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Sample records for dichromatic color vision

  1. Relative advantages of dichromatic and trichromatic color vision in camouflage breaking.

    Science.gov (United States)

    Troscianko, Jolyon; Wilson-Aggarwal, Jared; Griffiths, David; Spottiswoode, Claire N; Stevens, Martin

    2017-01-01

    There is huge diversity in visual systems and color discrimination abilities, thought to stem from an animal's ecology and life history. Many primate species maintain a polymorphism in color vision, whereby most individuals are dichromats but some females are trichromats, implying that selection sometimes favors dichromatic vision. Detecting camouflaged prey is thought to be a task where dichromatic individuals could have an advantage. However, previous work either has not been able to disentangle camouflage detection from other ecological or social explanations, or did not use biologically relevant cryptic stimuli to test this hypothesis under controlled conditions. Here, we used online "citizen science" games to test how quickly humans could detect cryptic birds (incubating nightjars) and eggs (of nightjars, plovers and coursers) under trichromatic and simulated dichromatic viewing conditions. Trichromats had an overall advantage, although there were significant differences in performance between viewing conditions. When searching for consistently shaped and patterned adult nightjars, simulated dichromats were more heavily influenced by the degree of pattern difference than were trichromats, and were poorer at detecting prey with inferior pattern and luminance camouflage. When searching for clutches of eggs-which were more variable in appearance and shape than the adult nightjars-the simulated dichromats learnt to detect the clutches faster, but were less sensitive to subtle luminance differences. These results suggest there are substantial differences in the cues available under viewing conditions that simulate different receptor types, and that these interact with the scene in complex ways to affect camouflage breaking.

  2. Color preference in red–green dichromats

    Science.gov (United States)

    Álvaro, Leticia; Moreira, Humberto; Lillo, Julio; Franklin, Anna

    2015-01-01

    Around 2% of males have red–green dichromacy, which is a genetic disorder of color vision where one type of cone photoreceptor is missing. Here we investigate the color preferences of dichromats. We aim (i) to establish whether the systematic and reliable color preferences of normal trichromatic observers (e.g., preference maximum at blue, minimum at yellow-green) are affected by dichromacy and (ii) to test theories of color preference with a dichromatic sample. Dichromat and normal trichromat observers named and rated how much they liked saturated, light, dark, and focal colors twice. Trichromats had the expected pattern of preference. Dichromats had a reliable pattern of preference that was different to trichromats, with a preference maximum rather than minimum at yellow and a much weaker preference for blue than trichromats. Color preference was more affected in observers who lacked the cone type sensitive to long wavelengths (protanopes) than in those who lacked the cone type sensitive to medium wavelengths (deuteranopes). Trichromats’ preferences were summarized effectively in terms of cone-contrast between color and background, and yellow-blue cone-contrast could account for dichromats’ pattern of preference, with some evidence for residual red–green activity in deuteranopes’ preference. Dichromats’ color naming also could account for their color preferences, with colors named more accurately and quickly being more preferred. This relationship between color naming and preference also was present for trichromat males but not females. Overall, the findings provide novel evidence on how dichromats experience color, advance the understanding of why humans like some colors more than others, and have implications for general theories of aesthetics. PMID:26170287

  3. The adaptive value of primate color vision for predator detection.

    Science.gov (United States)

    Pessoa, Daniel Marques Almeida; Maia, Rafael; de Albuquerque Ajuz, Rafael Cavalcanti; De Moraes, Pedro Zurvaino Palmeira Melo Rosa; Spyrides, Maria Helena Constantino; Pessoa, Valdir Filgueiras

    2014-08-01

    The complex evolution of primate color vision has puzzled biologists for decades. Primates are the only eutherian mammals that evolved an enhanced capacity for discriminating colors in the green-red part of the spectrum (trichromatism). However, while Old World primates present three types of cone pigments and are routinely trichromatic, most New World primates exhibit a color vision polymorphism, characterized by the occurrence of trichromatic and dichromatic females and obligatory dichromatic males. Even though this has stimulated a prolific line of inquiry, the selective forces and relative benefits influencing color vision evolution in primates are still under debate, with current explanations focusing almost exclusively at the advantages in finding food and detecting socio-sexual signals. Here, we evaluate a previously untested possibility, the adaptive value of primate color vision for predator detection. By combining color vision modeling data on New World and Old World primates, as well as behavioral information from human subjects, we demonstrate that primates exhibiting better color discrimination (trichromats) excel those displaying poorer color visions (dichromats) at detecting carnivoran predators against the green foliage background. The distribution of color vision found in extant anthropoid primates agrees with our results, and may be explained by the advantages of trichromats and dichromats in detecting predators and insects, respectively. © 2014 Wiley Periodicals, Inc.

  4. Derivation of Color Confusion Lines for Pseudo-Dichromat Observers from Color Discrimination Thresholds

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    Kahiro Matsudaira

    2011-05-01

    Full Text Available The objective is to develop a method of defining color confusion lines in the display RGB color space through color discrimination tasks. In the experiment, reference and test square patches were presented side by side on a CRT display. The subject's task is to set the test color where the color difference from the reference is just noticeable to him/her. In a single trial, the test color was only adjustable along one of 26 directions around the reference. Thus 26 colors with just noticeable difference (JND were obtained and made up a tube-like or an ellipsoidal shape around each reference. With color-anomalous subjects, the major axes of these shapes should be parallel to color confusion lines that have a common orientation vector corresponding to one of the cone excitation axes L, M, or S. In our method, the orientation vector was determined by minimizing the sum of the squares of the distances from JND colors to each confusion line. To assess the performance the method, the orientation vectors obtained by pseudo-dichromats (color normal observers with a dichromat simulator were compared to those theoretically calculated from the color vision model used in the simulator.

  5. The contribution of color to visual memory in X-chromosome-linked dichromats.

    Science.gov (United States)

    Gegenfurtner, K R; Wichmann, F A; Sharpe, L T

    1998-04-01

    We used a recognition memory paradigm to assess the visual memory of X-chromosome-linked dichromats for color images of natural scenes. The performance of 17 protanopes and 14 deuteranopes, who lack the second (red-green opponent) subsystem of color vision, but retain the primordial (yellow-blue opponent) subsystem, was compared with that of 36 color normal observers. During the presentation phase, 48 images of natural scenes were displayed on a CRT for durations between 50 and 1000 msec. Each image was followed by a random noise mask. Half of the images were presented in color and half in black and white. In the subsequent query phase, the same 48 images were intermixed with 48 new images and the subjects had to indicate which of the images they had already seen during the presentation phase. We find that the performance of the color normal observers increases with exposure duration. However, they perform 5-10% better for colored than for black and white images, even at exposure durations as short as 50 msec. Surprisingly, performance is not impaired for the dichromats, whose recognition performance is also better for colored than for black and white images. We conclude either that X-chromosome-linked dichromats may be able to compensate for their reduced chromatic information range when viewing complex natural scenes or that the chromatic information in most natural scenes, for the durations tested, is sufficiently represented by the surviving primordial color subsystem.

  6. Dichromatic Gray Pixel for Camera-agnostic Color Constancy

    OpenAIRE

    Qian, Yanlin; Chen, Ke; Nikkanen, Jarno; Kämäräinen, Joni-Kristian; Matas, Jiri

    2018-01-01

    We propose a novel statistical color constancy method, especially suitable for the Camera-agnostic Color Constancy, i.e. the scenario where nothing is known a priori about the capturing devices. The method, called Dichromatic Gray Pixel, or DGP, relies on a novel gray pixel detection algorithm derived using the Dichromatic Reflection Model. DGP is suitable for camera-agnostic color constancy since varying devices are set to make achromatic pixels look gray under standard neutral illumination....

  7. Considering the Influence of Nonadaptive Evolution on Primate Color Vision.

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    Rachel L Jacobs

    Full Text Available Color vision in primates is variable across species, and it represents a rare trait in which the genetic mechanisms underlying phenotypic variation are fairly well-understood. Research on primate color vision has largely focused on adaptive explanations for observed variation, but it remains unclear why some species have trichromatic or polymorphic color vision while others are red-green color blind. Lemurs, in particular, are highly variable. While some species are polymorphic, many closely-related species are strictly dichromatic. We provide the first characterization of color vision in a wild population of red-bellied lemurs (Eulemur rubriventer, Ranomafana National Park, Madagascar with a sample size (87 individuals; NX chromosomes = 134 large enough to detect even rare variants (0.95 probability of detection at ≥ 3% frequency. By sequencing exon 5 of the X-linked opsin gene we identified opsin spectral sensitivity based on known diagnostic sites and found this population to be dichromatic and monomorphic for a long wavelength allele. Apparent fixation of this long allele is in contrast to previously published accounts of Eulemur species, which exhibit either polymorphic color vision or only the medium wavelength opsin. This unexpected result may represent loss of color vision variation, which could occur through selective processes and/or genetic drift (e.g., genetic bottleneck. To indirectly assess the latter scenario, we genotyped 55 adult red-bellied lemurs at seven variable microsatellite loci and used heterozygosity excess and M-ratio tests to assess if this population may have experienced a recent genetic bottleneck. Results of heterozygosity excess but not M-ratio tests suggest a bottleneck might have occurred in this red-bellied lemur population. Therefore, while selection may also play a role, the unique color vision observed in this population might have been influenced by a recent genetic bottleneck. These results emphasize the

  8. Signatures of functional constraint at aye-aye opsin genes: the potential of adaptive color vision in a nocturnal primate.

    Science.gov (United States)

    Perry, George H; Martin, Robert D; Verrelli, Brian C

    2007-09-01

    While color vision perception is thought to be adaptively correlated with foraging efficiency for diurnal mammals, those that forage exclusively at night may not need color vision nor have the capacity for it. Indeed, although the basic condition for mammals is dichromacy, diverse nocturnal mammals have only monochromatic vision, resulting from functional loss of the short-wavelength sensitive opsin gene. However, many nocturnal primates maintain intact two opsin genes and thus have dichromatic capacity. The evolutionary significance of this surprising observation has not yet been elucidated. We used a molecular population genetics approach to test evolutionary hypotheses for the two intact opsin genes of the fully nocturnal aye-aye (Daubentonia madagascariensis), a highly unusual and endangered Madagascar primate. No evidence of gene degradation in either opsin gene was observed for any of 8 aye-aye individuals examined. Furthermore, levels of nucleotide diversity for opsin gene functional sites were lower than those for 15 neutrally evolving intergenic regions (>25 kb in total), which is consistent with a history of purifying selection on aye-aye opsin genes. The most likely explanation for these findings is that dichromacy is advantageous for aye-ayes despite their nocturnal activity pattern. We speculate that dichromatic nocturnal primates may be able to perceive color while foraging under moonlight conditions, and suggest that behavioral and ecological comparisons among dichromatic and monochromatic nocturnal primates will help to elucidate the specific activities for which color vision perception is advantageous.

  9. Recognition memory for colored and black-and-white scenes in normal and color deficient observers (dichromats).

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    Brédart, Serge; Cornet, Alyssa; Rakic, Jean-Marie

    2014-01-01

    Color deficient (dichromat) and normal observers' recognition memory for colored and black-and-white natural scenes was evaluated through several parameters: the rate of recognition, discrimination (A'), response bias (B"D), response confidence, and the proportion of conscious recollections (Remember responses) among hits. At the encoding phase, 36 images of natural scenes were each presented for 1 sec. Half of the images were shown in color and half in black-and-white. At the recognition phase, these 36 pictures were intermixed with 36 new images. The participants' task was to indicate whether an image had been presented or not at the encoding phase, to rate their level of confidence in his her/his response, and in the case of a positive response, to classify the response as a Remember, a Know or a Guess response. Results indicated that accuracy, response discrimination, response bias and confidence ratings were higher for colored than for black-and-white images; this advantage for colored images was similar in both groups of participants. Rates of Remember responses were not higher for colored images than for black-and-white ones, whatever the group. However, interestingly, Remember responses were significantly more often based on color information for colored than for black-and-white images in normal observers only, not in dichromats.

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

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    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.

  11. Lentes de contato filtrantes coloridas nas discromatopsias: relato de casos Absorptive and colored contact lenses in color-vision defects: case report

    Directory of Open Access Journals (Sweden)

    Luciene Chaves Fernandes

    2003-06-01

    test. Subject # 2 showed an subjective reduced glare, in external and internal environment. Visual acuity and color vision remained the same. The findings suggest the use of absorptive colored contact lenses to increase color judgement and reduce glare sensitivity in dichromatic subjects.

  12. 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: ...

  13. Number of discernible colors for color-deficient observers estimated from the MacAdam limits.

    Science.gov (United States)

    Perales, Esther; Martínez-Verdú, Francisco Miguel; Linhares, João Manuel Maciel; Nascimento, Sérgio Miguel Cardoso

    2010-10-01

    We estimated the number of colors perceived by color normal and color-deficient observers when looking at the theoretic limits of object-color stimuli. These limits, the optimal color stimuli, were computed for a color normal observer and CIE standard illuminant D65, and the resultant colors were expressed in the CIELAB and DIN99d color spaces. The corresponding color volumes for abnormal color vision were computed using models simulating for normal trichromatic observers the appearance for dichromats and anomalous trichomats. The number of colors perceived in each case was then computed from the color volumes enclosed by the optimal colors also known as MacAdam limits. It was estimated that dichromats perceive less than 1% of the colors perceived by normal trichromats and that anomalous trichromats perceive 50%-60% for anomalies in the medium-wavelength-sensitive and 60%-70% for anomalies in the long-wavelength-sensitive cones. Complementary estimates obtained similarly for the spectral locus of monochromatic stimuli suggest less impairment for color-deficient observers, a fact that is explained by the two-dimensional nature of the locus.

  14. 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 ...

  15. 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.

  16. Curing Color Blindness—Mice and Nonhuman Primates

    Science.gov (United States)

    Neitz, Maureen; Neitz, Jay

    2014-01-01

    It has been possible to use viral-mediated gene therapy to transform dichromatic (red-green color-blind) primates to trichromatic. Even though the third cone type was added after the end of developmental critical periods, treated animals acquired red-green color vision. What happened in the treated animals may represent a recapitulation of the evolution of trichromacy, which seems to have evolved with the acquisition of a third cone type without the need for subsequent modification to the circuitry. Some transgenic mice in which a third cone type was added also acquired trichromacy. However, compared with treated primates, red-green color vision in mice is poor, indicating large differences between mice and monkeys in their ability to take advantage of the new input. These results have implications for understanding the limits and opportunities for using gene therapy to treat vision disorders caused by defects in cone function. PMID:25147187

  17. Color Vision Defects in School Going Children

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    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.

  18. Temporary effects of alcohol on color vision

    Science.gov (United States)

    Geniusz, Maciej K.; Geniusz, Malwina; Szmigiel, Marta; Przeździecka-Dołyk, Joanna

    2017-09-01

    The color vision has been described as one to be very sensitive to the intake of several chemicals. The present research reviews the published literature that is concerned with color vision impairment due to alcohol. Most of this research considers people under long-term effects of alcohol. However, there is little information about temporary effects of alcohol on color vision. A group of ten volunteers aged 18-40 was studied. During the study levels of alcohol in the body were tested with a standard breathalyzer while color vision were studied using Farnsworth Munsell 100 Hue Color Vision Tests. Keywords: Col

  19. Sensory Drive, Color, and Color Vision.

    Science.gov (United States)

    Price, Trevor D

    2017-08-01

    Colors often appear to differ in arbitrary ways among related species. However, a fraction of color diversity may be explained because some signals are more easily perceived in one environment rather than another. Models show that not only signals but also the perception of signals should regularly evolve in response to different environments, whether these primarily involve detection of conspecifics or detection of predators and prey. Thus, a deeper understanding of how perception of color correlates with environmental attributes should help generate more predictive models of color divergence. Here, I briefly review our understanding of color vision in vertebrates. Then I focus on opsin spectral tuning and opsin expression, two traits involved in color perception that have become amenable to study. I ask how opsin tuning is correlated with ecological differences, notably the light environment, and how this potentially affects perception of conspecific colors. Although opsin tuning appears to evolve slowly, opsin expression levels are more evolutionarily labile but have been difficult to connect to color perception. The challenge going forward will be to identify how physiological differences involved in color vision, such as opsin expression levels, translate into perceptual differences, the selection pressures that have driven those differences, and ultimately how this may drive evolution of conspecific colors.

  20. Curing color blindness--mice and nonhuman primates.

    Science.gov (United States)

    Neitz, Maureen; Neitz, Jay

    2014-08-21

    It has been possible to use viral-mediated gene therapy to transform dichromatic (red-green color-blind) primates to trichromatic. Even though the third cone type was added after the end of developmental critical periods, treated animals acquired red-green color vision. What happened in the treated animals may represent a recapitulation of the evolution of trichromacy, which seems to have evolved with the acquisition of a third cone type without the need for subsequent modification to the circuitry. Some transgenic mice in which a third cone type was added also acquired trichromacy. However, compared with treated primates, red-green color vision in mice is poor, indicating large differences between mice and monkeys in their ability to take advantage of the new input. These results have implications for understanding the limits and opportunities for using gene therapy to treat vision disorders caused by defects in cone function. Copyright © 2014 Cold Spring Harbor Laboratory Press; all rights reserved.

  1. Functional photoreceptor loss revealed with adaptive optics: an alternate cause of color blindness.

    Science.gov (United States)

    Carroll, Joseph; Neitz, Maureen; Hofer, Heidi; Neitz, Jay; Williams, David R

    2004-06-01

    There is enormous variation in the X-linked L/M (long/middle wavelength sensitive) gene array underlying "normal" color vision in humans. This variability has been shown to underlie individual variation in color matching behavior. Recently, red-green color blindness has also been shown to be associated with distinctly different genotypes. This has opened the possibility that there may be important phenotypic differences within classically defined groups of color blind individuals. Here, adaptive optics retinal imaging has revealed a mechanism for producing dichromatic color vision in which the expression of a mutant cone photopigment gene leads to the loss of the entire corresponding class of cone photoreceptor cells. Previously, the theory that common forms of inherited color blindness could be caused by the loss of photoreceptor cells had been discounted. We confirm that remarkably, this loss of one-third of the cones does not impair any aspect of vision other than color.

  2. 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...

  3. Color in Computer Vision Fundamentals and Applications

    CERN Document Server

    Gevers, Theo; van de Weijer, Joost; Geusebroek, Jan-Mark

    2012-01-01

    While the field of computer vision drives many of today’s digital technologies and communication networks, the topic of color has emerged only recently in most computer vision applications. One of the most extensive works to date on color in computer vision, this book provides a complete set of tools for working with color in the field of image understanding. Based on the authors’ intense collaboration for more than a decade and drawing on the latest thinking in the field of computer science, the book integrates topics from color science and computer vision, clearly linking theor

  4. 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

  5. Color Calibration for Colorized Vision System with Digital Sensor and LED Array Illuminator

    Directory of Open Access Journals (Sweden)

    Zhenmin Zhu

    2016-01-01

    Full Text Available Color measurement by the colorized vision system is a superior method to achieve the evaluation of color objectively and continuously. However, the accuracy of color measurement is influenced by the spectral responses of digital sensor and the spectral mismatch of illumination. In this paper, two-color vision system illuminated by digital sensor and LED array, respectively, is presented. The Polynomial-Based Regression method is applied to solve the problem of color calibration in the sRGB and CIE  L⁎a⁎b⁎ color spaces. By mapping the tristimulus values from RGB to sRGB color space, color difference between the estimated values and the reference values is less than 3ΔE. Additionally, the mapping matrix ΦRGB→sRGB has proved a better performance in reducing the color difference, and it is introduced subsequently into the colorized vision system proposed for a better color measurement. Necessarily, the printed matter of clothes and the colored ceramic tile are chosen as the application experiment samples of our colorized vision system. As shown in the experimental data, the average color difference of images is less than 6ΔE. It indicates that a better performance of color measurement is obtained via the colorized vision system proposed.

  6. 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 ...

  7. Color Vision Losses in Autism Spectrum Disorders

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    Elaine C. Zachi

    2017-06-01

    Full Text Available Autism spectrum disorders (ASDs are neurodevelopmental conditions characterized by impairments in social/communication abilities and restricted behaviors. The present study aims to examine color vision discrimination in ASD children and adolescents without intellectual disability. The participants were also subdivided in order to compare color vision thresholds of autistic participants and those who achieved diagnostic criteria for Asperger Syndrome (AS. Nine subjects with autism, 11 participants with AS and 36 typically developing children and adolescents participated in the study. Color vision was assessed by the Cambridge Color Test (CCT. The Trivector protocol was administered to determine color discrimination thresholds along the protan, deutan, and tritan color confusion lines. Data from ASD participants were compared to tolerance limits for 90% of the population with 90% probability obtained from controls thresholds. Of the 20 ASD individuals examined, 6 (30% showed color vision losses. Elevated color discrimination thresholds were found in 3/9 participants with autism and in 3/11 AS participants. Diffuse and tritan deficits were found. Mechanisms for chromatic losses may be either at the retinal level and/or reflect reduced cortical integration.

  8. [Acquired disorders of color vision].

    Science.gov (United States)

    Lascu, Lidia; Balaş, Mihaela

    2002-01-01

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

  9. Progress in color night vision

    NARCIS (Netherlands)

    Toet, A.; Hogervorst, M.A.

    2012-01-01

    We present an overview of our recent progress and the current state-of-the-art techniques of color image fusion for night vision applications. Inspired by previously developed color opponent fusing schemes, we initially developed a simple pixel-based false color-mapping scheme that yielded fused

  10. 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.

  11. Color discrimination in the tufted capuchin monkey, Sapajus spp.

    Science.gov (United States)

    Goulart, Paulo Roney Kilpp; Bonci, Daniela Maria Oliveira; Galvão, Olavo de Faria; Silveira, Luiz Carlos de Lima; Ventura, Dora Fix

    2013-01-01

    The present study evaluated the efficacy of an adapted version of the Mollon-Reffin test for the behavioral investigation of color vision in capuchin monkeys. Ten tufted capuchin monkeys (Sapajus spp., formerly referred to as Cebus apella) had their DNA analyzed and were characterized as the following: one trichromat female, seven deuteranope dichromats (six males and one female), and two protanope males, one of which was identified as an "ML protanope." For their behavioral characterization, all of the subjects were tested at three regions of the Commission International de l'Eclairage (CIE) 1976 u'v' diagram, with each test consisting of 20 chromatic variation vectors that were radially distributed around the chromaticity point set as the test background. The phenotypes inferred from the behavioral data were in complete agreement with those predicted from the genetic analysis, with the threshold distribution clearly differentiating between trichromats and dichromats and the estimated confusion lines characteristically converging for deuteranopes and the "classic" protanope. The discrimination pattern of the ML protanope was intermediate between protan and deutan, with confusion lines horizontally oriented and parallel to each other. The observed phenotypic differentiation confirmed the efficacy of the Mollon-Reffin test paradigm as a useful tool for evaluating color discrimination in nonhuman primates. Especially noteworthy was the demonstration of behavioral segregation between the "classic" and "ML" protanopes, suggesting identifiable behavioral consequences of even slight variations in the spectral sensitivity of M/L photopigments in dichromats.

  12. Metacontrast masking is processed before grapheme-color synesthesia.

    Science.gov (United States)

    Bacon, Michael Patrick; Bridgeman, Bruce; Ramachandran, Vilayanur S

    2013-01-01

    We investigated the physiological mechanism of grapheme-color synesthesia using metacontrast masking. A metacontrast target is rendered invisible by a mask that is delayed by about 60 ms; the target and mask do not overlap in space or time. Little masking occurs, however, if the target and mask are simultaneous. This effect must be cortical, because it can be obtained dichoptically. To compare the data for synesthetes and controls, we developed a metacontrast design in which nonsynesthete controls showed weaker dichromatic masking (i.e., the target and mask were in different colors) than monochromatic masking. We accomplished this with an equiluminant target, mask, and background for each observer. If synesthetic color affected metacontrast, synesthetes should show monochromatic masking more similar to the weak dichromatic masking among controls, because synesthetes could add their synesthetic color to the monochromatic condition. The target-mask pairs used for each synesthete were graphemes that elicited strong synesthetic colors. We found stronger monochromatic than dichromatic U-shaped metacontrast for both synesthetes and controls, with optimal masking at an asynchrony of 66 ms. The difference in performance between the monochromatic and dichromatic conditions in the synesthetes indicates that synesthesia occurs at a later processing stage than does metacontrast masking.

  13. Breeding biology and the evolution of dynamic sexual dichromatism in frogs.

    Science.gov (United States)

    Bell, R C; Webster, G N; Whiting, M J

    2017-12-01

    Dynamic sexual dichromatism is a temporary colour change between the sexes and has evolved independently in a wide range of anurans, many of which are explosive breeders wherein males physically compete for access to females. Behavioural studies in a few species indicate that dynamic dichromatism functions as a visual signal in large breeding aggregations; however, the prevalence of this trait and the social and environmental factors underlying its expression are poorly understood. We compiled a database of 178 anurans with dynamic dichromatism that include representatives from 15 families and subfamilies. Dynamic dichromatism is common in two of the three subfamilies of hylid treefrogs. Phylogenetic comparative analyses of 355 hylid species (of which 95 display dynamic dichromatism) reveal high transition rates between dynamic dichromatism, ontogenetic (permanent) dichromatism and monochromatism reflecting the high evolutionary lability of this trait. Correlated evolution in hylids between dynamic dichromatism and forming large breeding aggregations indicates that the evolution of large breeding aggregations precedes the evolution of dynamic dichromatism. Multivariate phylogenetic logistic regression recovers the interaction between biogeographic distribution and forming breeding aggregations as a significant predictor of dynamic dichromatism in hylids. Accounting for macroecological differences between temperate and tropical regions, such as seasonality and the availability of breeding sites, may improve our understanding of ecological contexts in which dynamic dichromatism is likely to arise in tropical lineages and why it is retained in some temperate species and lost in others. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  14. Evolution of sexual dichromatism in relation to nesting habits in European passerines: a test of Wallace's hypothesis.

    Science.gov (United States)

    Soler, J J; Moreno, J

    2012-08-01

    Wallace proposed in 1868 that natural rather than sexual selection could explain the striking differences in avian plumage dichromatism. Thus, he predicted that nesting habits, through their association with nest predation, could drive changes in sexual dichromatism by enabling females in cavity nesters to become as conspicuous as males, whereas Darwin (1871, The Descent of Man and Selection in Relation to Sex, John Murray, London) argued that sexual selection was the sole explanation for dichromatism. Sexual dichromatism is currently used as indicating the strength of sexual selection, and therefore testing Wallace's claim with modern phylogentically controlled methodologies is of prime interest for comparing the roles of natural and sexual selection in affecting the evolution of avian coloration. Here, we have related information on nest attendance, sexual dichromatism and nesting habits (open and cavity nesting) to male and female plumage conspicuousness in European passerines. Nest incubation attendance does not explain male or female plumage conspicuousness but nest type does. Moreover, although females of monochromatic and cavity nesting species are more conspicuous than females of other species, males of monochromatic and open nesting species are those with more cryptic plumage. Finally, analyses of character evolution suggest that changes in nesting habits influence the probability of changes in both dichromatism and plumage conspicuousness of males but do not significantly affect those in females. These results strongly suggest a role of nesting habits in the evolution of plumage conspicuousness of males, and a role for sexual selection also in females, both factors affecting the evolution of sexual dichromatism. We discuss our findings in relation to the debate that Darwin and Wallace maintained more than one century ago on the importance of natural and sexual selection in driving the evolution of plumage conspicuousness and sexual dichromatism in birds

  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. Schopenhauer on vision and the colors.

    Science.gov (United States)

    Crone, R A

    1997-01-01

    Arthur Schopenhauer (1788-1860) published his book, On Vision and the Colors in 1816. He started from Aristotle's linear color system and Goethe's three pairs of contrast colors. His work preceded Hering's theory of opponent colors but his path to insight was blocked by his anti-Newtonianism and his neo-Hellenistic attitude toward science. Because of his theory of the subjectivity of colors he was a forerunner of the psycho-physiological variant of neo-Kantianism.

  17. Operational Assessment of Color Vision

    Science.gov (United States)

    2016-06-20

    YN0Ve_jXBUC&pg=PR11&source=gbs_selected_page s&cad=2#v=onepage&q&f=false. 5. Jeffries BJ. Color - blindness : its dangers and its detection. Boston (MA...Brussels, Belgium. Neuilly-sur-Seine (France): NATO; 1972. AGARD-CP-99. 11. Monlux DJ, Finne HA, Stephens MB. Color blindness and military fitness...unlimited. STINFO COPY AFRL-SA-WP-TR-2016-0008 Operational Assessment of Color Vision Steve Wright, O.D.; James Gaska, Ph.D

  18. Dynamic simulation of color blindness for studying color vision requirements in practice

    NARCIS (Netherlands)

    Lucassen, M.P.; Alferdinck, J.W.A.M.

    2006-01-01

    We report on a dynamic simulation of defective color vision. Using an RGB video camera connected to a PC or laptop, the captured and displayed RGB colors are translated by our software into modified RGB values that simulate the color appearance of a person with a color deficiency. Usually, the

  19. Dichromatic laser radiation effects on DNA of Escherichia coli and plasmids

    Science.gov (United States)

    Martins, W. A.; Polignano, G. A. C.; Guimarães, O. R.; Geller, M.; Paoli, F.; Fonseca, A. S.

    2015-04-01

    Dichromatic and consecutive laser radiations have attracted increased attention for clinical applications as offering new tools for the treatment of dysfunctional tissues in situations where monochromatic radiation is not effective. This work evaluated the survival, filamentation and morphology of Escherichia coli cells, and the induction of DNA lesions, in plasmid DNA exposed to low-intensity consecutive dichromatic laser radiation. Exponential and stationary wild type and formamidopyrimidine DNA glycosylase/MutM protein deficient E. coli cultures were exposed to consecutive low-intensity dichromatic laser radiation (infrared laser immediately after red laser) to study the survival, filamentation and morphology of bacterial cells. Plasmid DNA samples were exposed to dichromatic radiation to study DNA lesions by electrophoretic profile. Dichromatic laser radiation affects the survival, filamentation and morphology of E. coli cultures depending on the growth phase and the functional repair mechanism of oxidizing lesions in DNA, but does not induce single/double strands breaks or alkali-labile DNA lesions. Results show that low-intensity consecutive dichromatic laser radiation induces biological effects that differ from those induced by monochromatic laser radiation, suggesting that other therapeutic effects could be obtained using dichromatic radiation.

  20. 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.

  1. Physiological modeling for detecting degree of perception of a color-deficient person.

    Science.gov (United States)

    Rajalakshmi, T; Prince, Shanthi

    2017-04-01

    Physiological modeling of retina plays a vital role in the development of high-performance image processing methods to produce better visual perception. People with normal vision have an ability to discern different colors. The situation is different in the case of people with color blindness. The aim of this work is to develop a human visual system model for detecting the level of perception of people with red, green and blue deficiency by considering properties like luminance, spatial and temporal frequencies. Simulation results show that in the photoreceptor, outer plexiform and inner plexiform layers, the energy and intensity level of the red, green and blue component for a normal person is proved to be significantly higher than for dichromats. The proposed method explains with appropriate results that red and blue color blindness people could not perceive red and blue color completely.

  2. 76 FR 37690 - CooperVision, Inc.; Filing of Color Additive Petitions

    Science.gov (United States)

    2011-06-28

    ... color additives are intended to be copolymerized with various monomers for use as colored contact lens.... FDA-2011-C-0344 and FDA-2011-C-0463] CooperVision, Inc.; Filing of Color Additive Petitions AGENCY... Administration (FDA) is announcing that CooperVision, Inc., has filed two petitions proposing that the color...

  3. 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.

  4. 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.

  5. 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.

  6. 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).

  7. 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.

  8. 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.

  9. Railroad signal color and orientation : effects of color blindness and criteria for color vision field tests

    Science.gov (United States)

    2015-03-01

    This report concerns two issues: 1) whether color vision is necessary for locomotive crews who work on railroads where the signal system is either completely redundant with regard to signal color and signal orientation or the signal system only uses ...

  10. Red-Green Color Vision Impairment in Duchenne Muscular Dystrophy

    Science.gov (United States)

    Costa, Marcelo Fernandes ; Oliveira, Andre Gustavo Fernandes ; Feitosa-Santana, Claudia ; Zatz, Mayana ; Ventura, Dora Fix 

    2007-01-01

    The present study evaluated the color vision of 44 patients with Duchenne muscular dystrophy (DMD) (mean age 14.8 years; SD 4.9) who were submitted to a battery of four different color tests: Cambridge Colour Test (CCT), Neitz Anomaloscope, Ishihara, and American Optical Hardy-Rand-Rittler (AO H-R-R). Patients were divided into two groups according to the region of deletion in the dystrophin gene: upstream of exon 30 (n=12) and downstream of exon 30 (n=32). The control group was composed of 70 age-matched healthy male subjects with no ophthalmological complaints. Of the patients with DMD, 47% (21/44) had a red-green color vision defect in the CCT, confirmed by the Neitz Anomaloscope with statistical agreement (P.05). Of the patients with deletion downstream of exon 30, 66% had a red-green color defect. No color defect was found in the patients with deletion upstream of exon 30. A negative correlation between the color thresholds and age was found for the controls and patients with DMD, suggesting a nonprogressive color defect. The percentage (66%) of patients with a red-green defect was significantly higher than the expected <10% for the normal male population (P<.001). In contrast, patients with DMD with deletion upstream of exon 30 had normal color vision. This color defect might be partially explained by a retina impairment related to dystrophin isoform Dp260. PMID:17503325

  11. The Dichromatic Number of Infinite Families of Circulant Tournaments

    Directory of Open Access Journals (Sweden)

    Javier Nahid

    2017-02-01

    Full Text Available The dichromatic number dc(D of a digraph D is defined to be the minimum number of colors such that the vertices of D can be colored in such a way that every chromatic class induces an acyclic subdigraph in D. The cyclic circulant tournament is denoted by T=C→2n+1(1,2,…,n$T = \\overrightarrow C _{2n + 1} (1,2, \\ldots ,n$, where V (T = ℤ2n+1 and for every jump j ∈ {1, 2, . . . , n} there exist the arcs (a, a + j for every a ∈ ℤ2n+1. Consider the circulant tournament C→2n+1〈k〉$\\overrightarrow C _{2n + 1} \\left\\langle k \\right\\rangle $ obtained from the cyclic tournament by reversing one of its jumps, that is, C→2n+1 〈k〉$\\overrightarrow C _{2n + 1} \\left\\langle k \\right\\rangle $ has the same arc set as C→2n+1(1,2,…,n$\\overrightarrow C _{2n + 1} (1,2, \\ldots ,n$ except for j = k in which case, the arcs are (a, a − k for every a ∈ ℤ2n+1. In this paper, we prove that dc(C→2n+1 〈k〉∈{2,3,4}$dc ( {\\overrightarrow C _{2n + 1} \\left\\langle k \\right\\rangle } \\in \\{ 2,3,4\\}$ for every k ∈ {1, 2, . . . , n}. Moreover, we classify which circulant tournaments C→2n+1 〈k〉$\\overrightarrow C _{2n + 1} \\left\\langle k \\right\\rangle$ are vertex-critical r-dichromatic for every k ∈ {1, 2, . . . , n} and r ∈ {2, 3, 4}. Some previous results by Neumann-Lara are generalized.

  12. Extreme reversed sexual dichromatism in a bird without sex role reversal.

    Science.gov (United States)

    Heinsohn, Robert; Legge, Sarah; Endler, John A

    2005-07-22

    Brilliant plumage is typical of male birds, reflecting differential enhancement of male traits when females are the limiting sex. Brighter females are thought to evolve exclusively in response to sex role reversal. The striking reversed plumage dichromatism of Eclectus roratus parrots does not fit this pattern. We quantify plumage color in this species and show that very different selection pressures are acting on males and females. Male plumage reflects a compromise between the conflicting requirements for camouflage from predators while foraging and conspicuousness during display. Females are liberated from the need for camouflage but compete for rare nest hollows.

  13. 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 ...

  14. 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).

  15. Statistical and molecular analyses of evolutionary significance of red-green color vision and color blindness in vertebrates.

    Science.gov (United States)

    Yokoyama, Shozo; Takenaka, Naomi

    2005-04-01

    Red-green color vision is strongly suspected to enhance the survival of its possessors. Despite being red-green color blind, however, many species have successfully competed in nature, which brings into question the evolutionary advantage of achieving red-green color vision. Here, we propose a new method of identifying positive selection at individual amino acid sites with the premise that if positive Darwinian selection has driven the evolution of the protein under consideration, then it should be found mostly at the branches in the phylogenetic tree where its function had changed. The statistical and molecular methods have been applied to 29 visual pigments with the wavelengths of maximal absorption at approximately 510-540 nm (green- or middle wavelength-sensitive [MWS] pigments) and at approximately 560 nm (red- or long wavelength-sensitive [LWS] pigments), which are sampled from a diverse range of vertebrate species. The results show that the MWS pigments are positively selected through amino acid replacements S180A, Y277F, and T285A and that the LWS pigments have been subjected to strong evolutionary conservation. The fact that these positively selected M/LWS pigments are found not only in animals with red-green color vision but also in those with red-green color blindness strongly suggests that both red-green color vision and color blindness have undergone adaptive evolution independently in different species.

  16. Molecular patterns of X chromosome-linked color vision genes among 134 menof European ancestry

    International Nuclear Information System (INIS)

    Drummond-Borg, M.; Deeb, S.S.; Motulsky, A.G.

    1989-01-01

    The authors used Southern blot hybridization to study X chromosome-linked color vision genes encoding the apoproteins of red and green visual pigments in 134 unselected Caucasian men. One hundred and thirteen individuals (84.3%) had a normal arrangement of their color vision pigment genes. All had one red pigment gene; the number of green pigment genes ranged from one to five with a mode of two. The frequency of molecular genotypes indicative of normal color vision (84.3%) was significantly lower than had been observed in previous studies of color vision phenotypes. Color vision defects can be due to deletions of red or green pigment genes or due to formation of hybrid genes comprising portions of both red and green pigment genes. Characteristic anomalous patterns were seen in 15 (11.2%) individuals: 7 (5.2%) had patterns characteristic of deuteranomaly, 2 (1.5%) had patterns characteristic of deuteranopia, and 6 (4.5%) had protan patterns. Previously undescribed hybrid gene patterns consisting of both green and red pigment gene fragments in addition to normal red and green genes were observed in another 6 individuals (4.5%). Thus, DNA testing detected anomalous color vision pigment genes at a higher frequency than expected from phenotypic color vision tests

  17. Harnessing color vision for visual oximetry in central cyanosis.

    Science.gov (United States)

    Changizi, Mark; Rio, Kevin

    2010-01-01

    Central cyanosis refers to a bluish discoloration of the skin, lips, tongue, nails, and mucous membranes, and is due to poor arterial oxygenation. Although skin color is one of its characteristic properties, it has long been realized that by the time skin color signs become visible, oxygen saturation is dangerously low. Here we investigate the visibility of cyanosis in light of recent discoveries on what color vision evolved for in primates. We elucidate why low arterial oxygenation is visible at all, why it is perceived as blue, and why it can be so difficult to perceive. With a better understanding of the relationship between color vision and blood physiology, we suggest two simple techniques for greatly enhancing the clinician's ability to detect cyanosis and other clinical color changes. The first is called "skin-tone adaptation", wherein sheets, gowns, walls and other materials near a patient have a color close to that of the patient's skin, thereby optimizing a color-normal viewer's ability to sense skin color modulations. The second technique is called "biosensor color tabs", wherein adhesive tabs with a color matching the patient's skin tone are placed in several spots on the skin, and subsequent skin color changes have the effect of making the initially-invisible tabs change color, their hue and saturation indicating the direction and magnitude of the skin color shift.

  18. Reexamination of Color Vision Standards, Part I: Status of Color Use in ATC Displays and Demography of Color-Deficit Controllers

    National Research Council Canada - National Science Library

    Xing, Jing; Schroeder, David J

    2006-01-01

    This report describes the status of color use in current air traffic control (ATC) displays. It represents the first step in an effort to reexamine the color vision standards for air traffic controllers...

  19. Correlated evolution of migration and sexual dichromatism in the New World orioles (icterus).

    Science.gov (United States)

    Friedman, Nicholas R; Hofmann, Christopher M; Kondo, Beatrice; Omland, Kevin E

    2009-12-01

    The evolution of sexual dimorphism has long been attributed to sexual selection, specifically as it would drive repeated gains of elaborate male traits. In contrast to this pattern, New World oriole species all exhibit elaborate male plumage, and the repeated gains of sexual dichromatism observed in the genus are due to losses of female elaboration. Interestingly, most sexually dichromatic orioles belong to migratory or temperate-breeding clades. Using character scoring and ancestral state reconstructions from two recent studies in Icterus, we tested a hypothesis of correlated evolution between migration and sexual dichromatism. We employed two discrete phylogenetic comparative approaches: the concentrated changes test and Pagel's discrete likelihood test. Our results show that the evolution of these traits is significantly correlated (CCT: uncorrected P model of character evolution suggests that gains of sexual dichromatism are 23 times more likely to occur in migratory taxa. This study demonstrates that a life-history trait with no direct relationship with sexual selection has a strong influence on the evolution of sexual dichromatism. We recommend that researchers further investigate the role of selection on elaborate female traits in the evolution of sexual dimorphism.

  20. 75 FR 10808 - CIBA Vision Corp.; Withdrawal of Color Additive Petitions

    Science.gov (United States)

    2010-03-09

    ...) proposing that the color additive regulations be amended to provide for the safe use of Color Index (C.I... of Color Additives Exempt from Certification (21 CFR part 73) to provide for the safe use of C.I...) CIBA Vision Corp.; Withdrawal of Color Additive Petitions AGENCY: Food and Drug Administration, HHS...

  1. Bold colors in a cryptic lineage: do Eastern Indigo Snakes exhibit color dimorphism?

    Science.gov (United States)

    Deitloff, Jennifer; Johnson, Valerie M; Guyer, Craig

    2013-01-01

    Many species exhibit variation in the color of their scales, feathers, or fur. Various forms of natural selection, such as mimicry, crypsis, and species recognition, as well as sexual selection, can influence the evolution of color. Eastern Indigo Snakes (Drymarchon couperi), a federally threatened species, have coloration on the sides of the head and the chin that can vary from black to red or cream. Despite significant conservations efforts for this species, little is known about its biology in the field. Past researchers have proposed that the color variation on the head and chin is associated with the sex of the individual. Alternatively, color might vary among individuals because it is controlled by genes that are under natural selection or neutral evolution. We tested these alternative hypotheses by examining whether coloration of the sublabial, submaxillary, and ventral scales of this species differed by sex or among clutches. We used color spectrometry to characterize important aspects of color in two ways: by examining overall color differences across the entire color spectrum and by comparing differences within the ultraviolet, yellow, and red colorbands. We found that Eastern Indigo Snakes do not exhibit sexual dichromatism, but their coloration does vary among clutches; therefore, the pattern of sexual selection leading to sexual dichromatism observed in many squamates does not appear to play a role in the evolution and maintenance of color variation in Eastern Indigo Snakes. We suggest that future studies should focus on determining whether color variation in these snakes is determined by maternal effects or genetic components and if color is influenced by natural selection or neutral evolutionary processes. Studying species that exhibit bright colors within lineages that are not known for such coloration will contribute greatly to our understanding of the evolutionary and ecological factors that drive these differences.

  2. 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…

  3. What Is It Going to Be? Pattern and Potential Function of Natal Coat Change in Sexually Dichromatic Redfronted Lemurs (Eulemur fulvus rufus)

    DEFF Research Database (Denmark)

    Barthold, Julia A; Fichtel, Claudia; Kappeler, Peter M

    2009-01-01

    In some primate species, pelage colorations at birth contrast with adult colorations. The intensity of natal coats and their phylogenetic distribution is highly variable within primates. Natal coat coloration seems to change to adult coloration in most species when infants become independent from...... their mothers, but an accepted functional explanation for natal coats is not available. Here we describe pelage coloration change in sexually dichromatic redfronted lemurs (Eulemur fulvus rufus) in Kirindy Forest, and propose a new functional hypothesis for this phenomenon. In this species, infants are born...... infants and 2) examined behavioral developmental correlates of the coloration change. The color change took place between 7 and 17 weeks of age and coincided with advanced physical independence; a pattern also found in monochromatic primate species with natal coats. No behavioral differences between male...

  4. 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.

  5. Prevalence of congenital color vision defects in Saudi females of Arab origin.

    Science.gov (United States)

    Alabdelmoneam, Mussaed

    2011-09-01

    Inherited color vision deficiencies (CVD) vary in prevalence by population and by sex. The most common CVD is X chromosome-linked anomalous trichromacy. Prevalence varies significantly by sex and race. The frequency of color vision defects in Saudi females has not been studied previously. This study surveyed the prevalence of congenital color vision defects in Saudi females of Arab origin. Seven thousand four hundred sixty-seven female subjects (N = 7,467) from the Kingdom of Saudi Arabia were screened using both Ishihara pseudoisochromatic plates and the Farnsworth Dichotomous test (D-15). CVD subjects were tested further with the Farnsworth-Munsell 100 Hue test. Of 7,467 female subjects tested, 26 subjects were found to have defective color vision, for a prevalence of 0.35%. Sixteen subjects had a deutan defect, and 10 had a protan defect. Arab females have significantly lower prevalence of CVD when compared with published data from females of other races. Analysis of the 5 regions of Saudi Arabia showed no significant difference between the regions. Prevalence of CVD among Saudi females of Arab origin is 0.35% and is among the lowest of all published data. Copyright © 2011 American Optometric Association. Published by Elsevier Inc. All rights reserved.

  6. 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).

  7. Comparison of a multispectral vision system and a colorimeter for the assessment of meat color

    DEFF Research Database (Denmark)

    Trinderup, Camilla Himmelstrup; Dahl, Anders Bjorholm; Jensen, Kirsten

    2015-01-01

    The color assessment ability of a multispectral vision system is investigated by a comparison study with color measurements from a traditional colorimeter. The experiment involves fresh and processed meat samples. Meat is a complex material; heterogeneous with varying scattering and reflectance...... are equally capable of measuring color. Moreover the vision system provides a more color rich assessment of fresh meat samples with a glossier surface, than the colorimeter. Careful studies of the different sources of variation enable an assessment of the order of magnitude of the variability between methods...... accounting for other sources of variation leading to the conclusion that color assessment using a multispectral vision system is superior to traditional colorimeter assessments. (C) 2014 Elsevier Ltd. All rights reserved....

  8. Visual fields and eye morphology support color vision in a color-changing crab-spider.

    Science.gov (United States)

    Insausti, Teresita C; Defrize, Jérémy; Lazzari, Claudio R; Casas, Jérôme

    2012-03-01

    Vision plays a major role in many spiders, being involved in prey hunting, orientation or substrate choice, among others. In Misumena vatia, which experiences morphological color changes, vision has been reported to be involved in substrate color matching. Electrophysiological evidence reveals that at least two types of photoreceptors are present in this species, but these data are not backed up by morphological evidence. This work analyzes the functional structure of the eyes of this spider and relates it to its color-changing abilities. A broad superposition of the visual field of the different eyes was observed, even between binocular regions of principal and secondary eyes. The frontal space is simultaneously analyzed by four eyes. This superposition supports the integration of the visual information provided by the different eye types. The mobile retina of the principal eyes of this spider is organized in three layers of three different types of rhabdoms. The third and deepest layer is composed by just one large rhabdom surrounded by dark screening pigments that limit the light entry. The three pairs of secondary eyes have all a single layer of rhabdoms. Our findings provide strong support for an involvement of the visual system in color matching in this spider. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Eye guidance during real-world scene search: The role color plays in central and peripheral vision.

    Science.gov (United States)

    Nuthmann, Antje; Malcolm, George L

    2016-01-01

    The visual system utilizes environmental features to direct gaze efficiently when locating objects. While previous research has isolated various features' contributions to gaze guidance, these studies generally used sparse displays and did not investigate how features facilitated search as a function of their location on the visual field. The current study investigated how features across the visual field--particularly color--facilitate gaze guidance during real-world search. A gaze-contingent window followed participants' eye movements, restricting color information to specified regions. Scene images were presented in full color, with color in the periphery and gray in central vision or gray in the periphery and color in central vision, or in grayscale. Color conditions were crossed with a search cue manipulation, with the target cued either with a word label or an exact picture. Search times increased as color information in the scene decreased. A gaze-data based decomposition of search time revealed color-mediated effects on specific subprocesses of search. Color in peripheral vision facilitated target localization, whereas color in central vision facilitated target verification. Picture cues facilitated search, with the effects of cue specificity and scene color combining additively. When available, the visual system utilizes the environment's color information to facilitate different real-world visual search behaviors based on the location within the visual field.

