    2013-10-01

    We present age distribution matching, a theoretical formalism for predicting how galaxies of luminosity L and colour C occupy dark matter haloes. Our model supposes that there are just two fundamental properties of a halo that determine the colour and brightness of the galaxy it hosts: the maximum circular velocity Vmax and the redshift zstarve that correlates with the epoch at which the star formation in the galaxy ceases. The halo property zstarve is intended to encompass physical characteristics of halo mass assembly that may deprive the galaxy of its cold gas supply and, ultimately, quench its star formation. The new, defining feature of the model is that, at fixed luminosity, galaxy colour is in monotonic correspondence with zstarve, with the larger values of zstarve being assigned redder colours. We populate an N-body simulation with a mock galaxy catalogue based on age distribution matching and show that the resulting mock galaxy distribution accurately describes a variety of galaxy statistics. Our model suggests that halo and galaxy assembly are indeed correlated. We make publicly available our low-redshift, Sloan Digital Sky Survey Mr < -19 mock galaxy catalogue, and main progenitor histories of all z = 0 haloes, at http://logrus.uchicago.edu/~aphearin

  19. Colour-magnitude diagram of NGC 5053

    Energy Technology Data Exchange (ETDEWEB)

    Walker, M F; Pike, C D [California Univ., Santa Cruz (USA). Lick Observatory; McGee, J D

    1976-06-01

    The colour-magnitude diagram of NGC 5053 has been derived to V = 21.1 from photographic and electronographic observations. The electronographic observations were obtained with an experimental Spectracon image-converter, having photocathode and exit window dimensions of 20 x 30 mm, mounted at the prime-focus of the 120-in. Lick reflector. The photographic observations were obtained with the 20-in. Carnegie astrograph and the 36-in. Crossley reflector. The colour-magnitude diagram resembles that of M92, with the difference that a red horizontal branch is more pronounced than the asymptotic branch in NGC 5053. The topology of the horizontal branch is that of clusters with an intermediate metal content and is thus at variance with the mean period of the RR Lyr stars and the unreddened colour of the subgiant branch read at the magnitude level of the horizontal branch, both of which would indicate an extremely low metal content. If comparison of the colour-magnitude diagrams of NGC 5053 and M92 is valid, then the reddening of NGC 5053 is Esub(B-V) = 0.02 and the apparent distance modulus is m-M = 16.08 +- 0.08.

  20. [r,s,t]-colourings of paths

    Directory of Open Access Journals (Sweden)

    Marta Salvador Villà

    2007-01-01

    Full Text Available The concept of \\([r,s,t]\\-colourings was recently introduced by Hackmann, Kemnitz and Marangio [A. Kemnitz, M. Marangio, \\([r,s,t]\\-Colorings of Graphs, Discrete Math., to appear] as follows: Given non-negative integers \\(r\\, \\(s\\ and \\(t\\, an \\([r,s,t]\\-colouring of a graph \\(G=(V(G,E(G\\ is a mapping \\(c\\ from \\(V(G \\cup E(G\\ to the colour set \\(\\{1,2,\\ldots ,k\\}\\ such that \\(|c(v_i-c(v_j| \\geq r\\ for every two adjacent vertices \\(v_i\\, \\(v_j\\, \\(|c(e_i-c(e_j| \\geq s\\ for every two adjacent edges \\(e_i\\, \\(e_j\\, and \\(|c(v_i-c(e_j| \\geq t\\ for all pairs of incident vertices and edges, respectively. The \\([r,s,t]\\-chromatic number \\(\\chi_{r,s,t}(G\\ of \\(G\\ is defined to be the minimum \\(k\\ such that \\(G\\ admits an \\([r,s,t]\\-colouring. In this paper, we determine the \\([r,s,t]\\-chromatic number for paths.