  10. Validity of the Worth 4 Dot Test in Patients with Red-Green Color Vision Defect.

    Science.gov (United States)

    Bak, Eunoo; Yang, Hee Kyung; Hwang, Jeong-Min

    2017-05-01

    The Worth four dot test uses red and green glasses for binocular dissociation, and although it has been believed that patients with red-green color vision defects cannot accurately perform the Worth four dot test, this has not been validated. Therefore, the purpose of this study was to demonstrate the validity of the Worth four dot test in patients with congenital red-green color vision defects who have normal or abnormal binocular vision. A retrospective review of medical records was performed on 30 consecutive congenital red-green color vision defect patients who underwent the Worth four dot test. The type of color vision anomaly was determined by the Hardy Rand and Rittler (HRR) pseudoisochromatic plate test, Ishihara color test, anomaloscope, and/or the 100 hue test. All patients underwent a complete ophthalmologic examination. Binocular sensory status was evaluated with the Worth four dot test and Randot stereotest. The results were interpreted according to the presence of strabismus or amblyopia. Among the 30 patients, 24 had normal visual acuity without strabismus nor amblyopia and 6 patients had strabismus and/or amblyopia. The 24 patients without strabismus nor amblyopia all showed binocular fusional responses by seeing four dots of the Worth four dot test. Meanwhile, the six patients with strabismus or amblyopia showed various results of fusion, suppression, and diplopia. Congenital red-green color vision defect patients of different types and variable degree of binocularity could successfully perform the Worth four dot test. They showed reliable results that were in accordance with their estimated binocular sensory status.

  11. Principles of image processing in machine vision systems for the color analysis of minerals

    Science.gov (United States)

    Petukhova, Daria B.; Gorbunova, Elena V.; Chertov, Aleksandr N.; Korotaev, Valery V.

    2014-09-01

    At the moment color sorting method is one of promising methods of mineral raw materials enrichment. This method is based on registration of color differences between images of analyzed objects. As is generally known the problem with delimitation of close color tints when sorting low-contrast minerals is one of the main disadvantages of color sorting method. It is can be related with wrong choice of a color model and incomplete image processing in machine vision system for realizing color sorting algorithm. Another problem is a necessity of image processing features reconfiguration when changing the type of analyzed minerals. This is due to the fact that optical properties of mineral samples vary from one mineral deposit to another. Therefore searching for values of image processing features is non-trivial task. And this task doesn't always have an acceptable solution. In addition there are no uniform guidelines for determining criteria of mineral samples separation. It is assumed that the process of image processing features reconfiguration had to be made by machine learning. But in practice it's carried out by adjusting the operating parameters which are satisfactory for one specific enrichment task. This approach usually leads to the fact that machine vision system unable to estimate rapidly the concentration rate of analyzed mineral ore by using color sorting method. This paper presents the results of research aimed at addressing mentioned shortcomings in image processing organization for machine vision systems which are used to color sorting of mineral samples. The principles of color analysis for low-contrast minerals by using machine vision systems are also studied. In addition, a special processing algorithm for color images of mineral samples is developed. Mentioned algorithm allows you to determine automatically the criteria of mineral samples separation based on an analysis of representative mineral samples. Experimental studies of the proposed algorithm

  12. Applications of color machine vision in the agricultural and food industries

    Science.gov (United States)

    Zhang, Min; Ludas, Laszlo I.; Morgan, Mark T.; Krutz, Gary W.; Precetti, Cyrille J.

    1999-01-01

    Color is an important factor in Agricultural and the Food Industry. Agricultural or prepared food products are often grade by producers and consumers using color parameters. Color is used to estimate maturity, sort produce for defects, but also perform genetic screenings or make an aesthetic judgement. The task of sorting produce following a color scale is very complex, requires special illumination and training. Also, this task cannot be performed for long durations without fatigue and loss of accuracy. This paper describes a machine vision system designed to perform color classification in real-time. Applications for sorting a variety of agricultural products are included: e.g. seeds, meat, baked goods, plant and wood.FIrst the theory of color classification of agricultural and biological materials is introduced. Then, some tools for classifier development are presented. Finally, the implementation of the algorithm on real-time image processing hardware and example applications for industry is described. This paper also presented an image analysis algorithm and a prototype machine vision system which was developed for industry. This system will automatically locate the surface of some plants using digital camera and predict information such as size, potential value and type of this plant. The algorithm developed will be feasible for real-time identification in an industrial environment.

  13. [Colors and their meaning in culture and psychology--a historical outline and contemporary status of color vision theories].

    Science.gov (United States)

    Grzybowski, Andrzej; Lewicka, Romana; Torlińska, Teresa; Stelcer, Bogusław

    2008-01-01

    The mechanism of color perception has intrigued scholars from antiquity. However, the understanding of this phenomena only came with the recognition of the nature of light and visual perception. Ancient concepts, present in science until the Renaissance, were based more on philosophical considerations and theoretical speculations than on anatomical studies and a matter-of-fact assessment of physiological functions of the visual system. From antiquity to 17th century scientific approach to the concept of vision was dominated by two theories: intromission and extramission (emanation). Intromission theory, propagated by Alhazen (lbn al.-Haythama), Vitello, John Peckham, Roger Bacon and Leonardo da Vinci, assumed that the light was transmitted from the observed object perpendicularly to the transparent eye structures. Johannes Kepler was the first scholar to propose that the retina was the receptive part of the eye. In the first half of the 17th century, Kepler's groundbreaking optical achievements and anatomical discoveries of many other scientists cast new light on the understanding of the role of different eye structures, finally wiping out the intromission theory. A further major achievement contributing to the recognition of the true nature of colors was a theory presented by Newton in 1688. He argued that they were colored rays, and not white light, that were composed of homogenous and pure light. It was, however, not until the 19th century when two modern theories of color appeared, i.e. a trichromatic theory mostly associated with the names of Young and Hemlholtz, and an opponent colors theory of Hering. In the 20th century, the two theories--previously assumed as contradictory--were joined into the zone theories of color vision. Colors have their cultural and social meanings, as far as a very individual and personal interpretation. In the former function they are used to illustrate some cultural and sociological phenomena; in the latter, they are helpful in

  14. The organization of shape and color in vision and art.

    Science.gov (United States)

    Pinna, Baingio

    2011-01-01

    The aim of this work is to study the phenomenal organization of shape and color in vision and art in terms of microgenesis of the object perception and creation. The idea of "microgenesis" is that the object perception and creation takes time to develop. Our hypothesis is that the roles of shape and color are extracted in sequential order and in the same order these roles are also used by artists to paint objects. Boundary contours are coded before color contours. The microgenesis of the object formation was demonstrated (i) by introducing new conditions derived from the watercolor illusion, where the juxtaposed contours are displaced horizontally or vertically, and based on variations of Matisse's Woman, (ii) by studying descriptions and replications of visual objects in adults and children of different ages, and (iii) by analyzing the linguistic sequence and organization in a free naming task of the attributes related to shape and color. The results supported the idea of the microgenesis of the object perception, namely the temporal order in the formation of the roles of the object properties (shape before color). Some general principles were extracted from the experimental results. They can be a starting point to explore a new domain focused on the microgenesis of shape and color within the more general problem of object organization, where integrated and multidisciplinary studies based on art and vision science can be very useful.

  15. The organization of shape and color in Vision and Art

    Directory of Open Access Journals (Sweden)

    Baingio ePinna

    2011-10-01

    Full Text Available The aim of this work is to study the phenomenal organization of shape and color in vision and art in terms of microgenesis of the object perception and creation. The idea of ‘microgenesis’ is that the object perception and creation takes time to develop. Our hypothesis is that the roles of shape and color are extracted in sequential order and in the same order these roles are also used by artists to paint objects. Boundary contours are coded before color contours. The microgenesis of the object formation was demonstrated (i by introducing new conditions derived from the watercolor illusion, where the juxtaposed contours are displaced horizontally or vertically, and based on variations of Matisse’s Woman, (ii by studying descriptions and replications of visual objects in adults and children of different ages, and (iii by analyzing the linguistic sequence and organization in a free naming task of the attributes related to shape and color. The results supported the idea of the microgenesis of the object perception, namely the temporal order in the formation of the roles of the object properties (shape before color. Some general principles were extracted from the experimental results. They can be a starting point to explore a new domain focused on the microgenesis of shape and color within the more general problem of object organization, where integrated and multidisciplinary studies based on art and vision science can be very useful.

  16. Comparison of a multispectral vision system and a colorimeter for the assessment of meat color.

    Science.gov (United States)

    Trinderup, Camilla H; Dahl, Anders; Jensen, Kirsten; Carstensen, Jens Michael; Conradsen, Knut

    2015-04-01

    The color assessment ability of a multispectral vision system is investigated by a comparison study with color measurements from a traditional colorimeter. The experiment involves fresh and processed meat samples. Meat is a complex material; heterogeneous with varying scattering and reflectance properties, so several factors can influence the instrumental assessment of meat color. In order to assess whether two methods are equivalent, the variation due to these factors must be taken into account. A statistical analysis was conducted and showed that on a calibration sheet the two instruments are equally capable of measuring color. Moreover the vision system provides a more color rich assessment of fresh meat samples with a glossier surface, than the colorimeter. Careful studies of the different sources of variation enable an assessment of the order of magnitude of the variability between methods accounting for other sources of variation leading to the conclusion that color assessment using a multispectral vision system is superior to traditional colorimeter assessments. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Acquired Color Vision Defects and Hexane Exposure: A Study of San Francisco Bay Area Automotive Mechanics.

    Science.gov (United States)

    Beckman, Stella; Eisen, Ellen A; Bates, Michael N; Liu, Sa; Haegerstrom-Portnoy, Gunilla; Hammond, S Katharine

    2016-06-01

    Occupational exposure to solvents, including n-hexane, has been associated with acquired color vision defects. Blue-yellow defects are most common and may be due to neurotoxicity or retinal damage. Acetone may potentiate the neurotoxicity of n-hexane. We present results on nonhexane solvent and hexane exposure and color vision from a cross-sectional study of 835 automotive repair workers in the San Francisco Bay Area, California (2007-2013). Cumulative exposure was estimated from self-reported work history, and color vision was assessed using the Lanthony desaturated D-15 panel test. Log-binomial regression was used to estimate prevalence ratios for color vision defects. Acquired color vision defects were present in 29% of participants, of which 70% were blue-yellow. Elevated prevalence ratios were found for nonhexane solvent exposure, with a maximum of 1.31 (95% confidence interval (CI): 0.86, 2.00) for blue-yellow. Among participants aged ≤50 years, the prevalence ratio for blue-yellow defects was 2.17 (95% CI: 1.03, 4.56) in the highest quartile of nonhexane solvent exposure and 1.62 (95% CI: 0.97, 2.72) in the highest category of exposure to hexane with acetone coexposure. Cumulative exposures to hexane and nonhexane solvents in the highest exposure categories were associated with elevated prevalence ratios for color vision defects in younger participants. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Visual function and color vision in adults with Attention-Deficit/Hyperactivity Disorder.

    Science.gov (United States)

    Kim, Soyeon; Chen, Samantha; Tannock, Rosemary

    2014-01-01

    Color vision and self-reported visual function in everyday life in young adults with Attention-Deficit/Hyperactivity Disorder (ADHD) were investigated. Participants were 30 young adults with ADHD and 30 controls matched for age and gender. They were tested individually and completed the Visual Activities Questionnaire (VAQ), Farnsworth-Munsell 100 Hue Test (FMT) and A Quick Test of Cognitive Speed (AQT). The ADHD group reported significantly more problems in 4 of 8 areas on the VAQ: depth perception, peripheral vision, visual search and visual processing speed. Further analyses of VAQ items revealed that the ADHD group endorsed more visual problems associated with driving than controls. Color perception difficulties on the FMT were restricted to the blue spectrum in the ADHD group. FMT and AQT results revealed slower processing of visual stimuli in the ADHD group. A comprehensive investigation of mechanisms underlying visual function and color vision in adults with ADHD is warranted, along with the potential impact of these visual problems on driving performance. Copyright © 2013 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  19. Color vision tests comparison: Farnsworth D-15 versus Lanthony D-15

    Science.gov (United States)

    Szmigiel, Marta; Geniusz, Malwina; Geniusz, Maciej K.

    2017-09-01

    Disorder of color vision in humans is the inability to perceive differences between some or all of the colors that are normally perceived by others. Color blindness is usually a birth defect, a genetically determined. For this reason it is much more common in men than women. This paper presents the results of the test FarnsworthD-15 and Lanthony D-15 on a group of volunteers, both adults and children. The study was conducted to compare the results of both tests.

  20. Seeing the Light: Optics in Nature, Photography, Color, Vision, and Holography

    Science.gov (United States)

    Falk, David R.; Brill, Dieter R.; Stork, David G.

    1985-11-01

    The most complete and lucid nonmathematical study of light available. Chapters are self-contained, making the book flexible and easy to read. Coverage includes such non-traditional topics as processes of vision and the eye, atmospherical optical phenomena, color perception and illusions, color in nature and in art, Kirilian photography, and holography. Includes experiments that can be carried out with simple equipment. Chapters contain optional advanced sections, and appendixes review the mathematics for quantitative aspects. Illustrated, including a four-color insert.

  1. Color vision abnormality as an initial presentation of the complete type of congenital stationary night blindness

    Directory of Open Access Journals (Sweden)

    Tan X

    2013-08-01

    Full Text Available Xue Tan, Aya Aoki, Yasuo YanagiDepartment of Ophthalmology, University of Tokyo School of Medicine, Hongo, Bunkyo-ku, Tokyo, JapanAbstract: Patients with the complete form of congenital stationary night blindness (CSNB often have reduced visual acuity, myopia, impaired night vision, and sometimes nystagmus and strabismus, however, they seldom complain of color vision abnormality. A 17-year-old male who was at technical school showed abnormalities in the color perception test for employment, and was referred to our hospital for a detailed examination. He had no family history of color vision deficiency and no other symptoms. During the initial examination, his best-corrected visual acuity was 1.2 in both eyes. His fundus showed no abnormalities except for somewhat yellowish reflex in the fovea of both eyes. Electroretinogram (ERG showed a good response in cone ERG and 30 Hz flicker ERG, however, the bright flash, mixed rod and cone ERG showed a negative type with a reduced b-wave (positive deflection. There was no response in the rod ERG, either. From the findings of the typical ERG, the patient was diagnosed with complete congenital stationary night blindness. This case underscores the importance of ERG in order to diagnose the cause of a color vision anomaly.Keywords: congenital stationary night blindness, CSNB, electroretinogram, ERG, color vision defect

  2. Assessing color vision loss among solvent-exposed workers.

    Science.gov (United States)

    Mergler, D; Blain, L

    1987-01-01

    Acquired color vision loss has been associated with exposure to organic solvents in the workplace. However, not all tests of chromatic discrimination loss are designed to detect acquired, as opposed to congenital, loss. The Lanthony D-15 desaturated panel (D-15-d), a simple 15 cap color arrangement test, designed to identify mild acquired dyschromatopsia, can be administered rapidly in the field, under standard conditions. The objective of the present study was to evaluate the D-15-d among 23 solvent-exposed workers of a paint manufacturing plant, by comparing the results obtained with the D-15-d to those obtained with the Farnsworth-Munsell 100 Hue (FM-100), a highly sensitive measure of color vision loss. The D-15-d revealed a significantly higher prevalence of dyschromatopsia among the ten highly exposed workers (80%) as compared to the 13 moderately exposed workers (30.8%); FM-100 results revealed one false positive. All dyschromatopic workers presented blue-yellow loss; the FM-100 detected eight complex patterns, while the D-15-d identified 5. Comparison of D-15-d and FM-100 scores were highly correlated (corr. coeff. 0.87; p less than 0.001). Multiple regression analyses showed both scores to be significantly related to age and exposure level. The findings of this study indicate that the D-15-d is an adequate instrument for field study batteries. However, the FM-100 should be used for more detailed assessment.

  3. The evolution of opsins and color vision: connecting genotype to a complex phenotype

    Directory of Open Access Journals (Sweden)

    Natasha I Bloch

    2016-09-01

    Full Text Available Dissecting the genetic basis of adaptive traits is key to our understanding of evolutionary processes. A major and essential step in the study of evolutionary genetics is drawing link between genotype and phenotype, which depends on the difficult process of defining the phenotype at different levels, from functional to organismal. Visual pigments are a key component of the visual system and their evolution could also provide important clues on the evolution of visual sensory system in response to sexual and natural selection. As a system in which genotype can be linked to phenotype, I will use visual pigments and color vision, particularly in birds, as a case of a complex phenotype. I aim to emphasize the difficulties in drawing the genotype-phenotype relationship for complex phenotypes and to highlight the challenges of doing so for color vision. The use of vision-based receiver models to quantify animal colors and patterns is increasingly important in many fields of evolutionary research, spanning studies of mate choice, predation, camouflage and sensory ecology. Given these models impact on evolution and ecology, it is important to provide other researchers with the opportunity to better understand animal vision and the corresponding advantages and limitations of these models.

  4. 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.

  5. Assessment of Color Vision Among School Children: A Comparative Study Between The Ishihara Test and The Farnsworth D-15 Test

    Directory of Open Access Journals (Sweden)

    Rajesh Kishor Shrestha

    2016-10-01

    Full Text Available Introduction: Color vision is one of the important attribute of visual perception. The study was conducted at different schools of Kathmandu to compare the  ndings of the Ishihara Pseudoisochromatic test and the Farnsworth D-15 test.  Method: A cross-sectional study was conducted among 2120 students of four schools of Kathmandu. Assessment included visual acuity measurement, slit lamp examination of anterior segment and fundus examination with direct ophthalmoscopy. Each student was assessed with the Ishihara pseudoisochromatic test and the Farnsworth D-15 test. The Chi-square test was performed to analyse color vision defect detected by the Ishihara test and the Farnsworth D-15 test. Results: A total of 2120 students comprising of 1114 males (52.5% and 1006 females (47.5% were recruited in the study with mean age of 12.2 years (SD 2.3 years. The prevalence of color vision defect as indicated by the Ishihara was 2.6 and as indicated by the D-15 test was 2.15 in males.  Conclusion: For school color vision screening, the Ishihara color test and the Farnsworth D-15 test have equal capacity to detect congenital color vision defect and they complement each other.  Keywords: color vision; children; defect; Farnsworth D-15; Ishihara.

  6. Color vision abnormality as an initial presentation of the complete type of congenital stationary night blindness.

    Science.gov (United States)

    Tan, Xue; Aoki, Aya; Yanagi, Yasuo

    2013-01-01

    Patients with the complete form of congenital stationary night blindness (CSNB) often have reduced visual acuity, myopia, impaired night vision, and sometimes nystagmus and strabismus, however, they seldom complain of color vision abnormality. A 17-year-old male who was at technical school showed abnormalities in the color perception test for employment, and was referred to our hospital for a detailed examination. He had no family history of color vision deficiency and no other symptoms. During the initial examination, his best-corrected visual acuity was 1.2 in both eyes. His fundus showed no abnormalities except for somewhat yellowish reflex in the fovea of both eyes. Electroretinogram (ERG) showed a good response in cone ERG and 30 Hz flicker ERG, however, the bright flash, mixed rod and cone ERG showed a negative type with a reduced b-wave (positive deflection). There was no response in the rod ERG, either. From the findings of the typical ERG, the patient was diagnosed with complete congenital stationary night blindness. This case underscores the importance of ERG in order to diagnose the cause of a color vision anomaly.

  7. Performance of Color Camera Machine Vision in Automated Furniture Rough Mill Systems

    Science.gov (United States)

    D. Earl Kline; Agus Widoyoko; Janice K. Wiedenbeck; Philip A. Araman

    1998-01-01

    The objective of this study was to evaluate the performance of color camera machine vision for lumber processing in a furniture rough mill. The study used 134 red oak boards to compare the performance of automated gang-rip-first rough mill yield based on a prototype color camera lumber inspection system developed at Virginia Tech with both estimated optimum rough mill...

  8. Color vision predicts processing modes of goal activation during action cascading.

    Science.gov (United States)

    Jongkees, Bryant J; Steenbergen, Laura; Colzato, Lorenza S

    2017-09-01

    One of the most important functions of cognitive control is action cascading: the ability to cope with multiple response options when confronted with various task goals. A recent study implicates a key role for dopamine (DA) in this process, suggesting higher D1 efficiency shifts the action cascading strategy toward a more serial processing mode, whereas higher D2 efficiency promotes a shift in the opposite direction by inducing a more parallel processing mode (Stock, Arning, Epplen, & Beste, 2014). Given that DA is found in high concentration in the retina and modulation of retinal DA release displays characteristics of D2-receptors (Peters, Schweibold, Przuntek, & Müller, 2000), color vision discrimination might serve as an index of D2 efficiency. We used color discrimination, assessed with the Lanthony Desaturated Panel D-15 test, to predict individual differences (N = 85) in a stop-change paradigm that provides a well-established measure of action cascading. In this task it is possible to calculate an individual slope value for each participant that estimates the degree of overlap in task goal activation. When the stopping process of a previous task goal has not finished at the time the change process toward a new task goal is initiated (parallel processing), the slope value becomes steeper. In case of less overlap (more serial processing), the slope value becomes flatter. As expected, participants showing better color vision were more prone to activate goals in a parallel manner as indicated by a steeper slope. Our findings suggest that color vision might represent a predictor of D2 efficiency and the predisposed processing mode of goal activation during action cascading. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Color vision loss in patients treated with chloroquine

    Directory of Open Access Journals (Sweden)

    Ventura Dora F.

    2003-01-01

    Full Text Available Patients that make use of chloroquine or hydroxychloroquine, drugs which are frequently administered for treatment of rheumatoid arthritis, lupus erithromatosus or malaria, may suffer alterations in color vision and in contrast sensitivity. The present work evaluates the visual function of these patients in a joint study of the University of São Paulo (USP, in São Paulo, and of the Federal University of Pará (UFPA, in Belém. Thirty two chloroquine user patients without alterations in the eye fundus exam were evaluated in São Paulo (n=10; aged 38 to 71 years; mean=55,8 years and in Belém (n=22; aged 20 to 67; mean=40 years. The prescribed accumulated chloroquine dose was 45 to 430 g (mean=213 g; sd = 152 g for the São Paulo group, and 36 to 540 g (mean=174 g; sd=183 g for the Belém group. Tests were performed monocularly with corrected eye refractive state. Color discrimination was evaluated using the Cambridge Colour Test (CCT: the color discrimination threshold was measured first in the protan, deutan and tritan axes and, in succession, three MacAdam's ellipses were determined. The patient's color vision was also evaluated with color arrangement tests: the Farnsworth-Munsell 100 Hue (FM100, the Farnsworth-Munsell D15, and the Lanthony Desaturated (D15d tests. We also measured the contrast sensitivity for black-and-white sine wave grating of twenty two patients. The results were compared with controls without ophthalmologic or neuro-ophthalmologic pathologies. Twenty four patients presented acquired dyschromatopsia. There were cases of selective loss (11 patients and of diffuse loss (13 patients. Although losses were present in the FM100 there was no correlation between the FM100 error score and the ellipse area measured by the CCT. Moreover, three patients that scored normal in the FM100, failed to reach normal threshold in the CCT. The Lanthony test was less sensitive than the other two tests, since it failed to indicate loss in about

  10. Validity of FAA-approved color vision tests for class II and class III aeromedical screening.

    Science.gov (United States)

    1993-09-01

    All clinical color vision tests currently used in the medical examination of pilots were studied regarding validity for prediction of performance on practical tests of ability to discriminate the aviation signal colors, red, green, and white given un...

  11. Computer vision system in real-time for color determination on flat surface food

    Directory of Open Access Journals (Sweden)

    Erick Saldaña

    2013-03-01

    Full Text Available Artificial vision systems also known as computer vision are potent quality inspection tools, which can be applied in pattern recognition for fruits and vegetables analysis. The aim of this research was to design, implement and calibrate a new computer vision system (CVS in real-time for the color measurement on flat surface food. For this purpose was designed and implemented a device capable of performing this task (software and hardware, which consisted of two phases: a image acquisition and b image processing and analysis. Both the algorithm and the graphical interface (GUI were developed in Matlab. The CVS calibration was performed using a conventional colorimeter (Model CIEL* a* b*, where were estimated the errors of the color parameters: eL* = 5.001%, and ea* = 2.287%, and eb* = 4.314 % which ensure adequate and efficient automation application in industrial processes in the quality control in the food industry sector.

  12. Computer vision system in real-time for color determination on flat surface food

    Directory of Open Access Journals (Sweden)

    Erick Saldaña

    2013-01-01

    Full Text Available Artificial vision systems also known as computer vision are potent quality inspection tools, which can be applied in pattern recognition for fruits and vegetables analysis. The aim of this research was to design, implement and calibrate a new computer vision system (CVS in real - time f or the color measurement on flat surface food. For this purpose was designed and implemented a device capable of performing this task (software and hardware, which consisted of two phases: a image acquisition and b image processing and analysis. Both th e algorithm and the graphical interface (GUI were developed in Matlab. The CVS calibration was performed using a conventional colorimeter (Model CIEL* a* b*, where were estimated the errors of the color parameters: e L* = 5.001%, and e a* = 2.287%, and e b* = 4.314 % which ensure adequate and efficient automation application in industrial processes in the quality control in the food industry sector.

  13. Impact of congenital color vision defect on color‑related tasks among ...

    African Journals Online (AJOL)

    Aim: To assess the difficulties encountered by students with congenital color vision defects in daily living and school activities. Methods: A cross‑sectional descriptive study conducted among students of public secondary schools in Ibadan, Nigeria. Structured questionnaires were administered to all consenting students to ...

  14. 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.

  15. The Disunity of Color

    OpenAIRE

    Matthen, Mohan

    1999-01-01

    What is color? What is color vision? Most philosophers answer by reference to humans: to human color qualia, or to the environmental properties or "quality spaces" perceived by humans. It is argued, with reference to empirical findings concerning comparative color vision and the evolution of color vision, that all such attempts are mistaken. An adequate definition of color vision must eschew reference to its outputs in the human cognition and refer only to inputs: color vision consists in...

  16. Qualitative evaluations and comparisons of six night-vision colorization methods

    Science.gov (United States)

    Zheng, Yufeng; Reese, Kristopher; Blasch, Erik; McManamon, Paul

    2013-05-01

    Current multispectral night vision (NV) colorization techniques can manipulate images to produce colorized images that closely resemble natural scenes. The colorized NV images can enhance human perception by improving observer object classification and reaction times especially for low light conditions. This paper focuses on the qualitative (subjective) evaluations and comparisons of six NV colorization methods. The multispectral images include visible (Red-Green- Blue), near infrared (NIR), and long wave infrared (LWIR) images. The six colorization methods are channel-based color fusion (CBCF), statistic matching (SM), histogram matching (HM), joint-histogram matching (JHM), statistic matching then joint-histogram matching (SM-JHM), and the lookup table (LUT). Four categries of quality measurements are used for the qualitative evaluations, which are contrast, detail, colorfulness, and overall quality. The score of each measurement is rated from 1 to 3 scale to represent low, average, and high quality, respectively. Specifically, high contrast (of rated score 3) means an adequate level of brightness and contrast. The high detail represents high clarity of detailed contents while maintaining low artifacts. The high colorfulness preserves more natural colors (i.e., closely resembles the daylight image). Overall quality is determined from the NV image compared to the reference image. Nine sets of multispectral NV images were used in our experiments. For each set, the six colorized NV images (produced from NIR and LWIR images) are concurrently presented to users along with the reference color (RGB) image (taken at daytime). A total of 67 subjects passed a screening test ("Ishihara Color Blindness Test") and were asked to evaluate the 9-set colorized images. The experimental results showed the quality order of colorization methods from the best to the worst: CBCF colorization and for quantitative evaluation using an objective metric such as objective evaluation index

  17. Using photogrammetry and color scoring to assess sexual dimorphism in wild western gorillas (Gorilla gorilla).

    Science.gov (United States)

    Breuer, Thomas; Robbins, Martha M; Boesch, Christophe

    2007-11-01

    Investigating sexual dimorphism is important for our understanding of its influence on reproductive strategies including male-male competition, mate choice, and sexual conflict. Measuring physical traits in wild animals can be logistically challenging and disruptive for the animals. Therefore body size and ornament variation in wild primates have rarely been quantified. Gorillas are amongst the most sexually dimorphic and dichromatic primates. Adult males (silverbacks) possess a prominent sagittal crest, a pad of fibrous and fatty tissue on top of the head, have red crest coloration, their saddle appears silver, and they possess a silverline along their stomach. Here we measure levels of sexual dimorphism and within-male variation of body length, head size, and sexual dichromatism in a population of wild western gorillas using photogrammetry. Digital photogrammetry is a useful and precise method to measure sexual dimorphism in physical traits yielding sexual dimorphism indices (ISD), similar to those derived from traditional measurements of skeletal remains. Silverbacks were on an average 1.23 times longer in body length than adult females. Sexual dimorphism of head size was highest in measures of crest size (max ISD: 60.4) compared with measures of facial height (max ISD: 24.7). The most sexually dimorphic head size measures also showed the highest within-sex variation. We found no clear sex differences in crest coloration but there was large sexual dichromatism with high within-male variation in saddle coloration and silverline size. Further studies should examine if these sexually dimorphic traits are honest signals of competitive ability and confer an advantage in reproductive success.

  18. Dichromatic and monochromatic laser radiation effects on antibiotic resistance, biofilm formation, and division rate of Pantoea agglomerans

    Science.gov (United States)

    Thomé, A. M. C.; Souza, B. P.; Mendes, J. P. M.; Cardoso, A. F. R.; Soares, L. C.; Trajano, E. T. L.; Fonseca, A. S.

    2018-06-01

    Since infection is a common cause of delayed wound healing, it is important to understand the effect of low-level laser therapy (LLLT) in bacterial mechanisms. In this study we evaluated the effects of LLLT on antibiotic resistance, division rate, and biofilm formation of Pantoea agglomerans. P. agglomerans samples were isolated from human pressure injuries in humans and cultures were exposed to low-level monochromatic and simultaneous dichromatic laser radiation to study the susceptibility of an antimicrobial to ampicillin and piperacillin  +  tazobactam, quantification of areas of bacterial colonies, and biofilm formation of bacterial cells. Fluence, wavelength, and emission mode were used in the therapeutic protocols for wound healing. The data showed no changes in the areas of the colonies, but dichromatic laser radiation decreased biofilm formation, while a monochromatic red laser at low dose increased biofilm formation and infrared at high dose decreased antibiotic resistance to ampicillin. LLLT modulates antibiotic resistance and biofilm formation of P. agglomerans, but these depend on the laser irradiation parameters, since dichromatic laser radiation induces biological effects that differ from those induced by monochromatic laser radiation. Thus, simultaneous dichromatic low-level red and infrared lasers could be a new option for the treatment of infected wounds, reducing biofilm formation, without altering antibiotic resistance and the division rate of P. agglomerans cultures.

  19. 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…

  20. Measurement of meat color using a computer vision system.

    Science.gov (United States)

    Girolami, Antonio; Napolitano, Fabio; Faraone, Daniela; Braghieri, Ada

    2013-01-01

    The limits of the colorimeter and a technique of image analysis in evaluating the color of beef, pork, and chicken were investigated. The Minolta CR-400 colorimeter and a computer vision system (CVS) were employed to measure colorimetric characteristics. To evaluate the chromatic fidelity of the image of the sample displayed on the monitor, a similarity test was carried out using a trained panel. The panelists found the digital images of the samples visualized on the monitor very similar to the actual ones (Pmeat sample and the sample image on the monitor in order to evaluate the similarity between them (test A). Moreover, the panelists were asked to evaluate the similarity between two colors, both generated by the software Adobe Photoshop CS3 one using the L, a and b values read by the colorimeter and the other obtained using the CVS (test B); which of the two colors was more similar to the sample visualized on the monitor was also assessed (test C). The panelists found the digital images very similar to the actual samples (Pcolors the panelists found significant differences between them (Pcolor of the sample on the monitor was more similar to the CVS generated color than to the colorimeter generated color. The differences between the values of the L, a, b, hue angle and chroma obtained with the CVS and the colorimeter were statistically significant (Pcolor of meat. Instead, the CVS method seemed to give valid measurements that reproduced a color very similar to the real one. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Growing knowledge and understanding of dichromatism and sex reversal in Labridae

    NARCIS (Netherlands)

    Roede, Machteld J.

    1990-01-01

    A brief survey is given of current literature in comparison with former studies. Since the 18th century phenotypic diversity of Labridae is a matter of argument. At first in dribs and drabs, yet last decades at a rapid rate, dichromatic adult morphs are synonymized. There are few monochromatic

  2. Intelligent Color Vision System for Ripeness Classification of Oil Palm Fresh Fruit Bunch

    OpenAIRE

    Fadilah, Norasyikin; Mohamad-Saleh, Junita; Halim, Zaini Abdul; Ibrahim, Haidi; Ali, Syed Salim Syed

    2012-01-01

    Ripeness classification of oil palm fresh fruit bunches (FFBs) during harvesting is important to ensure that they are harvested during optimum stage for maximum oil production. This paper presents the application of color vision for automated ripeness classification of oil palm FFB. Images of oil palm FFBs of type DxP Yangambi were collected and analyzed using digital image processing techniques. Then the color features were extracted from those images and used as the inputs for Artificial Ne...

  3. Advances in understanding the molecular basis of the first steps in color vision

    Science.gov (United States)

    Hofmann, Lukas; Palczewski, Krzysztof

    2015-01-01

    Serving as one of our primary environmental inputs, vision is the most sophisticated sensory system in humans. Here, we present recent findings derived from energetics, genetics and physiology that provide a more advanced understanding of color perception in mammals. Energetics of cis–trans isomerization of 11-cis-retinal accounts for color perception in the narrow region of the electromagnetic spectrum and how human eyes can absorb light in the near infrared (IR) range. Structural homology models of visual pigments reveal complex interactions of the protein moieties with the light sensitive chromophore 11-cis-retinal and that certain color blinding mutations impair secondary structural elements of these G protein-coupled receptors (GPCRs). Finally, we identify unsolved critical aspects of color tuning that require future investigation. PMID:26187035

  4. High-speed potato grading and quality inspection based on a color vision system

    Science.gov (United States)

    Noordam, Jacco C.; Otten, Gerwoud W.; Timmermans, Toine J. M.; van Zwol, Bauke H.

    2000-03-01

    A high-speed machine vision system for the quality inspection and grading of potatoes has been developed. The vision system grades potatoes on size, shape and external defects such as greening, mechanical damages, rhizoctonia, silver scab, common scab, cracks and growth cracks. A 3-CCD line-scan camera inspects the potatoes in flight as they pass under the camera. The use of mirrors to obtain a 360-degree view of the potato and the lack of product holders guarantee a full view of the potato. To achieve the required capacity of 12 tons/hour, 11 SHARC Digital Signal Processors perform the image processing and classification tasks. The total capacity of the system is about 50 potatoes/sec. The color segmentation procedure uses Linear Discriminant Analysis (LDA) in combination with a Mahalanobis distance classifier to classify the pixels. The procedure for the detection of misshapen potatoes uses a Fourier based shape classification technique. Features such as area, eccentricity and central moments are used to discriminate between similar colored defects. Experiments with red and yellow skin-colored potatoes have shown that the system is robust and consistent in its classification.

  5. Effect of elimination of nitrogen and/or hypoxia or restricted visual environment on color vision and range of accommodation

    Science.gov (United States)

    Wolbarsht, M. L.; White, C. W.; Anderson, W. B., Jr.

    1973-01-01

    The effects upon range of accommodation and color vision of reduced atmospheric pressure, at partial and complete elimination of nitrogen, of hypoxia, and of exposure for varying periods of time to restricted visual environment, have been studied alone or in various combinations. Measurements were made on the electroretinogram, the electrooculogram, and the diameter of the retinal vessels as an indicator of blood flow to the retina at the time of total elimination of nitrogen. An objective method was used to test range of accommodation. In the color vision test the flicker colors of a Benham's top were matched with a colorimeter.

  6. New experimental diffractive-optical data on E.Land's Retinex mechanism in human color vision: Part II

    Science.gov (United States)

    Lauinger, N.

    2007-09-01

    A better understanding of the color constancy mechanism in human color vision [7] can be reached through analyses of photometric data of all illuminants and patches (Mondrians or other visible objects) involved in visual experiments. In Part I [3] and in [4, 5 and 6] the integration in the human eye of the geometrical-optical imaging hardware and the diffractive-optical hardware has been described and illustrated (Fig.1). This combined hardware represents the main topic of the NAMIROS research project (nano- and micro- 3D gratings for optical sensors) [8] promoted and coordinated by Corrsys 3D Sensors AG. The hardware relevant to (photopic) human color vision can be described as a diffractive or interference-optical correlator transforming incident light into diffractive-optical RGB data and relating local RGB onto global RGB data in the near-field behind the 'inverted' human retina. The relative differences at local/global RGB interference-optical contrasts are available to photoreceptors (cones and rods) only after this optical pre-processing.

  7. Basic design principles of colorimetric vision systems

    Science.gov (United States)

    Mumzhiu, Alex M.

    1998-10-01

    Color measurement is an important part of overall production quality control in textile, coating, plastics, food, paper and other industries. The color measurement instruments such as colorimeters and spectrophotometers, used for production quality control have many limitations. In many applications they cannot be used for a variety of reasons and have to be replaced with human operators. Machine vision has great potential for color measurement. The components for color machine vision systems, such as broadcast quality 3-CCD cameras, fast and inexpensive PCI frame grabbers, and sophisticated image processing software packages are available. However the machine vision industry has only started to approach the color domain. The few color machine vision systems on the market, produced by the largest machine vision manufacturers have very limited capabilities. A lack of understanding that a vision based color measurement system could fail if it ignores the basic principles of colorimetry is the main reason for the slow progress of color vision systems. the purpose of this paper is to clarify how color measurement principles have to be applied to vision systems and how the electro-optical design features of colorimeters have to be modified in order to implement them for vision systems. The subject of this presentation far exceeds the limitations of a journal paper so only the most important aspects will be discussed. An overview of the major areas of applications for colorimetric vision system will be discussed. Finally, the reasons why some customers are happy with their vision systems and some are not will be analyzed.

  8. Simulation of the color vision: decoding quantum-electric transduction

    Directory of Open Access Journals (Sweden)

    Élgion Lúcio da Silva Loreto

    2008-08-01

    Full Text Available We propose an experimental simulation, using accessible and low cost materials, on the biophysical mechanism of the color vision in accordance with the Young-Helmholtz s Trichromatic Theory, approaching mainly the coding and decoding process of electric signs that arrive to the cerebral cortex. The stimulus that unchains this process is given through transformation of the quantized energy of a light photon that takes place in the photocells of the retina of the human eye. The construction of a simple system of collection and analysis of data, using a multimeter, filters, LDR and LEDs allows us to establish connections between the visual system and the simulation model.

  9. 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.

  10. [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.

  11. A new technique for robot vision in autonomous underwater vehicles using the color shift in underwater imaging

    Science.gov (United States)

    2017-06-01

    FOR ROBOT VISION IN AUTONOMOUS UNDERWATER VEHICLES USING THE COLOR SHIFT IN UNDERWATER IMAGING by Jake A. Jones June 2017 Thesis Advisor...techniques to determine the distances from each pixel to the camera. 14. SUBJECT TERMS unmanned undersea vehicles (UUVs), autonomous ... AUTONOMOUS UNDERWATER VEHICLES USING THE COLOR SHIFT IN UNDERWATER IMAGING Jake A. Jones Lieutenant Commander, United States Navy B.S

  12. Epistatic adaptive evolution of human color vision.

    Directory of Open Access Journals (Sweden)

    Shozo Yokoyama

    2014-12-01

    Full Text Available Establishing genotype-phenotype relationship is the key to understand the molecular mechanism of phenotypic adaptation. This initial step may be untangled by analyzing appropriate ancestral molecules, but it is a daunting task to recapitulate the evolution of non-additive (epistatic interactions of amino acids and function of a protein separately. To adapt to the ultraviolet (UV-free retinal environment, the short wavelength-sensitive (SWS1 visual pigment in human (human S1 switched from detecting UV to absorbing blue light during the last 90 million years. Mutagenesis experiments of the UV-sensitive pigment in the Boreoeutherian ancestor show that the blue-sensitivity was achieved by seven mutations. The experimental and quantum chemical analyses show that 4,008 of all 5,040 possible evolutionary trajectories are terminated prematurely by containing a dehydrated nonfunctional pigment. Phylogenetic analysis further suggests that human ancestors achieved the blue-sensitivity gradually and almost exclusively by epistasis. When the final stage of spectral tuning of human S1 was underway 45-30 million years ago, the middle and long wavelength-sensitive (MWS/LWS pigments appeared and so-called trichromatic color vision was established by interprotein epistasis. The adaptive evolution of human S1 differs dramatically from orthologous pigments with a major mutational effect used in achieving blue-sensitivity in a fish and several mammalian species and in regaining UV vision in birds. These observations imply that the mechanisms of epistatic interactions must be understood by studying various orthologues in different species that have adapted to various ecological and physiological environments.

  13. Theoretical research on color indirect effects

    Science.gov (United States)

    Liu, T. C.; Liao, Changjun; Liu, Songhao

    1995-05-01

    Color indirect effects (CIE) means the physiological and psychological effects of color resulting from color vision. In this paper, we study CIE from the viewpoints of the integrated western and Chinese traditional medicine and the time quantum theory established by C. Y. Liu et al., respectively, and then put forward the color-automatic-nervous-subsystem model that could color excites parasympathetic subsystem and hot color excites sympathetic subsystem. Our theory is in agreement with modern color vision theory, and moreover, it leads to the resolution of the conflict between the color code theory and the time code theory oncolor vision. For the latitude phenomena on athlete stars number and the average lifespan, we also discuss the possibility of UV vision. The applications of our theory lead to our succeeding in explaining a number of physiological and psychological effects of color, in explaining the effects of age on color vision, and in explaining the Chinese chromophototherapy. We also discuss its application to neuroimmunology. This research provides the foundation of the clinical applications of chromophototherapy.

  14. 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...

  15. Color-based scale-invariant feature detection applied in robot vision

    Science.gov (United States)

    Gao, Jian; Huang, Xinhan; Peng, Gang; Wang, Min; Li, Xinde

    2007-11-01

    The scale-invariant feature detecting methods always require a lot of computation yet sometimes still fail to meet the real-time demands in robot vision fields. To solve the problem, a quick method for detecting interest points is presented. To decrease the computation time, the detector selects as interest points those whose scale normalized Laplacian values are the local extrema in the nonholonomic pyramid scale space. The descriptor is built with several subregions, whose width is proportional to the scale factor, and the coordinates of the descriptor are rotated in relation to the interest point orientation just like the SIFT descriptor. The eigenvector is computed in the original color image and the mean values of the normalized color g and b in each subregion are chosen to be the factors of the eigenvector. Compared with the SIFT descriptor, this descriptor's dimension has been reduced evidently, which can simplify the point matching process. The performance of the method is analyzed in theory in this paper and the experimental results have certified its validity too.

  16. Usability of light-emitting diodes in precision approach path indicator systems by individuals with marginal color vision.

    Science.gov (United States)

    2014-05-01

    To save energy, the FAA is planning to convert from incandescent lights to light-emitting diodes (LEDs) in : precision approach path indicator (PAPI) systems. Preliminary work on the usability of LEDs by color vision-waivered pilots (Bullough, Skinne...

  17. Wavelength Discrimination in Drosophila Suggests a Role of Rhodopsin 1 in Color Vision

    OpenAIRE

    Garbers, Christian; Wachtler, Thomas

    2016-01-01

    Among the five photoreceptor opsins in the eye of Drosophila, Rhodopsin 1 (Rh1) is expressed in the six outer photoreceptors. In a previous study that combined behavioral genetics with computational modeling, we demonstrated that flies can use the signals from Rh1 for color vision. Here, we provide an in-depth computational analysis of wildtype Drosophila wavelength discrimination specifically considering the consequences of different choices of computations in the preprocessing of the behavi...

  18. Serum low-density lipoprotein cholesterol level is strong risk factor for acquired color vision impairment in young to middle-aged Japanese men: the Okubo Color Study Report 2.

    Science.gov (United States)

    Shoji, Takuhei; Sakurai, Yutaka; Sato, Hiroki; Chihara, Etsuo; Ishida, Masahiro; Omae, Kazuyuki

    2010-06-01

    To investigate associations between blood low-density lipoprotein cholesterol (LDL-C) levels and the prevalence of acquired color vision impairment (ACVI) in middle-aged Japanese men. Participants in this cross-sectional study underwent color vision testing, ophthalmic examination, a standardized interview and examination of venous blood samples. Ishihara plates, a Lanthony 15-hue desaturated panel, and Standard pseudoisochromatic Plates part 2 were used to examine color vision ability. The Farnsworth-Munsell 100-hue test was performed to define ACVI. Smoking status and alcohol intake were recorded during the interview. We performed logistic regression analysis adjusted for age, LDL-C level, systemic hypertension, diabetes, cataract, glaucoma, overweight, smoking status, and alcohol intake. Adjusted odds ratios for four LDL-C levels were calculated. A total of 1042 men were enrolled, 872 participants were eligible for the study, and 31 subjects were diagnosed with ACVI. As compared to the lowest LDL-C category level (or=160 mg/dl). The multiple-adjusted ORs were 2.91 (95% CI, 0.87-9.70) for the 2nd highest category and 3.81 (95% CI, 1.03-14.05) for the highest level. Tests for trend were significant (Pmen with elevated LDL-C levels. These changes might be related to deteriorated neurologic function associated with lipid metabolite abnormalities. Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.

  19. 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.

  20. Predictors of vision impairment in Multiple Sclerosis.

    Science.gov (United States)

    Sanchez-Dalmau, Bernardo; Martinez-Lapiscina, Elena H; Pulido-Valdeolivas, Irene; Zubizarreta, Irati; Llufriu, Sara; Blanco, Yolanda; Sola-Valls, Nuria; Sepulveda, Maria; Guerrero, Ana; Alba, Salut; Andorra, Magi; Camos, Anna; Sanchez-Vela, Laura; Alfonso, Veronica; Saiz, Albert; Villoslada, Pablo

    2018-01-01

    Visual impairment significantly alters the quality of life of people with Multiple Sclerosis (MS). The objective of this study was to identify predictors (independent variables) of visual outcomes, and to define their relationship with neurological disability and retinal atrophy when assessed by optical coherence tomography (OCT). We performed a cross-sectional analysis of 119 consecutive patients with MS, assessing vision using high contrast visual acuity (LogMar), 2.5% and 1.25% low contrast visual acuity (Sloan charts), and color vision (Hardy-Rand-Rittler plates). Quality of vision is a patient reported outcome based on an individual's unique perception of his or her vision and was assessed with the Visual Functioning Questionnaire-25 (VFQ-25) with the 10 neuro-ophthalmologic items. MS disability was assessed using the expanded disability status scale (EDSS), the MS functional composite (MSFC) and the brief repetitive battery-neuropsychology (BRB-N). Retinal atrophy was assessed using spectral domain OCT, measuring the thickness of the peripapillar retinal nerve fiber layer (pRNFL) and the volume of the ganglion cell plus inner plexiform layer (GCIPL). The vision of patients with MS was impaired, particularly in eyes with prior optic neuritis. Retinal atrophy (pRNFL and GCIPL) was closely associated with impaired low contrast vision and color vision, whereas the volume of the GCIPL showed a trend (p = 0.092) to be associated with quality of vision. Multiple regression analysis revealed that EDSS was an explanatory variable for high contrast vision after stepwise analysis, GCIPL volume for low contrast vision, and GCIPL volume and EDSS for color vision. The explanatory variables for quality of vision were high contrast vision and color vision. In summary, quality of vision in MS depends on the impairment of high contrast visual acuity and color vision due to the disease.

  1. Color vision abnormality as the sole manifestation of posterior reversible encephalopathy due to post-partum HELLP syndrome.

    Science.gov (United States)

    Takahashi, Hironori; Matsubara, Teppei; Makino, Shinji; Horie, Kenji; Matsubara, Shigeki

    2017-03-01

    Posterior reversible encephalopathy syndrome (PRES) is associated with several symptoms; of those, visual acuity loss, light oversensitivity (photophobia), and light flashes (photopsia) are known as PRES-related eye symptoms. We report a post-partum woman with PRES associated with hemolysis, elevated liver enzymes, and low platelets syndrome (HELLP), in whom color vision abnormality (achromatopsia) was the sole manifestation. Cesarean section was performed at 28 weeks due to headache, epigastralgia, and severe hypertension. HELLP became evident after delivery. On post-partum day 1, she complained of achromatopsia, stating: "all things look brownish-gray". Ophthalmologic examination was normal, but brain magnetic resonance imaging showed occipital lobe lesions, indicative of PRES, and, interestingly, also color vision center (area V4) lesions, suggesting that the achromatopsia had been caused by brain damage. It may be prudent to question HELLP patients concerning achromatopsia. © 2017 Japan Society of Obstetrics and Gynecology.

  2. Space grating optical structure of the retina and RGB-color vision.

    Science.gov (United States)

    Lauinger, Norbert

    2017-02-01

    Diffraction of light at the spatial cellular phase grating outer nuclear layer of the retina could produce Fresnel near-field interferences in three RGB diffraction orders accessible to photoreceptors (cones/rods). At perpendicular light incidence the wavelengths of the RGB diffraction orders in photopic vision-a fundamental R-wave with two G+B-harmonics-correspond to the peak wavelengths of the spectral brightness sensitivity curves of the cones at 559 nmR, 537 nmG, and 447 nmB. In scotopic vision the R+G diffraction orders optically fuse at 512 nm, the peak value of the rod's spectral brightness sensitivity curve. The diffractive-optical transmission system with sender (resonator), space waves, and receiver antennae converts the spectral light components involved in imaging into RGB space. The colors seen at objects are diffractive-optical products in the eye, as the German philosopher A. Schopenhauer predicted. They are second related to the overall illumination in object space. The RGB transmission system is the missing link optically managing the spectral tuning of the RGB photopigments.

  3. Portable real-time color night vision

    NARCIS (Netherlands)

    Toet, A.; Hogervorst, M.A.

    2008-01-01

    We developed a simple and fast lookup-table based method to derive and apply natural daylight colors to multi-band night-time images. The method deploys an optimal color transformation derived from a set of samples taken from a daytime color reference image. The colors in the resulting colorized

  4. Contact Lenses for Color Blindness.

    Science.gov (United States)

    Badawy, Abdel-Rahman; Hassan, Muhammad Umair; Elsherif, Mohamed; Ahmed, Zubair; Yetisen, Ali K; Butt, Haider

    2018-06-01

    Color vision deficiency (color blindness) is an inherited genetic ocular disorder. While no cure for this disorder currently exists, several methods can be used to increase the color perception of those affected. One such method is the use of color filtering glasses which are based on Bragg filters. While these glasses are effective, they are high cost, bulky, and incompatible with other vision correction eyeglasses. In this work, a rhodamine derivative is incorporated in commercial contact lenses to filter out the specific wavelength bands (≈545-575 nm) to correct color vision blindness. The biocompatibility assessment of the dyed contact lenses in human corneal fibroblasts and human corneal epithelial cells shows no toxicity and cell viability remains at 99% after 72 h. This study demonstrates the potential of the dyed contact lenses in wavelength filtering and color vision deficiency management. © 2018 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Color machine vision system for process control in the ceramics industry

    Science.gov (United States)

    Penaranda Marques, Jose A.; Briones, Leoncio; Florez, Julian

    1997-08-01

    This paper is focused on the design of a machine vision system to solve a problem found in the manufacturing process of high quality polished porcelain tiles. This consists of sorting the tiles according to the criteria 'same appearance to the human eye' or in other words, by color and visual texture. In 1994 this problem was tackled and led to a prototype which became fully operational at production scale in a manufacturing plant, named Porcelanatto, S.A. The system has evolved and has been adapted to meet the particular needs of this manufacturing company. Among the main issues that have been improved, it is worth pointing out: (1) improvement to discern subtle variations in color or texture, which are the main features of the visual appearance; (2) inspection time reduction, as a result of algorithm optimization and the increasing computing power. Thus, 100 percent of the production can be inspected, reaching a maximum of 120 tiles/sec.; (3) adaptation to the different types and models of tiles manufactured. The tiles vary not only in their visible patterns but also in dimensions, formats, thickness and allowances. In this sense, one major problem has been reaching an optimal compromise: The system must be sensitive enough to discern subtle variations in color, but at the same time insensitive thickness variations in the tiles. The following parts have been used to build the system: RGB color line scan camera, 12 bits per channel, PCI frame grabber, PC, fiber optic based illumination and the algorithm which will be explained in section 4.

  6. Robust and fast license plate detection based on the fusion of color and edge feature

    Science.gov (United States)

    Cai, De; Shi, Zhonghan; Liu, Jin; Hu, Chuanping; Mei, Lin; Qi, Li

    2014-11-01

    Extracting a license plate is an important stage in automatic vehicle identification. The degradation of images and the computation intense make this task difficult. In this paper, a robust and fast license plate detection based on the fusion of color and edge feature is proposed. Based on the dichromatic reflection model, two new color ratios computed from the RGB color model are introduced and proved to be two color invariants. The global color feature extracted by the new color invariants improves the method's robustness. The local Sobel edge feature guarantees the method's accuracy. In the experiment, the detection performance is good. The detection results show that this paper's method is robust to the illumination, object geometry and the disturbance around the license plates. The method can also detect license plates when the color of the car body is the same as the color of the plates. The processing time for image size of 1000x1000 by pixels is nearly 0.2s. Based on the comparison, the performance of the new ratios is comparable to the common used HSI color model.

  7. Eleven Colors That Are Almost Never Confused

    Science.gov (United States)

    Boynton, Robert M.

    1989-08-01

    1.1. Three functions of color vision. Setting aside the complex psychological effects of color, related to esthetics, fashion, and mood, three relatively basic functions of color vision, which can be examined scientifically, are discernable. (1) With the eye in a given state of adaptation, color vision allows the perception of signals that otherwise would be below threshold, and therefore lost to perception. Evidence for this comes from a variety of two-color threshold experiments. (2) Visible contours can be maintained by color differences alone, regardless of the relative radiances of the two parts of the field whose junction defines the border. For achromatic vision, contour disappears at the isoluminant point. (3) Color specifies what seems to be an absolute property of a surface, one that enhances its recognizability and allows a clearer separation and classification of non-contiguous elements in the visual field.

  8. Comparison of the color of natural teeth measured by a colorimeter and Shade Vision System.

    Science.gov (United States)

    Cho, Byeong-Hoon; Lim, Yong-Kyu; Lee, Yong-Keun

    2007-10-01

    The objectives were to measure the difference in the color and color parameters of natural teeth measured by a tristimulus colorimeter (CM, used as a reference) and Shade Vision System (SV), and to determine the influence of color parameters on the color difference between the values measured by two instruments. Color of 12 maxillary and mandibular anterior teeth was measured by CM and SV for 47 volunteers (number of teeth=564). Color parameters such as CIE L*, a* and b* values, chroma and hue angle measured by two instruments were compared. Chroma was calculated as C*ab=(a*2 = b*2)1/2, and hue angle was calculated as h degrees =arctan(b*/a*). The influence of color parameters measured by CM on the color difference (DeltaE*(ab)) between the values measured by two instruments was analyzed with multiple regression analysis (alpha=0.01). Mean DeltaE*(ab) value between the values measured by two instruments was 21.7 (+/-3.7), and the mean difference in lightness (CIE L*) and chroma was 16.2 (+/-3.9) and 13.2 (+/-3.0), respectively. Difference in hue angle was high as 132.7 (+/-53.3) degrees . Except for the hue angle, all the color parameters showed significant correlations and the coefficient of determination (r(2)) was in the range of 0.089-0.478. Based on multiple regression analysis, the standardized partial correlation coefficient (beta) of the included predictors for the color difference was -0.710 for CIE L* and -0.300 for C*(ab) (p<0.01). All the color parameters showed significant but weak correlations except for hue angle. When lightness and chroma of teeth were high, color difference between the values measured by two instruments was small. Clinical accuracy of two instruments should be investigated further.

  9. Developing a machine vision system for simultaneous prediction of freshness indicators based on tilapia (Oreochromis niloticus) pupil and gill color during storage at 4°C.

    Science.gov (United States)

    Shi, Ce; Qian, Jianping; Han, Shuai; Fan, Beilei; Yang, Xinting; Wu, Xiaoming

    2018-03-15

    The study assessed the feasibility of developing a machine vision system based on pupil and gill color changes in tilapia for simultaneous prediction of total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA) and total viable counts (TVC) during storage at 4°C. The pupils and gills were chosen and color space conversion among RGB, HSI and L ∗ a ∗ b ∗ color spaces was performed automatically by an image processing algorithm. Multiple regression models were established by correlating pupil and gill color parameters with TVB-N, TVC and TBA (R 2 =0.989-0.999). However, assessment of freshness based on gill color is destructive and time-consuming because gill cover must be removed before images are captured. Finally, visualization maps of spoilage based on pupil color were achieved using image algorithms. The results show that assessment of tilapia pupil color parameters using machine vision can be used as a low-cost, on-line method for predicting freshness during 4°C storage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Computer vision based room interior design

    Science.gov (United States)

    Ahmad, Nasir; Hussain, Saddam; Ahmad, Kashif; Conci, Nicola

    2015-12-01

    This paper introduces a new application of computer vision. To the best of the author's knowledge, it is the first attempt to incorporate computer vision techniques into room interior designing. The computer vision based interior designing is achieved in two steps: object identification and color assignment. The image segmentation approach is used for the identification of the objects in the room and different color schemes are used for color assignment to these objects. The proposed approach is applied to simple as well as complex images from online sources. The proposed approach not only accelerated the process of interior designing but also made it very efficient by giving multiple alternatives.

  11. Preferred memory color difference between the deuteranomalous and normal color vision

    Science.gov (United States)

    Baek, YeSeul; Kwak, Youngshin; Woo, Sungjoo; Park, Chongwook

    2015-01-01

    The goal of this study is to evaluate the difference of the preferred hues of familiar objects between the color deficient observer and the normal observer. Thirteen test color images were chosen covering fruit colors, natural scene and human faces. It contained red, yellow, green, blue, purple and skin color. Two color deficient observer (deuteranomal) and two normal observers were participated in this experiment. They controlled the YCC hue of the objects in the images to obtain the most preferred and the most natural image. The selected images were analyzed using CIELAB values of each pixel. Data analysis results showed that in the case of naturalness, both groups selected the similar hues for the most of image, while, in the case of preference, the color deficient observer preferred more reddish or more greenish images. Since the deuteranomalous observer has relatively week perception for red and green region, they may prefer more reddish or greenish color. The color difference between natural hue and preferred hue of deuteranomal observer is bigger than those of normal observer.

  12. Evolution of cichlid vision via trans-regulatory divergence

    Directory of Open Access Journals (Sweden)

    O’Quin Kelly E

    2012-12-01

    Full Text Available Abstract Background Phenotypic evolution may occur through mutations that affect either the structure or expression of protein-coding genes. Although the evolution of color vision has historically been attributed to structural mutations within the opsin genes, recent research has shown that opsin regulatory mutations can also tune photoreceptor sensitivity and color vision. Visual sensitivity in African cichlid fishes varies as a result of the differential expression of seven opsin genes. We crossed cichlid species that express different opsin gene sets and scanned their genome for expression Quantitative Trait Loci (eQTL responsible for these differences. Our results shed light on the role that different structural, cis-, and trans-regulatory mutations play in the evolution of color vision. Results We identified 11 eQTL that contribute to the divergent expression of five opsin genes. On three linkage groups, several eQTL formed regulatory “hotspots” associated with the expression of multiple opsins. Importantly, however, the majority of the eQTL we identified (8/11 or 73% occur on linkage groups located trans to the opsin genes, suggesting that cichlid color vision has evolved primarily via trans-regulatory divergence. By modeling the impact of just two of these trans-regulatory eQTL, we show that opsin regulatory mutations can alter cichlid photoreceptor sensitivity and color vision at least as much as opsin structural mutations can. Conclusions Combined with previous work, we demonstrate that the evolution of cichlid color vision results from the interplay of structural, cis-, and especially trans-regulatory loci. Although there are numerous examples of structural and cis-regulatory mutations that contribute to phenotypic evolution, our results suggest that trans-regulatory mutations could contribute to phenotypic divergence more commonly than previously expected, especially in systems like color vision, where compensatory changes in the

  13. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume ... Costume Contact Lenses Can Ruin Vision Eye Makeup Safety In fact, it is illegal to sell colored ...

  14. The evolution of concepts of color vision.

    Science.gov (United States)

    Lee, Barry B

    2008-07-01

    The evolution of ideas about the way we see color was closely linked to physical theories of light. Proponents of both corpuscular and wave theories viewed light as a continuous spectrum. This was not easily reconciled with the fact that, for the human eye, all colors can be matched by mixture of three primaries. Physicists such as Mayer who described trichromatic color matching often assumed that there were just three types of rays in the spectrum. This argument was finally resolved by Thomas Young, who noted that trichromatic color matching was consistent with a continuous spectrum if there were just three receptors in the eye. This kind of conceptual mistake, in this case the confusion of the properties of the visual system with physical properties of light, has been common in the history of color science. As another example, the idea of trichromacy was disputed by those who viewed color sensations as opponent processes, red-green, blue-yellow and black-white. The discovery of color-opponent neurons in the visual pathway has partly resolved this dilemma. Much of the physiological substrate of the way we detect and distinguish colors is now established, but the link between the signals leaving the retina and the way we name and order colors is still poorly defined.

  15. Color Constancy by Deep Learning

    NARCIS (Netherlands)

    Lou, Z.; Gevers, T.; Hu, N.; Lucassen, M.P.; Xie, X.; Jones, M.W.; Tam, G.K.L.

    2015-01-01

    Computational color constancy aims to estimate the color of the light source. The performance of many vision tasks, such as object detection and scene understanding, may benefit from color constancy by estimating the correct object colors. Since traditional color constancy methods are based on

  16. 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.

  17. Spatial imaging in color and HDR: prometheus unchained

    Science.gov (United States)

    McCann, John J.

    2013-03-01

    The Human Vision and Electronic Imaging Conferences (HVEI) at the IS and T/SPIE Electronic Imaging meetings have brought together research in the fundamentals of both vision and digital technology. This conference has incorporated many color disciplines that have contributed to the theory and practice of today's imaging: color constancy, models of vision, digital output, high-dynamic-range imaging, and the understanding of perceptual mechanisms. Before digital imaging, silver halide color was a pixel-based mechanism. Color films are closely tied to colorimetry, the science of matching pixels in a black surround. The quanta catch of the sensitized silver salts determines the amount of colored dyes in the final print. The rapid expansion of digital imaging over the past 25 years has eliminated the limitations of using small local regions in forming images. Spatial interactions can now generate images more like vision. Since the 1950's, neurophysiology has shown that post-receptor neural processing is based on spatial interactions. These results reinforced the findings of 19th century experimental psychology. This paper reviews the role of HVEI in color, emphasizing the interaction of research on vision and the new algorithms and processes made possible by electronic imaging.

  18. Dirt detection on brown eggs by means of color computer vision.

    Science.gov (United States)

    Mertens, K; De Ketelaere, B; Kamers, B; Bamelis, F R; Kemps, B J; Verhoelst, E M; De Baerdemaeker, J G; Decuypere, E M

    2005-10-01

    In the last 20 yr, different methods for detecting defects in eggs were developed. Until now, no satisfying technique existed to sort and quantify dirt on eggshells. The work presented here focuses on the design of an off-line computer vision system to differentiate and quantify the presence of different dirt stains on brown eggs: dark (feces), white (uric acid), blood, and yolk stains. A system that provides uniform light exposure around the egg was designed. In this uniform light, pictures of dirty and clean eggs were taken, stored, and analyzed. The classification was based on a few standard logical operators, allowing for a quick implementation in an online set-up. In an experiment, 100 clean and 100 dirty eggs were used to validate the classification algorithm. The designed vision system showed an accuracy of 99% for the detection of dirt stains. Two percent of the clean eggs had a light-colored eggshell and were subsequently mistaken for showing large white stains. The accuracy of differentiation of the different kinds of dirt stains was 91%. Of the eggs with dark stains, 10.81% were mistaken for having bloodstains, and 33.33% of eggs with bloodstains were mistaken for having dark stains. The developed system is possibly a first step toward an on line dirt evaluation technique for brown eggs.

  19. Configuration color vision tests: the interaction between aging and the complexity of figure-ground segregation.

    Science.gov (United States)

    Stanford, T; Pollack, R H

    1984-09-01

    A cross-sectional study comparing response time and the percentage of items correctly identified in three color vision tests (Pflügertrident, HRR-AO pseudoisochromatic plates, and AO pseudoisochromatic plates) was carried out on 72 women (12 in each decade) ranging from ages 20 to 79 years. Overall, time scores increased across the age groups. Analysis of the correctness scores indicated that the AO pseudoisochromatic plates requiring the identification of numbers was more difficult than the other tests which consisted of geometric forms or the letter E. This differential difficulty increased as a function of age. There was no indication of color defect per se which led to the conclusion that figure complexity may be the key variable determining performance. The results were similar to those obtained by Lee and Pollack (1978) in their study of the Embedded Figures Test.

  20. Intelligent color vision system for ripeness classification of oil palm fresh fruit bunch.

    Science.gov (United States)

    Fadilah, Norasyikin; Mohamad-Saleh, Junita; Abdul Halim, Zaini; Ibrahim, Haidi; Syed Ali, Syed Salim

    2012-10-22

    Ripeness classification of oil palm fresh fruit bunches (FFBs) during harvesting is important to ensure that they are harvested during optimum stage for maximum oil production. This paper presents the application of color vision for automated ripeness classification of oil palm FFB. Images of oil palm FFBs of type DxP Yangambi were collected and analyzed using digital image processing techniques. Then the color features were extracted from those images and used as the inputs for Artificial Neural Network (ANN) learning. The performance of the ANN for ripeness classification of oil palm FFB was investigated using two methods: training ANN with full features and training ANN with reduced features based on the Principal Component Analysis (PCA) data reduction technique. Results showed that compared with using full features in ANN, using the ANN trained with reduced features can improve the classification accuracy by 1.66% and is more effective in developing an automated ripeness classifier for oil palm FFB. The developed ripeness classifier can act as a sensor in determining the correct oil palm FFB ripeness category.

  1. Intelligent Color Vision System for Ripeness Classification of Oil Palm Fresh Fruit Bunch

    Directory of Open Access Journals (Sweden)

    Haidi Ibrahim

    2012-10-01

    Full Text Available Ripeness classification of oil palm fresh fruit bunches (FFBs during harvesting is important to ensure that they are harvested during optimum stage for maximum oil production. This paper presents the application of color vision for automated ripeness classification of oil palm FFB. Images of oil palm FFBs of type DxP Yangambi were collected and analyzed using digital image processing techniques. Then the color features were extracted from those images and used as the inputs for Artificial Neural Network (ANN learning. The performance of the ANN for ripeness classification of oil palm FFB was investigated using two methods: training ANN with full features and training ANN with reduced features based on the Principal Component Analysis (PCA data reduction technique. Results showed that compared with using full features in ANN, using the ANN trained with reduced features can improve the classification accuracy by 1.66% and is more effective in developing an automated ripeness classifier for oil palm FFB. The developed ripeness classifier can act as a sensor in determining the correct oil palm FFB ripeness category.

  2. Perception of color emotions for single colors in red-green defective observers.

    Science.gov (United States)

    Sato, Keiko; Inoue, Takaaki

    2016-01-01

    It is estimated that inherited red-green color deficiency, which involves both the protan and deutan deficiency types, is common in men. For red-green defective observers, some reddish colors appear desaturated and brownish, unlike those seen by normal observers. Despite its prevalence, few studies have investigated the effects that red-green color deficiency has on the psychological properties of colors (color emotions). The current study investigated the influence of red-green color deficiency on the following six color emotions: cleanliness, freshness, hardness, preference, warmth, and weight. Specifically, this study aimed to: (1) reveal differences between normal and red-green defective observers in rating patterns of six color emotions; (2) examine differences in color emotions related to the three cardinal channels in human color vision; and (3) explore relationships between color emotions and color naming behavior. Thirteen men and 10 women with normal vision and 13 men who were red-green defective performed both a color naming task and an emotion rating task with 32 colors from the Berkeley Color Project (BCP). Results revealed noticeable differences in the cleanliness and hardness ratings between the normal vision observers, particularly in women, and red-green defective observers, which appeared mainly for colors in the orange to cyan range, and in the preference and warmth ratings for colors with cyan and purple hues. Similarly, naming errors also mainly occurred in the cyan colors. A regression analysis that included the three cone-contrasts (i.e., red-green, blue-yellow, and luminance) as predictors significantly accounted for variability in color emotion ratings for the red-green defective observers as much as the normal individuals. Expressly, for warmth ratings, the weight of the red-green opponent channel was significantly lower in color defective observers than in normal participants. In addition, the analyses for individual warmth ratings in

  3. Perception of color emotions for single colors in red-green defective observers

    Directory of Open Access Journals (Sweden)

    Keiko Sato

    2016-12-01

    Full Text Available It is estimated that inherited red-green color deficiency, which involves both the protan and deutan deficiency types, is common in men. For red-green defective observers, some reddish colors appear desaturated and brownish, unlike those seen by normal observers. Despite its prevalence, few studies have investigated the effects that red-green color deficiency has on the psychological properties of colors (color emotions. The current study investigated the influence of red-green color deficiency on the following six color emotions: cleanliness, freshness, hardness, preference, warmth, and weight. Specifically, this study aimed to: (1 reveal differences between normal and red-green defective observers in rating patterns of six color emotions; (2 examine differences in color emotions related to the three cardinal channels in human color vision; and (3 explore relationships between color emotions and color naming behavior. Thirteen men and 10 women with normal vision and 13 men who were red-green defective performed both a color naming task and an emotion rating task with 32 colors from the Berkeley Color Project (BCP. Results revealed noticeable differences in the cleanliness and hardness ratings between the normal vision observers, particularly in women, and red-green defective observers, which appeared mainly for colors in the orange to cyan range, and in the preference and warmth ratings for colors with cyan and purple hues. Similarly, naming errors also mainly occurred in the cyan colors. A regression analysis that included the three cone-contrasts (i.e., red-green, blue-yellow, and luminance as predictors significantly accounted for variability in color emotion ratings for the red-green defective observers as much as the normal individuals. Expressly, for warmth ratings, the weight of the red-green opponent channel was significantly lower in color defective observers than in normal participants. In addition, the analyses for individual warmth

  4. Conjunction of color and form without attention: evidence from an orientation-contingent color aftereffect.

    Science.gov (United States)

    Houck, M R; Hoffman, J E

    1986-05-01

    According to feature-integration theory (Treisman & Gelade, 1980), separable features such as color and shape exist in separate maps in preattentive vision and can be integrated only through the use of spatial attention. Many perceptual aftereffects, however, which are also assumed to reflect the features available in preattentive vision, are sensitive to conjunctions of features. One possible resolution of these views holds that adaptation to conjunctions depends on spatial attention. We tested this proposition by presenting observers with gratings varying in color and orientation. The resulting McCollough aftereffects were independent of whether the adaptation stimuli were presented inside or outside of the focus of spatial attention. Therefore, color and shape appear to be conjoined preattentively, when perceptual aftereffects are used as the measure. These same stimuli, however, appeared to be separable in two additional experiments that required observers to search for gratings of a specified color and orientation. These results show that different experimental procedures may be tapping into different stages of preattentive vision.

  5. Emerging from Water: Underwater Image Color Correction Based on Weakly Supervised Color Transfer

    OpenAIRE

    Li, Chongyi; Guo, Jichang; Guo, Chunle

    2017-01-01

    Underwater vision suffers from severe effects due to selective attenuation and scattering when light propagates through water. Such degradation not only affects the quality of underwater images but limits the ability of vision tasks. Different from existing methods which either ignore the wavelength dependency of the attenuation or assume a specific spectral profile, we tackle color distortion problem of underwater image from a new view. In this letter, we propose a weakly supervised color tr...

  6. Feedback from horizontal cells to cones mediates color induction and may facilitate color constancy in rainbow trout

    NARCIS (Netherlands)

    Sabbah, Shai; Zhu, Changhai; Hornsby, Mark A. W.; Kamermans, Maarten; Hawryshyn, Craig W.

    2013-01-01

    Color vision is most beneficial when the visual system is color constant and can correct the excitations of photoreceptors for differences in environmental irradiance. A phenomenon related to color constancy is color induction, where the color of an object shifts away from the color of its

  7. Converting a fluorescence spectrophotometer into a three-channel colorimeter for color vision research

    International Nuclear Information System (INIS)

    Pardo, P.J.; Perez, A.L.; Suero, M.I.

    2004-01-01

    An old fluorescence spectrophotometer was recycled to make a three-channel colorimeter. The various modifications involved in its design and implementation are described. An optical system was added that allows the fusion of two visual stimuli coming from the two monochromators of the spectrofluorimeter. Each of these stimuli has a wavelength and bandwidth control, and a third visual stimulus may be taken from a monochromator, a cathode ray tube, a thin film transistor screen, or any other light source. This freedom in the choice of source of the third chromatic channel, together with the characteristics of the visual stimuli from the spectrofluorimeter, give this design a great versatility in its application to novel visual experiments on color vision

  8. Converting a fluorescence spectrophotometer into a three-channel colorimeter for color vision research

    Science.gov (United States)

    Pardo, P. J.; Pérez, A. L.; Suero, M. I.

    2004-01-01

    An old fluorescence spectrophotometer was recycled to make a three-channel colorimeter. The various modifications involved in its design and implementation are described. An optical system was added that allows the fusion of two visual stimuli coming from the two monochromators of the spectrofluorimeter. Each of these stimuli has a wavelength and bandwidth control, and a third visual stimulus may be taken from a monochromator, a cathode ray tube, a thin film transistor screen, or any other light source. This freedom in the choice of source of the third chromatic channel, together with the characteristics of the visual stimuli from the spectrofluorimeter, give this design a great versatility in its application to novel visual experiments on color vision.

  9. Role-play facilitates children's mindreading of those with atypical color perception.

    Science.gov (United States)

    Furumi, Fumikazu; Koyasu, Masuo

    2014-01-01

    The present study examined the effects of role-play experience on children's mindreading ability. Forty-one primary school children (20 boys, 21 girls, mean age: 9.37 years, range: 8-11 years) were introduced to a communication task in which the use of mindreading was essential. During each trial, participants viewed a shelf, presented on a laptop, which contained several familiar objects, and they were instructed to touch an object on the shelf following an order issued by a "manager" who stood at the opposite side of the shelf. There were two managers: one was a monkey manager with normal color vision, and the other was a dog manager with restricted color vision. The monkey manager could see all the objects in the same colors as the participants, whereas the dog manager saw some objects in different colors. Participants were required to respond according to the manager's instruction. In the restricted color vision condition, the dog manager saw the colors of objects differently; thus, participants had to work out his intentions, according to his different perspective. In the normal color vision condition, all objects were in the same colors as those seen by the monkey manager. Before the test phase, participants in the role-play group were provided a role-play experience in which they assumed the role of the dog manager with restricted color vision. The experimental data were analyzed using a 2 × 2 mixed-design ANOVA (role-play condition × communication partner condition) to examine differences in the error rate. Both main effects and its interaction were significant. According to the post-hoc analyses, participants in the no-role-play condition made significantly more errors in the restricted color vision condition than in the normal color vision condition, whereas no such difference was found among participants in the role-play condition. These results suggest that role-play experience could facilitate mindreading of characters with restricted color vision.

  10. General principles in motion vision: color blindness of object motion depends on pattern velocity in honeybee and goldfish.

    Science.gov (United States)

    Stojcev, Maja; Radtke, Nils; D'Amaro, Daniele; Dyer, Adrian G; Neumeyer, Christa

    2011-07-01

    Visual systems can undergo striking adaptations to specific visual environments during evolution, but they can also be very "conservative." This seems to be the case in motion vision, which is surprisingly similar in species as distant as honeybee and goldfish. In both visual systems, motion vision measured with the optomotor response is color blind and mediated by one photoreceptor type only. Here, we ask whether this is also the case if the moving stimulus is restricted to a small part of the visual field, and test what influence velocity may have on chromatic motion perception. Honeybees were trained to discriminate between clockwise- and counterclockwise-rotating sector disks. Six types of disk stimuli differing in green receptor contrast were tested using three different rotational velocities. When green receptor contrast was at a minimum, bees were able to discriminate rotation directions with all colored disks at slow velocities of 6 and 12 Hz contrast frequency but not with a relatively high velocity of 24 Hz. In the goldfish experiment, the animals were trained to detect a moving red or blue disk presented in a green surround. Discrimination ability between this stimulus and a homogenous green background was poor when the M-cone type was not or only slightly modulated considering high stimulus velocity (7 cm/s). However, discrimination was improved with slower stimulus velocities (4 and 2 cm/s). These behavioral results indicate that there is potentially an object motion system in both honeybee and goldfish, which is able to incorporate color information at relatively low velocities but is color blind with higher speed. We thus propose that both honeybees and goldfish have multiple subsystems of object motion, which include achromatic as well as chromatic processing.

  11. Vision, eye disease, and art: 2015 Keeler Lecture.

    Science.gov (United States)

    Marmor, M F

    2016-02-01

    The purpose of this study was to examine normal vision and eye disease in relation to art. Ophthalmology cannot explain art, but vision is a tool for artists and its normal and abnormal characteristics may influence what an artist can do. The retina codes for contrast, and the impact of this is evident throughout art history from Asian brush painting, to Renaissance chiaroscuro, to Op Art. Art exists, and can portray day or night, only because of the way retina adjusts to light. Color processing is complex, but artists have exploited it to create shimmer (Seurat, Op Art), or to disconnect color from form (fauvists, expressionists, Andy Warhol). It is hazardous to diagnose eye disease from an artist's work, because artists have license to create as they wish. El Greco was not astigmatic; Monet was not myopic; Turner did not have cataracts. But when eye disease is documented, the effects can be analyzed. Color-blind artists limit their palette to ambers and blues, and avoid greens. Dense brown cataracts destroy color distinctions, and Monet's late canvases (before surgery) showed strange and intense uses of color. Degas had failing vision for 40 years, and his pastels grew coarser and coarser. He may have continued working because his blurred vision smoothed over the rough work. This paper can barely touch upon the complexity of either vision or art. However, it demonstrates some ways in which understanding vision and eye disease give insight into art, and thereby an appreciation of both art and ophthalmology.

  12. Evolution of female carotenoid coloration by sexual constraint in Carduelis finches

    Directory of Open Access Journals (Sweden)

    Cardoso Gonçalo C

    2010-03-01

    Full Text Available Abstract Background Females often express the same ornaments as males to a similar or lesser degree. Female ornaments can be adaptive, but little is known regarding their origins and mode of evolution. Current utility does not imply evolutionary causation, and therefore it is possible that female ornamentation evolved due to selection on females, as a correlated response to selection on males (sexual constraint, or a combination of both. We tested these ideas simulating simple models for the evolution of male and female correlated traits, and compared their predictions against the coloration of finches in the genus Carduelis. Results For carotenoid-based ornamental coloration, a model of sexual constraint on females fits the Carduelis data well. The two alternative models (sexual constraint on males, and mutual constraint were rejected as causing the similarities in carotenoid coloration between males and females. For melanin coloration, the correlation between the sexes was weaker, indicating that males and females evolved independently to a greater extent. Conclusions This indicates that sexual constraint on females was an important mechanism for the evolution of ornamental carotenoid coloration in females, but less so for melanin coloration. This does not mean that female carotenoid coloration is non-adaptive or maladaptive, because sexual dichromatism could evolve if it were maladaptive. It suggests, however, that most evolution of female carotenoid coloration was male-driven and, when adaptive, may not be an adaptation stricto sensu.

  13. 78 FR 12815 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2013-02-25

    .... The best corrected visual acuity in his right eye is light perception, and in his left eye, 20/20.... Lifelong. Stable. Visual fields WNL. Color WNL. No contraindications for commercial driving.'' Mr. Clark... color vision, 180 degrees of peripheral vision, no medical contraindication to commercial truck driving...

  14. [Web-based analysis of Stilling's color plates].

    Science.gov (United States)

    Kuchenbecker, J

    2014-12-01

    Color vision tests with pseudoisochromatic plates currently represent the most common procedure for the screening of congenital color vision deficiencies. By means of a web-based color vision test, new and old color plates can be tested for diagnostic quality without major effort. A total of 16 digitized Stilling's color plates of the 11th edition from 1907 were included in a web-based color vision test (http://www.farbsehtest.de). The χ(2)-test was used to check whether the Stilling color plates showed similar results to the nine previously evaluated Ishihara color plates. A total of 518 subjects including101 (19.5 %) female subjects with a mean age of 34.6 ± 17 years, took the web-based test with the 25 plates. For all participants the range for the correctly recognized plates was between 5.2 % (n = 27) and 97.7 % (n = 506) for the Stilling color plates and between 64.9 % (n = 336) and 100 % (n = 518) for the Ishihara color plates. For participants with more than 5 errors (n = 247), the range for correctly recognized plates was between 2.0 % (n = 5) and 98.0 % (n = 242) for the Stilling plates and between 42.5 % (n = 105) and 100 % (n = 247) for the Ishihara plates. Taking all color plates and all participants into account there was a significantly higher incidence of erroneous recognition of the Stilling color plates (3038 false and 5250 true answers) compared to the Ishihara color plates (1511 false and 3151 true answers) (p plates could be used for the test edition of the Velhagen/Broschmann/Kuchenbecker color plates from 2014. Overall, the Stilling color plates were recognized with a higher incidence of error by all participants in the web-based test compared to the utilized Ishihara color plates, which in most cases was attributable to ambiguity of some symbols.

  15. 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.

  16. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... lentes de contacto de color Sep. 26, 2013 It started as an impulsive buy from a souvenir ... Can Ruin Vision Eye Makeup Safety In fact, it is illegal to sell colored contact lenses without ...

  17. Role-play facilitates children’s mindreading of those with atypical color perception

    Directory of Open Access Journals (Sweden)

    Fumikazu eFurumi

    2014-07-01

    Full Text Available The present study examined the effects of role-play experience on children’s mindreading ability. Forty-one primary school children (20 boys, 21 girls, mean age: 9.37 years, range: 8–11 years were introduced to a communication task in which the use of mindreading was essential. During each trial, participants viewed a shelf, presented on a laptop, which contained several familiar objects, and they were instructed to touch an object on the shelf following an order issued by a manager who stood at the opposite side of the shelf. There were two managers: one was a monkey manager with normal color vision, and the other was a dog manager with restricted color vision. The monkey manager could see all the objects in the same colors as the participants, whereas the dog manager saw some objects in different colors. Participants were required to respond according to the manager's instruction. In the restricted color vision condition, the dog manager saw the colors of objects differently; thus, participants had to work out his intentions, according to his different perspective. In the normal color vision condition, all objects were in the same colors as those seen by the monkey manager. Before the test phase, participants in the role-play group were provided a role-play experience in which they assumed the role of the dog manager with restricted color vision. The experimental data were analyzed using a 2 x 2 mixed-design ANOVA (role-play condition x communication partner condition to examine differences in the error rate. Both main effects and its interaction were significant. According to the post-hoc analyses, participants in the no-role-play condition made significantly more errors in the restricted color vision condition than in the normal color vision condition, whereas no such difference was found among participants in the role-play condition. These results suggest that role-play experience could facilitate mindreading of characters with

  18. P1-15: Categorical Color Perception of LED Illuminant Color for Deuteranomals

    Directory of Open Access Journals (Sweden)

    Saeko Oishi

    2012-10-01

    Full Text Available Color information has great value in our everyday lives, but it is not mindful of people with color vision deficiency (CVD. We can choose several color names to categorize a lot of colors around us. Eleven color names (white, black, red, green, yellow, blue, brown, orange, pink, and gray are known as basic color categories, but people with CVD cannot necessarily describe colors as people who are color vision normal (CVN do. Previous studies showed that it was hard for people with CVD to discriminate illuminant color from object color, and their color perception changed largely depending on experimental conditions. In this study we investigated categorical color perception of illuminant color for deuteranomals, using a mixture of light which consists of a red, a green, and a blue LED as a test stimulus. We tested those stimuli with three luminance levels (180 cd/m2, 18 cd/m2, 1.8 cd/m2 and two visual angles (10 deg, 0.5 deg. Subjects were three deuteranomals and three people who are CVN. Our result showed that the categorical color of mild deuteranomals was similar to that of those who were CVN, but that of severe deuteranomals was not. Severe deuteranomals judged more low chromatic colors as achromatic colors than those who were CVN. The smaller visual angle or lower luminance level the test stimulus had, the more deuteranomals confused color. The results suggest that the effect of the Bezold-Brucke phenomenon is greater to deuteranomals than to those who are CVN. Furthermore, deuteranomals use not only chromatic information but also luminance information when they describe color.

  19. Use of Hyperspectral Imagery to Assess Cryptic Color Matching in Sargassum Associated Crabs.

    Directory of Open Access Journals (Sweden)

    Brandon J Russell

    Full Text Available Mats of the pelagic macroalgae Sargassum represent a complex environment for the study of marine camouflage at the air-sea interface. Endemic organisms have convergently evolved similar colors and patterns, but quantitative assessments of camouflage strategies are lacking. Here, spectral camouflage of two crab species (Portunus sayi and Planes minutus was assessed using hyperspectral imagery (HSI. Crabs matched Sargassum reflectance across blue and green wavelengths (400-550 nm and diverged at longer wavelengths. Maximum discrepancy was observed in the far-red (i.e., 675 nm where Chlorophyll a absorption occurred in Sargassum and not the crabs. In a quantum catch color model, both crabs showed effective color matching against blue/green sensitive dichromat fish, but were still discernible to tetrachromat bird predators that have visual sensitivity to far red wavelengths. The two species showed opposing trends in background matching with relation to body size. Variation in model parameters revealed that discrimination of crab and background was impacted by distance from the predator, and the ratio of cone cell types for bird predators. This is one of the first studies to detail background color matching in this unique, challenging ecosystem at the air-sea interface.

  20. Neuropharmacology of vision in goldfish: a review.

    Science.gov (United States)

    Mora-Ferrer, Carlos; Neumeyer, Christa

    2009-05-01

    The goldfish is one of the few animals exceptionally well analyzed in behavioral experiments and also in electrophysiological and neuroanatomical investigations of the retina. To get insight into the functional organization of the retina we studied color vision, motion detection and temporal resolution before and after intra-ocular injection of neuropharmaca with known effects on retinal neurons. Bicuculline, strychnine, curare, atropine, and dopamine D1- and D2-receptor antagonists were used. The results reviewed here indicate separate and parallel processing of L-cone contribution to different visual functions, and the influence of several neurotransmitters (dopamine, acetylcholine, glycine, and GABA) on motion vision, color vision, and temporal resolution.

  1. Color blindness among multiple sclerosis patients in Isfahan.

    Science.gov (United States)

    Shaygannejad, Vahid; Golabchi, Khodayar; Dehghani, Alireza; Ashtari, Fereshteh; Haghighi, Sepehr; Mirzendehdel, Mahsa; Ghasemi, Majid

    2012-03-01

    Multiple sclerosis (MS) is a disease of young and middle aged individuals with a demyelinative axonal damage nature in central nervous system that causes various signs and symptoms. As color vision needs normal function of optic nerve and macula, it is proposed that MS can alter it via influencing optic nerve. In this survey, we evaluated color vision abnormalities and its relationship with history of optic neuritis and abnormal visual evoked potentials (VEPs) among MS patients. The case group was included of clinically definitive MS patients and the same number of normal population was enrolled as the control group. Color vision of all the participants was evaluated by Ishihara test and then visual evoked potential (VEPs) and history of optic neuritis (ON) was assessed among them. Then, frequency of color blindness was compared between the case and the control group. Finally, color blinded patients were compared to those with the history of ON and abnormal VEPs. 63 MS patients and the same number of normal populations were enrolled in this study. 12 patients had color blindness based on the Ishihara test; only 3 of them were among the control group, which showed a significant different between the two groups (P = 0.013). There was a significant relationship between the color blindness and abnormal VEP (R = 0.53, P = 0.023) but not for the color blindness and ON (P = 0.67). This study demonstrates a significant correlation between color blindness and multiple sclerosis including ones with abnormal prolonged VEP latencies. Therefore, in individuals with acquired color vision impairment, an evaluation for potentially serious underlying diseases like MS is essential.

  2. Color blindness among multiple sclerosis patients in Isfahan

    Directory of Open Access Journals (Sweden)

    Vahid Shaygannejad

    2012-01-01

    Full Text Available Background: Multiple sclerosis (MS is a disease of young and middle aged individuals with a demyelinative axonal damage nature in central nervous system that causes various signs and symptoms. As color vision needs normal function of optic nerve and macula, it is proposed that MS can alter it via influencing optic nerve. In this survey, we evaluated color vision abnormalities and its relationship with history of optic neuritis and abnormal visual evoked potentials (VEPs among MS patients. Materials and Methods: The case group was included of clinically definitive MS patients and the same number of normal population was enrolled as the control group. Color vision of all the participants was evaluated by Ishihara test and then visual evoked potential (VEPs and history of optic neuritis (ON was assessed among them. Then, frequency of color blindness was compared between the case and the control group. Finally, color blinded patients were compared to those with the history of ON and abnormal VEPs. Results: 63 MS patients and the same number of normal populations were enrolled in this study. 12 patients had color blindness based on the Ishihara test; only 3 of them were among the control group, which showed a significant different between the two groups (P = 0.013. There was a significant relationship between the color blindness and abnormal VEP (R = 0.53, P = 0.023 but not for the color blindness and ON (P = 0.67. Conclusions: This study demonstrates a significant correlation between color blindness and multiple sclerosis including ones with abnormal prolonged VEP latencies. Therefore, in individuals with acquired color vision impairment, an evaluation for potentially serious underlying diseases like MS is essential.

  3. [The evaluation of color vision and its diagnostic value in predicting the risk of diabetic retinopathy in patients with glucose metabolism disorders].

    Science.gov (United States)

    Jończyk-Skórka, Katarzyna; Kowalski, Jan

    2017-07-21

    The aim of the study was to evaluate color vision and its diagnostic value in predicting the risk of diabetic retinopathy in patients with glucose metabolism disorders. The study involved 197 people, 92 women and 105 men aged 63.21 ± 8.74 years. In order to assess glucose metabolism disorders, patients were divided into three groups. The first group (DM) consisted of 60 people (16 women and 44 men aged 61.92 ± 8.46 years). These were people with type 2 diabetes. Second group (IFG IGT) consisted of 67 people (35 women and 32 men aged 65 ± 8.5 years). These were people who were diagnosed with impaired fasting glucose or impaired glucose tolerance. The third group, the control one (K) consisted of 70 people (41 women and 29 men aged 62.6 ± 9.06 years). They were healthy individuals. In order to assess diabetic retinopathy study population was divided into two groups. The first group (BZ) consisted of 177 patients (84 women and 93 men aged 62.9 ± 8.78 years) without diabetic retinopathy. The second group (NPDR) consisted of 20 patients (8 women and 12 men aged 65.95 ± 8.17 years) with diabetic retinopathy. Glucose metabolism disorders were diagnosed with glucose tolerance test (OGTT). Evaluation of retinopathy was based on eye examination. All patients underwent binocular Farnsworth-Munsell 100 Hue color vision test (test result is a Total Error Score - TES). In the healthy control group (K) there were less patients with diabetic retinopathy (p = 0,0101), and less patients with abnormal color vision test (p = 0,0001) than in other groups. Majority of patients in K group had generalized abnormalities of color vision while other groups demonstrated tritanomalią (p = 0,0018). It was discovered that sTES value adequately distinguishes group K from group IFG, IGT, DM (AUC = 0,673), group K from group DM (AUC = 0,701), and group K from group IFG IGT (AUC = 0,648) sTES does not differentiate groups IGT, IFG and DM (AUC = 0,563). It was shown that in IGT, IFG group s

  4. Multi-capability color night vision HD camera for defense, surveillance, and security

    Science.gov (United States)

    Pang, Francis; Powell, Gareth; Fereyre, Pierre

    2015-05-01

    e2v has developed a family of high performance cameras based on our next generation CMOS imagers that provide multiple features and capabilities to meet the range of challenging imaging applications in defense, surveillance, and security markets. Two resolution sizes are available: 1920x1080 with 5.3 μm pixels, and an ultra-low light level version at 1280x1024 with 10μm pixels. Each type is available in either monochrome or e2v's unique bayer pattern color version. The camera is well suited to accommodate many of the high demands for defense, surveillance, and security applications: compact form factor (SWAP+C), color night vision performance (down to 10-2 lux), ruggedized housing, Global Shutter, low read noise (<6e- in Global shutter mode and <2.5e- in Rolling shutter mode), 60 Hz frame rate, high QE especially in the enhanced NIR range (up to 1100nm). Other capabilities include active illumination and range gating. This paper will describe all the features of the sensor and the camera. It will be followed with a presentation of the latest test data with the current developments. Then, it will conclude with a description of how these features can be easily configured to meet many different applications. With this development, we can tune rather than create a full customization, making it more beneficial for many of our customers and their custom applications.

  5. Assessing Sexual Dicromatism: The Importance of Proper Parameterization in Tetrachromatic Visual Models.

    Directory of Open Access Journals (Sweden)

    Pierre-Paul Bitton

    Full Text Available Perceptual models of animal vision have greatly contributed to our understanding of animal-animal and plant-animal communication. The receptor-noise model of color contrasts has been central to this research as it quantifies the difference between two colors for any visual system of interest. However, if the properties of the visual system are unknown, assumptions regarding parameter values must be made, generally with unknown consequences. In this study, we conduct a sensitivity analysis of the receptor-noise model using avian visual system parameters to systematically investigate the influence of variation in light environment, photoreceptor sensitivities, photoreceptor densities, and light transmission properties of the ocular media and the oil droplets. We calculated the chromatic contrast of 15 plumage patches to quantify a dichromatism score for 70 species of Galliformes, a group of birds that display a wide range of sexual dimorphism. We found that the photoreceptor densities and the wavelength of maximum sensitivity of the short-wavelength-sensitive photoreceptor 1 (SWS1 can change dichromatism scores by 50% to 100%. In contrast, the light environment, transmission properties of the oil droplets, transmission properties of the ocular media, and the peak sensitivities of the cone photoreceptors had a smaller impact on the scores. By investigating the effect of varying two or more parameters simultaneously, we further demonstrate that improper parameterization could lead to differences between calculated and actual contrasts of more than 650%. Our findings demonstrate that improper parameterization of tetrachromatic visual models can have very large effects on measures of dichromatism scores, potentially leading to erroneous inferences. We urge more complete characterization of avian retinal properties and recommend that researchers either determine whether their species of interest possess an ultraviolet or near-ultraviolet sensitive SWS1

  6. Image Transform Based on the Distribution of Representative Colors for Color Deficient

    Science.gov (United States)

    Ohata, Fukashi; Kudo, Hiroaki; Matsumoto, Tetsuya; Takeuchi, Yoshinori; Ohnishi, Noboru

    This paper proposes the method to convert digital image containing distinguishing difficulty sets of colors into the image with high visibility. We set up four criteria, automatically processing by a computer, retaining continuity in color space, not making images into lower visible for people with normal color vision, and not making images not originally having distinguishing difficulty sets of colors into lower visible. We conducted the psychological experiment. We obtained the result that the visibility of a converted image had been improved at 60% for 40 images, and we confirmed the main criterion of the continuity in color space was kept.

  7. An Investigation of the Effects of Practice on Color Memory as a Function of Condition, Dimension and Color

    OpenAIRE

    Remus, Britten Grace

    2001-01-01

    Forty-two college aged participants took part in a mixed repeated measures factorial design experiment that assessed color memory as a function of condition (practice with feedback, practice without feedback and no practice), dimension (hue, saturation and lightness) and color (red, yellow, green and blue). Attention was focused on the distinction between memory color and color memory, color experience and preference, mechanisms of color perception and theories of color vision (see below). ...

  8. Key Informant Perceptions of Vision Loss in Children and ...

    African Journals Online (AJOL)

    tulyasys

    understand how vision can practically be assessed and how poor vision can affect a child, whether by limiting the ability to do activities of daily living or by limiting social interactions. In this group, there were some misconceptions regarding the use of color vision and the assessment of reading as a tool for vision assessment ...

  9. Industrial Color Physics

    CERN Document Server

    Klein, Georg A

    2010-01-01

    This unique book starts with a short historical overview of the development of the theories of color vision and applications of industrial color physics. The three dominant factors producing color - light source, color sample, and observer - are described in detail. The standardized color spaces are shown and related color values are applied to characteristic color qualities of absorption as well as of effect colorants. The fundamentals of spectrometric and colorimetric measuring techniques together with specific applications are described. Theoretical models for radiative transfer in transparent, translucent, and opaque layers are detailed; the two, three, and multi-flux approximations are presented for the first time in a coherent formalism. These methods constitute the fundamentals not only for the important classical methods, but also modern methods of recipe prediction applicable to all known colorants. The text is supplied with 52 tables, more than 200 partially colored illustrations, an appendix, and a...

  10. Color vision versus pattern visual evoked potentials in the assessment of subclinical optic pathway involvement in multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Fatih C Gundogan

    2013-01-01

    Full Text Available Background: Optic pathway involvement in multiple sclerosis is frequently the initial sign in the disease process. In most clinical applications, pattern visual evoked potential (PVEP is used in the assessment of optic pathway involvement. Objective: To question the value of PVEP against color vision assessment in the diagnosis of subclinical optic pathway involvement. Materials and Methods: This prospective, cross-sectional study included 20 multiple sclerosis patients without a history of optic neuritis, and 20 healthy control subjects. Farnsworth-Munsell (FM 100-Hue testing and PVEPs to 60-min arc and 15-min arc checks by using Roland-Consult RetiScan® system were performed. P 100 amplitude, P 100 latency in PVEP and total error scores (TES in FM 100-Hue test were assessed. Results: Expanded Disability Status Scale score and the time from diagnosis were 2.21 ± 2.53 (ranging from 0 to 7 and 4.1 ± 4.4 years. MS group showed significantly delayed P 100 latency for both checks (P 0.05 for all. 14 MS patients (70% had an increased TESs in FM-100 Hue, 11 (55% MS patients had delayed P 100 latency and 9 (45% had reduced P 100 amplitude. The areas under the ROC curves were 0.944 for FM-100 Hue test, 0.753 for P 100 latency, and 0.173 for P 100 amplitude. Conclusions: Color vision testing seems to be more sensitive than PVEP in detecting subclinical visual pathway involvement in MS.

  11. Spin relaxation dynamics of holes in intrinsic GaAs quantum wells studied by transient circular dichromatic absorption spectroscopy at room temperature.

    Science.gov (United States)

    Fang, Shaoyin; Zhu, Ruidan; Lai, Tianshu

    2017-03-21

    Spin relaxation dynamics of holes in intrinsic GaAs quantum wells is studied using time-resolved circular dichromatic absorption spectroscopy at room temperature. It is found that ultrafast dynamics is dominated by the cooperative contributions of band filling and many-body effects. The relative contribution of the two effects is opposite in strength for electrons and holes. As a result, transient circular dichromatic differential transmission (TCD-DT) with co- and cross-circularly polarized pump and probe presents different strength at several picosecond delay time. Ultrafast spin relaxation dynamics of excited holes is sensitively reflected in TCD-DT with cross-circularly polarized pump and probe. A model, including coherent artifact, thermalization of nonthermal carriers and the cooperative contribution of band filling and many-body effects, is developed, and used to fit TCD-DT with cross-circularly polarized pump and probe. Spin relaxation time of holes is achieved as a function of excited hole density for the first time at room temperature, and increases with hole density, which disagrees with a theoretical prediction based on EY spin relaxation mechanism, implying that EY mechanism may be not dominant hole spin relaxation mechanism at room temperature, but DP mechanism is dominant possibly.

  12. 75 FR 9480 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2010-03-02

    ... injury sustained as a child. The best corrected visual acuity in his right eye is light-perception only... medical opinion, Mr. Williford has sufficient visual acuity, color vision and peripheral vision to perform...

  13. Visual wetness perception based on image color statistics.

    Science.gov (United States)

    Sawayama, Masataka; Adelson, Edward H; Nishida, Shin'ya

    2017-05-01

    Color vision provides humans and animals with the abilities to discriminate colors based on the wavelength composition of light and to determine the location and identity of objects of interest in cluttered scenes (e.g., ripe fruit among foliage). However, we argue that color vision can inform us about much more than color alone. Since a trichromatic image carries more information about the optical properties of a scene than a monochromatic image does, color can help us recognize complex material qualities. Here we show that human vision uses color statistics of an image for the perception of an ecologically important surface condition (i.e., wetness). Psychophysical experiments showed that overall enhancement of chromatic saturation, combined with a luminance tone change that increases the darkness and glossiness of the image, tended to make dry scenes look wetter. Theoretical analysis along with image analysis of real objects indicated that our image transformation, which we call the wetness enhancing transformation, is consistent with actual optical changes produced by surface wetting. Furthermore, we found that the wetness enhancing transformation operator was more effective for the images with many colors (large hue entropy) than for those with few colors (small hue entropy). The hue entropy may be used to separate surface wetness from other surface states having similar optical properties. While surface wetness and surface color might seem to be independent, there are higher order color statistics that can influence wetness judgments, in accord with the ecological statistics. The present findings indicate that the visual system uses color image statistics in an elegant way to help estimate the complex physical status of a scene.

  14. An Adaptive Fuzzy-Based System to Simulate, Quantify and Compensate Color Blindness

    OpenAIRE

    Lee, Jinmi; Santos, Wellington Pinheiro dos

    2017-01-01

    About 8% of the male population of the world are affected by a determined type of color vision disturbance, which varies from the partial to complete reduction of the ability to distinguish certain colors. A considerable amount of color blind people are able to live all life long without knowing they have color vision disabilities and abnormalities. Nowadays the evolution of information technology and computer science, specifically image processing techniques and computer graphics, can be fun...

  15. Realtime Color Stereovision Processing

    National Research Council Canada - National Science Library

    Formwalt, Bryon

    2000-01-01

    .... This research takes a step forward in real time machine vision processing. It investigates techniques for implementing a real time stereovision processing system using two miniature color cameras...

  16. Butterfly wing coloration studied with a novel imaging scatterometer

    Science.gov (United States)

    Stavenga, Doekele

    2010-03-01

    Animal coloration functions for display or camouflage. Notably insects provide numerous examples of a rich variety of the applied optical mechanisms. For instance, many butterflies feature a distinct dichromatism, that is, the wing coloration of the male and the female differ substantially. The male Brimstone, Gonepteryx rhamni, has yellow wings that are strongly UV iridescent, but the female has white wings with low reflectance in the UV and a high reflectance in the visible wavelength range. In the Small White cabbage butterfly, Pieris rapae crucivora, the wing reflectance of the male is low in the UV and high at visible wavelengths, whereas the wing reflectance of the female is higher in the UV and lower in the visible. Pierid butterflies apply nanosized, strongly scattering beads to achieve their bright coloration. The male Pipevine Swallowtail butterfly, Battus philenor, has dorsal wings with scales functioning as thin film gratings that exhibit polarized iridescence; the dorsal wings of the female are matte black. The polarized iridescence probably functions in intraspecific, sexual signaling, as has been demonstrated in Heliconius butterflies. An example of camouflage is the Green Hairstreak butterfly, Callophrys rubi, where photonic crystal domains exist in the ventral wing scales, resulting in a matte green color that well matches the color of plant leaves. The spectral reflection and polarization characteristics of biological tissues can be rapidly and with unprecedented detail assessed with a novel imaging scatterometer-spectrophotometer, built around an elliptical mirror [1]. Examples of butterfly and damselfly wings, bird feathers, and beetle cuticle will be presented. [4pt] [1] D.G. Stavenga, H.L. Leertouwer, P. Pirih, M.F. Wehling, Optics Express 17, 193-202 (2009)

  17. Color-discrimination threshold determination using pseudoisochromatic test plates

    Directory of Open Access Journals (Sweden)

    Kaiva eJurasevska

    2014-11-01

    Full Text Available We produced a set of pseudoisochromatic plates for determining individual color-difference thresholds to assess test performance and test properties, and analyzed the results. We report a high test validity and classification ability for the deficiency type and severity level (comparable to that of the fourth edition of the Hardy–Rand–Rittler (HRR test. We discuss changes of the acceptable chromatic shifts from the protan and deutan confusion lines along the CIE xy diagram, and the high correlation of individual color-difference thresholds and the red–green discrimination index. Color vision was tested using an Oculus HMC anomaloscope, a Farnsworth D15, and an HRR test on 273 schoolchildren, and 57 other subjects with previously diagnosed red–green color-vision deficiency.

  18. Frequency of color blindness in pre-employment screening in a tertiary health care center in Pakistan.

    Science.gov (United States)

    Chhipa, Shaukat Ali; Hashmi, Farzeen K; Ali, Shehreen; Kamal, Mustafa; Ahmad, Khabir

    2017-01-01

    To describe the frequency of color vision deficiency among Pakistani adults presenting for pre-employment health screening in a tertiary care hospital. The cross-sectional study was carried out at the Aga Khan University Hospital, Karachi, and the data was collected for color vision deficiency, age, gender, and job applied for from pre-employment examination during 2013-2014. IBM SPSS 20 was used for statistical analysis. Three thousand four hundred and thirty seven persons underwent pre-employment screening during 2013 and 2014; 1837 (53.44%) were males and 1600 (46.65%) females. The mean age was 29.01 (±6.53) years. A total of 0.9% (32/3437) persons had color vision deficiency with male being 1.4% and female 0.4%. Color vision deficiency was observed in 0.9% of candidates screened for pre-employment health check up in a tertiary care hospital. The color vision deficiency was predominantly present in male individuals.

  19. Head-Mounted Display Technology for Low Vision Rehabilitation and Vision Enhancement

    Science.gov (United States)

    Ehrlich, Joshua R.; Ojeda, Lauro V.; Wicker, Donna; Day, Sherry; Howson, Ashley; Lakshminarayanan, Vasudevan; Moroi, Sayoko E.

    2017-01-01

    Purpose To describe the various types of head-mounted display technology, their optical and human factors considerations, and their potential for use in low vision rehabilitation and vision enhancement. Design Expert perspective. Methods An overview of head-mounted display technology by an interdisciplinary team of experts drawing on key literature in the field. Results Head-mounted display technologies can be classified based on their display type and optical design. See-through displays such as retinal projection devices have the greatest potential for use as low vision aids. Devices vary by their relationship to the user’s eyes, field of view, illumination, resolution, color, stereopsis, effect on head motion and user interface. These optical and human factors considerations are important when selecting head-mounted displays for specific applications and patient groups. Conclusions Head-mounted display technologies may offer advantages over conventional low vision aids. Future research should compare head-mounted displays to commonly prescribed low vision aids in order to compare their effectiveness in addressing the impairments and rehabilitation goals of diverse patient populations. PMID:28048975

  20. A Vision Chip for Color Segmentation and Pattern Matching

    Directory of Open Access Journals (Sweden)

    Ralph Etienne-Cummings

    2003-06-01

    Full Text Available A 128(H × 64(V × RGB CMOS imager is integrated with region-of-interest selection, RGB-to-HSI transformation, HSI-based pixel segmentation, (36bins × 12bits-HSI histogramming, and sum-of-absolute-difference (SAD template matching. Thirty-two learned color templates are stored and compared to each image. The chip captures the R, G, and B images using in-pixel storage before passing the pixel content to a multiplying digital-to-analog converter (DAC for white balancing. The DAC can also be used to pipe in images for a PC. The color processing uses a biologically inspired color opponent representation and an analog lookup table to determine the Hue (H of each pixel. Saturation (S is computed using a loser-take-all circuit. Intensity (I is given by the sum of the color components. A histogram of the segments of the image, constructed by counting the number of pixels falling into 36 Hue intervals of 10 degrees, is stored on a chip and compared against the histograms of new segments using SAD comparisons. We demonstrate color-based image segmentation and object recognition with this chip. Running at 30 fps, it uses 1 mW. To our knowledge, this is the first chip that integrates imaging, color segmentation, and color-based object recognition at the focal plane.

  1. Multispectral Imaging of Meat Quality - Color and Texture

    DEFF Research Database (Denmark)

    Trinderup, Camilla Himmelstrup

    transformations to the CIELAB color space, the common color space within food science. The results show that meat color assessment with a multispectral imaging is a great alternative to the traditional colorimeter, i.e. the vision system meets some of the limitations that the colorimeter possesses. To mention one...

  2. Encyclopedia of color science and technology

    CERN Document Server

    2016-01-01

    The Encyclopedia of Color Science and Technology provides an authoritative single source for understanding and applying the concepts of color to all fields of science and technology, including artistic and historical aspects of color. Many topics are discussed in this timely reference, including an introduction to the science of color, and entries on the physics, chemistry and perception of color. Color is described as it relates to optical phenomena of color and continues on through colorants and materials used to modulate color and also to human vision of color. The measurement of color is provided as is colorimetry, color spaces, color difference metrics, color appearance models, color order systems and cognitive color. Other topics discussed include industrial color, color imaging, capturing color, displaying color and printing color. Descriptions of color encodings, color management, processing color and applications relating to color synthesis for computer graphics are included in this work. The Encyclo...

  3. INVIS : Integrated night vision surveillance and observation system

    NARCIS (Netherlands)

    Toet, A.; Hogervorst, M.A.; Dijk, J.; Son, R. van

    2010-01-01

    We present the design and first field trial results of the all-day all-weather INVIS Integrated Night Vision surveillance and observation System. The INVIS augments a dynamic three-band false-color nightvision image with synthetic 3D imagery in a real-time display. The night vision sensor suite

  4. Consistency of color representation in smart phones.

    Science.gov (United States)

    Dain, Stephen J; Kwan, Benjamin; Wong, Leslie

    2016-03-01

    One of the barriers to the construction of consistent computer-based color vision tests has been the variety of monitors and computers. Consistency of color on a variety of screens has necessitated calibration of each setup individually. Color vision examination with a carefully controlled display has, as a consequence, been a laboratory rather than a clinical activity. Inevitably, smart phones have become a vehicle for color vision tests. They have the advantage that the processor and screen are associated and there are fewer models of smart phones than permutations of computers and monitors. Colorimetric consistency of display within a model may be a given. It may extend across models from the same manufacturer but is unlikely to extend between manufacturers especially where technologies vary. In this study, we measured the same set of colors in a JPEG file displayed on 11 samples of each of four models of smart phone (iPhone 4s, iPhone5, Samsung Galaxy S3, and Samsung Galaxy S4) using a Photo Research PR-730. The iPhones are white LED backlit LCD and the Samsung are OLEDs. The color gamut varies between models and comparison with sRGB space shows 61%, 85%, 117%, and 110%, respectively. The iPhones differ markedly from the Samsungs and from one another. This indicates that model-specific color lookup tables will be needed. Within each model, the primaries were quite consistent (despite the age of phone varying within each sample). The worst case in each model was the blue primary; the 95th percentile limits in the v' coordinate were ±0.008 for the iPhone 4 and ±0.004 for the other three models. The u'v' variation in white points was ±0.004 for the iPhone4 and ±0.002 for the others, although the spread of white points between models was u'v'±0.007. The differences are essentially the same for primaries at low luminance. The variation of colors intermediate between the primaries (e.g., red-purple, orange) mirror the variation in the primaries. The variation in

  5. Color indirect effects on melatonin regulation

    Science.gov (United States)

    Mian, Tian; Liu, Timon C.; Li, Yan

    2002-04-01

    Color indirect effect (CIE) is referred to as the physiological and psychological effects of color resulting from color vision. In previous papers, we have studied CIE from the viewpoints of the integrated western and Chinese traditional medicine, put forward the color-autonomic- nervous-subsystem model (CAM), and provided its time-theory foundation. In this paper, we applied it to study light effects on melatonin regulation in humans, and suggested that it is CIE that mediates light effects on melatonin suppression.

  6. Long-term occupational exposure to organic solvents affects color vision, contrast sensitivity and visual fields.

    Directory of Open Access Journals (Sweden)

    Thiago Leiros Costa

    Full Text Available The purpose of this study was to evaluate the visual outcome of chronic occupational exposure to a mixture of organic solvents by measuring color discrimination, achromatic contrast sensitivity and visual fields in a group of gas station workers. We tested 25 workers (20 males and 25 controls with no history of chronic exposure to solvents (10 males. All participants had normal ophthalmologic exams. Subjects had worked in gas stations on an average of 9.6 ± 6.2 years. Color vision was evaluated with the Lanthony D15d and Cambridge Colour Test (CCT. Visual field assessment consisted of white-on-white 24-2 automatic perimetry (Humphrey II-750i. Contrast sensitivity was measured for sinusoidal gratings of 0.2, 0.5, 1.0, 2.0, 5.0, 10.0 and 20.0 cycles per degree (cpd. Results from both groups were compared using the Mann-Whitney U test. The number of errors in the D15d was higher for workers relative to controls (p<0.01. Their CCT color discrimination thresholds were elevated compared to the control group along the protan, deutan and tritan confusion axes (p<0.01, and their ellipse area and ellipticity were higher (p<0.01. Genetic analysis of subjects with very elevated color discrimination thresholds excluded congenital causes for the visual losses. Automated perimetry thresholds showed elevation in the 9°, 15° and 21° of eccentricity (p<0.01 and in MD and PSD indexes (p<0.01. Contrast sensitivity losses were found for all spatial frequencies measured (p<0.01 except for 0.5 cpd. Significant correlation was found between previous working years and deutan axis thresholds (rho = 0.59; p<0.05, indexes of the Lanthony D15d (rho=0.52; p<0.05, perimetry results in the fovea (rho= -0.51; p<0.05 and at 3, 9 and 15 degrees of eccentricity (rho= -0.46; p<0.05. Extensive and diffuse visual changes were found, suggesting that specific occupational limits should be created.

  7. Combining fine texture and coarse color features for color texture classification

    Science.gov (United States)

    Wang, Junmin; Fan, Yangyu; Li, Ning

    2017-11-01

    Color texture classification plays an important role in computer vision applications because texture and color are two fundamental visual features. To classify the color texture via extracting discriminative color texture features in real time, we present an approach of combining the fine texture and coarse color features for color texture classification. First, the input image is transformed from RGB to HSV color space to separate texture and color information. Second, the scale-selective completed local binary count (CLBC) algorithm is introduced to extract the fine texture feature from the V component in HSV color space. Third, both H and S components are quantized at an optimal coarse level. Furthermore, the joint histogram of H and S components is calculated, which is considered as the coarse color feature. Finally, the fine texture and coarse color features are combined as the final descriptor and the nearest subspace classifier is used for classification. Experimental results on CUReT, KTH-TIPS, and New-BarkTex databases demonstrate that the proposed method achieves state-of-the-art classification performance. Moreover, the proposed method is fast enough for real-time applications.

  8. Eficiência dos testes cromáticos de comparação na discromatopsia hereditária: relato de casos Efficiency of color vision tests in hereditary dyschromatopsia: case report

    Directory of Open Access Journals (Sweden)

    Luciene Chaves Fernandes

    2008-08-01

    Full Text Available As autoras relatam dois casos de discromatopsia hereditária e discutem a eficiência dos testes cromáticos no diagnóstico de uma discromatopsia. Os pacientes foram reprovados em diferentes concursos públicos federais por apresentarem diagnóstico de discromatopsia hereditária pelo teste de Ishihara. Submeteram-se a exame oftalmológico, com resultados dentro da normalidade. Procuraram novo parecer para melhor caracterização da sua discromatopsia. Não havia sintomas relacionados à deficiência. Os testes Panel D15 simples, D28 de Roth mostraram-se normais e o D15 dessaturado confirmou deutanomalia no caso 1. No segundo caso os testes de comparação mostraram alterações sem significado cromático. O diagnóstico de uma discromatopsia é muito complexo. As autoras destacam a importância de realização de testes de visão cromática complementares ao teste de Ishihara para diagnóstico de uma discromatopsia.The authors describe two cases of hereditary dyschromatopsia and discuss the efficiency of the color vision tests. The patients were disapproved in different federal public examinations because Ishihara's test diagnosed hereditary dyschromatopsia. Ophthalmological evaluation was normal. No symptoms related to dyschromatopsia were presented. Panels D15 and Roth D 28 were normal. Desaturated D 15 showed deuteranomaly in case one. In the second case the comparative color vision tests showed nonspecific disorder. The diagnosis of dyschromatopsia is complex. The authors recommend comparative color vision tests to complement the Ishihara test for a better understanding of the color deficiency.

  9. Machine Vision System for Color Sorting Wood Edge-Glued Panel Parts

    Science.gov (United States)

    Qiang Lu; S. Srikanteswara; W. King; T. Drayer; Richard Conners; D. Earl Kline; Philip A. Araman

    1997-01-01

    This paper describes an automatic color sorting system for hardwood edge-glued panel parts. The color sorting system simultaneously examines both faces of a panel part and then determines which face has the "better" color given specified color uniformity and priority defined by management. The real-time color sorting system software and hardware are briefly...

  10. Effect of interface voids on electroluminescence colors for ZnO microdisk/p-GaN heterojunction light-emitting diodes

    Science.gov (United States)

    Mo, Ran; Choi, Ji Eun; Kim, Hyeong Jin; Jeong, Junseok; Kim, Jong Chan; Kim, Yong-Jin; Jeong, Hu Young; Hong, Young Joon

    2017-10-01

    This study investigates the influence of voids on the electroluminescence (EL) emission color of ZnO microdisk/p-GaN heterojunction light-emitting diodes (LEDs). For this study, position-controlled microdisk arrays were fabricated on patterned p-GaN via wet chemical epitaxy of ZnO, and specifically, the use of trisodium citrate dihydrate (TCD) yielded high-density voids at the bottom of the microdisk. Greenish yellow or whitish blue EL was emitted from the microdisk LEDs formed with or without TCD, respectively, at reverse-bias voltages. Such different EL colors were found to be responsible for the relative EL intensity ratio between indigo and yellow emission peaks, which were originated from radiative recombination at p-GaN and ZnO, respectively. The relative EL intensity between dichromatic emissions is discussed in terms of (i) junction edge effect provoked by interfacial voids and (ii) electron tunneling probability depending on the depletion layer geometry.

  11. Impact of Congenital Color Vision Defect on Color‑related Tasks ...

    African Journals Online (AJOL)

    Table 1]. In activities of daily .... Watching sports because of color of team jersey. 1628 (99.6). 2 (0.1). 2 (0.1). 1 (0.1). 2 (0.1). 1635 (100) .... difficulty with selecting colors of clothes, identifying colors in sports, workplace, hobbies, and road signals.

  12. Cross-orientation masking in human color vision: application of a two-stage model to assess dichoptic and monocular sources of suppression.

    Science.gov (United States)

    Kim, Yeon Jin; Gheiratmand, Mina; Mullen, Kathy T

    2013-05-28

    Cross-orientation masking (XOM) occurs when the detection of a test grating is masked by a superimposed grating at an orthogonal orientation, and is thought to reveal the suppressive effects mediating contrast normalization. Medina and Mullen (2009) reported that XOM was greater for chromatic than achromatic stimuli at equivalent spatial and temporal frequencies. Here we address whether the greater suppression found in binocular color vision originates from a monocular or interocular site, or both. We measure monocular and dichoptic masking functions for red-green color contrast and achromatic contrast at three different spatial frequencies (0.375, 0.75, and 1.5 cpd, 2 Hz). We fit these functions with a modified two-stage masking model (Meese & Baker, 2009) to extract the monocular and interocular weights of suppression. We find that the weight of monocular suppression is significantly higher for color than achromatic contrast, whereas dichoptic suppression is similar for both. These effects are invariant across spatial frequency. We then apply the model to the binocular masking data using the measured values of the monocular and interocular sources of suppression and show that these are sufficient to account for color binocular masking. We conclude that the greater strength of chromatic XOM has a monocular origin that transfers through to the binocular site.

  13. A robust embedded vision system feasible white balance algorithm

    Science.gov (United States)

    Wang, Yuan; Yu, Feihong

    2018-01-01

    White balance is a very important part of the color image processing pipeline. In order to meet the need of efficiency and accuracy in embedded machine vision processing system, an efficient and robust white balance algorithm combining several classical ones is proposed. The proposed algorithm mainly has three parts. Firstly, in order to guarantee higher efficiency, an initial parameter calculated from the statistics of R, G and B components from raw data is used to initialize the following iterative method. After that, the bilinear interpolation algorithm is utilized to implement demosaicing procedure. Finally, an adaptive step adjustable scheme is introduced to ensure the controllability and robustness of the algorithm. In order to verify the proposed algorithm's performance on embedded vision system, a smart camera based on IMX6 DualLite, IMX291 and XC6130 is designed. Extensive experiments on a large amount of images under different color temperatures and exposure conditions illustrate that the proposed white balance algorithm avoids color deviation problem effectively, achieves a good balance between efficiency and quality, and is suitable for embedded machine vision processing system.

  14. A Sensitive Dynamic and Active Pixel Vision Sensor for Color or Neural Imaging Applications.

    Science.gov (United States)

    Moeys, Diederik Paul; Corradi, Federico; Li, Chenghan; Bamford, Simeon A; Longinotti, Luca; Voigt, Fabian F; Berry, Stewart; Taverni, Gemma; Helmchen, Fritjof; Delbruck, Tobi

    2018-02-01

    Applications requiring detection of small visual contrast require high sensitivity. Event cameras can provide higher dynamic range (DR) and reduce data rate and latency, but most existing event cameras have limited sensitivity. This paper presents the results of a 180-nm Towerjazz CIS process vision sensor called SDAVIS192. It outputs temporal contrast dynamic vision sensor (DVS) events and conventional active pixel sensor frames. The SDAVIS192 improves on previous DAVIS sensors with higher sensitivity for temporal contrast. The temporal contrast thresholds can be set down to 1% for negative changes in logarithmic intensity (OFF events) and down to 3.5% for positive changes (ON events). The achievement is possible through the adoption of an in-pixel preamplification stage. This preamplifier reduces the effective intrascene DR of the sensor (70 dB for OFF and 50 dB for ON), but an automated operating region control allows up to at least 110-dB DR for OFF events. A second contribution of this paper is the development of characterization methodology for measuring DVS event detection thresholds by incorporating a measure of signal-to-noise ratio (SNR). At average SNR of 30 dB, the DVS temporal contrast threshold fixed pattern noise is measured to be 0.3%-0.8% temporal contrast. Results comparing monochrome and RGBW color filter array DVS events are presented. The higher sensitivity of SDAVIS192 make this sensor potentially useful for calcium imaging, as shown in a recording from cultured neurons expressing calcium sensitive green fluorescent protein GCaMP6f.

  15. DLP™-based dichoptic vision test system

    Science.gov (United States)

    Woods, Russell L.; Apfelbaum, Henry L.; Peli, Eli

    2010-01-01

    It can be useful to present a different image to each of the two eyes while they cooperatively view the world. Such dichoptic presentation can occur in investigations of stereoscopic and binocular vision (e.g., strabismus, amblyopia) and vision rehabilitation in clinical and research settings. Various techniques have been used to construct dichoptic displays. The most common and most flexible modern technique uses liquid-crystal (LC) shutters. When used in combination with cathode ray tube (CRT) displays, there is often leakage of light from the image intended for one eye into the view of the other eye. Such interocular crosstalk is 14% even in our state of the art CRT-based dichoptic system. While such crosstalk may have minimal impact on stereo movie or video game experiences, it can defeat clinical and research investigations. We use micromirror digital light processing (DLP™) technology to create a novel dichoptic visual display system with substantially lower interocular crosstalk (0.3% remaining crosstalk comes from the LC shutters). The DLP system normally uses a color wheel to display color images. Our approach is to disable the color wheel, synchronize the display directly to the computer's sync signal, allocate each of the three (former) color presentations to one or both eyes, and open and close the LC shutters in synchrony with those color events.

  16. Development and clinical application of a color pediatric visual acuity chart

    Directory of Open Access Journals (Sweden)

    Shu-Guo Yin

    2014-12-01

    Full Text Available AIM: To introduce a new color pediatric visual acuity chart and its clinical application.METHODS:The color pediatric visual acuity chart was designed based on principle of visual angle. The optotype on the color chart had graphics. The progression rate of optotype size between 2 lines was 10(101/2 and 1.2589. A regular geometric progression of optotype sizes and distribution was employed to arrange 8 lines with 11 optotype on the color chart. The testing distance was 3m. The visual acuity score could be recorded as logarithm of the minimum angle of resolution notation or decimal notation. The reliability of naked distant measurements with this new chart was tested in one eye of 100 children(4 ~6 years oldtaking the Chinese national standard logarithm visual acuity chart standard. RESULTS: The color pediatric visual acuity chart and logarithmic chart controls, visual acuity test results that in the two groups had no significant difference(t=1.2671, P>0.05. Two sets of vision data existed positive correlation(r=0.924, PCONCLUSION:Children are easier to accept used new color pediatric visual acuity chart to inspect vision. New chart is reliability and apply to children's vision screening.

  17. Reduced Discrimination in the Tritanopic Confusion Line for Congenital Color Deficiency Adults.

    Science.gov (United States)

    Costa, Marcelo F; Goulart, Paulo R K; Barboni, Mirella T S; Ventura, Dora F

    2016-01-01

    In congenital color blindness the red-green discrimination is impaired resulting in an increased confusion between those colors with yellow. Our post-receptoral physiological mechanisms are organized in two pathways for color perception, a red-green (protanopic and deuteranopic) and a blue-yellow (tritanopic). We argue that the discrimination losses in the yellow area in congenital color vision deficiency subjects could generate a subtle loss of discriminability in the tritanopic channel considering discrepancies with yellow perception. We measured color discrimination thresholds for blue and yellow of tritanopic channel in congenital color deficiency subjects. Chromaticity thresholds were measured around a white background (0.1977 u', 0.4689 v' in the CIE 1976) consisting of a blue-white and white-yellow thresholds in a tritanopic color confusion line of 21 congenital colorblindness subjects (mean age = 27.7; SD = 5.6 years; 14 deuteranomalous and 7 protanomalous) and of 82 (mean age = 25.1; SD = 3.7 years) normal color vision subjects. Significant increase in the whole tritanopic axis was found for both deuteranomalous and protanomalous subjects compared to controls for the blue-white (F 2,100 = 18.80; p color confusion axis is significantly reduced in congenital color vision deficiency compared to normal subjects. Since yellow discrimination was impaired the balance of the blue-yellow channels is impaired justifying the increased thresholds found for blue-white discrimination. The weighting toward the yellow region of the color space with the deuteranomalous contributing to that perceptual distortion is discussed in terms of physiological mechanisms.

  18. Soft Computing Techniques in Vision Science

    CERN Document Server

    Yang, Yeon-Mo

    2012-01-01

    This Special Edited Volume is a unique approach towards Computational solution for the upcoming field of study called Vision Science. From a scientific firmament Optics, Ophthalmology, and Optical Science has surpassed an Odyssey of optimizing configurations of Optical systems, Surveillance Cameras and other Nano optical devices with the metaphor of Nano Science and Technology. Still these systems are falling short of its computational aspect to achieve the pinnacle of human vision system. In this edited volume much attention has been given to address the coupling issues Computational Science and Vision Studies.  It is a comprehensive collection of research works addressing various related areas of Vision Science like Visual Perception and Visual system, Cognitive Psychology, Neuroscience, Psychophysics and Ophthalmology, linguistic relativity, color vision etc. This issue carries some latest developments in the form of research articles and presentations. The volume is rich of contents with technical tools ...

  19. Broiler skin and meat color changes during storage.

    Science.gov (United States)

    Petracci, M; Fletcher, D L

    2002-10-01

    The importance of poultry skin and meat color (both absolute and variations in color) in the market place have been well established. It has also been reported that these colors change over time. With the development of computer-assisted vision grading systems, the changes in skin and meat color during and after processing have become important, based on calibrations and assessment values based on color. Four independent experiments were conducted to determine the pattern of color change in broiler skin and meat during processing and storage. Skin color change was measured on subscald (57 C) and semiscald (50 C) breast skin surfaces and on breast and leg meat, on the carcass and following deboning and packaging. A reflectance colorimeter was used to determine lightness (L*), redness (a*), and yellowness (b*) at 20-min intervals for the first 3 h, at 30-min intervals between 3 and 8 h, hourly between 8 and 12 h, and daily up to 8 d postmortem. Results clearly show that color values for both skin and meat changed dramatically for the first 6 h postmortem, after which the changes were less pronounced. The skin from semiscalded birds showed less change than the skin from subscalded birds. These results indicate that on-line vision systems need to take into account the dramatic changes in skin and meat color during the first 6 h postmortem, after which the color changes may be less important.

  20. Compensation for longitudinal chromatic aberration in the eye of the firefly squid, Watasenia scintillans.

    Science.gov (United States)

    Kröger, Ronald H H; Gislén, Anna

    2004-01-01

    The camera eyes of fishes and cephalopods have come forth by convergent evolution. In a variety of vertebrates capable of color vision, longitudinal chromatic aberration (LCA) of the optical system is corrected for by the exactly tuned longitudinal spherical aberration (LSA) of the crystalline lens. The LSA leads to multiple focal lengths, such that several wavelengths can be focused on the retina. We investigated whether that is also the case in the firefly squid (Watasenia scintillans), a cephalopod species that is likely to have color vision. It was found that the lens of W. scintillans is virtually free of LSA and uncorrected for LCA. However, the eye does not suffer from LCA because of a banked retina. Photoreceptors sensitive to short and long wavelengths are located at appropriate distances from the lens, such that they receive well-focused images. Such a design is an excellent solution for the firefly squid because a large area of the retina is monochromatically organized and it allows for double use of the surface area in the dichromatically organized part of the retina. However, it is not a universal solution since compensation for LCA by a banked retina requires that eye size and/or spectral separation between photopigments is small.

  1. Fuzzy-based simulation of real color blindness.

    Science.gov (United States)

    Lee, Jinmi; dos Santos, Wellington P

    2010-01-01

    About 8% of men are affected by color blindness. That population is at a disadvantage since they cannot perceive a substantial amount of the visual information. This work presents two computational tools developed to assist color blind people. The first one tests color blindness and assess its severity. The second tool is based on Fuzzy Logic, and implements a method proposed to simulate real red and green color blindness in order to generate synthetic cases of color vision disturbance in a statistically significant amount. Our purpose is to develop correction tools and obtain a deeper understanding of the accessibility problems faced by people with chromatic visual impairment.

  2. A multi-stage color model revisited: implications for a gene therapy cure for red-green colorblindness.

    Science.gov (United States)

    Mancuso, Katherine; Mauck, Matthew C; Kuchenbecker, James A; Neitz, Maureen; Neitz, Jay

    2010-01-01

    In 1993, DeValois and DeValois proposed a 'multi-stage color model' to explain how the cortex is ultimately able to deconfound the responses of neurons receiving input from three cone types in order to produce separate red-green and blue-yellow systems, as well as segregate luminance percepts (black-white) from color. This model extended the biological implementation of Hurvich and Jameson's Opponent-Process Theory of color vision, a two-stage model encompassing the three cone types combined in a later opponent organization, which has been the accepted dogma in color vision. DeValois' model attempts to satisfy the long-remaining question of how the visual system separates luminance information from color, but what are the cellular mechanisms that establish the complicated neural wiring and higher-order operations required by the Multi-stage Model? During the last decade and a half, results from molecular biology have shed new light on the evolution of primate color vision, thus constraining the possibilities for the visual circuits. The evolutionary constraints allow for an extension of DeValois' model that is more explicit about the biology of color vision circuitry, and it predicts that human red-green colorblindness can be cured using a retinal gene therapy approach to add the missing photopigment, without any additional changes to the post-synaptic circuitry.

  3. Color discrimination impairment in workers exposed to mercury vapor.

    Science.gov (United States)

    Urban, Pavel; Gobba, Fabriziomaria; Nerudová, Jana; Lukás, Edgar; Cábelková, Zdena; Cikrt, Miroslav

    2003-08-01

    To study color discrimination impairment in workers exposed to elemental mercury (Hg) vapor. Twenty-four male workers from a chloralkali plant exposed to Hg vapor, aged 42+/-9.8 years, duration of exposure 14.7+/-9.7 years, were examined. The 8h TWA air-borne Hg concentration in workplace was 59 microg/m(3); mean Hg urinary excretion (HgU) was 20.5+/-19.3 microg/g creatinine; mean Hg urinary excretion after the administration of a chelating agent, sodium 2,3-dimercapto-1-propane-sulfonate (DMPS), was 751.9+/-648 microg/48h. Twenty-four age- and gender-matched control subjects were compared. Visual acuity, alcohol intake, smoking habits, and history of diseases or drugs potentially influencing color vision were registered. The Lanthony 15-Hue desaturated test (L-D15-d) was used to assess color vision. The results were expressed quantitatively as Bowman's Color Confusion Index (CCI), and qualitatively according to Verriest's classification of acquired dyschromatopsias. The CCI was significantly higher in the exposed group than in the control (mean CCI 1.15 versus 1.04; P=0.04). The proportion of subjects with errorless performance on the Lanthony test was significantly lower in the Hg exposed group compared to referents (52% versus 73%; P=0.035). The exposed group showed higher frequency of type III dyschromatopsias (blue-yellow confusion axis) in comparison with the control group (12.5% versus 8.3%), however, the difference did not reach statistical significance. Multiple regression did not show any significant relationship between the CCI, and age, alcohol consumption, or measures of exposure. In agreement with previous studies by Cavalleri et al. [Toxicol. Lett. 77 (1995) 351; Environ. Res. Sec. A 77 (1998) 173], the results of this study support the hypothesis that exposure to mercury vapor can induce sub-clinical color vision impairment. This effect was observed at an exposure level below the current biological limit for occupational exposure to mercury. This

  4. Human V4 Activity Patterns Predict Behavioral Performance in Imagery of Object Color.

    Science.gov (United States)

    Bannert, Michael M; Bartels, Andreas

    2018-04-11

    Color is special among basic visual features in that it can form a defining part of objects that are engrained in our memory. Whereas most neuroimaging research on human color vision has focused on responses related to external stimulation, the present study investigated how sensory-driven color vision is linked to subjective color perception induced by object imagery. We recorded fMRI activity in male and female volunteers during viewing of abstract color stimuli that were red, green, or yellow in half of the runs. In the other half we asked them to produce mental images of colored, meaningful objects (such as tomato, grapes, banana) corresponding to the same three color categories. Although physically presented color could be decoded from all retinotopically mapped visual areas, only hV4 allowed predicting colors of imagined objects when classifiers were trained on responses to physical colors. Importantly, only neural signal in hV4 was predictive of behavioral performance in the color judgment task on a trial-by-trial basis. The commonality between neural representations of sensory-driven and imagined object color and the behavioral link to neural representations in hV4 identifies area hV4 as a perceptual hub linking externally triggered color vision with color in self-generated object imagery. SIGNIFICANCE STATEMENT Humans experience color not only when visually exploring the outside world, but also in the absence of visual input, for example when remembering, dreaming, and during imagery. It is not known where neural codes for sensory-driven and internally generated hue converge. In the current study we evoked matching subjective color percepts, one driven by physically presented color stimuli, the other by internally generated color imagery. This allowed us to identify area hV4 as the only site where neural codes of corresponding subjective color perception converged regardless of its origin. Color codes in hV4 also predicted behavioral performance in an

  5. Cross-media color reproduction using the frequency-based spatial gamut mapping algorithm based on human color vision

    Science.gov (United States)

    Wu, Guangyuan; Niu, Shijun; Li, Xiaozhou; Hu, Guichun

    2018-04-01

    Due to the increasing globalization of printing industry, remoting proofing will become the inevitable development trend. Cross-media color reproduction will occur in different color gamuts using remote proofing technologies, which usually leads to the problem of incompatible color gamut. In this paper, to achieve equivalent color reproduction between a monitor and a printer, a frequency-based spatial gamut mapping algorithm is proposed for decreasing the loss of visual color information. The design of algorithm is based on the contrast sensitivity functions (CSF), which exploited CSF spatial filter to preserve luminance of the high spatial frequencies and chrominance of the low frequencies. First we show a general framework for how to apply CSF spatial filter in retention of relevant visual information. Then we compare the proposed framework with HPMINDE, CUSP, Bala's algorithm. The psychophysical experimental results indicated the good performance of the proposed algorithm.

  6. Quality Parameters of Six Cultivars of Blueberry Using Computer Vision

    Directory of Open Access Journals (Sweden)

    Silvia Matiacevich

    2013-01-01

    Full Text Available Background. Blueberries are considered an important source of health benefits. This work studied six blueberry cultivars: “Duke,” “Brigitta”, “Elliott”, “Centurion”, “Star,” and “Jewel”, measuring quality parameters such as °Brix, pH, moisture content using standard techniques and shape, color, and fungal presence obtained by computer vision. The storage conditions were time (0–21 days, temperature (4 and 15°C, and relative humidity (75 and 90%. Results. Significant differences (P<0.05 were detected between fresh cultivars in pH, °Brix, shape, and color. However, the main parameters which changed depending on storage conditions, increasing at higher temperature, were color (from blue to red and fungal presence (from 0 to 15%, both detected using computer vision, which is important to determine a shelf life of 14 days for all cultivars. Similar behavior during storage was obtained for all cultivars. Conclusion. Computer vision proved to be a reliable and simple method to objectively determine blueberry decay during storage that can be used as an alternative approach to currently used subjective measurements.

  7. Using color and grayscale images to teach histology to color-deficient medical students.

    Science.gov (United States)

    Rubin, Lindsay R; Lackey, Wendy L; Kennedy, Frances A; Stephenson, Robert B

    2009-01-01

    Examination of histologic and histopathologic microscopic sections relies upon differential colors provided by staining techniques, such as hematoxylin and eosin, to delineate normal tissue components and to identify pathologic alterations in these components. Given the prevalence of color deficiency (commonly called "color blindness") in the general population, it is likely that this reliance upon color differentiation poses a significant obstacle for several medical students beginning a course of study that includes examination of histologic slides. In the past, first-year medical students at Michigan State University who identified themselves as color deficient were encouraged to use color transparency overlays or tinted contact lenses to filter out problematic colors. Recently, however, we have offered such students a computer monitor adjusted to grayscale for in-lab work, as well as grayscale copies of color photomicrographs for examination purposes. Grayscale images emphasize the texture of tissues and the contrasts between tissues as the students learn histologic architecture. Using this approach, color-deficient students have quickly learned to compensate for their deficiency by focusing on cell and tissue structure rather than on color variation. Based upon our experience with color-deficient students, we believe that grayscale photomicrographs may also prove instructional for students with normal (trichromatic) color vision, by encouraging them to consider structural characteristics of cells and tissues that may otherwise be overshadowed by stain colors.

  8. Role of vision and mechanoreception in bed bug, Cimex lectularius L. behavior.

    Directory of Open Access Journals (Sweden)

    Narinderpal Singh

    Full Text Available The role of olfactory cues such as carbon dioxide, pheromones, and kairomones in bed bug, Cimex lectularius L. behavior has been demonstrated. However, the role of vision and mechanoreception in bed bug behavior is poorly understood. We investigated bed bug vision by determining their responses to different colors, vertical objects, and their ability to detect colors and vertical objects under low and complete dark conditions. Results show black and red paper harborages are preferred compared to yellow, green, blue, and white harborages. A bed bug trapping device with a black or red exterior surface was significantly more attractive to bed bugs than that with a white exterior surface. Bed bugs exhibited strong orientation behavior toward vertical objects. The height (15 vs. 30 cm tall and color (brown vs. black of the vertical object had no significant effect on orientation behavior of bed bugs. Bed bugs could differentiate color and detect vertical objects at very low background light conditions, but not in complete darkness. Bed bug preference to different substrate textures (mechanoreception was also explored. Bed bugs preferred dyed tape compared to painted tape, textured painted plastic, and felt. These results revealed that substrate color, presence of vertical objects, and substrate texture affect host-seeking and harborage-searching behavior of bed bugs. Bed bugs may use a combination of vision, mechanoreception, and chemoreception to locate hosts and seek harborages.

  9. Color constancy in Japanese animation

    Science.gov (United States)

    Ichihara, Yasuyo G.

    2006-01-01

    In this study, we measure the colors used in a Japanese Animations. The result can be seen on CIE-xy color spaces. It clearly shows that the color system is not a natural appearance system but an imagined and artistic appearance system. Color constancy of human vision can tell the difference in skin and hair colors between under moonlight and day light. Human brain generates a match to the memorized color of an object from daylight viewing conditions to the color of the object in different viewing conditions. For example, Japanese people always perceive the color of the Rising Sun in the Japanese flag as red even in a different viewing condition such as under moonlight. Color images captured by a camera cannot present those human perceptions. However, Japanese colorists in Animation succeeded in painting the effects of color constancy not only under moonlight but also added the memory matching colors. They aim to create a greater impact on viewer's perceptions by using the effect of the memory matching colors. In this paper, we propose the Imagined Japanese Animation Color System. This system in art is currently a subject of research in Japan. Its importance is that it could also provide an explanation on how human brain perceives the same color under different viewing conditions.

  10. Interference generalized cross-section for the multiphoton detachment of H- in dichromatic fields

    International Nuclear Information System (INIS)

    Mercouris, Theodoros; Haritos, Costas; Nicolaides, Cleanthes A

    2005-01-01

    The paper reports results from the application of the many-electron, many-photon theory on the system 'H - 1s 2 1 S state plus two fields of weak strengths, F 1 and F 2 '. The two fields have commensurate frequencies (ω, 2ω) and (ω, 3ω), with ω ranging from 0.011 au to 0.028 au, field strengths from 5 x 10 -5 au to 1.7 x 10 -3 au and a phase difference ψ. It is possible to determine the regime where the dichromatic field is weak and to define and compute a corresponding 'interference generalized cross-section'. This cross-section is an intrinsic property of each state as a function of the pair (ω, mω), m = 2, 3,.... Its knowledge is directly relevant to deciding on the degree of effectiveness of coherent quantum control. The calculations show that, with respect to ψ, H - is more receptive to control if frequencies are low. The computed effects are large enough so as to be measurable

  11. Reduced Discrimination in the Tritanopic Confusion Line for Congenital Color Deficiency Adults

    Directory of Open Access Journals (Sweden)

    Marcelo Fernandes Costa

    2016-03-01

    Full Text Available In congenital color blindness the red-green discrimination is impaired resulting in an increased confusion between those colors with yellow. Our post-receptoral physiological mechanisms are organized in two pathways for color perception, a red-green (protanopic and deuteranopic and a blue-yellow (tritanopic. We argue that the discrimination losses in the yellow area in congenital color vision deficiency subjects could generate a subtle loss of discriminability in the tritanopic channel considering discrepancies with yellow perception. We measured color discrimination thresholds for blue and yellow of tritanopic channel in congenital color deficiency subjects. Chromaticity thresholds were measured around a white background (0.1977 u’, 0.4689 v’ in the CIE 1976 consisting of a blue-white and white-yellow thresholds in a tritanopic color confusion line of 21 congenital colorblindness subjects (mean age = 27.7; SD= 5.6 years; 14 deuteranomalous and 7 protanomalous and of 82 (mean age = 25.1; SD= 3.7 years normal color vision subjects. Significant increase in the whole tritanopic axis was found for both deuteranomalous and protanomalous subjects compared to controls for the blue-white (F2,100= 18.80; p< 0.0001 and white-yellow (F2,100= 22.10; p< 0.0001 thresholds. A Principal Component Analysis found a weighting toward to the yellow thresholds induced by deuteranomalous subjects. In conclusion, the discrimination in the tritanopic color confusion axis is significantly reduced in congenital color vision deficiency compared to normal subjects. Since yellow discrimination was impaired the balance of the blue-yellow channels is impaired justifying the increased thresholds found for blue-white discrimination. The weighting toward the yellow region of the color space with the deuteranomalous contributing to that perceptual distortion is discussed in terms of physiological mechanisms.

  12. The fabrication of a multi-spectral lens array and its application in assisting color blindness

    Science.gov (United States)

    Di, Si; Jin, Jian; Tang, Guanrong; Chen, Xianshuai; Du, Ruxu

    2016-01-01

    This article presents a compact multi-spectral lens array and describes its application in assisting color-blindness. The lens array consists of 9 microlens, and each microlens is coated with a different color filter. Thus, it can capture different light bands, including red, orange, yellow, green, cyan, blue, violet, near-infrared, and the entire visible band. First, the fabrication process is described in detail. Second, an imaging system is setup and a color blindness testing card is selected as the sample. By the system, the vision results of normal people and color blindness can be captured simultaneously. Based on the imaging results, it is possible to be used for helping color-blindness to recover normal vision.

  13. Color Space and Its Divisions: Color Order from Antiquity to the Present

    Science.gov (United States)

    Kuehni, Rolf G.

    2003-03-01

    It has been postulated that humans can differentiate between millions of gradations in color. Not surprisingly, no completely adequate, detailed catalog of colors has yet been devised, however the quest to understand, record, and depict color is as old as the quest to understand the fundamentals of the physical world and the nature of human consciousness. Rolf Kuehni's Color Space and Its Divisions: Color Order from Antiquity to the Present represents an ambitious and unprecedented history of man's inquiry into color order, focusing on the practical applications of the most contemporary developments in the field. Kuehni devotes much of his study to geometric, three-dimensional arrangements of color experiences, a type of system developed only in the mid-nineteenth century. Color spaces are of particular interest for color quality-control purposes in the manufacturing and graphics industries. The author analyzes three major color order systems in detail: Munsell, OSA-UCS, and NCS. He presents historical and current information on color space developments in color vision, psychology, psychophysics, and color technology. Chapter topics include: A historical account of color order systems Fundamentals of psychophysics and the relationship between stimuli and experience Results of perceptual scaling of colors according to attributes History of the development of mathematical color space and difference formulas Analysis of the agreements and discrepancies in psychophysical data describing color differences An experimental plan for the reliable, replicated perceptual data necessary to make progress in the field Experts in academia and industry, neuroscientists, designers, art historians, and anyone interested in the nature of color will find Color Space and Its Divisions to be the authoritative reference in its field.

  14. Scanner-based macroscopic color variation estimation

    Science.gov (United States)

    Kuo, Chunghui; Lai, Di; Zeise, Eric

    2006-01-01

    Flatbed scanners have been adopted successfully in the measurement of microscopic image artifacts, such as granularity and mottle, in print samples because of their capability of providing full color, high resolution images. Accurate macroscopic color measurement relies on the use of colorimeters or spectrophotometers to provide a surrogate for human vision. The very different color response characteristics of flatbed scanners from any standard colorimetric response limits the utility of a flatbed scanner as a macroscopic color measuring device. This metamerism constraint can be significantly relaxed if our objective is mainly to quantify the color variations within a printed page or between pages where a small bias in measured colors can be tolerated as long as the color distributions relative to the individual mean values is similar. Two scenarios when converting color from the device RGB color space to a standardized color space such as CIELab are studied in this paper, blind and semi-blind color transformation, depending on the availability of the black channel information. We will show that both approaches offer satisfactory results in quantifying macroscopic color variation across pages while the semi-blind color transformation further provides fairly accurate color prediction capability.

  15. Color features for quality control in ceramic tile industry

    Science.gov (United States)

    Kukkonen, Saku; Kaelviaeinen, Heikki; Parkkinen, Jussi P.

    2001-02-01

    We study visual quality control in the ceramics industry. In the manufacturing, it is important that in each set of tiles, every single tile looks similar. Currently, the estimation is usually done by human vision. Our goal is to design a machine vision system that can estimate the sufficient similarity, or same appearance, to the human eye. Our main approach is to use accurate spectral representation of color, and compare spectral features to the RGB color features. A laboratory system for color measurements is built. Experimentations with five classes of brown tiles are presented and discussed. In addition to the k-nearest neighbor (k-NN) classifier, a neural network called the self-organizing map (SOM) is used to provide understanding of the spectral features. Every single spectrum in each tile of a training set is used as input to a 2D SOM. The SOM is analyzed to understand how spectra are clustered. As a result, tiles are classified using a trained 2D SOM. It is also of interest to know whether the order of spectral colors can be determined. In our approach, all spectra are clustered in a 1D SOM, and each pixel spectrum) is presented by pseudocolors according to the trained nodes. Finally, the results are compared to experiments with human vision.

  16. The influence of active vision on the exoskeleton of intelligent agents

    Science.gov (United States)

    Smith, Patrice; Terry, Theodore B.

    2016-04-01

    Chameleonization occurs when a self-learning autonomous mobile system's (SLAMR) active vision scans the surface of which it is perched causing the exoskeleton to changes colors exhibiting a chameleon effect. Intelligent agents having the ability to adapt to their environment and exhibit key survivability characteristics of its environments would largely be due in part to the use of active vision. Active vision would allow the intelligent agent to scan its environment and adapt as needed in order to avoid detection. The SLAMR system would have an exoskeleton, which would change, based on the surface it was perched on; this is known as the "chameleon effect." Not in the common sense of the term, but from the techno-bio inspired meaning as addressed in our previous paper. Active vision, utilizing stereoscopic color sensing functionality would enable the intelligent agent to scan an object within its close proximity, determine the color scheme, and match it; allowing the agent to blend with its environment. Through the use of its' optical capabilities, the SLAMR system would be able to further determine its position, taking into account spatial and temporal correlation and spatial frequency content of neighboring structures further ensuring successful background blending. The complex visual tasks of identifying objects, using edge detection, image filtering, and feature extraction are essential for an intelligent agent to gain additional knowledge about its environmental surroundings.

  17. Drying and radial shrinkage characteristics and changes in color ...

    African Journals Online (AJOL)

    Drying and radial shrinkage characteristics and changes in color and shape of carrots tissues during air drying were studied. Slices dimensions were obtained by computer vision and the color was quantified by chroma, hue, whitening index and total carotenoids contents. The drying time became shorter of 1 h when ...

  18. 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

  19. On the purposes of color for living beings: toward a theory of color organization.

    Science.gov (United States)

    Pinna, Baingio; Reeves, Adam

    2015-01-01

    Phylogenetic and paleontological evidence indicates that in the animal kingdom the ability to perceive colors evolved independently several times over the course of millennia. This implies a high evolutionary neural investment and suggests that color vision provides some fundamental biological benefits. What are these benefits? Why are some animals so colorful? What are the adaptive and perceptual meanings of polychromatism? We suggest that in addition to the discrimination of light and surface chromaticity, sensitivity to color contributes to the whole, the parts and the fragments of perceptual organization. New versions of neon color spreading and the watercolor illusion indicate that the visual purpose of color in humans is threefold: to inter-relate each chromatic component of an object, thus favoring the emergence of the whole; to support a part-whole organization in which components reciprocally enhance each other by amodal completion; and, paradoxically, to reveal fragments and hide the whole-that is, there is a chromatic parceling-out process of separation, division, and fragmentation of the whole. The evolution of these contributions of color to organization needs to be established, but traces of it can be found in Harlequin camouflage by animals and in the coloration of flowers.

  20. Fabric Weave Pattern and Yarn Color Recognition and Classification Using a Deep ELM Network

    Directory of Open Access Journals (Sweden)

    Babar Khan

    2017-10-01

    Full Text Available Usually, a fabric weave pattern is recognized using methods which identify the warp floats and weft floats. Although these methods perform well for uniform or repetitive weave patterns, in the case of complex weave patterns, these methods become computationally complex and the classification error rates are comparatively higher. Furthermore, the fault-tolerance (invariance and stability (selectivity of the existing methods are still to be enhanced. We present a novel biologically-inspired method to invariantly recognize the fabric weave pattern (fabric texture and yarn color from the color image input. We proposed a model in which the fabric weave pattern descriptor is based on the HMAX model for computer vision inspired by the hierarchy in the visual cortex, the color descriptor is based on the opponent color channel inspired by the classical opponent color theory of human vision, and the classification stage is composed of a multi-layer (deep extreme learning machine. Since the weave pattern descriptor, yarn color descriptor, and the classification stage are all biologically inspired, we propose a method which is completely biologically plausible. The classification performance of the proposed algorithm indicates that the biologically-inspired computer-aided-vision models might provide accurate, fast, reliable and cost-effective solution to industrial automation.

  1. Newborns' Discrimination of Chromatic from Achromatic Stimuli.

    Science.gov (United States)

    Adams, Russell J.; And Others

    1986-01-01

    Two experiments assessed the extent of newborns' ability to discriminate color. Results imply that newborns have some, albeit limited, capacity to discriminate chromatic from achromatic stimuli, and hence, are at least dichromats. (Author/DR)

  2. Keeping Older Adults with Vision Loss Safe: Chronic Conditions and Comorbidities that Influence Functional Mobility

    Science.gov (United States)

    Riddering, Anne T.

    2008-01-01

    Age-related macular degeneration (AMD) is a leading cause of vision loss in Americans aged 60 and older. The loss of central vision from AMD can decrease visual acuity, contrast sensitivity, glare sensitivity, color discrimination, and the ability to adapt to changes in lighting conditions. Older adults with vision loss often have other chronic,…

  3. A Novel Mechanism for Color Vision: Pupil Shape and Chromatic Aberration Can Provide Spectral Discrimination for Color Blind Organisms.

    OpenAIRE

    Stubbs, Christopher; Stubbs, Alexander

    2015-01-01

    We present a mechanism by which organisms with only a single photoreceptor, that have a monochromatic view of the world, can achieve color discrimination. The combination of an off axis pupil and the principle of chromatic aberration (where light of different colors focus at different distances behind a lens) can combine to provide color-blind animals with a way to distinguish colors. As a specific example we constructed a computer model of the visual system of cephalopods, (octopus, squid, a...

  4. A Novel Mechanism for Color Vision: Pupil Shape and Chromatic Aberration Can Provide Spectral Discrimination for Color Blind Organisms.

    OpenAIRE

    Stubbs, Alexander L; Stubbs, Christopher William

    2016-01-01

    We present a mechanism by which organisms with only a single photoreceptor, that have a monochromatic view of the world, can achieve color discrimination. The combination of an off axis pupil and the principle of chromatic aberration (where light of different colors focus at different distances behind a lens) can combine to provide color-blind animals with a way to distinguish colors. As a specific example we constructed a computer model of the visual system of cephalopods, (octopus, squid, a...

  5. Biological origins of color categorization.

    Science.gov (United States)

    Skelton, Alice E; Catchpole, Gemma; Abbott, Joshua T; Bosten, Jenny M; Franklin, Anna

    2017-05-23

    The biological basis of the commonality in color lexicons across languages has been hotly debated for decades. Prior evidence that infants categorize color could provide support for the hypothesis that color categorization systems are not purely constructed by communication and culture. Here, we investigate the relationship between infants' categorization of color and the commonality across color lexicons, and the potential biological origin of infant color categories. We systematically mapped infants' categorical recognition memory for hue onto a stimulus array used previously to document the color lexicons of 110 nonindustrialized languages. Following familiarization to a given hue, infants' response to a novel hue indicated that their recognition memory parses the hue continuum into red, yellow, green, blue, and purple categories. Infants' categorical distinctions aligned with common distinctions in color lexicons and are organized around hues that are commonly central to lexical categories across languages. The boundaries between infants' categorical distinctions also aligned, relative to the adaptation point, with the cardinal axes that describe the early stages of color representation in retinogeniculate pathways, indicating that infant color categorization may be partly organized by biological mechanisms of color vision. The findings suggest that color categorization in language and thought is partially biologically constrained and have implications for broader debate on how biology, culture, and communication interact in human cognition.

  6. Color consilience: color through the lens of art practice, history, philosophy, and neuroscience.

    Science.gov (United States)

    Conway, Bevil R

    2012-03-01

    Paintings can be interpreted as the product of the complex neural machinery that translates physical light signals into behavior, experience, and emotion. The brain mechanisms responsible for vision and perception have been sculpted during evolution and further modified by cultural exposure and development. By closely examining artists' paintings and practices, we can discover hints to how the brain works, and achieve insight into the discoveries and inventions of artists and their impact on culture. Here, I focus on an integral aspect of color, color contrast, which poses a challenge for artists: a mark situated on an otherwise blank canvas will appear a different color in the context of the finished painting. How do artists account for this change in color during the production of a painting? In the broader context of neural and philosophical considerations of color, I discuss the practices of three modern masters, Henri Matisse, Paul Cézanne, and Claude Monet, and suggest that the strategies they developed not only capitalized on the neural mechanisms of color, but also influenced the trajectory of western art history. © 2012 New York Academy of Sciences.

  7. Ability of Bottle Cap Color to Facilitate Accurate Patient-Physician Communication Regarding Medication Identity in Patients with Glaucoma.

    Science.gov (United States)

    Dave, Pujan; Villarreal, Guadalupe; Friedman, David S; Kahook, Malik Y; Ramulu, Pradeep Y

    2015-12-01

    To determine the accuracy of patient-physician communication regarding topical ophthalmic medication use based on bottle cap color, particularly among individuals who may have acquired color vision deficiency from glaucoma. Cross-sectional, clinical study. Patients aged ≥18 years with primary open-angle, primary angle-closure, pseudoexfoliation, or pigment dispersion glaucoma, bilateral visual acuity of ≥20/400, and no concurrent conditions that may affect color vision. A total of 100 patients provided color descriptions of 11 distinct medication bottle caps. Color descriptors were then presented to 3 physicians. Physicians matched each color descriptor to the medication they thought the descriptor was describing. Frequency of patient-physician agreement, occurring when all 3 physicians accurately matched the color descriptor to the correct medication. Multivariate regression models evaluated whether patient-physician agreement decreased with degree of better-eye visual field (VF) damage, color descriptor heterogeneity, or color vision deficiency, as determined by the Hardy-Rand-Rittler (HRR) score and Lanthony D15 color confusion index (D15 CCI). Subjects had a mean age of 69 (±11) years, with VF mean deviation of -4.7 (±6.0) and -10.9 (±8.4) decibels (dB) in the better- and worse-seeing eyes, respectively. Patients produced 102 unique color descriptors to describe the colors of the 11 bottle caps. Among individual patients, the mean number of medications demonstrating agreement was 6.1/11 (55.5%). Agreement was less than 15% for 4 medications (prednisolone acetate [generic], betaxolol HCl [Betoptic; Alcon Laboratories Inc., Fort Worth, TX], brinzolamide/brimonidine [Simbrinza; Alcon Laboratories Inc.], and latanoprost [Xalatan; Pfizer, Inc., New York, NY]). Lower HRR scores and higher D15 CCI (both indicating worse color vision) were associated with greater VF damage (P communication using bottle cap color alone may be common and could lead to confusion

  8. Monitoring system of multiple fire fighting based on computer vision

    Science.gov (United States)

    Li, Jinlong; Wang, Li; Gao, Xiaorong; Wang, Zeyong; Zhao, Quanke

    2010-10-01

    With the high demand of fire control in spacious buildings, computer vision is playing a more and more important role. This paper presents a new monitoring system of multiple fire fighting based on computer vision and color detection. This system can adjust to the fire position and then extinguish the fire by itself. In this paper, the system structure, working principle, fire orientation, hydrant's angle adjusting and system calibration are described in detail; also the design of relevant hardware and software is introduced. At the same time, the principle and process of color detection and image processing are given as well. The system runs well in the test, and it has high reliability, low cost, and easy nodeexpanding, which has a bright prospect of application and popularization.

  9. Color Image Quality Assessment Based on CIEDE2000

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2012-01-01

    Full Text Available Combining the color difference formula of CIEDE2000 and the printing industry standard for visual verification, we present an objective color image quality assessment method correlated with subjective vision perception. An objective score conformed to subjective perception (OSCSP Q was proposed to directly reflect the subjective visual perception. In addition, we present a general method to calibrate correction factors of color difference formula under real experimental conditions. Our experiment results show that the present DE2000-based metric can be consistent with human visual system in general application environment.

  10. Sistema para la solución de problemas de cómputo basado en el Método de los Grafos Dicromáticos (System for computer troubleshooting method based on dichromatic graphs

    Directory of Open Access Journals (Sweden)

    Yosveni Escalona Escalona

    2013-06-01

    Full Text Available Resumen El presente artículo propone una herramienta de resolución de problemas de cómputo basado en el Método de los Grafos Dicromáticos. Además, se describe la arquitectura diseñada, así como las herramientas y tecnologías empleadas para la implementación de la solución. La propuesta constituye un aporte al valor práctico del Método de los Grafos Dicromáticos tomando en cuenta la integración con otras herramientas existentes para la aplicación del dicho métodos en problemas ingenieriles. Abstract This paper proposes a tool for troubleshooting calculations based on the Dichromatic Graphs Method. It also describes the designed architecture as well as the tools and technologies used to implement solutions. The proposal is a contribution to the practical value of the Dichromatic Graphs Method, taking into account integration with other existing tools for the implementation of these methods in complex engineering problems

  11. Effects of blue light-filtering intraocular lenses on the macula, contrast sensitivity, and color vision after a long-term follow-up.

    Science.gov (United States)

    Kara-Junior, Newton; Espindola, Rodrigo F; Gomes, Beatriz A F; Ventura, Bruna; Smadja, David; Santhiago, Marcony R

    2011-12-01

    To evaluate the possible side effects and potential protection 5 years after implantation of an intraocular lens (IOL) with a blue-light filter (yellow tinted). Ophthalmology Department, University of São Paulo, São Paulo, Brazil. Prospective randomized clinical study. Patients with bilateral visually significant cataract randomly received an ultraviolet (UV) and blue light-filtering IOL (Acrysof Natural SN60AT) in 1 eye and an acrylic UV light-filtering only IOL (Acrysof SA60AT) in the fellow eye. The primary outcome measures were contrast sensitivity, color vision, and macular findings 5 years after surgery. The study enrolled 60 eyes of 30 patients. There were no significant clinical or optical coherence tomography findings in terms of age-related macular degeneration in any eye. There were no statistically significant differences in central macular thickness between the 2 IOL groups (P=.712). There were also no significant between-group differences under photopic or scotopic conditions at any spatial frequency studied. No statistically significant differences in the color discrimination test were found between the 2 IOL groups (P=.674). After 5 years, there were no significant differences in color perception, scotopic contrast sensitivity, or photopic contrast sensitivity between the blue light-filtering (yellow-tinted) IOL and the IOL with a UV-light filter only (untinted). The potential advantage of the tinted IOL in providing protection to macular cells remains unclear. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  12. Advances in low-level color image processing

    CERN Document Server

    Smolka, Bogdan

    2014-01-01

    Color perception plays an important role in object recognition and scene understanding both for humans and intelligent vision systems. Recent advances in digital color imaging and computer hardware technology have led to an explosion in the use of color images in a variety of applications including medical imaging, content-based image retrieval, biometrics, watermarking, digital inpainting, remote sensing, visual quality inspection, among many others. As a result, automated processing and analysis of color images has become an active area of research, to which the large number of publications of the past two decades bears witness. The multivariate nature of color image data presents new challenges for researchers and practitioners as the numerous methods developed for single channel images are often not directly applicable to multichannel  ones. The goal of this volume is to summarize the state-of-the-art in the early stages of the color image processing pipeline.

  13. Development of a vision-based pH reading system

    Science.gov (United States)

    Hur, Min Goo; Kong, Young Bae; Lee, Eun Je; Park, Jeong Hoon; Yang, Seung Dae; Moon, Ha Jung; Lee, Dong Hoon

    2015-10-01

    pH paper is generally used for pH interpretation in the QC (quality control) process of radiopharmaceuticals. pH paper is easy to handle and useful for small samples such as radio-isotopes and radioisotope (RI)-labeled compounds for positron emission tomography (PET). However, pHpaper-based detecting methods may have some errors due limitations of eye sight and inaccurate readings. In this paper, we report a new device for pH reading and related software. The proposed pH reading system is developed with a vision algorithm based on the RGB library. The pH reading system is divided into two parts. First is the reading device that consists of a light source, a CCD camera and a data acquisition (DAQ) board. To improve the accuracy of the sensitivity, we utilize the three primary colors of the LED (light emission diode) in the reading device. The use of three colors is better than the use of a single color for a white LED because of wavelength. The other is a graph user interface (GUI) program for a vision interface and report generation. The GUI program inserts the color codes of the pH paper into the database; then, the CCD camera captures the pH paper and compares its color with the RGB database image in the reading mode. The software captures and reports information on the samples, such as pH results, capture images, and library images, and saves them as excel files.

  14. 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

  15. Scene recognition and colorization for vehicle infrared images

    Science.gov (United States)

    Hou, Junjie; Sun, Shaoyuan; Shen, Zhenyi; Huang, Zhen; Zhao, Haitao

    2016-10-01

    In order to make better use of infrared technology for driving assistance system, a scene recognition and colorization method is proposed in this paper. Various objects in a queried infrared image are detected and labelled with proper categories by a combination of SIFT-Flow and MRF model. The queried image is then colorized by assigning corresponding colors according to the categories of the objects appeared. The results show that the strategy here emphasizes important information of the IR images for human vision and could be used to broaden the application of IR images for vehicle driving.

  16. Prior Knowledge about Objects Determines Neural Color Representation in Human Visual Cortex.

    Science.gov (United States)

    Vandenbroucke, A R E; Fahrenfort, J J; Meuwese, J D I; Scholte, H S; Lamme, V A F

    2016-04-01

    To create subjective experience, our brain must translate physical stimulus input by incorporating prior knowledge and expectations. For example, we perceive color and not wavelength information, and this in part depends on our past experience with colored objects ( Hansen et al. 2006; Mitterer and de Ruiter 2008). Here, we investigated the influence of object knowledge on the neural substrates underlying subjective color vision. In a functional magnetic resonance imaging experiment, human subjects viewed a color that lay midway between red and green (ambiguous with respect to its distance from red and green) presented on either typical red (e.g., tomato), typical green (e.g., clover), or semantically meaningless (nonsense) objects. Using decoding techniques, we could predict whether subjects viewed the ambiguous color on typical red or typical green objects based on the neural response of veridical red and green. This shift of neural response for the ambiguous color did not occur for nonsense objects. The modulation of neural responses was observed in visual areas (V3, V4, VO1, lateral occipital complex) involved in color and object processing, as well as frontal areas. This demonstrates that object memory influences wavelength information relatively early in the human visual system to produce subjective color vision. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  17. Addressing Diversity in the Decade of Behavior: Focus on Women of Color.

    Science.gov (United States)

    Russo, Nancy Felipe; Vaz, Kim

    2001-01-01

    Discusses the lives of women of color, illustrating diversity-minded feminist principles that may inform research and program development related to other aspects of diversity. Notes perspectives and priorities of women of color in psychology. Considers why implementing feminist psychology's inclusive vision for research is a continuing struggle,…

  18. Analyses of multi-color plant-growth light sources in achieving maximum photosynthesis efficiencies with enhanced color qualities.

    Science.gov (United States)

    Wu, Tingzhu; Lin, Yue; Zheng, Lili; Guo, Ziquan; Xu, Jianxing; Liang, Shijie; Liu, Zhuguagn; Lu, Yijun; Shih, Tien-Mo; Chen, Zhong

    2018-02-19

    An optimal design of light-emitting diode (LED) lighting that benefits both the photosynthesis performance for plants and the visional health for human eyes has drawn considerable attention. In the present study, we have developed a multi-color driving algorithm that serves as a liaison between desired spectral power distributions and pulse-width-modulation duty cycles. With the aid of this algorithm, our multi-color plant-growth light sources can optimize correlated-color temperature (CCT) and color rendering index (CRI) such that photosynthetic luminous efficacy of radiation (PLER) is maximized regardless of the number of LEDs and the type of photosynthetic action spectrum (PAS). In order to illustrate the accuracies of the proposed algorithm and the practicalities of our plant-growth light sources, we choose six color LEDs and German PAS for experiments. Finally, our study can help provide a useful guide to improve light qualities in plant factories, in which long-term co-inhabitance of plants and human beings is required.

  19. Real-time vision systems

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.; Hernandez, J.E.; Lu, Shin-yee [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    Many industrial and defence applications require an ability to make instantaneous decisions based on sensor input of a time varying process. Such systems are referred to as `real-time systems` because they process and act on data as it occurs in time. When a vision sensor is used in a real-time system, the processing demands can be quite substantial, with typical data rates of 10-20 million samples per second. A real-time Machine Vision Laboratory (MVL) was established in FY94 to extend our years of experience in developing computer vision algorithms to include the development and implementation of real-time vision systems. The laboratory is equipped with a variety of hardware components, including Datacube image acquisition and processing boards, a Sun workstation, and several different types of CCD cameras, including monochrome and color area cameras and analog and digital line-scan cameras. The equipment is reconfigurable for prototyping different applications. This facility has been used to support several programs at LLNL, including O Division`s Peacemaker and Deadeye Projects as well as the CRADA with the U.S. Textile Industry, CAFE (Computer Aided Fabric Inspection). To date, we have successfully demonstrated several real-time applications: bullet tracking, stereo tracking and ranging, and web inspection. This work has been documented in the ongoing development of a real-time software library.

  20. Visual Perception with Color for Architectural Aesthetics

    NARCIS (Netherlands)

    Bittermann, M.S.; Ciftcioglu, O.

    2016-01-01

    Studies on computer-based visual perception and aesthetical judgment for architectural design are presented. In the model, both color and the geometric aspects of human vision are jointly taken into account, quantifying the perception of an individual object, as well as a scene consisting of several

  1. Event-Based Color Segmentation With a High Dynamic Range Sensor

    Directory of Open Access Journals (Sweden)

    Alexandre Marcireau

    2018-04-01

    Full Text Available This paper introduces a color asynchronous neuromorphic event-based camera and a methodology to process color output from the device to perform color segmentation and tracking at the native temporal resolution of the sensor (down to one microsecond. Our color vision sensor prototype is a combination of three Asynchronous Time-based Image Sensors, sensitive to absolute color information. We devise a color processing algorithm leveraging this information. It is designed to be computationally cheap, thus showing how low level processing benefits from asynchronous acquisition and high temporal resolution data. The resulting color segmentation and tracking performance is assessed both with an indoor controlled scene and two outdoor uncontrolled scenes. The tracking's mean error to the ground truth for the objects of the outdoor scenes ranges from two to twenty pixels.

  2. Evaluation of reliability and validity of three dental color-matching devices.

    Science.gov (United States)

    Tsiliagkou, Aikaterini; Diamantopoulou, Sofia; Papazoglou, Efstratios; Kakaboura, Afrodite

    2016-01-01

    To assess the repeatability and accuracy of three dental color-matching devices under standardized and freehand measurement conditions. Two shade guides (Vita Classical A1-D4, Vita; and Vita Toothguide 3D-Master, Vita), and three color-matching devices (Easyshade, Vita; SpectroShade, MHT Optic Research; and ShadeVision, X-Rite) were used. Five shade tabs were selected from the Vita Classical A1-D4 (A2, A3.5, B1, C4, D3), and five from the Vita Toothguide 3D-Master (1M1, 2R1.5, 3M2, 4L2.5, 5M3) shade guides. Each shade tab was recorded 15 continuous, repeated times with each device under two different measurement conditions (standardized, and freehand). Both qualitative (color shade) and quantitative (L, a, and b) color characteristics were recorded. The color difference (ΔE) of each recorded value with the known values of the shade tab was calculated. The repeatability of each device was evaluated by the coefficient of variance. The accuracy of each device was determined by comparing the recorded values with the known values of the reference shade tab (one sample t test; α = 0.05). The agreement between the recorded shade and the reference shade tab was calculated. The influence of the parameters (devices and conditions) on the parameter ΔE was investigated (two-way ANOVA). Comparison of the devices was performed with Bonferroni pairwise post-hoc analysis. Under standardized conditions, repeatability of all three devices was very good, except for ShadeVision with Vita Classical A1-D4. Accuracy ranged from good to fair, depending on the device and the shade guide. Under freehand conditions, repeatability and accuracy for Easyshade and ShadeVision were negatively influenced, but not for SpectroShade, regardless of the shade guide. Based on the total of the color parameters assessed per device, SpectroShade was the most reliable of the three color-matching devices studied.

  3. Visual Attention to Movement and Color in Children with Cortical Visual Impairment

    Science.gov (United States)

    Cohen-Maitre, Stacey Ann; Haerich, Paul

    2005-01-01

    This study investigated the ability of color and motion to elicit and maintain visual attention in a sample of children with cortical visual impairment (CVI). It found that colorful and moving objects may be used to engage children with CVI, increase their motivation to use their residual vision, and promote visual learning.

  4. Computer vision and machine learning with RGB-D sensors

    CERN Document Server

    Shao, Ling; Kohli, Pushmeet

    2014-01-01

    This book presents an interdisciplinary selection of cutting-edge research on RGB-D based computer vision. Features: discusses the calibration of color and depth cameras, the reduction of noise on depth maps and methods for capturing human performance in 3D; reviews a selection of applications which use RGB-D information to reconstruct human figures, evaluate energy consumption and obtain accurate action classification; presents an approach for 3D object retrieval and for the reconstruction of gas flow from multiple Kinect cameras; describes an RGB-D computer vision system designed to assist t

  5. Cone pigment polymorphism in New World monkeys: are all pigments created equal?

    Science.gov (United States)

    Rowe, Mickey P; Jacobs, Gerald H

    2004-01-01

    Most platyrrhine monkeys have a triallelic M/L opsin gene polymorphism that underlies significant individual variations in color vision. A survey of the frequencies of these polymorphic genes suggests that the three alleles occur with equal frequency among squirrel monkeys (subfamily Cebinae), but are not equally frequent in a number of species from the subfamily Callitrichinae. This departure from equal frequency in the Callitrichids should slightly increase the ratio of dichromats to trichromats in the population and significantly alter the relative representation of the three possible dichromatic and trichromatic phenotypes. A particular feature of the inequality is that it leads to a relative increase in the number of trichromats whose M/L pigments have the largest possible spectral separation. To assess whether these trichromatic phenotypes are equally well equipped to make relevant visual discriminations, psychophysical experiments were run on human observers. A technique involving the functional substitution of photopigments was used to simulate the discrimination between fruits among a background of leaves. The goal of the simulation was to reproduce in the cones of human observers excitations equivalent to those produced in monkey cones as the animals view fruit. Three different viewing conditions were examined involving variations in the relative luminances of fruit and leaves and the spectrum of the illuminant. In all cases, performance was best for simulated trichromacies including M/L pigments with the largest spectral separation. Thus, the inequality of opsin gene frequency in Callitrichid monkeys may reflect adaptive pressures.

  6. Protanopia (red color-blindness) in medaka: a simple system for producing color-blind fish and testing their spectral sensitivity.

    Science.gov (United States)

    Homma, Noriko; Harada, Yumi; Uchikawa, Tamaki; Kamei, Yasuhiro; Fukamachi, Shoji

    2017-02-06

    Color perception is important for fish to survive and reproduce in nature. Visual pigments in the retinal photoreceptor cells are responsible for receiving light stimuli, but the function of the pigments in vivo has not been directly investigated in many animals due to the lack of color-blind lines and appropriate color-perception tests. In this study, we established a system for producing color-blind fish and testing their spectral sensitivity. First, we disrupted long-wavelength-sensitive (LWS) opsins of medaka (Oryzias latipes) using the CRISPR/Cas9 system to make red-color-blind lines. Single guide RNAs were designed using the consensus sequences between the paralogous LWSa and LWSb genes to simultaneously introduce double-frameshift mutations. Next, we developed a non-invasive and no-prior-learning test for spectral sensitivity by applying an optomotor response (OMR) test under an Okazaki Large Spectrograph (OLS), termed the O-O test. We constructed an electrical-rotary cylinder with black/white stripes, into which a glass aquarium containing one or more fish was placed under various monochromatic light conditions. The medaka were irradiated by the OLS every 10 nm, from wavelengths of 700 nm to 900 nm, and OMR was evaluated under each condition. We confirmed that the lws - medaka were indeed insensitive to red light (protanopia). While the control fish responded to wavelengths of up to 830 nm (λ = 830 nm), the lws - mutants responded up to λ = 740 nm; however, this difference was not observed after adaptation to dark: both the control and lws - fish could respond up to λ = 820 ~ 830 nm. These results suggest that the lws - mutants lost photopic red-cone vision, but retained scotopic rod vision. Considering that the peak absorption spectra (λ max ) of medaka LWSs are about 560 nm, but the light-adapted control medaka could respond behaviorally to light at λ = 830 nm, red-cone vision could cover an unexpectedly wide range of

  7. [Research on developping the spectral dataset for Dunhuang typical colors based on color constancy].

    Science.gov (United States)

    Liu, Qiang; Wan, Xiao-Xia; Liu, Zhen; Li, Chan; Liang, Jin-Xing

    2013-11-01

    The present paper aims at developping a method to reasonably set up the typical spectral color dataset for different kinds of Chinese cultural heritage in color rendering process. The world famous wall paintings dating from more than 1700 years ago in Dunhuang Mogao Grottoes was taken as typical case in this research. In order to maintain the color constancy during the color rendering workflow of Dunhuang culture relics, a chromatic adaptation based method for developping the spectral dataset of typical colors for those wall paintings was proposed from the view point of human vision perception ability. Under the help and guidance of researchers in the art-research institution and protection-research institution of Dunhuang Academy and according to the existing research achievement of Dunhuang Research in the past years, 48 typical known Dunhuang pigments were chosen and 240 representative color samples were made with reflective spectral ranging from 360 to 750 nm was acquired by a spectrometer. In order to find the typical colors of the above mentioned color samples, the original dataset was devided into several subgroups by clustering analysis. The grouping number, together with the most typical samples for each subgroup which made up the firstly built typical color dataset, was determined by wilcoxon signed rank test according to the color inconstancy index comprehensively calculated under 6 typical illuminating conditions. Considering the completeness of gamut of Dunhuang wall paintings, 8 complementary colors was determined and finally the typical spectral color dataset was built up which contains 100 representative spectral colors. The analytical calculating results show that the median color inconstancy index of the built dataset in 99% confidence level by wilcoxon signed rank test was 3.28 and the 100 colors are distributing in the whole gamut uniformly, which ensures that this dataset can provide reasonable reference for choosing the color with highest

  8. A deblocking algorithm based on color psychology for display quality enhancement

    Science.gov (United States)

    Yeh, Chia-Hung; Tseng, Wen-Yu; Huang, Kai-Lin

    2012-12-01

    This article proposes a post-processing deblocking filter to reduce blocking effects. The proposed algorithm detects blocking effects by fusing the results of Sobel edge detector and wavelet-based edge detector. The filtering stage provides four filter modes to eliminate blocking effects at different color regions according to human color vision and color psychology analysis. Experimental results show that the proposed algorithm has better subjective and objective qualities for H.264/AVC reconstructed videos when compared to several existing methods.

  9. Atlantic salmon skin and fillet color changes effected by perimortem handling stress, rigor mortis, and ice storage.

    Science.gov (United States)

    Erikson, U; Misimi, E

    2008-03-01

    The changes in skin and fillet color of anesthetized and exhausted Atlantic salmon were determined immediately after killing, during rigor mortis, and after ice storage for 7 d. Skin color (CIE L*, a*, b*, and related values) was determined by a Minolta Chroma Meter. Roche SalmoFan Lineal and Roche Color Card values were determined by a computer vision method and a sensory panel. Before color assessment, the stress levels of the 2 fish groups were characterized in terms of white muscle parameters (pH, rigor mortis, and core temperature). The results showed that perimortem handling stress initially significantly affected several color parameters of skin and fillets. Significant transient fillet color changes also occurred in the prerigor phase and during the development of rigor mortis. Our results suggested that fillet color was affected by postmortem glycolysis (pH drop, particularly in anesthetized fillets), then by onset and development of rigor mortis. The color change patterns during storage were different for the 2 groups of fish. The computer vision method was considered suitable for automated (online) quality control and grading of salmonid fillets according to color.

  10. P1-9: Relationship between Color Shifts in Land's Two-Color Method and Higher- and Lower-Level Visual Information

    Directory of Open Access Journals (Sweden)

    Saki Iwaida

    2012-10-01

    Full Text Available Land's two-color method gives rise to apparent full-color perception, even though only two colors (e.g., red and gray are used. Previous studies indicate that chromatic adaptation, color memory, and inductive effects contribute to the shifts of color perception from real to illusory colors (e.g., Kuriki, 2006 Vision Research 46 3055–3066. This paper investigates the relationship between the color shifts induced by Land images and the skewness of the luminance histogram. In Experiment 1, several Land images are created based on a yellow ball, and the magnitude of the color shifts of the images are measured. The results of Experiment 1 show a significant correlation between the magnitude of the color shifts and skewness, suggesting that skewness is critical for the color shifts. In Experiment 2, we test the hypothesis that color shifts depends on just skewness; the color shifts should be invariant even if the Land images are scrambled. However, the results of Experiment 2 demonstrate that scrambled Land images exhibit less intense color shifts, suggesting that color shifts are determined by the object's overall shape or surface gloss, not just skewness. Taken together, we conclude that both low-level visual processes, such as those associated with luminance histogram skew, and high-level cognitive functions, such as object interpretation or understanding of surface gloss, are involved in the color shift of Land images.

  11. Homeostatic study of the effects of sportswear color on the contest outcome

    Science.gov (United States)

    Yuan, Jian-Qin; Liu, Timon Cheng-Yi; Wu, Ren-Le; Ruan, Chang-Xiong; He, Li-Mei; Liu, Song-Hao

    2008-12-01

    There are effects of sportswear color on the contest outcome. It has been explained from the psychological and perceptual viewpoints, respectively. It was studied by integrating the homeostatic theory of exercise training and autonomic nervous model of color vision in this paper. It was found that the effects of sportswear color on the contest outcome depend on autonomic nervous homeostasis (ANH). Color can be classified into hot color such as red, orange and yellow and cold color such as green, blue and violet. If the athletes have been in ANH, there are no effects of sportswear color on the contest outcome. If the autonomic nervous system is far from ANH due to exercise induced fatigue, wearing cold color had no predominance for cold-hot matches, and wearing white had no predominance for white-color matches.

  12. Psychophysical Evaluation of Achromatic and Chromatic Vision of Workers Chronically Exposed to Organic Solvents

    International Nuclear Information System (INIS)

    Lacerda, E.M.D.B.; Lima, M.G.; Silveira, L.C.D.S.; Rodrigues, A.R.; Teixeira, C.E.C.; De Lima, L.J.B.; Silveira, L.C.D.S.; Ventura, D.F.; Ventura, D.F.

    2012-01-01

    The purpose of this paper was to evaluate achromatic and chromatic vision of workers chronically exposed to organic solvents through psychophysical methods. Thirty-one gas station workers (31.5 ± 8.4 years old) were evaluated. Psychophysical tests were achromatic tests (Snellen chart, spatial and temporal contrast sensitivity, and visual perimetry) and chromatic tests (Ishihara's test, color discrimination ellipses, and Farnsworth-Munsell 100 hue test FM100). Spatial contrast sensitivities of exposed workers were lower than the control at spatial frequencies of 20 and 30 cpd whilst the temporal contrast sensitivity was preserved. Visual field losses were found in 10-30 degrees of eccentricity in the solvent exposed workers. The exposed workers group had higher error values of FM100 and wider color discrimination ellipses area compared to the controls. Workers occupationally exposed to organic solvents had abnormal visual functions, mainly color vision losses and visual field constriction

  13. Multiple spectral channels in branchiopods. I. Vision in dim light and neural correlates.

    Science.gov (United States)

    Lessios, Nicolas; Rutowski, Ronald L; Cohen, Jonathan H; Sayre, Marcel E; Strausfeld, Nicholas J

    2018-05-22

    Animals that have true color vision possess several spectral classes of photoreceptors. Pancrustaceans (Hexapoda+Crustacea) that integrate spectral information about their reconstructed visual world do so from photoreceptor terminals supplying their second optic neuropils, with subsequent participation of the third (lobula) and deeper centers (optic foci). Here, we describe experiments and correlative neural arrangements underlying convergent visual pathways in two species of branchiopod crustaceans that have to cope with a broad range of spectral ambience and illuminance in ephemeral pools, yet possess just two optic neuropils, the lamina and the optic tectum. Electroretinographic recordings and multimodel inference based on modeled spectral absorptance were used to identify the most likely number of spectral photoreceptor classes in their compound eyes. Recordings from the retina provide support for four color channels. Neuroanatomical observations resolve arrangements in their laminas that suggest signal summation at low light intensities, incorporating chromatic channels. Neuroanatomical observations demonstrate that spatial summation in the lamina of the two species are mediated by quite different mechanisms, both of which allow signals from several ommatidia to be pooled at single lamina monopolar cells. We propose that such summation provides sufficient signal for vision at intensities equivalent to those experienced by insects in terrestrial habitats under dim starlight. Our findings suggest that despite the absence of optic lobe neuropils necessary for spectral discrimination utilized by true color vision, four spectral photoreceptor classes have been maintained in Branchiopoda for vision at very low light intensities at variable ambient wavelengths that typify conditions in ephemeral freshwater habitats. © 2018. Published by The Company of Biologists Ltd.

  14. Seeing red to being red: conserved genetic mechanism for red cone oil droplets and co-option for red coloration in birds and turtles.

    Science.gov (United States)

    Twyman, Hanlu; Valenzuela, Nicole; Literman, Robert; Andersson, Staffan; Mundy, Nicholas I

    2016-08-17

    Avian ketocarotenoid pigments occur in both the red retinal oil droplets that contribute to colour vision and bright red coloration used in signalling. Turtles are the only other tetrapods with red retinal oil droplets, and some also display red carotenoid-based coloration. Recently, the CYP2J19 gene was strongly implicated in ketocarotenoid synthesis in birds. Here, we investigate CYP2J19 evolution in relation to colour vision and red coloration in reptiles using genomic and expression data. We show that turtles, but not crocodiles or lepidosaurs, possess a CYP2J19 orthologue, which arose via gene duplication before turtles and archosaurs split, and which is strongly and specifically expressed in the ketocarotenoid-containing retina and red integument. We infer that CYP2J19 initially functioned in colour vision in archelosaurs and conclude that red ketocarotenoid-based coloration evolved independently in birds and turtles via gene regulatory changes of CYP2J19 Our results suggest that red oil droplets contributed to colour vision in dinosaurs and pterosaurs. © 2016 The Author(s).

  15. UV photoreceptors and UV-yellow wing pigments in Heliconius butterflies allow a color signal to serve both mimicry and intraspecific communication.

    Science.gov (United States)

    Bybee, Seth M; Yuan, Furong; Ramstetter, Monica D; Llorente-Bousquets, Jorge; Reed, Robert D; Osorio, Daniel; Briscoe, Adriana D

    2012-01-01

    Mimetic wing coloration evolves in butterflies in the context of predator confusion. Unless butterfly eyes have adaptations for discriminating mimetic color variation, mimicry also carries a risk of confusion for the butterflies themselves. Heliconius butterfly eyes, which express recently duplicated ultraviolet (UV) opsins, have such an adaptation. To examine bird and butterfly color vision as sources of selection on butterfly coloration, we studied yellow wing pigmentation in the tribe Heliconiini. We confirmed, using reflectance and mass spectrometry, that only Heliconius use 3-hydroxy-DL-kynurenine (3-OHK), which looks yellow to humans but reflects both UV- and long-wavelength light, whereas butterflies in related genera have chemically unknown yellow pigments mostly lacking UV reflectance. Modeling of these color signals reveals that the two UV photoreceptors of Heliconius are better suited to separating 3-OHK from non-3-OHK spectra compared with the photoreceptors of related genera or birds. The co-occurrence of potentially enhanced UV vision and a UV-reflecting yellow wing pigment could allow unpalatable Heliconius private intraspecific communication in the presence of mimics. Our results are the best available evidence for the correlated evolution of a color signal and color vision. They also suggest that predator visual systems are error prone in the context of mimicry. © 2011 by The University of Chicago.

  16. Dermatological Feasibility of Multimodal Facial Color Imaging Modality for Cross-Evaluation of Facial Actinic Keratosis

    Science.gov (United States)

    Bae, Youngwoo; Son, Taeyoon; Nelson, J. Stuart; Kim, Jae-Hong; Choi, Eung Ho; Jung, Byungjo

    2010-01-01

    Background/Purpose Digital color image analysis is currently considered as a routine procedure in dermatology. In our previous study, a multimodal facial color imaging modality (MFCIM), which provides a conventional, parallel- and cross-polarization, and fluorescent color image, was introduced for objective evaluation of various facial skin lesions. This study introduces a commercial version of MFCIM, DermaVision-PRO, for routine clinical use in dermatology and demonstrates its dermatological feasibility for cross-evaluation of skin lesions. Methods/Results Sample images of subjects with actinic keratosis or non-melanoma skin cancers were obtained at four different imaging modes. Various image analysis methods were applied to cross-evaluate the skin lesion and, finally, extract valuable diagnostic information. DermaVision-PRO is potentially a useful tool as an objective macroscopic imaging modality for quick prescreening and cross-evaluation of facial skin lesions. Conclusion DermaVision-PRO may be utilized as a useful tool for cross-evaluation of widely distributed facial skin lesions and an efficient database management of patient information. PMID:20923462

  17. Colors vision effect: learning and teaching strategies based on reading nature images

    Science.gov (United States)

    Castillo, D.; Jiménez, Y.; Vivanco, O.; Cuenca, L.; Granda, C.; Sánchez, A.

    2017-09-01

    The present work shows the teaching and motivation of University students to think about optics and color effects. The methodology consists of studying the different optical phenomena that occur through the sunsets and then do a correlation of this information with the phenomena and optical effects of the color of class presentations; to determine the motivation and attention of students.

  18. Computer Vision Utilization for Detection of Green House Tomato under Natural Illumination

    Directory of Open Access Journals (Sweden)

    H Mohamadi Monavar

    2013-02-01

    Full Text Available Agricultural sector experiences the application of automated systems since two decades ago. These systems are applied to harvest fruits in agriculture. Computer vision is one of the technologies that are most widely used in food industries and agriculture. In this paper, an automated system based on computer vision for harvesting greenhouse tomatoes is presented. A CCD camera takes images from workspace and tomatoes with over 50 percent ripeness are detected through an image processing algorithm. In this research three color spaces including RGB, HSI and YCbCr and three algorithms including threshold recognition, curvature of the image and red/green ratio were used in order to identify the ripe tomatoes from background under natural illumination. The average error of threshold recognition, red/green ratio and curvature of the image algorithms were 11.82%, 10.03% and 7.95% in HSI, RGB and YCbCr color spaces, respectively. Therefore, the YCbCr color space and curvature of the image algorithm were identified as the most suitable for recognizing fruits under natural illumination condition.

  19. Color vision in attention-deficit/hyperactivity disorder: a pilot visual evoked potential study.

    Science.gov (United States)

    Kim, Soyeon; Banaschewski, Tobias; Tannock, Rosemary

    2015-01-01

    Individuals with attention-deficit/hyperactivity disorder (ADHD) are reported to manifest visual problems (including ophthalmological and color perception, particularly for blue-yellow stimuli), but findings are inconsistent. Accordingly, this study investigated visual function and color perception in adolescents with ADHD using color Visual Evoked Potentials (cVEP), which provides an objective measure of color perception. Thirty-one adolescents (aged 13-18), 16 with a confirmed diagnosis of ADHD, and 15 healthy peers, matched for age, gender, and IQ participated in the study. All underwent an ophthalmological exam, as well as electrophysiological testing color Visual Evoked Potentials (cVEP), which measured the latency and amplitude of the neural P1 response to chromatic (blue-yellow, red-green) and achromatic stimuli. No intergroup differences were found in the ophthalmological exam. However, significantly larger P1 amplitude was found for blue and yellow stimuli, but not red/green or achromatic stimuli, in the ADHD group (particularly in the medicated group) compared to controls. Larger amplitude in the P1 component for blue-yellow in the ADHD group compared to controls may account for the lack of difference in color perception tasks. We speculate that the larger amplitude for blue-yellow stimuli in early sensory processing (P1) might reflect a compensatory strategy for underlying problems including compromised retinal input of s-cones due to hypo-dopaminergic tone. Copyright © 2014 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  20. A Software Application to Detect Dental Color

    Directory of Open Access Journals (Sweden)

    Dan SÎMPĂLEAN

    2015-09-01

    Full Text Available Choosing dental color for missing teeth or tooth reconstruction is an important step and it usually raises difficulties for dentists due to a significant amount of subjective factors that can influence the color selection. Dental reconstruction presumes the combination between dentistry and chromatics, thus implying important challenges. Purpose: The aim of this study was to develop and implement a software application for detecting dental color to come to the aid of dentists and largely to remove the inherent subjectiveness of the human vision. Basic Methods: The implemented application was named Color Detection and the application’s source code is written using the C++ language. During application development, for creating the GUI (graphical user interface the wxWidgets 2.8 library it was used. Results: The application displays the average color of the selected area of interest, the reference color from the key collection existent in the program and also the degree of similarity between the original (the selected area of interest and the nearest reference key. This degree of similarity is expressed as a percentage. Conclusions: The Color Detection Program, by eliminating the subjectivity inherent to human sight, can help the dentist to select an appropriate dental color with precision.

  1. Evaluation of a color fused dual-band NVG

    NARCIS (Netherlands)

    Hogervorst, M.A.; Toet, A.

    2009-01-01

    We designed and evaluated a dual-band Night Vision Goggles sensor system. The sensor system consists of two optically aligned NVGs fitted with filters splitting the sensitive range into a visual and a near-infrared band. The Color-the-night technique (Hogervorst & Toet, FUSION2008) was used to fuse

  2. Correlation between three color coordinates of human teeth

    Science.gov (United States)

    Lee, Yong-Keun

    2014-11-01

    The objective was to determine whether there were significant correlations in the three color coordinates within each of two color coordinate systems, such as the Commission Internationale de l'Eclairage (CIE) L*a*b* system, and the lightness, chroma, and hue angle system, of human vital teeth. The color of six maxillary and six mandibular anterior teeth was measured by the Shade Vision System. Pearson correlations between each pair of the color coordinates were determined (α=0.01). The influence of two color coordinates on the other color coordinate was determined with a multiple regression analysis (α=0.01). Based on correlation analyses, all the color coordinate pairs showed significant correlations except for the chroma and hue angle pair. The CIE L* was negatively correlated with the CIE a*, b*, and chroma, but positively correlated with the hue angle. The CIE a* was positively correlated with the CIE b* and chroma. Tooth color coordinates were correlated each other. Lighter teeth were less chromatic both in the CIE a* and b* coordinates. Therefore, it was postulated that the three color coordinates of human teeth were harmonized within certain color attribute ranges, and a lack of correlations in these coordinates might indicate external/internal discolorations and/or anomalies of teeth.

  3. 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

  4. Hyperspectral imaging of cuttlefish camouflage indicates good color match in the eyes of fish predators.

    Science.gov (United States)

    Chiao, Chuan-Chin; Wickiser, J Kenneth; Allen, Justine J; Genter, Brock; Hanlon, Roger T

    2011-05-31

    Camouflage is a widespread phenomenon throughout nature and an important antipredator tactic in natural selection. Many visual predators have keen color perception, and thus camouflage patterns should provide some degree of color matching in addition to other visual factors such as pattern, contrast, and texture. Quantifying camouflage effectiveness in the eyes of the predator is a challenge from the perspectives of both biology and optical imaging technology. Here we take advantage of hyperspectral imaging (HSI), which records full-spectrum light data, to simultaneously visualize color match and pattern match in the spectral and the spatial domains, respectively. Cuttlefish can dynamically camouflage themselves on any natural substrate and, despite their colorblindness, produce body patterns that appear to have high-fidelity color matches to the substrate when viewed directly by humans or with RGB images. Live camouflaged cuttlefish on natural backgrounds were imaged using HSI, and subsequent spectral analysis revealed that most reflectance spectra of individual cuttlefish and substrates were similar, rendering the color match possible. Modeling color vision of potential di- and trichromatic fish predators of cuttlefish corroborated the spectral match analysis and demonstrated that camouflaged cuttlefish show good color match as well as pattern match in the eyes of fish predators. These findings (i) indicate the strong potential of HSI technology to enhance studies of biological coloration and (ii) provide supporting evidence that cuttlefish can produce color-coordinated camouflage on natural substrates despite lacking color vision.

  5. Fault-Tolerant Vision for Vehicle Guidance in Agriculture

    DEFF Research Database (Denmark)

    Blas, Morten Rufus

    , and aiding sensors such as GPS provide means to detect and isolate single faults in the system. In addition, learning is employed to adapt the system to variational changes in the natural environment. 3D vision is enhanced by learning texture and color information. Intensity gradients on small neighborhoods...... dropout of 3D vision, faults in classification, or other defects, redundant information should be utilized. Such information can be used to diagnose faulty behavior and to temporarily continue operation with a reduced set of sensors when faults or artifacts occur. Additional sensors include GPS receivers...... and inertial sensors. To fully utilize the possibilities in 3D vision, the system must also be able to learn and adapt to changing environments. By learning features of the environment new diagnostic relations can be generated by creating redundant feed-forward information about crop location. Also, by mapping...

  6. Color change, phenotypic plasticity, and camouflage

    Directory of Open Access Journals (Sweden)

    Martin eStevens

    2016-05-01

    Full Text Available The ability to change appearance over a range of timescales is widespread in nature, existing in many invertebrate and vertebrate groups. This can include color change occurring in seconds, minutes, and hours, to longer term changes associated with phenotypic plasticity and development. A major function is for camouflage against predators because color change and plasticity enables animals to match their surroundings and potentially reduce the risk of predation. Recently, we published findings (Stevens et al. 2014a showing how shore crabs can change their appearance and better match the background to predator vision in the short term. This, coupled with a number of past studies, emphasizes the potential that animals have to modify their appearance for camouflage. However, the majority of studies on camouflage and color plasticity have focused on a small number of species capable of unusually rapid changes. There are many broad questions that remain about the nature, mechanisms, evolution, and adaptive value of color change and plasticity for concealment. Here, I discuss past work and outline six questions relating to color change and plasticity, as well as major avenues for future work.

  7. Vision related quality of life in patients with type 2 diabetes in the EUROCONDOR trial.

    Science.gov (United States)

    Trento, Marina; Durando, Olga; Lavecchia, Sonia; Charrier, Lorena; Cavallo, Franco; Costa, Miguel Angelo; Hernández, Cristina; Simó, Rafael; Porta, Massimo

    2017-07-01

    To evaluate vision related quality of life in the patients enrolled in The European Consortium for the Early Treatment of Diabetic Retinopathy, a clinical trial on prevention of diabetic retinopathy. Four-hundred-forty-nine patients, 153 women, with type 2 Diabetes and no or mild diabetic retinopathy were enrolled in a 2-year multicenter randomized controlled trial. The 25-item National Eye Institute Visual Functioning Questionnaire was used to explore 12 subscales of vision related quality of life. The patients were 62.8 ± 6.7 years old and had 11.1 ± 5.6 years known disease duration. Diabetic retinopathy was absent in 193 (43.0 %) and mild in 256 (57.0 %). Patients without diabetic retinopathy were older, had shorter diabetes duration and used less insulin and glucose-lowering agents but did not differ by gender, best corrected visual acuity or any subscale, except vision specific mental health and vision specific role difficulties. Patients with reduced retinal thickness at the ganglion cell layer (n = 36) did not differ for diabetic retinopathy but were older, had lower best corrected visual acuity and worse scores for ocular pain, color vision and peripheral vision. On multivariable analysis, worse scores for general vision remained associated with reduced retinal thickness, diabetes duration and best corrected visual acuity, and scores for visual specific mental health with diabetic retinopathy and lower best corrected visual acuity. Visual specific role difficulties were only associated with reduced best corrected visual acuity. Scores for driving decreased among females, with worsening of Hemoglobin A1c and best corrected visual acuity. Color vision depended only on reduced retinal thickness, and peripheral vision on both reduced thickness and best corrected visual acuity. The National Eye Institute Visual Functioning Questionnaire could detect subtle changes in patients' perception of visual function, despite absent/minimal diabetic

  8. Losses of functional opsin genes, short-wavelength cone photopigments, and color vision--a significant trend in the evolution of mammalian vision.

    Science.gov (United States)

    Jacobs, Gerald H

    2013-03-01

    All mammalian cone photopigments are derived from the operation of representatives from two opsin gene families (SWS1 and LWS in marsupial and eutherian mammals; SWS2 and LWS in monotremes), a process that produces cone pigments with respective peak sensitivities in the short and middle-to-long wavelengths. With the exception of a number of primate taxa, the modal pattern for mammals is to have two types of cone photopigment, one drawn from each of the gene families. In recent years, it has been discovered that the SWS1 opsin genes of a widely divergent collection of eutherian mammals have accumulated mutational changes that render them nonfunctional. This alteration reduces the retinal complements of these species to a single cone type, thus rendering ordinary color vision impossible. At present, several dozen species from five mammalian orders have been identified as falling into this category, but the total number of mammalian species that have lost short-wavelength cones in this way is certain to be much larger, perhaps reaching as high as 10% of all species. A number of circumstances that might be used to explain this widespread cone loss can be identified. Among these, the single consistent fact is that the species so affected are nocturnal or, if they are not technically nocturnal, they at least feature retinal organizations that are typically associated with that lifestyle. At the same time, however, there are many nocturnal mammals that retain functional short-wavelength cones. Nocturnality thus appears to set the stage for loss of functional SWS1 opsin genes in mammals, but it cannot be the sole circumstance.

  9. Automated Vision Test Development and Validation

    Science.gov (United States)

    2016-11-01

    crystal display monitor (NEC Multisync, P232W) at 1920x1080 resolution. Proper calibration was confirmed using a spot photometer/colorimeter (X-Rite i1...visual input to the right and left eye was achieved using liquid crystal display shuttered glasses (NVIDIA 3D Vision 2). The stereo target (Figure 4...threshold on the automated tasks. • Subjects had a lower (better) threshold on color testing for all cone types using the OCCT due to a ceiling

  10. Creating photorealistic virtual model with polarization-based vision system

    Science.gov (United States)

    Shibata, Takushi; Takahashi, Toru; Miyazaki, Daisuke; Sato, Yoichi; Ikeuchi, Katsushi

    2005-08-01

    Recently, 3D models are used in many fields such as education, medical services, entertainment, art, digital archive, etc., because of the progress of computational time and demand for creating photorealistic virtual model is increasing for higher reality. In computer vision field, a number of techniques have been developed for creating the virtual model by observing the real object in computer vision field. In this paper, we propose the method for creating photorealistic virtual model by using laser range sensor and polarization based image capture system. We capture the range and color images of the object which is rotated on the rotary table. By using the reconstructed object shape and sequence of color images of the object, parameter of a reflection model are estimated in a robust manner. As a result, then, we can make photorealistic 3D model in consideration of surface reflection. The key point of the proposed method is that, first, the diffuse and specular reflection components are separated from the color image sequence, and then, reflectance parameters of each reflection component are estimated separately. In separation of reflection components, we use polarization filter. This approach enables estimation of reflectance properties of real objects whose surfaces show specularity as well as diffusely reflected lights. The recovered object shape and reflectance properties are then used for synthesizing object images with realistic shading effects under arbitrary illumination conditions.

  11. 'Everest' Panorama; 20-20 Vision

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] 'Everest' Panorama 20-20 Vision (QTVR) [figure removed for brevity, see original site] 'Everest' Panorama Animation If a human with perfect vision donned a spacesuit and stepped onto the martian surface, the view would be as clear as this sweeping panorama taken by NASA's Mars Exploration Rover Spirit. That's because the rover's panoramic camera has the equivalent of 20-20 vision. Earthlings can take a virtual tour of the scenery by zooming in on their computer screens many times to get a closer look at, say, a rock outcrop or a sand drift, without losing any detail. This level of clarity is unequaled in the history of Mars exploration. It took Spirit three days, sols 620 to 622 (Oct. 1 to Oct. 3, 2005), to acquire all the images combined into this mosaic, called the 'Everest Panorama,' looking outward in every direction from the true summit of 'Husband Hill.' During that period, the sky changed in color and brightness due to atmospheric dust variations, as shown in contrasting sections of this mosaic. Haze occasionally obscured the view of the hills on the distant rim of Gusev Crater 80 kilometers (50 miles) away. As dust devils swooped across the horizon in the upper right portion of the panorama, the robotic explorer changed the filters on the camera from red to green to blue, making the dust devils appear red, green, and blue. In reality, the dust devils are similar in color to the reddish-brown soils of Mars. No attempt was made to 'smooth' the sky in this mosaic, as has been done in other panoramic-camera mosaics to simulate the view one would get by taking in the landscape all at once. The result is a sweeping vista that allows viewers to observe weather changes on Mars. The summit of Husband Hill is a broad plateau of rock outcrops and windblown drifts about 100 meters (300 feet) higher than the surrounding plains of Gusev Crater. In the distance, near the center of the mosaic, is the 'South Basin,' the

  12. Neuropathies of the optic nerve and visual evoked potentials with special reference to color vision and differential light threshold measured with the computer perimeter OCTOPUS.

    Science.gov (United States)

    Wildberger, H

    1984-10-31

    The contrast evoked potentials (VEPs) to different check sizes were recorded in about 200 cases of discrete optic neuropathies (ON) of different origin. Differential light threshold (DLT) was tested with the computer perimeter OCTOPUS. Saturated and desaturated tests were applied to evaluate the degree of acquired color vision deficiency. Delayed VEP responses are not confined to optic neuritis (RBN) alone and the different latency times obtained from other ON are confluent. The delay may be due to demyelination, to an increasing dominance of paramacular VEP subcomponents or to an increasing dominance of the upper half-field responses. Recording with smaller check sizes has the advantage that discrete dysfunctions in the visual field (VF) center are more easily detected: a correlation between amplitudes and visual acuity is best in strabismic amblyopias, is less expressed in maculopathies of the retina and weak in ON. The absence or reduction of amplitudes to smaller check sizes, however, is an important indication of a disorder in the VF center of ON in an early or recovered stage. Acquired color vision defects of the tritan-like type are more confined to discrete ON, whereas the red/green type is reserved to more severe ON. The DLT of the VF center is reduced in a different, significant and non significant extent in discrete optic neuropathies and the correlation between DLT and visual acuity is weak. A careful numerical analysis is needed in types of discrete ON where the central DLT lies within normal statistical limits: a side difference of the DLT between the affected and the normal fellow eye is always present. Evaluation of visual fatigue effects and of the relative sensitivity loss of VF center and VF periphery may provide further diagnostic information.

  13. 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

  14. Research of principles for estimating the freshness of meat products by color analysis method

    Science.gov (United States)

    Gorbunova, Elena V.; Chertov, Aleksandr N.; Petukhova, Daria B.; Alekhin, Artem A.; Korotaev, Valery V.

    2015-03-01

    Color is one of the most important metrics of foodstuffs quality. It gives an indication of freshness, ingredient composition as well as about the presence or absence of falsification. Most often, the color is estimated visually, and thus, the evaluation is subjective. By automating the color analysis a wide application for this method could be found. The aim of this research is to study the principles of color analysis as applied to the task of evaluating the freshness of meat products using modern machine vision systems. From a scientific point of view, the color of meat depends on the proportion of myoglobin and its derivatives. It's the main pigment that characterizes the freshness of meat. Further color of meat can change due to oxidation of myoglobin during storage. Myoglobin exists in three forms. There are oxygenated form, oxidized form and form without oxygen. The meat color changes not only due to the conversion of one form into another. The content of amino acids and ammonia are another characteristics and constant signs of meat products spoilage. The paper presents the results of meat color computer simulation based on data on the content of various forms of myoglobin in different proportions. The spectral characteristic of the light source used to illuminate the meat sample is taken into account. Also the experimental studies were conducted using samples of beef. As a result the correlations between said biochemical indicators of the quality and color of the meat obtained with the help of machine vision system were found.

  15. Predicting Visual Disability in Glaucoma With Combinations of Vision Measures.

    Science.gov (United States)

    Lin, Stephanie; Mihailovic, Aleksandra; West, Sheila K; Johnson, Chris A; Friedman, David S; Kong, Xiangrong; Ramulu, Pradeep Y

    2018-04-01

    We characterized vision in glaucoma using seven visual measures, with the goals of determining the dimensionality of vision, and how many and which visual measures best model activity limitation. We analyzed cross-sectional data from 150 older adults with glaucoma, collecting seven visual measures: integrated visual field (VF) sensitivity, visual acuity, contrast sensitivity (CS), area under the log CS function, color vision, stereoacuity, and visual acuity with noise. Principal component analysis was used to examine the dimensionality of vision. Multivariable regression models using one, two, or three vision tests (and nonvisual predictors) were compared to determine which was best associated with Rasch-analyzed Glaucoma Quality of Life-15 (GQL-15) person measure scores. The participants had a mean age of 70.2 and IVF sensitivity of 26.6 dB, suggesting mild-to-moderate glaucoma. All seven vision measures loaded similarly onto the first principal component (eigenvectors, 0.220-0.442), which explained 56.9% of the variance in vision scores. In models for GQL scores, the maximum adjusted- R 2 values obtained were 0.263, 0.296, and 0.301 when using one, two, and three vision tests in the models, respectively, though several models in each category had similar adjusted- R 2 values. All three of the best-performing models contained CS. Vision in glaucoma is a multidimensional construct that can be described by several variably-correlated vision measures. Measuring more than two vision tests does not substantially improve models for activity limitation. A sufficient description of disability in glaucoma can be obtained using one to two vision tests, especially VF and CS.

  16. Age of Onset of Blindness and the Development of the Semantics of Color Names.

    Science.gov (United States)

    Marmor, Gloria Strauss

    The relationship between age of onset of blindness and development of knowledge of color relations was examined with 16 college students who had been born totally blind, 16 who had been blinded totally at approximately 15 years of age, and 16 who had normal vision. Ss were asked to judge the similarities between color names, and judgments were…

  17. Real-time three-dimensional surface measurement by color encoded light projection

    International Nuclear Information System (INIS)

    Chen, S. Y.; Li, Y. F.; Guan, Q.; Xiao, G.

    2006-01-01

    Existing noncontact methods for surface measurement suffer from the disadvantages of poor reliability, low scanning speed, or high cost. The authors present a method for real-time three-dimensional data acquisition by a color-coded vision sensor composed of common components. The authors use a digital projector controlled by computer to generate desired color light patterns. The unique indexing of the light codes is a key problem and is solved in this study so that surface perception can be performed with only local pattern analysis of the neighbor color codes in a single image. Experimental examples and performance analysis are provided

  18. Color vision in ADHD: part 2--does attention influence color perception?

    Science.gov (United States)

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

    2014-10-24

    To investigate the impact of exogenous covert attention on chromatic (blue and red) and achromatic visual perception in adults with and without Attention Deficit Hyperactivity Disorder (ADHD). Exogenous covert attention, which is a transient, automatic, stimulus-driven form of attention, is a key mechanism for selecting relevant information in visual arrays. 30 adults diagnosed with ADHD and 30 healthy adults, matched on age and gender, performed a psychophysical task designed to measure the effects of exogenous covert attention on perceived color saturation (blue, red) and contrast sensitivity. The effects of exogenous covert attention on perceived blue and red saturation levels and contrast sensitivity were similar in both groups, with no differences between males and females. Specifically, exogenous covert attention enhanced the perception of blue saturation and contrast sensitivity, but it had no effect on the perception of red saturation. The findings suggest that exogenous covert attention is intact in adults with ADHD and does not account for the observed impairments in the perception of chromatic (blue and red) saturation.

  19. Psychophysical Measurements of Luminance Contrast Sensitivity and Color Discrimination with Transparent and Blue-Light Filter Intraocular Lenses.

    Science.gov (United States)

    da Costa, Marcelo Fernandes; Júnior, Augusto Paranhos; Lottenberg, Claudio Luiz; Castro, Leonardo Cunha; Ventura, Dora Fix

    2017-12-01

    The purpose of this study was to measure luminance contrast sensitivity and color vision thresholdfs in normal subjects using a blue light filter lens and transparent intraocular lens material. Monocular luminance grating contrast sensitivity was measured with Psycho for Windows (version 2.36; Cambridge Research Systems) at 3.0, 6.0, 12.0, 20.0, and 30.0 cycles per degree of visual angle (cpd) in 15 normal subjects (eight female), with a mean age of 21.6 years (SD = 3.8 years). Chromatic discrimination was assessed with the Cambridge colour test (CCT) along the protan, deutan, and tritan color confusion axes. Both tests were performed in a darkened room under two situations: with a transparent lens and with blue light filter lens. Subjective impressions were taken by subjects regarding their visual experience under both conditions. No difference was found between the luminance contrast sensitivity measured with transparent and blue light filter. However, 13/15 (87%) of the subjects reported more comfortable vision with the blue filter. In the color vision test, tritan thresholds were significantly higher for the blue filter compared with the transparent filter (p = 0.003). For protan and deutan thresholds no differences were found. Blue-yellow color vision is impaired with the blue light filter, and no impairment occurs with the transparent filter. No significant differences in thresholds were found in the luminance contrast sensitivity comparing the blue light and transparent filters. The impact of short wavelength light filtering on intrinsically photosensitive retinal ganglion cells is also discussed.

  20. The incidence of color blindness among some school children of Pokhara, Western Nepal.

    Science.gov (United States)

    Niroula, D R; Saha, C G

    2010-03-01

    The incidence of color blindness varies from race to race and different in different geographical area. Since, there is no such report about the prevalence of color blindness in the western part of Nepal, the present study had been conducted to find out the incidence of color blindness among school children of Pokhara city, western Nepal. Participant's (n=964, 474 boys, 490 girls, age group 10 to 19 years) color vision was tested by using Ishihara chart (38 plates). Among 474 boys, 18 boys were color blind with the prevalence of 3.8%. None of girls were found to be color blind. Out of 18 color blind boys, nine, six and three boys were the victims of deuteranopia, deuteranomaly and protanomaly respectively. The incidence of color blindness were more amongst the Darji (14.3%) and Newar (9.1%) ethnic groups.

  1. The Verriest Lecture: Color lessons from space, time, and motion

    Science.gov (United States)

    Shevell, Steven K.

    2012-01-01

    The appearance of a chromatic stimulus depends on more than the wavelengths composing it. The scientific literature has countless examples showing that spatial and temporal features of light influence the colors we see. Studying chromatic stimuli that vary over space, time or direction of motion has a further benefit beyond predicting color appearance: the unveiling of otherwise concealed neural processes of color vision. Spatial or temporal stimulus variation uncovers multiple mechanisms of brightness and color perception at distinct levels of the visual pathway. Spatial variation in chromaticity and luminance can change perceived three-dimensional shape, an example of chromatic signals that affect a percept other than color. Chromatic objects in motion expose the surprisingly weak link between the chromaticity of objects and their physical direction of motion, and the role of color in inducing an illusory motion direction. Space, time and motion – color’s colleagues – reveal the richness of chromatic neural processing. PMID:22330398

  2. Color-based free-space segmentation using online disparity-supervised learning

    NARCIS (Netherlands)

    Sanberg, W.P.; Dubbelman, G.; de With, P.H.N.

    2015-01-01

    This work contributes to vision processing for Advanced Driver Assist Systems (ADAS) and intelligent vehicle applications. We propose a color-only stixel segmentation framework to segment traffic scenes into free, drivable space and obstacles, which has a reduced latency to improve the real-time

  3. Bio-Inspired Asynchronous Pixel Event Tricolor Vision Sensor.

    Science.gov (United States)

    Lenero-Bardallo, Juan Antonio; Bryn, D H; Hafliger, Philipp

    2014-06-01

    This article investigates the potential of the first ever prototype of a vision sensor that combines tricolor stacked photo diodes with the bio-inspired asynchronous pixel event communication protocol known as Address Event Representation (AER). The stacked photo diodes are implemented in a 22 × 22 pixel array in a standard STM 90 nm CMOS process. Dynamic range is larger than 60 dB and pixels fill factor is 28%. The pixels employ either simple pulse frequency modulation (PFM) or a Time-to-First-Spike (TFS) mode. A heuristic linear combination of the chip's inherent pseudo colors serves to approximate RGB color representation. Furthermore, the sensor outputs can be processed to represent the radiation in the near infrared (NIR) band without employing external filters, and to color-encode direction of motion due to an asymmetry in the update rates of the different diode layers.

  4. Innate Color Preference of Zebrafish and Its Use in Behavioral Analyses.

    Science.gov (United States)

    Park, Jong-Su; Ryu, Jae-Ho; Choi, Tae-Ik; Bae, Young-Ki; Lee, Suman; Kang, Hae Jin; Kim, Cheol-Hee

    2016-10-01

    Although innate color preference of motile organisms may provide clues to behavioral biases, it has remained a longstanding question. In this study, we investigated innate color preference of zebrafish larvae. A cross maze with different color sleeves around each arm was used for the color preference test (R; red, G; green, B; blue, Y; yellow). The findings showed that 5 dpf zebrafish larvae preferred blue over other colors (B > R > G > Y). To study innate color recognition further, tyrosinase mutants were generated using CRISPR/Cas9 system. As a model for oculocutaneous albinism (OCA) and color vision impairment, tyrosinase mutants demonstrated diminished color sensation, indicated mainly by hypopigmentation of the retinal pigment epithelium (RPE). Due to its relative simplicity and ease, color preference screening using zebrafish larvae is suitable for high-throughput screening applications. This system may potentially be applied to the analysis of drug effects on larval behavior or the detection of sensory deficits in neurological disorder models, such as autism-related disorders, using mutant larvae generated by the CRISPR/Cas9 technique.

  5. 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...

  6. "APOPTOSIS COLOR." SCREENING STRATEGY FOR DIAGNOSIS EARLY STAGES OF PRIMARY OPEN-ANGLE GLAUCOMA

    Directory of Open Access Journals (Sweden)

    M. A. Kovalevskaya

    2017-01-01

    Full Text Available Purpose: to develop a screening strategy for the early diagnosis of primary open-angle glaucoma.Patients and Methods: 1 group — 250 patients with suspected glaucoma (42–75 years, 2 — 250 with the 1st stage primary open-angle glaucoma (42–61, 3 — 3,000 healthy persons (35 to 50. Surveys: visometry, tonometry iCare, biomicroscopy, gonioscopy, pachymeria, ophthalmoscopy with a high dioptric lens of 60 D, standard automated perimetry of the SITA-Standard and SITA-SWAP program, assessing the color sensitivity according to the Famsworth-Munsell 100 HueTes method.Results: 1 group — SITA-SWAP: MD -2,55±0,7 dB, PSD 2,46±1,15 dB. Mansell test: TES = 58.6±18.7 (p<0.05, average level of color recognition; mild deficiency of color vision — 41–100 TES; by the RGB system: colors of the first order; tone in RGB (0–239: blue — 160; HCV: blue — 240; range of wavelengths: blue — 440–485 nm; frequency: blue — 620–680 THz. 2 group — on SITA-SWAP: MD — 5,13±1,3 dB, PSD 2,58±0,9 dB. Mansell test: TES = 86,9±21,8; average level of color recognition; mild deficiency of color vision; single deviations in the system of blue (azure, blue, blue; color I order (blue, III order (blue, azure; tone in RGB — (0–239: blue (azure, blue — 140, blue — 160; HCV — blue (azure, blue — 210, blue — 240; range of wavelengths: 450–500 nm (blue — 485–500, blue — 440–485; frequencies: 600–680 THz (blue — 600–620, blue — 620–680. Control group — SITA-SWAP within the norm, Mansell test: TES = 40,1±17,3 (p<0.05, medium level of color recognition, lack of color vision absent / mild, single deviations.Conclusion: in patients with glaucoma suspicion, the score of errors was higher than in the control group with Munsell test. In patients with glaucoma, the number of errors is greater than in patients with suspected glaucoma, and 2.2 times higher than in the control group.

  7. Complementary shifts in photoreceptor spectral tuning unlock the full adaptive potential of ultraviolet vision in birds.

    Science.gov (United States)

    Toomey, Matthew B; Lind, Olle; Frederiksen, Rikard; Curley, Robert W; Riedl, Ken M; Wilby, David; Schwartz, Steven J; Witt, Christopher C; Harrison, Earl H; Roberts, Nicholas W; Vorobyev, Misha; McGraw, Kevin J; Cornwall, M Carter; Kelber, Almut; Corbo, Joseph C

    2016-07-12

    Color vision in birds is mediated by four types of cone photoreceptors whose maximal sensitivities (λmax) are evenly spaced across the light spectrum. In the course of avian evolution, the λmax of the most shortwave-sensitive cone, SWS1, has switched between violet (λmax > 400 nm) and ultraviolet (λmax < 380 nm) multiple times. This shift of the SWS1 opsin is accompanied by a corresponding short-wavelength shift in the spectrally adjacent SWS2 cone. Here, we show that SWS2 cone spectral tuning is mediated by modulating the ratio of two apocarotenoids, galloxanthin and 11’,12’-dihydrogalloxanthin, which act as intracellular spectral filters in this cell type. We propose an enzymatic pathway that mediates the differential production of these apocarotenoids in the avian retina, and we use color vision modeling to demonstrate how correlated evolution of spectral tuning is necessary to achieve even sampling of the light spectrum and thereby maintain near-optimal color discrimination.

  8. Multi-sparse dictionary colorization algorithm based on the feature classification and detail enhancement

    Science.gov (United States)

    Yan, Dan; Bai, Lianfa; Zhang, Yi; Han, Jing

    2018-02-01

    For the problems of missing details and performance of the colorization based on sparse representation, we propose a conceptual model framework for colorizing gray-scale images, and then a multi-sparse dictionary colorization algorithm based on the feature classification and detail enhancement (CEMDC) is proposed based on this framework. The algorithm can achieve a natural colorized effect for a gray-scale image, and it is consistent with the human vision. First, the algorithm establishes a multi-sparse dictionary classification colorization model. Then, to improve the accuracy rate of the classification, the corresponding local constraint algorithm is proposed. Finally, we propose a detail enhancement based on Laplacian Pyramid, which is effective in solving the problem of missing details and improving the speed of image colorization. In addition, the algorithm not only realizes the colorization of the visual gray-scale image, but also can be applied to the other areas, such as color transfer between color images, colorizing gray fusion images, and infrared images.

  9. How do we select multiple features? Transient costs for selecting two colors rather than one, persistent costs for color-location conjunctions.

    Science.gov (United States)

    Lo, Shih-Yu; Holcombe, Alex O

    2014-02-01

    In a previous study Lo, Howard, & Holcombe (Vision Research 63:20-33, 2012), selecting two colors did not induce a performance cost, relative to selecting one color. For example, requiring possible report of both a green and a red target did not yield a worse performance than when both targets were green. Yet a cost of selecting multiple colors was observed when selection needed be contingent on both color and location. When selecting a red target to the left and a green target to the right, superimposing a green distractor to the left and a red distractor to the right impeded performance. Possibly, participants cannot confine attention to a color at a particular location. As a result, distractors that share the target colors disrupt attentional selection of the targets. The attempt to select the targets must then be repeated, which increases the likelihood that the trial terminates when selection is not effective, even for long trials. Consistent with this, here we find a persistent cost of selecting two colors when the conjunction of color and location is needed, but the cost is confined to short exposure durations when the observer just has to monitor red and green stimuli without the need to use the location information. These results suggest that selecting two colors is time-consuming but effective, whereas selection of simultaneous conjunctions is never entirely successful.

  10. Prediction of pork loin quality using online computer vision system and artificial intelligence model.

    Science.gov (United States)

    Sun, Xin; Young, Jennifer; Liu, Jeng-Hung; Newman, David

    2018-06-01

    The objective of this project was to develop a computer vision system (CVS) for objective measurement of pork loin under industry speed requirement. Color images of pork loin samples were acquired using a CVS. Subjective color and marbling scores were determined according to the National Pork Board standards by a trained evaluator. Instrument color measurement and crude fat percentage were used as control measurements. Image features (18 color features; 1 marbling feature; 88 texture features) were extracted from whole pork loin color images. Artificial intelligence prediction model (support vector machine) was established for pork color and marbling quality grades. The results showed that CVS with support vector machine modeling reached the highest prediction accuracy of 92.5% for measured pork color score and 75.0% for measured pork marbling score. This research shows that the proposed artificial intelligence prediction model with CVS can provide an effective tool for predicting color and marbling in the pork industry at online speeds. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Performance evaluation of various classifiers for color prediction of rice paddy plant leaf

    Science.gov (United States)

    Singh, Amandeep; Singh, Maninder Lal

    2016-11-01

    The food industry is one of the industries that uses machine vision for a nondestructive quality evaluation of the produce. These quality measuring systems and softwares are precalculated on the basis of various image-processing algorithms which generally use a particular type of classifier. These classifiers play a vital role in making the algorithms so intelligent that it can contribute its best while performing the said quality evaluations by translating the human perception into machine vision and hence machine learning. The crop of interest is rice, and the color of this crop indicates the health status of the plant. An enormous number of classifiers are available to solve the purpose of color prediction, but choosing the best among them is the focus of this paper. Performance of a total of 60 classifiers has been analyzed from the application point of view, and the results have been discussed. The motivation comes from the idea of providing a set of classifiers with excellent performance and implementing them on a single algorithm for the improvement of machine vision learning and, hence, associated applications.

  12. Molecular Basis for Ultraviolet Vision in Invertebrates

    OpenAIRE

    Salcedo, Ernesto; Zheng, Lijun; Phistry, Meridee; Bagg, Eve E.; Britt, Steven G.

    2003-01-01

    Invertebrates are sensitive to a broad spectrum of light that ranges from UV to red. Color sensitivity in the UV plays an important role in foraging, navigation, and mate selection in both flying and terrestrial invertebrate animals. Here, we show that a single amino acid polymorphism is responsible for invertebrate UV vision. This residue (UV: lysine vs blue:asparagine or glutamate) corresponds to amino acid position glycine 90 (G90) in bovine rhodopsin, a site affected in autosomal dominant...

  13. Generating Selected Color using RGB, Auxiliary Lights, and Simplex Search

    Directory of Open Access Journals (Sweden)

    Kim HyungTae

    2015-01-01

    Full Text Available A mixed light source generates various colors, with the potential to adjust intensities of multiple LEDs, which makes it possible to generate arbitrary colors. Currently, PCs and OSs provide color selection windows that can obtain the RGB or HSL color coordinates of a user’s selection. Mixed light sources are usually composed of LEDs in the primary colors, with LEDs in auxiliary colors such as white and yellow used in a few cases. When using auxiliary color LEDs, the number of LED inputs, the dimming levels, is larger than the number of elements in the color coordinate, which causes an under-determined problem. This study proposed how to determine the dimming levels of LEDs based on the selected color. Commercial LEDs have di_erent optical power values and impure color coordinates, even if they are RGB. Hence, the characteristics of the LEDs were described using a linear model derived from the tri-stimulus values (an XYZ color coordinate model and dimming levels. Color mixing models were derived for the arbitrary number of auxiliary color LEDs. The under-determined problem was solved using a simplex search method without an inverse matrix operation. The proposed method can be applied to a machine vision system and an RGBW light mixer for semiconductor inspection. The dimming levels, obtained using the proposed method were better than derived using other methods.

  14. A Multiple Sensor Machine Vision System for Automatic Hardwood Feature Detection

    Science.gov (United States)

    D. Earl Kline; Richard W. Conners; Daniel L. Schmoldt; Philip A. Araman; Robert L. Brisbin

    1993-01-01

    A multiple sensor machine vision prototype is being developed to scan full size hardwood lumber at industrial speeds for automatically detecting features such as knots holes, wane, stain, splits, checks, and color. The prototype integrates a multiple sensor imaging system, a materials handling system, a computer system, and application software. The prototype provides...

  15. The Achromatic ‘Philosophical Zombie', a Syndrome of Cerebral Achromatopsia with Color Anopsognosia

    Directory of Open Access Journals (Sweden)

    Antonio Carota

    2013-04-01

    Full Text Available We describe a patient with persistent cerebral achromatopsia occurring after bilateral occipital strokes. Blinded color recognition was assessed with a computerized experimental paradigm and the patient reported the degree of confidence in the response exactness on a visual percent scale. Color recognition was accurate and above chance (Fisher's exact test, p < 0.002. The degree of confidence in the answers showed a significant correlation with recognition scores (Spearman rank order correlation, p < 0.0001. These findings constitute the exceptional condition of what we called color anopsognosia (not knowing of seeing colors and recall the theoretic figure of the ‘philosophical zombie'. However, the cognitive mechanisms of the dissociation between a subjective colorless vision and good performance for color naming still remain poorly understood.

  16. [A study of biomechanical method for urine test based on color difference estimation].

    Science.gov (United States)

    Wang, Chunhong; Zhou, Yue; Zhao, Hongxia; Zhou, Fengkun

    2008-02-01

    The biochemical analysis of urine is an important inspection and diagnosis method in hospitals. The conventional method of urine analysis covers mainly colorimetric visual appraisement and automation detection, in which the colorimetric visual appraisement technique has been superseded basically, and the automation detection method is adopted in hospital; moreover, the price of urine biochemical analyzer on market is around twenty thousand RMB yuan (Y), which is hard to enter into ordinary families. It is known that computer vision system is not subject to the physiological and psychological influence of person, its appraisement standard is objective and steady. Therefore, according to the color theory, we have established a computer vision system, which can carry through collection, management, display, and appraisement of color difference between the color of standard threshold value and the color of urine test paper after reaction with urine liquid, and then the level of an illness can be judged accurately. In this paper, we introduce the Urine Test Biochemical Analysis method, which is new and can be popularized in families. Experimental result shows that this test method is easy-to-use and cost-effective. It can realize the monitoring of a whole course and can find extensive applications.

  17. Characteristics and New Measurement Method of NCSFs of Individual Color Mechanisms of Human Vision

    International Nuclear Information System (INIS)

    Jing-Jing, Ge; Zhao-Qi, Wang; Yan, Wang; Kan-Xing, Zhao

    2010-01-01

    We propose a new method for determining neural contrast sensitivity functions (NCSFs) of isolated color mechanisms based on the measurements of wave-front aberrations and isoluminant color contrast sensitivity functions (CSFs). Compared with the traditional method, this technique avoids the coherent noise and speckle noise, which are brought by the interference of laser beams, and has great flexibility for the measurements of NCSF of different color mechanisms. Our experiments indicate that the mean NCSF and CSF of the red mechanism are higher than those of the green mechanism, respectively, while those of the blue mechanism are the lowest. However the relative heights of the peak of NCSF and CSF between red and green mechanisms vary in subjects. There are some individuals whose peak values of NCSF and/or CSF of green mechanism are higher than that of the red mechanism. The NCSFs and CSFs of isolated color mechanisms all exhibit the similar characteristics and variation tendency. With the statistical average, the NCSFs of the red, green and blue mechanisms are higher than the corresponding CSFs in the whole spatial frequency. Compared with the corresponding CSFs curves, the peaks of the NCSFs of isolated color mechanisms shift toward higher spatial frequencies, especially for that of blue mechanism which has a largest shift of 3.9c/deg

  18. Single Lens Dual-Aperture 3D Imaging System: Color Modeling

    Science.gov (United States)

    Bae, Sam Y.; Korniski, Ronald; Ream, Allen; Fritz, Eric; Shearn, Michael

    2012-01-01

    In an effort to miniaturize a 3D imaging system, we created two viewpoints in a single objective lens camera. This was accomplished by placing a pair of Complementary Multi-band Bandpass Filters (CMBFs) in the aperture area. Two key characteristics about the CMBFs are that the passbands are staggered so only one viewpoint is opened at a time when a light band matched to that passband is illuminated, and the passbands are positioned throughout the visible spectrum, so each viewpoint can render color by taking RGB spectral images. Each viewpoint takes a different spectral image from the other viewpoint hence yielding a different color image relative to the other. This color mismatch in the two viewpoints could lead to color rivalry, where the human vision system fails to resolve two different colors. The difference will be closer if the number of passbands in a CMBF increases. (However, the number of passbands is constrained by cost and fabrication technique.) In this paper, simulation predicting the color mismatch is reported.

  19. Dichromatic light halting using double spin coherence gratings

    International Nuclear Information System (INIS)

    Ham, Byoung S; Hahn, Joonseong

    2011-01-01

    Light control by another light has drawn much attention in nonlinear quantum optics. Achieving all-optical control of the refractive index has been a key issue in all-optical information processing. Ultraslow light has been a good candidate for this purpose, where a giant phase shift can be achieved. The recent presentation of stationary light utilizing ultraslow light is an advanced example of such research. The stationary light functions as cavity quantum electrodynamics, where no high-Q-factor mirror pair is needed. In this paper, we report on two-color halted light pulses inside a solid medium, where the trapping time is comparable with that of ultraslow light but is much longer than quantum mapping storage time. The observed two-color halted light is achieved by means of double Raman optical field-excited spin coherence gratings, where slow light enhanced backward nondegenerate four-wave mixing processes play a major role.

  20. Dichromatic light halting using double spin coherence gratings

    Energy Technology Data Exchange (ETDEWEB)

    Ham, Byoung S; Hahn, Joonseong, E-mail: bham@inha.ac.kr [Center for Photon Information Processing, School of Electrical Engineering, Inha University, 253 Yoghyun-dong, Nam-gu, Incheon 402-751 (Korea, Republic of)

    2011-08-15

    Light control by another light has drawn much attention in nonlinear quantum optics. Achieving all-optical control of the refractive index has been a key issue in all-optical information processing. Ultraslow light has been a good candidate for this purpose, where a giant phase shift can be achieved. The recent presentation of stationary light utilizing ultraslow light is an advanced example of such research. The stationary light functions as cavity quantum electrodynamics, where no high-Q-factor mirror pair is needed. In this paper, we report on two-color halted light pulses inside a solid medium, where the trapping time is comparable with that of ultraslow light but is much longer than quantum mapping storage time. The observed two-color halted light is achieved by means of double Raman optical field-excited spin coherence gratings, where slow light enhanced backward nondegenerate four-wave mixing processes play a major role.

  1. How To Control Color Appearance With Instrumentation

    Science.gov (United States)

    Burns, Margaret E.

    1980-05-01

    Colorimetry, as defined by the International Commission on Illumination, is the measurement of colors, made possible by the properties of the eye and based on a set of conventions. Instrumentation for measuring object color, therefore, must be based on a human observer. The intent is to design an instrument that in effect responds as a person would, so that research development, production control and quality control areas have some means of assessing the acceptability of the appearance of a product. Investigations of a human observer's psychological response to color, and the manner in which visual observations are made, give the instrument designer and manufacturer data necessary to answer two questions: a. How can we put numbers (instrument read-out) on a perception that occurs in the brain of the observer? b. What can we learn from examination of a visual observing situation that will guide us in our design of an instrumental simulation of this situation? Involving as it does our own daily, almost unconscious, practice of making judgments concerning the things we see, the design and manufacture of color measurement instruments is an exceedingly interesting field. The advances being made concurrently today in research concerning human color vision and in optical and electronic technology will make possible increasingly useful instrumentation for quality control of product color.

  2. Color encoding in biologically-inspired convolutional neural networks.

    Science.gov (United States)

    Rafegas, Ivet; Vanrell, Maria

    2018-05-11

    Convolutional Neural Networks have been proposed as suitable frameworks to model biological vision. Some of these artificial networks showed representational properties that rival primate performances in object recognition. In this paper we explore how color is encoded in a trained artificial network. It is performed by estimating a color selectivity index for each neuron, which allows us to describe the neuron activity to a color input stimuli. The index allows us to classify whether they are color selective or not and if they are of a single or double color. We have determined that all five convolutional layers of the network have a large number of color selective neurons. Color opponency clearly emerges in the first layer, presenting 4 main axes (Black-White, Red-Cyan, Blue-Yellow and Magenta-Green), but this is reduced and rotated as we go deeper into the network. In layer 2 we find a denser hue sampling of color neurons and opponency is reduced almost to one new main axis, the Bluish-Orangish coinciding with the dataset bias. In layers 3, 4 and 5 color neurons are similar amongst themselves, presenting different type of neurons that detect specific colored objects (e.g., orangish faces), specific surrounds (e.g., blue sky) or specific colored or contrasted object-surround configurations (e.g. blue blob in a green surround). Overall, our work concludes that color and shape representation are successively entangled through all the layers of the studied network, revealing certain parallelisms with the reported evidences in primate brains that can provide useful insight into intermediate hierarchical spatio-chromatic representations. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Development of a body motion interactive system with a weight voting mechanism and computer vision technology

    Science.gov (United States)

    Lin, Chern-Sheng; Chen, Chia-Tse; Shei, Hung-Jung; Lay, Yun-Long; Chiu, Chuang-Chien

    2012-09-01

    This study develops a body motion interactive system with computer vision technology. This application combines interactive games, art performing, and exercise training system. Multiple image processing and computer vision technologies are used in this study. The system can calculate the characteristics of an object color, and then perform color segmentation. When there is a wrong action judgment, the system will avoid the error with a weight voting mechanism, which can set the condition score and weight value for the action judgment, and choose the best action judgment from the weight voting mechanism. Finally, this study estimated the reliability of the system in order to make improvements. The results showed that, this method has good effect on accuracy and stability during operations of the human-machine interface of the sports training system.

  4. A MULTI-STAGE COLOR MODEL REVISITED: IMPLICATIONS FOR A GENE THERAPY CURE FOR RED-GREEN COLORBLINDNESS

    OpenAIRE

    Mancuso, Katherine; Mauck, Matthew C.; Kuchenbecker, James A.; Neitz, Maureen; Neitz, Jay

    2010-01-01

    In 1993, DeValois and DeValois proposed a “multi-stage color model” to explain how the cortex is ultimately able to deconfound the responses of neurons receiving input from three cone types in order to produce separate red-green and blue-yellow systems, as well as segregate luminance percepts (black-white) from color. This model extended the biological implementation of Hurvich and Jameson’s Opponent-Process Theory of color vision, a two-stage model encompassing the three cone types combined ...

  5. [Vision test program for ophthalmologists on Apple II, IIe and IIc computers].

    Science.gov (United States)

    Huber, C

    1985-03-01

    A microcomputer program for the Apple II family of computers on a monochrome and a color screen is described. The program draws most of the tests used by ophthalmologists, and is offered as an alternative to a projector system. One advantage of the electronic generation of drawings is that true random orientation of Pflueger's E is possible. Tests are included for visual acuity (Pflueger's E, Landolt rings, numbers and children's drawings). Colored tests include a duochrome test, simple color vision tests, a fixation help with a musical background, a cobalt blue test and a Worth figure. In the astigmatic dial a mobile pointer helps to determine the axis. New tests can be programmed by the user and exchanged on disks among collageues.

  6. Colors Identification for Blind People using Cell Phone

    International Nuclear Information System (INIS)

    Dominguez, A L; Graffigna, J P

    2011-01-01

    Assistive Technology (AT) is an interdisciplinary research area that allows finding solutions to the individual with disability by easing or improving the functions or the skills for accomplishing daily activities. A technology can be considered 'assistive' if it is fit for the needs, skills and capabilities of the person, taking into account mainly the intended activity and the limitations of the context and environs where the person performs such activity. The current work intends to solve the problems of vision impaired persons to recognize colors. To this aim, a Java application for cell phones has been made which lets complement the mobiles' technology with that of image processing. The means to obtain the colors from a view are based on analysing the different color models join to a mechanism to reduce the collected data. This paper describes preliminary experiences, methodology and results considering the user perception.

  7. Colors Identification for Blind People using Cell Phone

    Science.gov (United States)

    Dominguez, A. L.; Graffigna, J. P.

    2011-12-01

    Assistive Technology (AT) is an interdisciplinary research area that allows finding solutions to the individual with disability [1] by easing or improving the functions or the skills for accomplishing daily activities. A technology can be considered "assistive" if it is fit for the needs, skills and capabilities of the person, taking into account mainly the intended activity and the limitations of the context and environs where the person performs such activity. The current work intends to solve the problems of vision impaired persons to recognize colors. To this aim, a Java application for cell phones has been made which lets complement the mobiles' technology with that of image processing. The means to obtain the colors from a view are based on analysing the different color models join to a mechanism to reduce the collected data. This paper describes preliminary experiences, methodology and results considering the user perception.

  8. The fossil record, function, and possible origins of shell color patterns in Paleozoic marine invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Kobluk, D.R. (Univ. of Toronto, Ontario (Canada)); Mapes, R.H. (Ohio Univ., Athens (USA))

    1989-02-01

    Fossil invertebrate shells and carapaces displaying preserved original color patterns are among the rarest fossils. The fossil record of color patterns extends into the Middle Cambrian where the trilobite Anomocare displays a fan-like array of stripes on the pygidium. About 180 Paleozic genera are known with patterns, including trilobites, cephalopods, gastropods, brachiopods, bivalves, crinoids, and crustaceans. Based upon an analysis of these taxa, it appears that patterns and pigments in middle and late Paleozoic invertebrates may have served several functions such as warning displays, light screening, camouflage, or waste disposal. However, the presence of color patterns in fossil invertebrates in the early Paleozoic may have developed prior to the evolution of vision sufficiently sophisticated to see them. This suggests that camouflage and warning displays were not the original functions of color patterns, and that in the earliest Paleozoic they may not have been functional. The authors propose a hypothesis that involves three developmental phases in the evolution of invertebrate color patterns: (1) the incorporation of metabolic by-products, perhaps some pigmented and some not pigmented, into shells and carapaces as a means of disposal of dietary or metabolic wastes, (2) use of these pigments and patterns as an environmental adaptation, such as light screening, and (3) display during and following the evolution of vision in predators sufficiently sophisticated to see the patterns.

  9. The watercolor illusion and neon color spreading: a unified analysis of new cases and neural mechanisms

    Science.gov (United States)

    Pinna, Baingio; Grossberg, Stephen

    2005-10-01

    Coloration and figural properties of neon color spreading and the watercolor illusion are studied using phenomenal and psychophysical observations. Coloration properties of both effects can be reduced to a common limiting condition, a nearby color transition called the two-dot limiting case, which clarifies their perceptual similarities and dissimilarities. The results are explained by the FACADE neural model of biological vision. The model proposes how local properties of color transitions activate spatial competition among nearby perceptual boundaries, with boundaries of lower-contrast edges weakened by competition more than boundaries of higher-contrast edges. This asymmetry induces spreading of more color across these boundaries than conversely. The model also predicts how depth and figure-ground effects are generated in these illusions.

  10. Sex differences in color preferences transcend extreme differences in culture and ecology.

    Science.gov (United States)

    Sorokowski, Piotr; Sorokowska, Agnieszka; Witzel, Christoph

    2014-10-01

    At first glance, color preferences might seem to be the most subjective and context-dependent aspects of color cognition. Yet they are not. The present study compares color preferences of women and men from an industrialized and a remote, nonindustrialized culture. In particular, we investigated preferences in observers from Poland and from the Yali in Papua, respectively. Not surprisingly, we found that color preferences clearly differed between the two communities and also between sexes. However, despite the pronounced cultural differences, the way in which men and women differed from each other was almost the same in both cultures. At the same time, this sexual contrast was not specific to biological components of color vision. Our results reveal a pattern of sexual dimorphism that transcends extreme differences in culture and ecology. They point toward strong cross-cultural constraints beyond the biological predispositions of nature and the cultural particularities of nurture.

  11. Vision under mesopic and scotopic illumination

    Directory of Open Access Journals (Sweden)

    Andrew J Zele

    2015-01-01

    Full Text Available Evidence has accumulated that rod activation under mesopic and scotopic light levels alters visual perception and performance. Here we review the most recent developments in the measurement of rod and cone contributions to mesopic color perception and temporal processing, with a focus on data measured using the four-primary photostimulator method that independently controls rod and cone excitations. We discuss the findings in the context of rod inputs to the three primary retinogeniculate pathways to understand rod contributions to mesopic vision. Additionally, we present evidence that hue perception is possible under scotopic, pure rod-mediated conditions that involves cortical mechanisms.

  12. 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.

  13. 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.

  14. Real-time implementation of a color sorting system

    Science.gov (United States)

    Srikanteswara, Srikathyanyani; Lu, Qiang O.; King, William; Drayer, Thomas H.; Conners, Richard W.; Kline, D. Earl; Araman, Philip A.

    1997-09-01

    Wood edge glued panels are used extensively in the furniture and cabinetry industries. They are used to make doors, tops, and sides of solid wood furniture and cabinets. Since lightly stained furniture and cabinets are gaining in popularity, there is an increasing demand to color sort the parts used to make these edge glued panels. The goal of the sorting processing is to create panels that are uniform in both color and intensity across their visible surface. If performed manually, the color sorting of edge-glued panel parts is very labor intensive and prone to error. This paper describes a complete machine vision system for performing this sort. This system uses two color line scan cameras for image input and a specially designed custom computing machine to allow real-time implementation. Users define the number of color classes that are to be used. An 'out' class is provided to handle unusually colored parts. The system removes areas of character mark, e.g., knots, mineral streak, etc., from consideration when assigning a color class to a part. The system also includes a better face algorithm for determining which part face would be the better to put on the side of the panel that will show. The throughput is two linear feet per second. Only a four inch between part spacing is required. This system has undergone extensive in plant testing and will be commercially available in the very near future. The results of this testing will be presented.

  15. La strana storia della luce e del colore

    CERN Document Server

    Guzzi, Rodolfo

    2011-01-01

    Sino al 1600 la luce era oggetto di studio degli scienziati ed il colore dei filosofi. Questa dicotomia fu superata dall’Esperimentum Crucis di Newton che spiego’ come la luce contenesse il colore. Il libro analizza le teorie che furono sviluppate dai greci, per evolversi successivamente nelle teorie degli scienziati arabi e approdare al medio evo. Con l’Esperimentum Crucis Newton dimostro’ che la luce conteneva i colori primari. Tra gli esperimenti che egli fece ci furono anche quelli sulla percezione che risultarono sbagliati; solo Goethe capi’ quale era la vera portata di quegli esperimenti e li rifece dando una interpretazione che, oggi, sappiamo essere vera, ma che a quel tempo fu alquanto osteggiata. Nel frattempo la comunita’ scientifica progrediva sul concetto di visione e di sensazione, poiche’ gli strumenti di indagine si raffinavano. Bisogna pero’ arrivare ai giorni nostri per avere una spiegazione sul comportamento della luce e del colore e come questa viene percepita da noi. Solo ...

  16. An effective image classification method with the fusion of invariant feature and a new color descriptor

    Science.gov (United States)

    Mansourian, Leila; Taufik Abdullah, Muhamad; Nurliyana Abdullah, Lili; Azman, Azreen; Mustaffa, Mas Rina

    2017-02-01

    Pyramid Histogram of Words (PHOW), combined Bag of Visual Words (BoVW) with the spatial pyramid matching (SPM) in order to add location information to extracted features. However, different PHOW extracted from various color spaces, and they did not extract color information individually, that means they discard color information, which is an important characteristic of any image that is motivated by human vision. This article, concatenated PHOW Multi-Scale Dense Scale Invariant Feature Transform (MSDSIFT) histogram and a proposed Color histogram to improve the performance of existing image classification algorithms. Performance evaluation on several datasets proves that the new approach outperforms other existing, state-of-the-art methods.

  17. Stimulation of functional vision in children with perinatal brain damage.

    Science.gov (United States)

    Alimović, Sonja; Mejaski-Bosnjak, Vlatka

    2011-01-01

    Cerebral visual impairment (CVI) is one of the most common causes of bilateral visual loss, which frequently occurs due to perinatal brain injury. Vision in early life has great impact on acquisition of basic comprehensions which are fundamental for further development. Therefore, early detection of visual problems and early intervention is necessary. The aim of the present study is to determine specific visual functioning of children with perinatal brain damage and the influence of visual stimulation on development of functional vision at early age of life. We initially assessed 30 children with perinatal brain damage up to 3 years of age, who were reffered to our pediatric low vision cabinet in "Little house" from child neurologists, ophthalmologists Type and degree of visual impairment was determined according to functional vision assessment of each child. On the bases of those assessments different kind of visual stimulations were carried out with children who have been identified to have a certain visual impairment. Through visual stimulation program some of the children were stimulated with light stimulus, some with different materials under the ultraviolet (UV) light, and some with bright color and high contrast materials. Children were also involved in program of early stimulation of overall sensory motor development. Goals and methods of therapy were determined individually, based on observation of child's possibilities and need. After one year of program, reassessment was done. Results for visual functions and functional vision were compared to evaluate the improvement of the vision development. These results have shown that there was significant improvement in functional vision, especially in visual attention and visual communication.

  18. Color-Blindness vs. Race Matters: Pre-School Education and the Need for a Communal Vision

    Science.gov (United States)

    Hein, Christina Judith

    2004-01-01

    The author discerns two trends ruling with many of the teachers, intellectuals, and citizens of the United States. One is the color-blind-myth that Williams (1997) cites in her essay, "The Emperor's New Clothes": "I don't think about color, therefore your problems don't exist," is the phrase that she attributes to this "school of idealism". The…

  19. Etude des potentialités de la vision artificielle pour la reconnaissance optique des semences immatures de chicorée industrielle (Cichorium intybus L.

    Directory of Open Access Journals (Sweden)

    Ooms, D.

    2010-01-01

    Full Text Available Study of the potentialities of machine vision used for optical selection of immature seeds of industrial chicory (Cichorium intybus L.. The commercial production of industrial chicory seeds (cypselae includes the postharvest elimination of non-viable seeds by non-destructive tools. For this purpose, two machine vision methods are described for the detection of non-viable seeds: color vision and fluorescence imaging. The analysis of color images of 1,500 seeds of the 'Nausica' variety allows only the recognition of desiccated and undeveloped seeds. This is caused by the large variability of seed color, shape and texture. Fluorescence imaging is set up in order to analyze the repartition of chlorophyll fluorescence, a marker of seed maturity, on different areas of the seed (pericarp, radicle tip and pappus. A very sensitive system is needed due to the low chlorophyll content and the large amount of seeds to be sorted. A fluorescence imaging system is proposed. Its distinctive feature is the possibility to modify the spectrum of the light source (in order to optimize the sensibility of the machine vision system and to record the evolution of fluorescence repartition with time. The system is functional and delivers images of fluorescence repartition within external cypsela tissues. It could allow to analyze the fluorescence of a large sample of seeds to correlate fluorescence features to germinability and maturity.

  20. Can invertebrates see the e-vector of polarization as a separate modality of light?

    Science.gov (United States)

    Labhart, Thomas

    2016-12-15

    The visual world is rich in linearly polarized light stimuli, which are hidden from the human eye. But many invertebrate species make use of polarized light as a source of valuable visual information. However, exploiting light polarization does not necessarily imply that the electric (e)-vector orientation of polarized light can be perceived as a separate modality of light. In this Review, I address the question of whether invertebrates can detect specific e-vector orientations in a manner similar to that of humans perceiving spectral stimuli as specific hues. To analyze e-vector orientation, the signals of at least three polarization-sensitive sensors (analyzer channels) with different e-vector tuning axes must be compared. The object-based, imaging polarization vision systems of cephalopods and crustaceans, as well as the water-surface detectors of flying backswimmers, use just two analyzer channels. Although this excludes the perception of specific e-vector orientations, a two-channel system does provide a coarse, categoric analysis of polarized light stimuli, comparable to the limited color sense of dichromatic, 'color-blind' humans. The celestial compass of insects employs three or more analyzer channels. However, that compass is multimodal, i.e. e-vector information merges with directional information from other celestial cues, such as the solar azimuth and the spectral gradient in the sky, masking e-vector information. It seems that invertebrate organisms take no interest in the polarization details of visual stimuli, but polarization vision grants more practical benefits, such as improved object detection and visual communication for cephalopods and crustaceans, compass readings to traveling insects, or the alert 'water below!' to water-seeking bugs. © 2016. Published by The Company of Biologists Ltd.

  1. 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 ...

  2. A simple approach to a vision-guided unmanned vehicle

    Science.gov (United States)

    Archibald, Christopher; Millar, Evan; Anderson, Jon D.; Archibald, James K.; Lee, Dah-Jye

    2005-10-01

    This paper describes the design and implementation of a vision-guided autonomous vehicle that represented BYU in the 2005 Intelligent Ground Vehicle Competition (IGVC), in which autonomous vehicles navigate a course marked with white lines while avoiding obstacles consisting of orange construction barrels, white buckets and potholes. Our project began in the context of a senior capstone course in which multi-disciplinary teams of five students were responsible for the design, construction, and programming of their own robots. Each team received a computer motherboard, a camera, and a small budget for the purchase of additional hardware, including a chassis and motors. The resource constraints resulted in a simple vision-based design that processes the sequence of images from the single camera to determine motor controls. Color segmentation separates white and orange from each image, and then the segmented image is examined using a 10x10 grid system, effectively creating a low resolution picture for each of the two colors. Depending on its position, each filled grid square influences the selection of an appropriate turn magnitude. Motor commands determined from the white and orange images are then combined to yield the final motion command for video frame. We describe the complete algorithm and the robot hardware and we present results that show the overall effectiveness of our control approach.

  3. 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.

  4. 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.

  5. 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.

  6. Image processing analysis of traditional Gestalt vision experiments

    Science.gov (United States)

    McCann, John J.

    2002-06-01

    In the late 19th century, the Gestalt Psychology rebelled against the popular new science of Psychophysics. The Gestalt revolution used many fascinating visual examples to illustrate that the whole is greater than the sum of all the parts. Color constancy was an important example. The physical interpretation of sensations and their quantification by JNDs and Weber fractions were met with innumerable examples in which two 'identical' physical stimuli did not look the same. The fact that large changes in the color of the illumination failed to change color appearance in real scenes demanded something more than quantifying the psychophysical response of a single pixel. The debates continues today with proponents of both physical, pixel-based colorimetry and perceptual, image- based cognitive interpretations. Modern instrumentation has made colorimetric pixel measurement universal. As well, new examples of unconscious inference continue to be reported in the literature. Image processing provides a new way of analyzing familiar Gestalt displays. Since the pioneering experiments by Fergus Campbell and Land, we know that human vision has independent spatial channels and independent color channels. Color matching data from color constancy experiments agrees with spatial comparison analysis. In this analysis, simple spatial processes can explain the different appearances of 'identical' stimuli by analyzing the multiresolution spatial properties of their surrounds. Benary's Cross, White's Effect, the Checkerboard Illusion and the Dungeon Illusion can all be understood by the analysis of their low-spatial-frequency components. Just as with color constancy, these Gestalt images are most simply described by the analysis of spatial components. Simple spatial mechanisms account for the appearance of 'identical' stimuli in complex scenes. It does not require complex, cognitive processes to calculate appearances in familiar Gestalt experiments.

  7. Color naming deficits and attention-deficit/hyperactivity disorder: A retinal dopaminergic hypothesis

    Directory of Open Access Journals (Sweden)

    Tannock Rosemary

    2006-01-01

    Full Text Available Abstract Background Individuals with Attention-Deficit/Hyperactive Disorder (ADHD have unexplained difficulties on tasks requiring speeded processing of colored stimuli. Color vision mechanisms, particularly short-wavelength (blue-yellow pathways, are highly sensitive to various diseases, toxins and drugs that alter dopaminergic neurotransmission. Thus, slow color processing might reflect subtle impairments in the perceptual encoding stage of stimulus color, which arise from hypodopaminergic functioning. Presentation of hypotheses 1 Color perception of blue-yellow (but not red-green stimuli is impaired in ADHD as a result of deficient retinal dopamine; 2 Impairments in the blue-yellow color mechanism in ADHD contribute to poor performance on speeded color naming tasks that include a substantial proportion of blue-yellow stimuli; and 3 Methylphenidate increases central dopamine and is also believed to increase retinal dopamine, thereby normalizing blue-yellow color perception, which in turn improves performance on the speeded color naming tasks. Testing the hypothesis Requires three approaches, including:1 direct assessment of color perception in individuals with ADHD to determine whether blue-yellow color perception is selectively impaired; 2 determination of relationship between performance on neuropsychological tasks requiring speeded color processing and color perception; and 3 randomized, controlled pharmacological intervention with stimulant medication to examine the effects of enhancing central dopamine on color perception and task performance Implications of hypothesis If substantiated, the findings of color perception problems would necessitate a re-consideration of current neuropsychological models of attention-deficit/hyperactivity disorder, guide psycho-education, academic instruction, and require consideration of stimulus color in many of the widely used neuropsychological tests.

  8. Phases of daylight and the stability of color perception in the near peripheral human retina.

    Science.gov (United States)

    Panorgias, Athanasios; Kulikowski, Janus J; Parry, Neil R A; McKeefry, Declan J; Murray, Ian J

    2012-03-01

    Typical daylight extends from blue (morning sky) to orangey red (evening sky) and is represented mathematically as the Daylight Locus in color space. In this study, we investigate the impact of this daylight variation on human color vision. Thirty-eight color normal human observers performed an asymmetric color match in the near peripheral visual field. Unique hues were identified using a naming paradigm. The observers' performance for matching was almost perfectly coincident with the Daylight Locus but declined markedly in other regions. Interobserver variability reached a conspicuous minimum adjacent to the Daylight Locus and was maximal in the red and yellowish-green regions. In the naming task, unique blue and yellow were virtually coincident with the Daylight Locus. The results suggest that the mechanisms of color perception mediated by the phylogenetically older (blue-yellow) color pathway have been strongly influenced by the different phases of daylight.

  9. Color in Image and Video Processing: Most Recent Trends and Future Research Directions

    Directory of Open Access Journals (Sweden)

    Tominaga Shoji

    2008-01-01

    Full Text Available Abstract The motivation of this paper is to provide an overview of the most recent trends and of the future research directions in color image and video processing. Rather than covering all aspects of the domain this survey covers issues related to the most active research areas in the last two years. It presents the most recent trends as well as the state-of-the-art, with a broad survey of the relevant literature, in the main active research areas in color imaging. It also focuses on the most promising research areas in color imaging science. This survey gives an overview about the issues, controversies, and problems of color image science. It focuses on human color vision, perception, and interpretation. It focuses also on acquisition systems, consumer imaging applications, and medical imaging applications. Next it gives a brief overview about the solutions, recommendations, most recent trends, and future trends of color image science. It focuses on color space, appearance models, color difference metrics, and color saliency. It focuses also on color features, color-based object tracking, scene illuminant estimation and color constancy, quality assessment and fidelity assessment, color characterization and calibration of a display device. It focuses on quantization, filtering and enhancement, segmentation, coding and compression, watermarking, and lastly on multispectral color image processing. Lastly, it addresses the research areas which still need addressing and which are the next and future perspectives of color in image and video processing.

  10. Color in Image and Video Processing: Most Recent Trends and Future Research Directions

    Directory of Open Access Journals (Sweden)

    Konstantinos N. Plataniotis

    2008-05-01

    Full Text Available The motivation of this paper is to provide an overview of the most recent trends and of the future research directions in color image and video processing. Rather than covering all aspects of the domain this survey covers issues related to the most active research areas in the last two years. It presents the most recent trends as well as the state-of-the-art, with a broad survey of the relevant literature, in the main active research areas in color imaging. It also focuses on the most promising research areas in color imaging science. This survey gives an overview about the issues, controversies, and problems of color image science. It focuses on human color vision, perception, and interpretation. It focuses also on acquisition systems, consumer imaging applications, and medical imaging applications. Next it gives a brief overview about the solutions, recommendations, most recent trends, and future trends of color image science. It focuses on color space, appearance models, color difference metrics, and color saliency. It focuses also on color features, color-based object tracking, scene illuminant estimation and color constancy, quality assessment and fidelity assessment, color characterization and calibration of a display device. It focuses on quantization, filtering and enhancement, segmentation, coding and compression, watermarking, and lastly on multispectral color image processing. Lastly, it addresses the research areas which still need addressing and which are the next and future perspectives of color in image and video processing.

  11. Image mosaicking based on feature points using color-invariant values

    Science.gov (United States)

    Lee, Dong-Chang; Kwon, Oh-Seol; Ko, Kyung-Woo; Lee, Ho-Young; Ha, Yeong-Ho

    2008-02-01

    In the field of computer vision, image mosaicking is achieved using image features, such as textures, colors, and shapes between corresponding images, or local descriptors representing neighborhoods of feature points extracted from corresponding images. However, image mosaicking based on feature points has attracted more recent attention due to the simplicity of the geometric transformation, regardless of distortion and differences in intensity generated by camera motion in consecutive images. Yet, since most feature-point matching algorithms extract feature points using gray values, identifying corresponding points becomes difficult in the case of changing illumination and images with a similar intensity. Accordingly, to solve these problems, this paper proposes a method of image mosaicking based on feature points using color information of images. Essentially, the digital values acquired from a real digital color camera are converted to values of a virtual camera with distinct narrow bands. Values based on the surface reflectance and invariant to the chromaticity of various illuminations are then derived from the virtual camera values and defined as color-invariant values invariant to changing illuminations. The validity of these color-invariant values is verified in a test using a Macbeth Color-Checker under simulated illuminations. The test also compares the proposed method using the color-invariant values with the conventional SIFT algorithm. The accuracy of the matching between the feature points extracted using the proposed method is increased, while image mosaicking using color information is also achieved.

  12. Red, Purple and Pink: The Colors of Diffusion on Pinterest

    Science.gov (United States)

    Bakhshi, Saeideh; Gilbert, Eric

    2015-01-01

    Many lab studies have shown that colors can evoke powerful emotions and impact human behavior. Might these phenomena drive how we act online? A key research challenge for image-sharing communities is uncovering the mechanisms by which content spreads through the community. In this paper, we investigate whether there is link between color and diffusion. Drawing on a corpus of one million images crawled from Pinterest, we find that color significantly impacts the diffusion of images and adoption of content on image sharing communities such as Pinterest, even after partially controlling for network structure and activity. Specifically, Red, Purple and pink seem to promote diffusion, while Green, Blue, Black and Yellow suppress it. To our knowledge, our study is the first to investigate how colors relate to online user behavior. In addition to contributing to the research conversation surrounding diffusion, these findings suggest future work using sophisticated computer vision techniques. We conclude with a discussion on the theoretical, practical and design implications suggested by this work—e.g. design of engaging image filters. PMID:25658423

  13. Color-Image Classification Using MRFs for an Outdoor Mobile Robot

    Directory of Open Access Journals (Sweden)

    Moises Alencastre-Miranda

    2005-02-01

    Full Text Available In this paper, we suggest to use color-image classification (in several phases using Markov Random Fields (MRFs in order to understand natural images from outdoor environment's scenes for a mobile robot. We skip preprocessing phase having same results and better performance. In segmentation phase, we implement a color segmentation method considering I3 color space measure average in little image's cells obtained from a single split step. In classification phase, a MRF was used to identify regions as one of three selected classes; here, we consider at the same time the intrinsic color features of the image and the neighborhood system between image's cells. Finally, we use region growing and contextual information to correct misclassification errors. We have implemented and tested those phases with several images taken at our campus' gardens. We include some results in off-line processing mode and in on-line execution mode on an outdoor mobile robot. The vision system has been used for reactive exploration in an outdoor environment.

  14. The disparate histories of binocular vision and binaural hearing.

    Science.gov (United States)

    Wade, Nicholas J

    2018-01-01

    Vision and hearing are dependent on disparities of spatial patterns received by two eyes and on time and intensity differences to two ears. However, the experiences of a single world have masked attention to these disparities. While eyes and ears are paired, there has not been parity in the attention directed to their functioning. Phenomena involving binocular vision were commented upon since antiquity whereas those about binaural hearing are much more recent. This history is compared with respect to the experimental manipulations of dichoptic and dichotic stimuli and the instruments used to stimulate the paired organs. Binocular color mixing led to studies of binaural hearing and direction and distance in visual localization were analyzed before those for auditory localization. Experimental investigations began in the nineteenth century with the invention of instruments like the stereoscope and pseudoscope, soon to be followed by their binaural equivalents, the stethophone and pseudophone.

  15. Fiber optic coherent laser radar 3D vision system

    International Nuclear Information System (INIS)

    Clark, R.B.; Gallman, P.G.; Slotwinski, A.R.; Wagner, K.; Weaver, S.; Xu, Jieping

    1996-01-01

    This CLVS will provide a substantial advance in high speed computer vision performance to support robotic Environmental Management (EM) operations. This 3D system employs a compact fiber optic based scanner and operator at a 128 x 128 pixel frame at one frame per second with a range resolution of 1 mm over its 1.5 meter working range. Using acousto-optic deflectors, the scanner is completely randomly addressable. This can provide live 3D monitoring for situations where it is necessary to update once per second. This can be used for decontamination and decommissioning operations in which robotic systems are altering the scene such as in waste removal, surface scarafacing, or equipment disassembly and removal. The fiber- optic coherent laser radar based system is immune to variations in lighting, color, or surface shading, which have plagued the reliability of existing 3D vision systems, while providing substantially superior range resolution

  16. Colorimetric Characterization of Mobile Devices for Vision Applications.

    Science.gov (United States)

    de Fez, Dolores; Luque, Maria José; García-Domene, Maria Carmen; Camps, Vicente; Piñero, David

    2016-01-01

    Available applications for vision testing in mobile devices usually do not include detailed setup instructions, sacrificing rigor to obtain portability and ease of use. In particular, colorimetric characterization processes are generally obviated. We show that different mobile devices differ also in colorimetric profile and that those differences limit the range of applications for which they are most adequate. The color reproduction characteristics of four mobile devices, two smartphones (Samsung Galaxy S4, iPhone 4s) and two tablets (Samsung Galaxy Tab 3, iPad 4), have been evaluated using two procedures: 3D LUT (Look Up Table) and a linear model assuming primary constancy and independence of the channels. The color reproduction errors have been computed with the CIEDE2000 color difference formula. There is good constancy of primaries but large deviations of additivity. The 3D LUT characterization yields smaller reproduction errors and dispersions for the Tab 3 and iPhone 4 devices, but for the iPad 4 and S4, both models are equally good. The smallest reproduction errors occur with both Apple devices, although the iPad 4 has the highest number of outliers of all devices with both colorimetric characterizations. Even though there is good constancy of primaries, the large deviations of additivity exhibited by the devices and the larger reproduction errors make any characterization based on channel independence not recommendable. The smartphone screens show, in average, the best color reproduction performance, particularly the iPhone 4, and therefore, they are more adequate for applications requiring precise color reproduction.

  17. Alien vision exploring the electromagnetic spectrum with imaging technology

    CERN Document Server

    Richards, Austin A

    2011-01-01

    Austin Richards takes readers on a visual tour of the electromagnetic spectrum beyond the range of human sight, using imaging technology as the means to ""see"" invisible light. Dozens of colorful images and clear, concise descriptions make this an intriguing, accessible technical book. Richards explains the light spectrum, including visible light, and describes the advanced imaging technologies that enable humans to synthesize our own version of ""alien"" vision at different wavelengths, with applications ranging from fire fighting and law enforcement to botany and medicine. The second editio

  18. Modeling human color categorization: Color discrimination and color memory

    OpenAIRE

    Heskes, T.; van den Broek, Egon; Lucas, P.; Hendriks, Maria A.; Vuurpijl, L.G.; Puts, M.J.H.; Wiegerinck, W.

    2003-01-01

    Color matching in Content-Based Image Retrieval is done using a color space and measuring distances between colors. Such an approach yields non-intuitive results for the user. We introduce color categories (or focal colors), determine that they are valid, and use them in two experiments. The experiments conducted prove the difference between color categorization by the cognitive processes color discrimination and color memory. In addition, they yield a Color Look-Up Table, which can improve c...

  19. A combined vision-inertial fusion approach for 6-DoF object pose estimation

    Science.gov (United States)

    Li, Juan; Bernardos, Ana M.; Tarrío, Paula; Casar, José R.

    2015-02-01

    The estimation of the 3D position and orientation of moving objects (`pose' estimation) is a critical process for many applications in robotics, computer vision or mobile services. Although major research efforts have been carried out to design accurate, fast and robust indoor pose estimation systems, it remains as an open challenge to provide a low-cost, easy to deploy and reliable solution. Addressing this issue, this paper describes a hybrid approach for 6 degrees of freedom (6-DoF) pose estimation that fuses acceleration data and stereo vision to overcome the respective weaknesses of single technology approaches. The system relies on COTS technologies (standard webcams, accelerometers) and printable colored markers. It uses a set of infrastructure cameras, located to have the object to be tracked visible most of the operation time; the target object has to include an embedded accelerometer and be tagged with a fiducial marker. This simple marker has been designed for easy detection and segmentation and it may be adapted to different service scenarios (in shape and colors). Experimental results show that the proposed system provides high accuracy, while satisfactorily dealing with the real-time constraints.

  20. 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

  1. Digital camera auto white balance based on color temperature estimation clustering

    Science.gov (United States)

    Zhang, Lei; Liu, Peng; Liu, Yuling; Yu, Feihong

    2010-11-01

    Auto white balance (AWB) is an important technique for digital cameras. Human vision system has the ability to recognize the original color of an object in a scene illuminated by a light source that has a different color temperature from D65-the standard sun light. However, recorded images or video clips, can only record the original information incident into the sensor. Therefore, those recorded will appear different from the real scene observed by the human. Auto white balance is a technique to solve this problem. Traditional methods such as gray world assumption, white point estimation, may fail for scenes with large color patches. In this paper, an AWB method based on color temperature estimation clustering is presented and discussed. First, the method gives a list of several lighting conditions that are common for daily life, which are represented by their color temperatures, and thresholds for each color temperature to determine whether a light source is this kind of illumination; second, an image to be white balanced are divided into N blocks (N is determined empirically). For each block, the gray world assumption method is used to calculate the color cast, which can be used to estimate the color temperature of that block. Third, each calculated color temperature are compared with the color temperatures in the given illumination list. If the color temperature of a block is not within any of the thresholds in the given list, that block is discarded. Fourth, the remaining blocks are given a majority selection, the color temperature having the most blocks are considered as the color temperature of the light source. Experimental results show that the proposed method works well for most commonly used light sources. The color casts are removed and the final images look natural.

  2. Color perception differentiates Alzheimer's Disease (AD) from Vascular Dementia (VaD) patients.

    Science.gov (United States)

    Arnaoutoglou, N A; Arnaoutoglou, M; Nemtsas, P; Costa, V; Baloyannis, S J; Ebmeier, K P

    2017-08-01

    Alzheimer's Disease (AD) and Vascular Dementia (VaD) are the most common causes of dementia in older people. Both diseases appear to have similar clinical symptoms, such as deficits in attention and executive function, but specific cognitive domains are affected. Current cohort studies have shown a close relationship between αβ deposits and age-related macular degeneration (Johnson et al., 2002; Ratnayaka et al., 2015). Additionally, a close link between the thinning of the retinal nerve fiber (RNFL) and AD patients has been described, while it has been proposed that AD patients suffer from a non-specific type of color blindness (Pache et al., 2003). Our study included 103 individuals divided into three groups: A healthy control group (n = 35), AD (n = 32) according to DSM-IV-TR, NINCDS-ADRDA criteria, and VaD (n = 36) based on ΝΙΝDS-AIREN, as well as Magnetic Resonance Imaging (MRI) results. The severity of patient's cognitive impairment, was measured with the Mini-Mental State Examination (MMSE) and was classified according to the Reisberg global deterioration scale (GDS). Visual perception was examined using the Ishihara plates: "Ishihara Color Vision Test - 38 Plate." The three groups were not statistically different for demographic data (age, gender, and education). The Ishihara color blindness test has a sensitivity of 80.6% and a specificity of 87.5% to discriminate AD and VaD patients when an optimal (32.5) cut-off value of performance is used. Ishihara Color Vision Test - 38 Plate is a promising potential method as an easy and not time-consuming screening test for the differential diagnosis of dementia between AD and VaD.

  3. Color development and acrylamide content of pre-dried potato chips

    DEFF Research Database (Denmark)

    Pedreschi, Franco; León, Jorge; Mery, Domingo

    2007-01-01

    The objective of this work was to study the development of color formation in pre-dried potato slices during frying and acrylamide formation in the final potato chips. Color measurement was done by using an inexpensive computer vision technique which allowed quantifying representatively...... and precisely the color of complex surfaces such as those of potato chips in L*a*b* units from RGB images. Prior to frying, potato slices (Desiree variety, diameter: 37 mm, width: 2.2 mm) were blanched in hot water at 85 degrees C for 3.5 min. Unblanched slices were considered as the control. Slices of the same...... dimensions were blanched as in the previous step, and then air-dried until reaching a moisture content of 60% (wet basis). These samples were called pre-dried potato slices. Potato slices were fried at 120 degrees C, 140 degrees C, 160 degrees C and 180 degrees C until reaching moisture contents of similar...

  4. 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 ...

  5. Mobile Atmospheric Sensing using Vision Approach

    International Nuclear Information System (INIS)

    Huang, Yuchun; Cui, Weihong; Rui, Yi

    2014-01-01

    Air quality monitoring, especially the atmospheric phenomenon of thick haze, has been an acute problem in most countries and a hot topic in the atmospheric sensing. Recently thick haze occurs more frequently in most cities of China due to the rapid growth of traffic, farming, wildfires, and industrial development. It forms a low-hanging shroud that impairs visibility and becomes a respiratory health threat. Traditionally the dust, smoke, and other particles in relatively dry sky are reported at fixed meteorological stations. The coverage of these sampling stations is limited and cannot accommodate with the emergent incidence of thick haze from industrial pollution. In addition, the visual effect of thick haze is not yet investigated in the current practice. Thick haze appears colorful veil (e.g., yellowish, brownish-grey, etc) in video log images and results in a loss of contrast in the subject due to the light scattering through haze particles. This paper proposes an intuitive and mobile atmospheric sensing using vision approach. Based on the video log images collected by a mobile sensing vehicle, a Haze Veil Index (HVI) is proposed to identify the type and severity level of thick haze from the color and texture perspective. HVI characterizes the overall veil effect of haze spatially. HVI first identifies the haze color from the color deviation histogram of the white-balanced hazy image. The white-balancing is conducted with the most haze-opaque pixels in the dark channel and seed growing strategy. Then pixel-wise haze severity level of atmospheric veil is inferred by approximating the upper veil limit with the dark color of each pixel in a hazy image. The proposed method is tested on a diverse set of actual hazy video log images under varying atmospheric conditions and backgrounds in Wuhan City, China. Experimental results show the proposed HVI is effective for visually atmospheric sensing. The proposed method is promising for haze monitoring and prediction in

  6. 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 ...

  7. Yarbus's Conceptions on the General Mechanisms of Color Perception.

    Science.gov (United States)

    Nikolaev, Petr P; Rozhkova, Galina I

    2015-01-01

    In the last series of papers published during 1975 to 1980, Alfred Yarbus tried to formulate general conceptions concerning the basic principles of retinal image processing in the human visual system. The original ideas of Yarbus were based on the results of his numerous and various experiments carried out with extraordinary inventiveness and great skill. Being concentrated primarily on the problems of color vision, Alfred Yarbus dreamed of elaborating a comprehensive model that would simulate visual information processing at the monocular precognitive level in the visual system of humans with normal trichromatic color perception. In this article, the most important of Yarbus' experimental paradigms, findings, statements, and conclusions are systematized and considered in relation to the classical theories of color perception and, in particular, fundamental theses of the Nyberg school. The perceptual model developed by Alfred Yarbus remained incomplete. Nevertheless, it is already evident that some intrinsic contradictions make it inadequate in terms of comprehensive modeling. However, certain partial advantages deserve more thorough appreciation and further investigation. © The Author(s) 2015.

  8. Research on detection method of UAV obstruction based on binocular vision

    Science.gov (United States)

    Zhu, Xiongwei; Lei, Xusheng; Sui, Zhehao

    2018-04-01

    For the autonomous obstacle positioning and ranging in the process of UAV (unmanned aerial vehicle) flight, a system based on binocular vision is constructed. A three-stage image preprocessing method is proposed to solve the problem of the noise and brightness difference in the actual captured image. The distance of the nearest obstacle is calculated by using the disparity map that generated by binocular vision. Then the contour of the obstacle is extracted by post-processing of the disparity map, and a color-based adaptive parameter adjustment algorithm is designed to extract contours of obstacle automatically. Finally, the safety distance measurement and obstacle positioning during the UAV flight process are achieved. Based on a series of tests, the error of distance measurement can keep within 2.24% of the measuring range from 5 m to 20 m.

  9. Response saturation of monochromatic increments on intense achromatic backgrounds: implications for color-opponent organization in human vision

    Science.gov (United States)

    Drum, Bruce; Sternheim, Charles E.

    2005-10-01

    We present evidence that steady achromatic adapting fields can produce response saturation in color-opponent pathways. We measured tvi (log increment threshold illuminance versus log background illuminance) functions at four test wavelengths (430, 490, 575, and 660 nm) and nine background illuminances from 4.0 to 5.6 log Td. Foveal, 2° diameter, 1 s duration test stimuli were presented on a concentric, perceptually white (5128°K color temperature), 7° diameter, steady background. Thresholds were obtained by the method of adjustment, after which the test stimulus illuminances were increased 0.6 log unit and the subject estimated percentages of red, yellow, green, blue, and white. Average tvi slopes for two subjects were 2.06 for 430 nm, 1.6 for 490 nm, 1.11 for 575 nm and 1.34 for 660 nm, consistent with the estimated ratios of chromatic to achromatic sensitivity at the same wavelengths. Also, the percentage of white seen in the suprathreshold increments increased with increasing background illuminance despite increases in excitation purity. These findings imply that steady, intense, achromatic backgrounds can produce response saturation in color-opponent mechanisms at wavelengths across the visible spectrum. The saturation was more extreme at short wavelengths than at middle or long wavelengths, producing a tritanopic condition at the highest background illuminances. The tritanopia reduced color space to a predominately red-blue dichromacy, in agreement with previous findings. The results support a multistage opponent-color model in which precortical koniocellular and parvocellular opponent pathways interact to produce the observed red-green and yellow-blue color-opponent channels at a cortical level.

  10. Vision, healing brush, and fiber bundles

    Science.gov (United States)

    Georgiev, Todor

    2005-03-01

    The Healing Brush is a tool introduced for the first time in Adobe Photoshop (2002) that removes defects in images by seamless cloning (gradient domain fusion). The Healing Brush algorithms are built on a new mathematical approach that uses Fibre Bundles and Connections to model the representation of images in the visual system. Our mathematical results are derived from first principles of human vision, related to adaptation transforms of von Kries type and Retinex theory. In this paper we present the new result of Healing in arbitrary color space. In addition to supporting image repair and seamless cloning, our approach also produces the exact solution to the problem of high dynamic range compression of17 and can be applied to other image processing algorithms.

  11. Modeling human color categorization: Color discrimination and color memory

    NARCIS (Netherlands)

    Heskes, T.; van den Broek, Egon; Lucas, P.; Hendriks, Maria A.; Vuurpijl, L.G.; Puts, M.J.H.; Wiegerinck, W.

    2003-01-01

    Color matching in Content-Based Image Retrieval is done using a color space and measuring distances between colors. Such an approach yields non-intuitive results for the user. We introduce color categories (or focal colors), determine that they are valid, and use them in two experiments. The

  12. Bio-inspired color sketch for eco-friendly printing

    Science.gov (United States)

    Safonov, Ilia V.; Tolstaya, Ekaterina V.; Rychagov, Michael N.; Lee, Hokeun; Kim, Sang Ho; Choi, Donchul

    2012-01-01

    Saving of toner/ink consumption is an important task in modern printing devices. It has a positive ecological and social impact. We propose technique for converting print-job pictures to a recognizable and pleasant color sketches. Drawing a "pencil sketch" from a photo relates to a special area in image processing and computer graphics - non-photorealistic rendering. We describe a new approach for automatic sketch generation which allows to create well-recognizable sketches and to preserve partly colors of the initial picture. Our sketches contain significantly less color dots then initial images and this helps to save toner/ink. Our bio-inspired approach is based on sophisticated edge detection technique for a mask creation and multiplication of source image with increased contrast by this mask. To construct the mask we use DoG edge detection, which is a result of blending of initial image with its blurred copy through the alpha-channel, which is created from Saliency Map according to Pre-attentive Human Vision model. Measurement of percentage of saved toner and user study proves effectiveness of proposed technique for toner saving in eco-friendly printing mode.

  13. Stable structural color patterns displayed on transparent insect wings.

    Science.gov (United States)

    Shevtsova, Ekaterina; Hansson, Christer; Janzen, Daniel H; Kjærandsen, Jostein

    2011-01-11

    Color patterns play central roles in the behavior of insects, and are important traits for taxonomic studies. Here we report striking and stable structural color patterns--wing interference patterns (WIPs)--in the transparent wings of small Hymenoptera and Diptera, patterns that have been largely overlooked by biologists. These extremely thin wings reflect vivid color patterns caused by thin film interference. The visibility of these patterns is affected by the way the insects display their wings against various backgrounds with different light properties. The specific color sequence displayed lacks pure red and matches the color vision of most insects, strongly suggesting that the biological significance of WIPs lies in visual signaling. Taxon-specific color patterns are formed by uneven membrane thickness, pigmentation, venation, and hair placement. The optically refracted pattern is also stabilized by microstructures of the wing such as membrane corrugations and spherical cell structures that reinforce the pattern and make it essentially noniridescent over a large range of light incidences. WIPs can be applied to map the micromorphology of wings through direct observation and are useful in several fields of biology. We demonstrate their usefulness as identification patterns to solve cases of cryptic species complexes in tiny parasitic wasps, and indicate their potentials for research on the genetic control of wing development through direct links between the transregulatory wing landscape and interference patterns we observe in Drosophila model species. Some species display sexually dimorphic WIPs, suggesting sexual selection as one of the driving forces for their evolution.

  14. Evolutionary history of the Lake Tanganyika cichlid tribe Lamprologini (Teleostei: Perciformes) derived from mitochondrial and nuclear DNA data

    OpenAIRE

    Sturmbauer, Christian; Salzburger, Walter; Duftner, Nina; Schelly, Robert; Koblmueller, Stephan

    2010-01-01

    Lake Tanganyika comprises a cichlid species flock with substrate-breeding and mouthbrooding lineages. While sexual selection via mate choice on male mating color is thought to boost speciation rates in mouthbrooding cichlids, this is not the case in substrate-breeding lamprologines, which mostly form stable pairs and lack sexual dichromatism. We present a comprehensive reconstruction of the evolution of the cichlid tribe Lamprologini, based upon mtDNA sequences and multilocus nuclear DNA (AFL...

  15. Image color reduction method for color-defective observers using a color palette composed of 20 particular colors

    Science.gov (United States)

    Sakamoto, Takashi

    2015-01-01

    This study describes a color enhancement method that uses a color palette especially designed for protan and deutan defects, commonly known as red-green color blindness. The proposed color reduction method is based on a simple color mapping. Complicated computation and image processing are not required by using the proposed method, and the method can replace protan and deutan confusion (p/d-confusion) colors with protan and deutan safe (p/d-safe) colors. Color palettes for protan and deutan defects proposed by previous studies are composed of few p/d-safe colors. Thus, the colors contained in these palettes are insufficient for replacing colors in photographs. Recently, Ito et al. proposed a p/dsafe color palette composed of 20 particular colors. The author demonstrated that their p/d-safe color palette could be applied to image color reduction in photographs as a means to replace p/d-confusion colors. This study describes the results of the proposed color reduction in photographs that include typical p/d-confusion colors, which can be replaced. After the reduction process is completed, color-defective observers can distinguish these confusion colors.

  16. Restoration of color in a remote sensing image and its quality evaluation

    Science.gov (United States)

    Zhang, Zuxun; Li, Zhijiang; Zhang, Jianqing; Wang, Zhihe

    2003-09-01

    This paper is focused on the restoration of color remote sensing (including airborne photo). A complete approach is recommended. It propose that two main aspects should be concerned in restoring a remote sensing image, that are restoration of space information, restoration of photometric information. In this proposal, the restoration of space information can be performed by making the modulation transfer function (MTF) as degradation function, in which the MTF is obtained by measuring the edge curve of origin image. The restoration of photometric information can be performed by improved local maximum entropy algorithm. What's more, a valid approach in processing color remote sensing image is recommended. That is splits the color remote sensing image into three monochromatic images which corresponding three visible light bands and synthesizes the three images after being processed separately with psychological color vision restriction. Finally, three novel evaluation variables are obtained based on image restoration to evaluate the image restoration quality in space restoration quality and photometric restoration quality. An evaluation is provided at last.

  17. Perceived color shift of ceramics according to the change of illuminating light with spectroradiometer

    Science.gov (United States)

    Cha, Hyun-Suk; Yu, Bin

    2013-01-01

    PURPOSE Perceived color of ceramics changes by the spectral power distribution of ambient light. This study aimed to quantify the amount of shifts in color and color coordinates of clinically simulated seven all-ceramics due to the switch of three ambient light sources using a human vision simulating spectroradiometer. MATERIALS AND METHODS CIE color coordinates, such as L*, a* and b*,of ceramic specimens were measured under three light sources, which simulate the CIE standard illuminant D65 (daylight), A (incandescent lamp), and F9 (fluorescent lamp). Shifts in color and color coordinate by the switch of lights were determined. Influence of the switched light (D65 to A, or D65 to F9), shade of veneer ceramics (A2 or A3), and brand of ceramics on the shifts was analyzed by a three-way ANOVA. RESULTS Shifts in color and color coordinates were influenced by three factors (P 5.5). When switched to A, CIE a* increased (Δa*: 5.6 to 7.6), however, CIE b* increased (Δb*: 4.9 to 7.8) when switched to F9. CONCLUSION Clinically simulated ceramics demonstrated clinically unacceptable color shifts according to the switches in ambient lights based on spectroradiometric readings. Therefore, shade matching and compatibility evaluation should be performed considering ambient lighting conditions and should be done under most relevant lighting condition. PMID:24049567

  18. Alouatta trichromatic color vision: cone spectra and physiological responses studied with microspectrophotometry and single unit retinal electrophysiology.

    Science.gov (United States)

    Silveira, Luiz Carlos L; Saito, Cézar A; da Silva Filho, Manoel; Kremers, Jan; Bowmaker, James K; Lee, Barry B

    2014-01-01

    The howler monkeys (Alouatta sp.) are the only New World primates to exhibit routine trichromacy. Both males and females have three cone photopigments. However, in contrast to Old World monkeys, Alouatta has a locus control region upstream of each opsin gene on the X-chromosome and this might influence the retinal organization underlying its color vision. Post-mortem microspectrophotometry (MSP) was performed on the retinae of two male Alouatta to obtain rod and cone spectral sensitivities. The MSP data were consistent with only a single opsin being expressed in each cone and electrophysiological data were consistent with this primate expressing full trichromacy. To study the physiological organization of the retina underlying Alouatta trichromacy, we recorded from retinal ganglion cells of the same animals used for MSP measurements with a variety of achromatic and chromatic stimulus protocols. We found MC cells and PC cells in the Alouatta retina with similar properties to those previously found in the retina of other trichromatic primates. MC cells showed strong phasic responses to luminance changes and little response to chromatic pulses. PC cells showed strong tonic response to chromatic changes and small tonic response to luminance changes. Responses to other stimulus protocols (flicker photometry; changing the relative phase of red and green modulated lights; temporal modulation transfer functions) were also similar to those recorded in other trichromatic primates. MC cells also showed a pronounced frequency double response to chromatic modulation, and with luminance modulation response saturation accompanied by a phase advance between 10-20 Hz, characteristic of a contrast gain mechanism. This indicates a very similar retinal organization to Old-World monkeys. Cone-specific opsin expression in the presence of a locus control region for each opsin may call into question the hypothesis that this region exclusively controls opsin expression.

  19. Machine vision system for automated detection of stained pistachio nuts

    Science.gov (United States)

    Pearson, Tom C.

    1995-01-01

    A machine vision system was developed to separate stained pistachio nuts, which comprise of about 5% of the California crop, from unstained nuts. The system may be used to reduce labor involved with manual grading or to remove aflatoxin contaminated product from low grade process streams. The system was tested on two different pistachio process streams: the bi- chromatic color sorter reject stream and the small nut shelling stock stream. The system had a minimum overall error rate of 14% for the bi-chromatic sorter reject stream and 15% for the small shelling stock stream.

  20. 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…

  1. Cholesteric Liquid Crystal Based Reflex Color Reflective Displays

    Science.gov (United States)

    Khan, Asad

    2012-02-01

    Bistable color cholesteric liquid crystal displays are unique LCDs that exhibit high reflectivity, good contrast, extremely low power operation, and are amenable to versatile roll-to-roll manufacturing. The display technology, now branded as Reflex has been in commercialized products since 1996. It has been the subject of extensive research and development globally by a variety of parties in both academic and industrial settings. Today, the display technology is in volume production for applications such as dedicated eWriters (Boogie Board), full color electronic skins (eSkin), and displays for smart cards. The flexibility comes from polymerization induced phase separation using unique materials unparalleled in any other display technology. The blend of monomers, polymers, cross linkers, and other components along with nematic liquid crystals and chiral dopants is created and processed in such ways so as to enable highly efficient manufactrable displays using ultra thin plastic substrates -- often as thin as 50μm. Other significant aspects include full color by stacking or spatial separation, night vision capability, ultra high resolution, as well as active matrix capabilities. Of particular note is the stacking approach of Reflex based displays to show full color. This approach for reflective color displays is unique to this technology. Owing to high transparency in wavelength bands outside the selective reflection band, three primarily color layers can be stacked on top of each other and reflect without interfering with other layers. This highly surprising architecture enables the highest reflectivity of any other reflective electronic color display technology. The optics, architecture, electro-topics, and process techniques will be discussed. This presentation will focus on the physics of the core technology and color, it's evolution from rigid glass based displays to flexible displays, development of products from the paradigm shifting concepts to consumer

  2. Influence of Surrounding Colors in the Illuminant-Color Mode on Color Constancy

    Directory of Open Access Journals (Sweden)

    Kazuho Fukuda

    2011-05-01

    Full Text Available On color constancy, we showed that brighter surrounding colors had greater influence than dim colors (Uchikawa, Kitazawa, MacLeod, Fukuda, 2010 APCV. Increasing luminance of a stimulus causes the change in appearance from the surface-color to the illuminant-color mode. However it is unknown whether the visual system considers such color appearance mode of surrounding colors to achieve color constancy. We investigated the influence of surrounding colors that appeared illuminant on color constancy. The stimulus was composed of a central test stimulus and surrounding six colors: bright and dim red, green and blue. The observers adjusted the chromaticity of the test stimulus to be appeared as an achromatic surface. The luminance balance of three bright surrounding colors was equalized with that of the optimal colors in three illuminant conditions, then, the luminance of one of the three bright colors was varied in the range beyond the critical luminance of color appearance mode transition. The results showed that increasing luminance of a bright surrounding color shifted the observers' achromatic setting toward its chromaticity, but this effect diminished for the surrounding color in the illuminant-color mode. These results suggest that the visual system considers color appearance mode of surrounding colors to accomplish color constancy.

  3. Use of discrete chromatic space to tune the image tone in a color image mosaic

    Science.gov (United States)

    Zhang, Zuxun; Li, Zhijiang; Zhang, Jianqing; Zheng, Li

    2003-09-01

    Color image process is a very important problem. However, the main approach presently of them is to transfer RGB colour space into another colour space, such as HIS (Hue, Intensity and Saturation). YIQ, LUV and so on. Virutally, it may not be a valid way to process colour airborne image just in one colour space. Because the electromagnetic wave is physically altered in every wave band, while the color image is perceived based on psychology vision. Therefore, it's necessary to propose an approach accord with physical transformation and psychological perception. Then, an analysis on how to use relative colour spaces to process colour airborne photo is discussed and an application on how to tune the image tone in colour airborne image mosaic is introduced. As a practice, a complete approach to perform the mosaic on color airborne images via taking full advantage of relative color spaces is discussed in the application.

  4. Potential application of machine vision technology to saffron (Crocus sativus L.) quality characterization.

    Science.gov (United States)

    Kiani, Sajad; Minaei, Saeid

    2016-12-01

    Saffron quality characterization is an important issue in the food industry and of interest to the consumers. This paper proposes an expert system based on the application of machine vision technology for characterization of saffron and shows how it can be employed in practical usage. There is a correlation between saffron color and its geographic location of production and some chemical attributes which could be properly used for characterization of saffron quality and freshness. This may be accomplished by employing image processing techniques coupled with multivariate data analysis for quantification of saffron properties. Expert algorithms can be made available for prediction of saffron characteristics such as color as well as for product classification. Copyright © 2016. Published by Elsevier Ltd.

  5. 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.

  6. Making a vision document tangible using "vision-tactics-metrics" tables.

    Science.gov (United States)

    Drury, Ivo; Slomski, Carol

    2006-01-01

    We describe a method of making a vision document tangible by attaching specific tactics and metrics to the key elements of the vision. We report on the development and early use of a "vision-tactics-metrics" table in a department of surgery. Use of the table centered the vision in the daily life of the department and its faculty, and facilitated cultural change.

  7. Nonrandom Composition of Flower Colors in a Plant Community: Mutually Different Co-Flowering Natives and Disturbance by Aliens

    Science.gov (United States)

    Makino, Takashi T.; Yokoyama, Jun

    2015-01-01

    When pollinators use flower color to locate food sources, a distinct color can serve as a reproductive barrier against co-flowering species. This anti-interference function of flower color may result in a community assembly of plant species displaying mutually different flower colors. However, such color dispersion is not ubiquitous, suggesting a variable selection across communities and existence of some opposing factors. We conducted a 30-week study in a plant community and measured the floral reflectances of 244 species. The reflectances were evaluated in insect color spaces (bees, swallowtails, and flies), and the dispersion was compared with random expectations. We found that co-existing colors were overdispersed for each analyzed pollinator type, and this overdispersion was statistically significant for bees. Furthermore, we showed that exclusion of 32 aliens from the analysis significantly increased the color dispersion of native flowers in every color space. This result indicated that aliens disturbed a native plant–pollinator network via similarly colored flowers. Our results demonstrate the masking effects of aliens in the detection of color dispersion of native flowers and that variations in pollinator vision yield different outcomes. Our results also support the hypothesis that co-flowering species are one of the drivers of color diversification and affect the community assembly. PMID:26650121

  8. Nonrandom Composition of Flower Colors in a Plant Community: Mutually Different Co-Flowering Natives and Disturbance by Aliens.

    Directory of Open Access Journals (Sweden)

    Takashi T Makino

    Full Text Available When pollinators use flower color to locate food sources, a distinct color can serve as a reproductive barrier against co-flowering species. This anti-interference function of flower color may result in a community assembly of plant species displaying mutually different flower colors. However, such color dispersion is not ubiquitous, suggesting a variable selection across communities and existence of some opposing factors. We conducted a 30-week study in a plant community and measured the floral reflectances of 244 species. The reflectances were evaluated in insect color spaces (bees, swallowtails, and flies, and the dispersion was compared with random expectations. We found that co-existing colors were overdispersed for each analyzed pollinator type, and this overdispersion was statistically significant for bees. Furthermore, we showed that exclusion of 32 aliens from the analysis significantly increased the color dispersion of native flowers in every color space. This result indicated that aliens disturbed a native plant-pollinator network via similarly colored flowers. Our results demonstrate the masking effects of aliens in the detection of color dispersion of native flowers and that variations in pollinator vision yield different outcomes. Our results also support the hypothesis that co-flowering species are one of the drivers of color diversification and affect the community assembly.

  9. Color blindness defect and medical laboratory technologists: unnoticed problems and the care for screening.

    Science.gov (United States)

    Dargahi, Hossein; Einollahi, Nahid; Dashti, Nasrin

    2010-01-01

    Color-blindness is the inability to perceive differences between some color that other people can distinguish. Using a literature search, the results indicate the prevalence of color vision deficiency in the medical profession and its on medical skills. Medical laboratory technicians and technologists employees should also screen for color blindness. This research aimed to study color blindness prevalence among Hospitals' Clinical Laboratories' Employees and Students in Tehran University of Medical Sciences (TUMS). A cross-sectional descriptive and analytical study was conducted among 633 TUMS Clinical Laboratory Sciences' Students and Hospitals' Clinical Laboratories' Employees to detect color-blindness problems by Ishihara Test. The tests were first screened with certain pictures, then compared to the Ishihara criteria to be possible color defective were tested further with other plates to determine color - blindness defects. The data was saved using with SPSS software and analyzed by statistical methods. This is the first study to determine the prevalence of color - blindness in Clinical Laboratory Sciences' Students and Employees. 2.4% of TUMS Medical Laboratory Sciences Students and Hospitals' Clinical Laboratories' Employees are color-blind. There is significant correlation between color-blindness and sex and age. But the results showed that there is not significant correlation between color-blindness defect and exposure to chemical agents, type of job, trauma and surgery history, history of familial defect and race. It would be a wide range of difficulties by color blinded students and employees in their practice of laboratory diagnosis and techniques with a potentially of errors. We suggest color blindness as a medical conditions should restrict employment choices for medical laboratory technicians and technologists job in Iran.

  10. Pioneering Studies on Cephalopod's Eye and Vision at the Stazione Zoologica Anton Dohrn (1883-1977).

    Science.gov (United States)

    Dröscher, Ariane

    2016-01-01

    From the late nineteenth century onwards, the phenomena of vision and the anatomy and physiology of the eye of marine animals induced many zoologists, ethologists, physiologists, anatomists, biochemists, and ophthalmologists to travel to the Zoological Station in Naples. Initially, their preferred research objects were fish, but it soon became evident that cephalopods have features which make them particularly suited to research. After the first studies, which outlined the anatomical structure of cephalopods' eyes and optic nerves, the research rapidly shifted to the electrophysiology and biochemistry of vision. In the twentieth century these results were integrated with behavioral tests and training techniques. Between 1909 and 1913 also the well-known debate on color vision between ophthalmologist Carl von Hess and zoologist Karl von Frisch took place in Naples. Largely unknown is that the debate also concerned cephalopods. A comparative historical analysis of these studies shows how different experimental devices, theoretical frameworks, and personal factors gave rise to two diametrically opposing views.

  11. Visão das cores em escolares: avaliação de um novo teste Color vision in school-age children: evalution a new test

    Directory of Open Access Journals (Sweden)

    Guilherme M. Martins

    2001-08-01

    Full Text Available OBJETIVO: comparar os resultados de um teste de visão de cores padrão (teste de Ishihara com um teste criado pelos autores (teste do giz de cera na detecção da discromatopsia congênita. MÉTODOS: foi realizado um estudo transversal com 712 crianças da rede escolar pública (3 escolas e privada (1 escola de Porto Alegre, Rio Grande do Sul. Desta amostra aleatória, haviam sido excluídas crianças com dificuldades na alfabetização e doenças sistêmicas e oculares reconhecidas. Foram aplicados seqüencialmente os testes de Ishihara (versão resumida de 14 pranchas e o teste do giz de cera (desenvolvido pelos autores. Cada teste foi aplicado por examinadores diferentes e avaliados por um terceiro examinador. RESULTADOS: o teste do giz de cera apresentou especificidade de 100% (99,3-100% e sensibilidade de 38,5% (15,1-67,7%, quando comparado ao teste de Ishihara. A prevalência da discromatopsia congênita nesta amostra populacional foi de 2,6% nos meninos e 0,9% nas meninas. CONCLUSÕES: o teste do giz de cera apresentou especificidade superior ao teste de Ishihara no grupo estudado, mas sua sensibilidade não se mostrou adequada para um teste de rastreamento. Há necessidade de aperfeiçoá-lo para aumentar sua sensibilidade, isto é, sua capacidade de detectar a discromatopsia congênita.OBJECTIVE: To compare standard color vision test results (Ishihara test with a new test developed by the authors ("crayon" test for the detection of congenital dyschromatopsia. METHODS: Cross-sectional study of 712 children from three public schools and one private school in the city of Porto Alegre, state of Rio Grande do Sul. Children with learning disabilities, or systemic and ocular diseases were excluded from this random sample. Two color vision tests, Ishihara test (short version with 14 plates and crayon test (developed by the authors were sequentially applied. Each test was applied by different evaluators and analyzed by a third evaluator

  12. Longwing (Heliconius) butterflies combine a restricted set of pigmentary and structural coloration mechanisms.

    Science.gov (United States)

    Wilts, Bodo D; Vey, Aidan J M; Briscoe, Adriana D; Stavenga, Doekele G

    2017-11-21

    Longwing butterflies, Heliconius sp., also called heliconians, are striking examples of diversity and mimicry in butterflies. Heliconians feature strongly colored patterns on their wings, arising from wing scales colored by pigments and/or nanostructures, which serve as an aposematic signal. Here, we investigate the coloration mechanisms among several species of Heliconius by applying scanning electron microscopy, (micro)spectrophotometry, and imaging scatterometry. We identify seven kinds of colored scales within Heliconius whose coloration is derived from pigments, nanostructures or both. In yellow-, orange- and red-colored wing patches, both cover and ground scales contain wavelength-selective absorbing pigments, 3-OH-kynurenine, xanthommatin and/or dihydroxanthommatin. In blue wing patches, the cover scales are blue either due to interference of light in the thin-film lower lamina (e.g., H. doris) or in the multilayered lamellae in the scale ridges (so-called ridge reflectors, e.g., H. sara and H. erato); the underlying ground scales are black. In the white wing patches, both cover and ground scales are blue due to their thin-film lower lamina, but because they are stacked upon each other and at the wing substrate, a faint bluish to white color results. Lastly, green wing patches (H. doris) have cover scales with blue-reflecting thin films and short-wavelength absorbing 3-OH-kynurenine, together causing a green color. The pigmentary and structural traits are discussed in relation to their phylogenetic distribution and the evolution of vision in this highly interesting clade of butterflies.

  13. Design, development and evaluation of an online grading system for peeled pistachios equipped with machine vision technology and support vector machine

    Directory of Open Access Journals (Sweden)

    Hosein Nouri-Ahmadabadi

    2017-12-01

    Full Text Available In this study, an intelligent system based on combined machine vision (MV and Support Vector Machine (SVM was developed for sorting of peeled pistachio kernels and shells. The system was composed of conveyor belt, lighting box, camera, processing unit and sorting unit. A color CCD camera was used to capture images. The images were digitalized by a capture card and transferred to a personal computer for further analysis. Initially, images were converted from RGB color space to HSV color ones. For segmentation of the acquired images, H-component in the HSV color space and Otsu thresholding method were applied. A feature vector containing 30 color features was extracted from the captured images. A feature selection method based on sensitivity analysis was carried out to select superior features. The selected features were presented to SVM classifier. Various SVM models having a different kernel function were developed and tested. The SVM model having cubic polynomial kernel function and 38 support vectors achieved the best accuracy (99.17% and then was selected to use in online decision-making unit of the system. By launching the online system, it was found that limiting factors of the system capacity were related to the hardware parts of the system (conveyor belt and pneumatic valves used in the sorting unit. The limiting factors led to a distance of 8 mm between the samples. The overall accuracy and capacity of the sorter were obtained 94.33% and 22.74 kg/h, respectively. Keywords: Pistachio kernel, Sorting, Machine vision, Sensitivity analysis, Support vector machine

  14. The elementary representation of spatial and color vision in the human retina.

    Science.gov (United States)

    Sabesan, Ramkumar; Schmidt, Brian P; Tuten, William S; Roorda, Austin

    2016-09-01

    The retina is the most accessible element of the central nervous system for linking behavior to the activity of isolated neurons. We unraveled behavior at the elementary level of single input units-the visual sensation generated by stimulating individual long (L), middle (M), and short (S) wavelength-sensitive cones with light. Spectrally identified cones near the fovea of human observers were targeted with small spots of light, and the type, proportion, and repeatability of the elicited sensations were recorded. Two distinct populations of cones were observed: a smaller group predominantly associated with signaling chromatic sensations and a second, more numerous population linked to achromatic percepts. Red and green sensations were mainly driven by L- and M-cones, respectively, although both cone types elicited achromatic percepts. Sensations generated by cones were rarely stochastic; rather, they were consistent over many months and were dominated by one specific perceptual category. Cones lying in the midst of a pure spectrally opponent neighborhood, an arrangement purported to be most efficient in producing chromatic signals in downstream neurons, were no more likely to signal chromatic percepts. Overall, the results are consistent with the idea that the nervous system encodes high-resolution achromatic information and lower-resolution color signals in separate pathways that emerge as early as the first synapse. The lower proportion of cones eliciting color sensations may reflect a lack of evolutionary pressure for the chromatic system to be as fine-grained as the high-acuity achromatic system.

  15. Color vision in attention-deficit/hyperactivity disorder: A pilot visual evoked potential study

    Directory of Open Access Journals (Sweden)

    Soyeon Kim

    2015-04-01

    Conclusion: Larger amplitude in the P1 component for blue–yellow in the ADHD group compared to controls may account for the lack of difference in color perception tasks. We speculate that the larger amplitude for blue–yellow stimuli in early sensory processing (P1 might reflect a compensatory strategy for underlying problems including compromised retinal input of s-cones due to hypo-dopaminergic tone.

  16. 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 ...

  17. Processing of Color Words Activates Color Representations

    Science.gov (United States)

    Richter, Tobias; Zwaan, Rolf A.

    2009-01-01

    Two experiments were conducted to investigate whether color representations are routinely activated when color words are processed. Congruency effects of colors and color words were observed in both directions. Lexical decisions on color words were faster when preceding colors matched the color named by the word. Color-discrimination responses…

  18. Color categories and color appearance

    Science.gov (United States)

    Webster, Michael A.; Kay, Paul

    2011-01-01

    We examined categorical effects in color appearance in two tasks, which in part differed in the extent to which color naming was explicitly required for the response. In one, we measured the effects of color differences on perceptual grouping for hues that spanned the blue–green boundary, to test whether chromatic differences across the boundary were perceptually exaggerated. This task did not require overt judgments of the perceived colors, and the tendency to group showed only a weak and inconsistent categorical bias. In a second case, we analyzed results from two prior studies of hue scaling of chromatic stimuli (De Valois, De Valois, Switkes, & Mahon, 1997; Malkoc, Kay, & Webster, 2005), to test whether color appearance changed more rapidly around the blue–green boundary. In this task observers directly judge the perceived color of the stimuli and these judgments tended to show much stronger categorical effects. The differences between these tasks could arise either because different signals mediate color grouping and color appearance, or because linguistic categories might differentially intrude on the response to color and/or on the perception of color. Our results suggest that the interaction between language and color processing may be highly dependent on the specific task and cognitive demands and strategies of the observer, and also highlight pronounced individual differences in the tendency to exhibit categorical responses. PMID:22176751

  19. AN INVESTIGATION OF VISION PROBLEMS AND THE VISION CARE SYSTEM IN RURAL CHINA.

    Science.gov (United States)

    Bai, Yunli; Yi, Hongmei; Zhang, Linxiu; Shi, Yaojiang; Ma, Xiaochen; Congdon, Nathan; Zhou, Zhongqiang; Boswell, Matthew; Rozelle, Scott

    2014-11-01

    This paper examines the prevalence of vision problems and the accessibility to and quality of vision care in rural China. We obtained data from 4 sources: 1) the National Rural Vision Care Survey; 2) the Private Optometrists Survey; 3) the County Hospital Eye Care Survey; and 4) the Rural School Vision Care Survey. The data from each of the surveys were collected by the authors during 2012. Thirty-three percent of the rural population surveyed self-reported vision problems. Twenty-two percent of subjects surveyed had ever had a vision exam. Among those who self-reported having vision problems, 34% did not wear eyeglasses. Fifty-four percent of those with vision problems who had eyeglasses did not have a vision exam prior to receiving glasses. However, having a vision exam did not always guarantee access to quality vision care. Four channels of vision care service were assessed. The school vision examination program did not increase the usage rate of eyeglasses. Each county-hospital was staffed with three eye-doctors having one year of education beyond high school, serving more than 400,000 residents. Private optometrists often had low levels of education and professional certification. In conclusion, our findings shows that the vision care system in rural China is inadequate and ineffective in meeting the needs of the rural population sampled.

  20. Ultraviolet vision in lacertid lizards: evidence from retinal structure, eye transmittance, SWS1 visual pigment genes and behaviour.

    Science.gov (United States)

    Pérez i de Lanuza, Guillem; Font, Enrique

    2014-08-15

    Ultraviolet (UV) vision and UV colour patches have been reported in a wide range of taxa and are increasingly appreciated as an integral part of vertebrate visual perception and communication systems. Previous studies with Lacertidae, a lizard family with diverse and complex coloration, have revealed the existence of UV-reflecting patches that may function as social signals. However, confirmation of the signalling role of UV coloration requires demonstrating that the lizards are capable of vision in the UV waveband. Here we use a multidisciplinary approach to characterize the visual sensitivity of a diverse sample of lacertid species. Spectral transmission measurements of the ocular media show that wavelengths down to 300 nm are transmitted in all the species sampled. Four retinal oil droplet types can be identified in the lacertid retina. Two types are pigmented and two are colourless. Fluorescence microscopy reveals that a type of colourless droplet is UV-transmitting and may thus be associated with UV-sensitive cones. DNA sequencing shows that lacertids have a functional SWS1 opsin, very similar at 13 critical sites to that in the presumed ancestral vertebrate (which was UV sensitive) and other UV-sensitive lizards. Finally, males of Podarcis muralis are capable of discriminating between two views of the same stimulus that differ only in the presence/absence of UV radiance. Taken together, these results provide convergent evidence of UV vision in lacertids, very likely by means of an independent photopigment. Moreover, the presence of four oil droplet types suggests that lacertids have a four-cone colour vision system. © 2014. Published by The Company of Biologists Ltd.

  1. Preferred skin color enhancement for photographic color reproduction

    Science.gov (United States)

    Zeng, Huanzhao; Luo, Ronnier

    2011-01-01

    Skin tones are the most important colors among the memory color category. Reproducing skin colors pleasingly is an important factor in photographic color reproduction. Moving skin colors toward their preferred skin color center improves the color preference of skin color reproduction. Several methods to morph skin colors to a smaller preferred skin color region has been reported in the past. In this paper, a new approach is proposed to further improve the result of skin color enhancement. An ellipsoid skin color model is applied to compute skin color probabilities for skin color detection and to determine a weight for skin color adjustment. Preferred skin color centers determined through psychophysical experiments were applied for color adjustment. Preferred skin color centers for dark, medium, and light skin colors are applied to adjust skin colors differently. Skin colors are morphed toward their preferred color centers. A special processing is applied to avoid contrast loss in highlight. A 3-D interpolation method is applied to fix a potential contouring problem and to improve color processing efficiency. An psychophysical experiment validates that the method of preferred skin color enhancement effectively identifies skin colors, improves the skin color preference, and does not objectionably affect preferred skin colors in original images.

  2. Express quality control of chicken eggs by machine vision

    Science.gov (United States)

    Gorbunova, Elena V.; Chertov, Aleksandr N.; Peretyagin, Vladimir S.; Korotaev, Valery V.; Arbuzova, Evgeniia A.

    2017-06-01

    The urgency of the task of analyzing the foodstuffs quality is determined by the strategy for the formation of a healthy lifestyle and the rational nutrition of the world population. This applies to products, such as chicken eggs. In particular, it is necessary to control the chicken eggs quality at the farm production prior to incubation in order to eliminate the possible hereditary diseases, as well as high embryonic mortality and a sharp decrease in the quality of the bred young. Up to this day, in the market there are no objective instruments of contactless express quality control as analytical equipment that allow the high-precision quality examination of the chicken eggs, which is determined by the color parameters of the eggshell (color uniformity) and yolk of eggs, and by the presence in the eggshell of various defects (cracks, growths, wrinkles, dirty). All mentioned features are usually evaluated only visually (subjectively) with the help of normalized color standards and ovoscopes. Therefore, this work is devoted to the investigation of the application opportunities of contactless express control method with the help of technical vision to implement the chicken eggs' quality analysis. As a result of the studies, a prototype with the appropriate software was proposed. Experimental studies of this equipment on a representative sample of eggs from chickens of different breeds have been carried out (the total number of analyzed samples exceeds 300 pieces). The correctness of the color analysis was verified by spectrophotometric studies of the surface of the eggshell.

  3. Tomato grading system using machine vision technology and neuro-fuzzy networks (ANFIS

    Directory of Open Access Journals (Sweden)

    H Izadi

    2016-04-01

    Full Text Available Introduction: The quality of agricultural products is associated with their color, size and health, grading of fruits is regarded as an important step in post-harvest processing. In most cases, manual sorting inspections depends on available manpower, time consuming and their accuracy could not be guaranteed. Machine Vision is known to be a useful tool for external features measurement (e.g. size, shape, color and defects and in recent century, Machine Vision technology has been used for shape sorting. The main purpose of this study was to develop new method for tomato grading and sorting using Neuro-fuzzy system (ANFIS and to compare the accuracies of the ANFIS predicted results with those suggested by a human expert. Materials and Methods: In this study, a total of 300 image of tomatoes (Rev ground was randomly harvested, classified in 3 ripeness stage, 3 sizes and 2 health. The grading and sorting mechanism consisted of a lighting chamber (cloudy sky, lighting source and a digital camera connected to a computer. The images were recorded in a special chamber with an indirect radiation (cloudy sky with four florescent lampson each sides and camera lens was entire to lighting chamber by a hole which was only entranced to outer and covered by a camera lens. Three types of features were extracted from final images; Shap, color and texture. To receive these features, we need to have images both in color and binary format in procedure shown in Figure 1. For the first group; characteristics of the images were analysis that could offer information an surface area (S.A., maximum diameter (Dmax, minimum diameter (Dmin and average diameters. Considering to the importance of the color in acceptance of food quality by consumers, the following classification was conducted to estimate the apparent color of the tomato; 1. Classified as red (red > 90% 2. Classified as red light (red or bold pink 60-90% 3. Classified as pink (red 30-60% 4. Classified as Turning

  4. 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 ...

  5. 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.

  6. 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.

  7. SIFT-CCH: Increasing the SIFT distinctness by color co-occurrence histograms

    OpenAIRE

    ANCUTI, Cosmin; BEKAERT, Philippe

    2007-01-01

    Describing regions in a distinctive way, in order to find correct correspondences in images of two separated views, represents a complex and essential task of computer vision. Until now, SIFT (Scale Invariant Feature Transform) has been proven to be the most reliable descriptor among the others. One of the main drawbacks of SIFT is its vulnerability to color images, being designed mainly for the gray images. To overcome this problem and also to increase the overall distinctness of the SIFT ...

  8. 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 ...

  9. Automated segmentation of geographic atrophy of the retinal epithelium via random forests in AREDS color fundus images☆

    Science.gov (United States)

    Feeny, Albert K.; Tadarati, Mongkol; Freund, David E.; Bressler, Neil M.; Burlina, Philippe

    2015-01-01

    Background Age-related macular degeneration (AMD), left untreated, is the leading cause of vision loss in people older than 55. Severe central vision loss occurs in the advanced stage of the disease, characterized by either the in growth of choroidal neovascularization (CNV), termed the “wet” form, or by geographic atrophy (GA) of the retinal pigment epithelium (RPE) involving the center of the macula, termed the “dry” form. Tracking the change in GA area over time is important since it allows for the characterization of the effectiveness of GA treatments. Tracking GA evolution can be achieved by physicians performing manual delineation of GA area on retinal fundus images. However, manual GA delineation is time-consuming and subject to inter-and intra-observer variability. Methods We have developed a fully automated GA segmentation algorithm in color fundus images that uses a supervised machine learning approach employing a random forest classifier. This algorithm is developed and tested using a dataset of images from the NIH-sponsored Age Related Eye Disease Study (AREDS). GA segmentation output was compared against a manual delineation by a retina specialist. Results Using 143 color fundus images from 55 different patient eyes, our algorithm achieved PPV of 0.82±0.19, and NPV of 0:95±0.07. Discussion This is the first study, to our knowledge, applying machine learning methods to GA segmentation on color fundus images and using AREDS imagery for testing. These preliminary results show promising evidence that machine learning methods may have utility in automated characterization of GA from color fundus images. PMID:26318113

  10. Automated segmentation of geographic atrophy of the retinal epithelium via random forests in AREDS color fundus images.

    Science.gov (United States)

    Feeny, Albert K; Tadarati, Mongkol; Freund, David E; Bressler, Neil M; Burlina, Philippe

    2015-10-01

    Age-related macular degeneration (AMD), left untreated, is the leading cause of vision loss in people older than 55. Severe central vision loss occurs in the advanced stage of the disease, characterized by either the in growth of choroidal neovascularization (CNV), termed the "wet" form, or by geographic atrophy (GA) of the retinal pigment epithelium (RPE) involving the center of the macula, termed the "dry" form. Tracking the change in GA area over time is important since it allows for the characterization of the effectiveness of GA treatments. Tracking GA evolution can be achieved by physicians performing manual delineation of GA area on retinal fundus images. However, manual GA delineation is time-consuming and subject to inter-and intra-observer variability. We have developed a fully automated GA segmentation algorithm in color fundus images that uses a supervised machine learning approach employing a random forest classifier. This algorithm is developed and tested using a dataset of images from the NIH-sponsored Age Related Eye Disease Study (AREDS). GA segmentation output was compared against a manual delineation by a retina specialist. Using 143 color fundus images from 55 different patient eyes, our algorithm achieved PPV of 0.82±0.19, and NPV of 0:95±0.07. This is the first study, to our knowledge, applying machine learning methods to GA segmentation on color fundus images and using AREDS imagery for testing. These preliminary results show promising evidence that machine learning methods may have utility in automated characterization of GA from color fundus images. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Do focal colors look particularly "colorful"?

    Science.gov (United States)

    Witzel, Christoph; Franklin, Anna

    2014-04-01

    If the most typical red, yellow, green, and blue were particularly colorful (i.e., saturated), they would "jump out to the eye." This would explain why even fundamentally different languages have distinct color terms for these focal colors, and why unique hues play a prominent role in subjective color appearance. In this study, the subjective saturation of 10 colors around each of these focal colors was measured through a pairwise matching task. Results show that subjective saturation changes systematically across hues in a way that is strongly correlated to the visual gamut, and exponentially related to sensitivity but not to focal colors.

  12. 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...

  13. A Retrospective Study of Causes of Low Vision in Saud Arabia, A Case of Eye World Medical Complex in Riyadh.

    Science.gov (United States)

    Z Alotaibi, Abdullah

    2015-10-20

    Vision is the ability of seeing with a definite understanding of features, color and contrast, and to distinguish between objects visually. In the year 1999, the World Health Organization (WHO) and the International Agency for the Prevention of Blindness formulated a worldwide project for the eradication of preventable loss of sight with the subject of "Vision 2020: the Right to Sight". This global program aims to eradicate preventable loss of sight by the year 2020. This study was conducted to determine the main causes of low vision in Saudi Arabia and also to assess their visual improvement after using low vision aids (LVD).The study is a retrospective study and was conducted in low vision clinic at Eye World Medical Complex in Riyadh, Saudi Arabia. The file medical record of 280 patients attending low vision clinics from February 2008 to June 2010 was included. A data sheet was filled which include: age, gender, cause of low vision, unassisted visual acuity for long distances and short distances, low vision devices needed for long distances and short distances that provides best visual acuity. The result shows that the main cause of low vision was Optic atrophy (28.9%). Retinitis pigmentosa was the second cause of low vision, accounting for 73 patients (26%) followed by Diabetic retinopathy and Macular degeneration with 44 patients (15.7%) and 16 patients (5.7%) respectively. Inter family marriage could be one of the main causes of low vision. Public awareness should be embarked on for enlightenment on ocular diseases result in consanguineous marriage. Also, it is an important issue to start establishing low vision clinics in order to improve the situation.

  14. Improving scale invariant feature transform-based descriptors with shape-color alliance robust feature

    Science.gov (United States)

    Wang, Rui; Zhu, Zhengdan; Zhang, Liang

    2015-05-01

    Constructing appropriate descriptors for interest points in image matching is a critical aspect task in computer vision and pattern recognition. A method as an extension of the scale invariant feature transform (SIFT) descriptor called shape-color alliance robust feature (SCARF) descriptor is presented. To address the problem that SIFT is designed mainly for gray images and lack of global information for feature points, the proposed approach improves the SIFT descriptor by means of a concentric-rings model, as well as integrating the color invariant space and shape context with SIFT to construct the SCARF descriptor. The SCARF method developed is more robust than the conventional SIFT with respect to not only the color and photometrical variations but also the measuring similarity as a global variation between two shapes. A comparative evaluation of different descriptors is carried out showing that the SCARF approach provides better results than the other four state-of-the-art related methods.

  15. HIV-related ocular microangiopathic syndrome and color contrast sensitivity.

    Science.gov (United States)

    Geier, S A; Hammel, G; Bogner, J R; Kronawitter, U; Berninger, T; Goebel, F D

    1994-06-01

    Color vision deficits in patients with acquired immunodeficiency syndrome (AIDS) or human immunodeficiency virus (HIV) disease were reported, and a retinal pathogenic mechanism was proposed. The purpose of this study was to evaluate the association of color vision deficits with HIV-related retinal microangiopathy. A computer graphics system was used to measure protan, deutan, and tritan color contrast sensitivity (CCS) thresholds in 60 HIV-infected patients. Retinal microangiopathy was measured by counting the number of cotton-wool spots, and conjunctival blood-flow sludging was determined. Additional predictors were CD4+ count, age, time on aerosolized pentamidine, time on zidovudine, and Walter Reed staging. The relative influence of each predictor was calculated by stepwise multiple regression analysis (inclusion criterion; incremental P value = < 0.05) using data for the right eyes (RE). The results were validated by using data for the left eyes (LE) and both eyes (BE). The only included predictors in multiple regression analyses for the RE were number of cotton-wool spots (tritan: R = .70; deutan: R = .46; and protan: R = .58; P < .0001 for all axes) and age (tritan: increment of R [Ri] = .05, P = .002; deutan: Ri = .10, P = .004; and protan: Ri = .05, P = .002). The predictors time on zidovudine (Ri = .05, P = .002) and Walter Reed staging (Ri = .03, P = .01) were additionally included in multiple regression analysis for tritan LE. The results for deutan LE were comparable to those for the RE. In the analysis for protan LE, the only included predictor was number of cotton-wool spots. In the analyses for BE, no further predictors were included. The predictors Walter Reed staging and CD4+ count showed a significant association with all three criteria in univariate analysis. Additionally, tritan CCS was significantly associated with conjunctival blood-flow sludging. CCS deficits in patients with HIV disease are primarily associated with the number of cotton

  16. Color- and motion-specific units in the tectum opticum of goldfish.

    Science.gov (United States)

    Gruber, Morna; Behrend, Konstantin; Neumeyer, Christa

    2016-01-05

    Extracellular recordings were performed from 69 units at different depths between 50 and [Formula: see text]m below the surface of tectum opticum in goldfish. Using large field stimuli (86[Formula: see text] visual angle) of 21 colored HKS-papers we were able to record from 54 color-sensitive units. The colored papers were presented for 5[Formula: see text]s each. They were arranged in the sequence of the color circle in humans separated by gray of medium brightness. We found 22 units with best responses between orange, red and pink. About 12 of these red-sensitive units were of the opponent "red-ON/blue-green-OFF" type as found in retinal bipolar- and ganglion cells as well. Most of them were also activated or inhibited by black and/or white. Some units responded specifically to red either with activation or inhibition. 18 units were sensitive to blue and/or green, 10 of them to both colors and most of them to black as well. They were inhibited by red, and belonged to the opponent "blue-green-ON/red-OFF" type. Other units responded more selectively either to blue, to green or to purple. Two units were selectively sensitive to yellow. A total of 15 units were sensitive to motion, stimulated by an excentrically rotating black and white random dot pattern. Activity of these units was also large when a red-green random dot pattern of high L-cone contrast was used. Activity dropped to zero when the red-green pattern did not modulate the L-cones. Neither of these motion selective units responded to any color. The results directly show color-blindness of motion vision, and confirm the hypothesis of separate and parallel processing of "color" and "motion".

  17. Using color management in color document processing

    Science.gov (United States)

    Nehab, Smadar

    1995-04-01

    Color Management Systems have been used for several years in Desktop Publishing (DTP) environments. While this development hasn't matured yet, we are already experiencing the next generation of the color imaging revolution-Device Independent Color for the small office/home office (SOHO) environment. Though there are still open technical issues with device independent color matching, they are not the focal point of this paper. This paper discusses two new and crucial aspects in using color management in color document processing: the management of color objects and their associated color rendering methods; a proposal for a precedence order and handshaking protocol among the various software components involved in color document processing. As color peripherals become affordable to the SOHO market, color management also becomes a prerequisite for common document authoring applications such as word processors. The first color management solutions were oriented towards DTP environments whose requirements were largely different. For example, DTP documents are image-centric, as opposed to SOHO documents that are text and charts centric. To achieve optimal reproduction on low-cost SOHO peripherals, it is critical that different color rendering methods are used for the different document object types. The first challenge in using color management of color document processing is the association of rendering methods with object types. As a result of an evolutionary process, color matching solutions are now available as application software, as driver embedded software and as operating system extensions. Consequently, document processing faces a new challenge, the correct selection of the color matching solution while avoiding duplicate color corrections.

  18. 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

  19. Detection of Two Types of Weed through Machine Vision System: Improving Site-Specific Spraying

    Directory of Open Access Journals (Sweden)

    S Sabzi

    2018-03-01

    Full Text Available Introduction With increase in world population, one of the approaches to provide food is using site-specific management system or so-called precision farming. In this management system, management of crop production inputs such as fertilizers, lime, herbicides, seed, etc. is done based on farm location features, with the aim of reducing waste, increasing revenues and maintaining environmental quality. Precision farming involves various aspects and is applicable on farm fields at all stages of tillage, planting, and harvesting. Today, in line with precision farming purposes, and to control weeds, pests, and diseases, all the efforts of specialists in precision farming is to reduce the amount of chemical substances in products. Although herbicides improve the quality and quantity of agricultural production, the possibility of applying inappropriately and unreasonably is very high. If the dose is too low, weed control is not performed correctly. Otherwise, If the dosage is too high, herbicides can be toxic for crops, can be transferred to soil and stay in it for a long time, and can penetrate to groundwater. By applying herbicides to variable rate, the potential for significant cost savings and reduced environmental damage to the products and environment will be possible. It is evident that in large-scale modern agriculture, individual management of each plant without using some advanced technologies is not possible. using machine vision systems is one of precision farming techniques to identify weeds. This study aimed to detect three plant such as Centaurea depressa M.B, Malvaneglecta and Potato plant using machine vision system. Materials and Methods In order to train algorithm of designed machine vision system, a platform that moved with the speed of 10.34 was used for shooting of Marfona potato fields. This platform was consisted of a chassis, camera (DFK23GM021,CMOS, 120 f/s, Made in Germany, and a processor system equipped with Matlab 2015

  20. Automatic color preference correction for color reproduction

    Science.gov (United States)

    Tsukada, Masato; Funayama, Chisato; Tajima, Johji

    2000-12-01

    The reproduction of natural objects in color images has attracted a great deal of attention. Reproduction more pleasing colors of natural objects is one of the methods available to improve image quality. We developed an automatic color correction method to maintain preferred color reproduction for three significant categories: facial skin color, green grass and blue sky. In this method, a representative color in an object area to be corrected is automatically extracted from an input image, and a set of color correction parameters is selected depending on the representative color. The improvement in image quality for reproductions of natural image was more than 93 percent in subjective experiments. These results show the usefulness of our automatic color correction method for the reproduction of preferred colors.

  1. Visions of Vision: An Exploratory Study of the Role College and University Presidents Play in Developing Institutional Vision

    Science.gov (United States)

    McWade, Jessica C.

    2014-01-01

    This qualitative research explores how college and university presidents engage in the process of developing formal institutional vision. The inquiry identifies roles presidents play in vision development, which is often undertaken as part of strategic-planning initiatives. Two constructs of leadership and institutional vision are used to examine…

  2. Embedding Color Watermarks in Color Images

    Directory of Open Access Journals (Sweden)

    Wu Tung-Lin

    2003-01-01

    Full Text Available Robust watermarking with oblivious detection is essential to practical copyright protection of digital images. Effective exploitation of the characteristics of human visual perception to color stimuli helps to develop the watermarking scheme that fills the requirement. In this paper, an oblivious watermarking scheme that embeds color watermarks in color images is proposed. Through color gamut analysis and quantizer design, color watermarks are embedded by modifying quantization indices of color pixels without resulting in perceivable distortion. Only a small amount of information including the specification of color gamut, quantizer stepsize, and color tables is required to extract the watermark. Experimental results show that the proposed watermarking scheme is computationally simple and quite robust in face of various attacks such as cropping, low-pass filtering, white-noise addition, scaling, and JPEG compression with high compression ratios.

  3. Real-time stereo generation for surgical vision during minimal invasive robotic surgery

    Science.gov (United States)

    Laddi, Amit; Bhardwaj, Vijay; Mahapatra, Prasant; Pankaj, Dinesh; Kumar, Amod

    2016-03-01

    This paper proposes a framework for 3D surgical vision for minimal invasive robotic surgery. It presents an approach for generating the three dimensional view of the in-vivo live surgical procedures from two images captured by very small sized, full resolution camera sensor rig. A pre-processing scheme is employed to enhance the image quality and equalizing the color profile of two images. Polarized Projection using interlacing two images give a smooth and strain free three dimensional view. The algorithm runs in real time with good speed at full HD resolution.

  4. 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 ...

  5. Static and dynamic postural control in low-vision and normal-vision adults.

    Science.gov (United States)

    Tomomitsu, Mônica S V; Alonso, Angelica Castilho; Morimoto, Eurica; Bobbio, Tatiana G; Greve, Julia M D

    2013-04-01

    This study aimed to evaluate the influence of reduced visual information on postural control by comparing low-vision and normal-vision adults in static and dynamic conditions. Twenty-five low-vision subjects and twenty-five normal sighted adults were evaluated for static and dynamic balance using four protocols: 1) the Modified Clinical Test of Sensory Interaction on Balance on firm and foam surfaces with eyes opened and closed; 2) Unilateral Stance with eyes opened and closed; 3) Tandem Walk; and 4) Step Up/Over. The results showed that the low-vision group presented greater body sway compared with the normal vision during balance on a foam surface (p≤0.001), the Unilateral Stance test for both limbs (p≤0.001), and the Tandem Walk test. The low-vision group showed greater step width (p≤0.001) and slower gait speed (p≤0.004). In the Step Up/Over task, low-vision participants were more cautious in stepping up (right p≤0.005 and left p≤0.009) and in executing the movement (p≤0.001). These findings suggest that visual feedback is crucial for determining balance, especially for dynamic tasks and on foam surfaces. Low-vision individuals had worse postural stability than normal-vision adults in terms of dynamic tests and balance on foam surfaces.

  6. Generalization of Figure-Ground Segmentation from Binocular to Monocular Vision in an Embodied Biological Brain Model

    Science.gov (United States)

    2011-08-01

    figure and ground the luminance cue breaks down and gestalt contours can fail to pop out. In this case we rely on color, which, having weak stereopsis...REPORT Generalization of Figure - Ground Segmentation from Monocular to Binocular Vision in an Embodied Biological Brain Model 14. ABSTRACT 16. SECURITY...U.S. Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 15. SUBJECT TERMS figure - ground , neural network, object

  7. News from Online: A Spectrum of Color

    Science.gov (United States)

    Sweeney Judd, Carolyn

    1999-06-01

    --appreciate the beautiful visible electromagnetic spectrum at http://www.scimedia.com/chem-ed/light/graphics/em-visib.jpg. Great spectroscopy tutorials from Brian Tissue of the Virginia Polytechnic Institute and State University are found at Science Media's site. One of my favorite graphics ( http://www.scimedia.com/chem-ed/light/graphics/em-rad.gif) reminds us of why light is electromagnetic radiation. But how to we actually see color? Go to the Access Excellence Classic Collection sponsored by Genentech, Inc. (http://www.gene.com/ae/AE/AEC/CC/). From here, go to How We See: The First Steps of Human Vision at http://www.gene.com/ae/AE/AEC/CC/vision_background.html. Here are good graphics and explanations of the roles of rod and cone cells, and lots more! And marvel a little the next time you see a rainbow. World Wide Web Addresses About Rainbows http://www.unidata.ucar.edu/staff/blynds/rnbw.html Project SkyMath: Making Mathematical Connections http://www.unidata.ucar.edu/staff/blynds/Skymath.html The Weather Underground at the University of Michigan--Blue- Skies http://groundhog.sprl.umich.edu/BS.html Why is the Sky Blue http://acept.la.asu.edu/PiN/act/sky/sky.shtml Patterns in NatureLight and Optics Activities http://acept.la.asu.edu/PiN/act/activities.shtml Circles of Lightthe Mathematics of Rainbows http://www.geom.umn.edu/education/calc-init/rainbow/ The Physics of a Rainbow http://science.kongju.ac.kr/phys/shin/experiment/ntnujava /Rainbow/rainbow.html The NTNU Virtual Physics Laboratory http://science.kongju.ac.kr/phys/shin/experiment/ntnujava /index.html Shadow/Image and Color http://science.kongju.ac.kr/phys/shin/experiment/ntnujava/shadow/shadow.html Thomas Chasteen's Chemistry-Based QuickTime Movies, Animations, and Streaming Audio http://www.shsu.edu/~chm_tgc/sounds/sound.html Tuneable Monochromator http://www.shsu.edu/~chemistry/monochromator/mono.gif The Chemiluminescence Home Page http://www.shsu.edu/~chm_tgc/chemilumdir/movie.html Science Hypermedia Home Page http

  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. Color evaluation of computer-generated color rainbow holography

    International Nuclear Information System (INIS)

    Shi, Yile; Wang, Hui; Wu, Qiong

    2013-01-01

    A color evaluation approach for computer-generated color rainbow holography (CGCRH) is presented. Firstly, the relationship between color quantities of a computer display and a color computer-generated holography (CCGH) colorimetric system is discussed based on color matching theory. An isochromatic transfer relationship of color quantity and amplitude of object light field is proposed. Secondly, the color reproduction mechanism and factors leading to the color difference between the color object and the holographic image that is reconstructed by CGCRH are analyzed in detail. A quantitative color calculation method for the holographic image reconstructed by CGCRH is given. Finally, general color samples are selected as numerical calculation test targets and the color differences between holographic images and test targets are calculated based on our proposed method. (paper)

  10. Color planner for designers based on color emotions

    Science.gov (United States)

    Cheng, Ka-Man; Xin, John H.; Taylor, Gail

    2002-06-01

    During the color perception process, an associated feeling or emotion is induced in our brains, and this kind of emotion is termed as 'color emotion.' The researchers in the field of color emotions have put many efforts in quantifying color emotions with the standard color specifications and evaluating the influence of hue, lightness and chroma to the color emotions of human beings. In this study, a color planner was derived according to these findings so that the correlation of color emotions and standard color specifications was clearly indicated. Since people of different nationalities usually have different color emotions as different cultural and traditional backgrounds, the subjects in this study were all native Hong Kong Chinese and the color emotion words were all written in Chinese language in the visual assessments. Through the color planner, the designers from different areas, no matter fashion, graphic, interior or web site etc., can select suitable colors for inducing target color emotions to the customers or product-users since different colors convey different meanings to them. In addition, the designers can enhance the functionality and increase the attractiveness of their designed products by selecting suitable colors.

  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. [Neural correlates of priming in vision: evidence from neuropsychology and neuroimaging].

    Science.gov (United States)

    Kristjánsson, Arni

    2005-04-01

    When we look around us, we are overall more likely to notice objects that we have recently looked at; an effect known as priming. For example, when the color or shape of a visual search target is repeated, observers find the target faster than otherwise. Here I summarize recent research undertaken to uncover the temporary changes in brain activity that accompany these priming effects. In light of the fact that priming seems to have a large effect on how attention is allocated, we investigated priming effects in a visual search task on patients suffering from the neurological disorder "hemispatial neglect" in which patients typically fail to notice display items in one of their visual hemifields. Priming of target color was relatively normal for these patients, while priming of target location seemed to require awareness of the briefly presented visual search target. An experiment with functional magnetic resonance imaging of normal observers revealed that both color and location priming had a strong modulatory influence on attentional mechanisms of the frontal and parietal cortex. Color priming was also correlated with changes in activity in visual cortex as well as color processing areas in the temporal lobe. Location priming was correlated with changes in activity near the temporo- parietal junction and lateral inferior frontal cortex, areas that have been connected with attentional capture; which ties well with our finding of deficits of location priming for the neglect patients who indeed have lesions in the temporo-parietal junction. Overall, the results confirm the tight coupling of visual attention and priming in vision, and also that the visual areas of the brain show some modulation of activity as priming develops.

  13. Computer vision for automatic inspection of agricultural produce

    Science.gov (United States)

    Molto, Enrique; Blasco, Jose; Benlloch, Jose V.

    1999-01-01

    Fruit and vegetables suffer different manipulations from the field to the final consumer. These are basically oriented towards the cleaning and selection of the product in homogeneous categories. For this reason, several research projects, aimed at fast, adequate produce sorting and quality control are currently under development around the world. Moreover, it is possible to find manual and semi- automatic commercial system capable of reasonably performing these tasks.However, in many cases, their accuracy is incompatible with current European market demands, which are constantly increasing. IVIA, the Valencian Research Institute of Agriculture, located in Spain, has been involved in several European projects related with machine vision for real-time inspection of various agricultural produces. This paper will focus on the work related with two products that have different requirements: fruit and olives. In the case of fruit, the Institute has developed a vision system capable of providing assessment of the external quality of single fruit to a robot that also receives information from other senors. The system use four different views of each fruit and has been tested on peaches, apples and citrus. Processing time of each image is under 500 ms using a conventional PC. The system provides information about primary and secondary color, blemishes and their extension, and stem presence and position, which allows further automatic orientation of the fruit in the final box using a robotic manipulator. Work carried out in olives was devoted to fast sorting of olives for consumption at table. A prototype has been developed to demonstrate the feasibility of a machine vision system capable of automatically sorting 2500 kg/h olives using low-cost conventional hardware.

  14. Color and Contour Based Identification of Stem of Coconut Bunch

    Science.gov (United States)

    Kannan Megalingam, Rajesh; Manoharan, Sakthiprasad K.; Reddy, Rajesh G.; Sriteja, Gone; Kashyap, Ashwin

    2017-08-01

    Vision is the key component of Artificial Intelligence and Automated Robotics. Sensors or Cameras are the sight organs for a robot. Only through this, they are able to locate themselves or identify the shape of a regular or an irregular object. This paper presents the method of Identification of an object based on color and contour recognition using a camera through digital image processing techniques for robotic applications. In order to identify the contour, shape matching technique is used, which takes the input data from the database provided, and uses it to identify the contour by checking for shape match. The shape match is based on the idea of iterating through each contour of the threshold image. The color is identified on HSV Scale, by approximating the desired range of values from the database. HSV data along with iteration is used for identifying a quadrilateral, which is our required contour. This algorithm could also be used in a non-deterministic plane, which only uses HSV values exclusively.

  15. Colorization-Based RGB-White Color Interpolation using Color Filter Array with Randomly Sampled Pattern.

    Science.gov (United States)

    Oh, Paul; Lee, Sukho; Kang, Moon Gi

    2017-06-28

    Recently, several RGB-White (RGBW) color filter arrays (CFAs) have been proposed, which have extra white (W) pixels in the filter array that are highly sensitive. Due to the high sensitivity, the W pixels have better SNR (Signal to Noise Ratio) characteristics than other color pixels in the filter array, especially, in low light conditions. However, most of the RGBW CFAs are designed so that the acquired RGBW pattern image can be converted into the conventional Bayer pattern image, which is then again converted into the final color image by using conventional demosaicing methods, i.e., color interpolation techniques. In this paper, we propose a new RGBW color filter array based on a totally different color interpolation technique, the colorization algorithm. The colorization algorithm was initially proposed for colorizing a gray image into a color image using a small number of color seeds. Here, we adopt this algorithm as a color interpolation technique, so that the RGBW color filter array can be designed with a very large number of W pixels to make the most of the highly sensitive characteristics of the W channel. The resulting RGBW color filter array has a pattern with a large proportion of W pixels, while the small-numbered RGB pixels are randomly distributed over the array. The colorization algorithm makes it possible to reconstruct the colors from such a small number of RGB values. Due to the large proportion of W pixels, the reconstructed color image has a high SNR value, especially higher than those of conventional CFAs in low light condition. Experimental results show that many important information which are not perceived in color images reconstructed with conventional CFAs are perceived in the images reconstructed with the proposed method.

  16. Of colored numbers and numbered colors: interactive processes in grapheme-color synesthesia.

    Science.gov (United States)

    Gebuis, Titia; Nijboer, Tanja C W; van der Smagt, Maarten J

    2009-01-01

    Grapheme-color synesthetes experience a specific color when they see a grapheme but they do not report to perceive a grapheme when a color is presented. In this study, we investigate whether color can still evoke number-processes even when a vivid number experience is absent. We used color-number and number-color priming, both revealing faster responses in congruent compared to incongruent conditions. Interestingly, the congruency effect was of similar magnitude for both conditions, and a numerical distance effect was present only in the color-number priming task. In addition, a priming task in which synesthetes had to judge the parity of a colored number revealed faster responses in parity congruent than in parity incongruent trials. These combined results demonstrate that synesthesia is indeed bi-directional and of similar strength in both directions. Furthermore, they illustrate the precise nature of these interactions and show that the direction of these interactions is determined by task demands, not by the more vividly experienced aspect of the stimulus.

  17. Study On Technology Based Home Vision Screening And Creating Awareness On Eye Health

    Directory of Open Access Journals (Sweden)

    Nirav Mehta

    2015-08-01

    Full Text Available Introduction Technology is one of most important factor in todays life. IPAD is leading as people can make use of technology by just pressing buttons. Networking technology and education makes communication easier and helps people in easy education and awareness. Aim amp objectives The main aim of the study is to educate and aware among people regarding eye health and the check the visual function of their eye by using Apple I pad. Material and Methodology The following study is a home based vision screening program using IPAD which uses the basic tests like visual acuity color vision contrast sensitivity and amsler tests for checking the basic functions of the eye. The study was performed in many societies moving from one place to another using IPAD as a tool. Reliability of ipad was checked a pilot study on 25 subjects visual acuity colour vision and contrast sensitivity was taken on both ipad and Original chart like snellen ishihara and pellirobson and compared in which the results and the accuracy were same. The study also contains questionnaire on the awareness and education about eye health. The subjects included in the study were an age group of 10 to 70. Subjects like infants and blind were not included in the study. Results During the study it was observed that there is no significant difference in testing of visual acuity between ipad and Snellen standard chart. The subjects responded actively towards screening and that home vision screening can be possible. During the study it was found that 40 subjects out of 100 needed further detailed check-up and were referred in Rotary eye hospital hospital but only 3 out of 40 came for it. This shows that they are less aware and education about their eye health. Software used in IPAD were visual acuity color vision contrast sensitivity and amsler tests A questionnaire was also asked which indicated less awareness among the common people. Conclusion We examined with just an ipad and not an

  18. Barriers to accessing low vision services.

    Science.gov (United States)

    Pollard, Tamara L; Simpson, John A; Lamoureux, Ecosse L; Keeffe, Jill E

    2003-07-01

    To investigate barriers to accessing low vision services in Australia. Adults with a vision impairment (vision difficulties, duration of vision loss and satisfaction with vision and also examined issues of awareness of low vision services and referral to services. Focus groups were also conducted with vision impaired (Vision Australia Foundation. The discussions were recorded and transcribed. The questionnaire revealed that referral to low vision services was associated with a greater degree of vision loss (p = 0.002) and a greater self-perception of low vision (p = 0.005) but that referral was not associated with satisfaction (p = 0.144) or difficulties related to vision (p = 0.169). Participants with mild and moderate vision impairment each reported similar levels of difficulties with daily activities and satisfaction with their vision (p > 0.05). However, there was a significant difference in the level of difficulties experienced with daily activities between those with mild-moderate and severe vision impairment (p low vision services related to awareness of services among the general public and eye care professionals, understanding of low vision and the services available, acceptance of low vision, the referral process, and transport. In addition to the expected difficulties with lack of awareness of services by people with low vision, many people do not understand what the services provide and do not identify themselves as having low vision. Knowledge of these barriers, from the perspective of people with low vision, can now be used to guide the development and content of future health-promotion campaigns.

  19. Gene loss, adaptive evolution and the co-evolution of plumage coloration genes with opsins in birds.

    Science.gov (United States)

    Borges, Rui; Khan, Imran; Johnson, Warren E; Gilbert, M Thomas P; Zhang, Guojie; Jarvis, Erich D; O'Brien, Stephen J; Antunes, Agostinho

    2015-10-06

    The wide range of complex photic systems observed in birds exemplifies one of their key evolutionary adaptions, a well-developed visual system. However, genomic approaches have yet to be used to disentangle the evolutionary mechanisms that govern evolution of avian visual systems. We performed comparative genomic analyses across 48 avian genomes that span extant bird phylogenetic diversity to assess evolutionary changes in the 17 representatives of the opsin gene family and five plumage coloration genes. Our analyses suggest modern birds have maintained a repertoire of up to 15 opsins. Synteny analyses indicate that PARA and PARIE pineal opsins were lost, probably in conjunction with the degeneration of the parietal organ. Eleven of the 15 avian opsins evolved in a non-neutral pattern, confirming the adaptive importance of vision in birds. Visual conopsins sw1, sw2 and lw evolved under negative selection, while the dim-light RH1 photopigment diversified. The evolutionary patterns of sw1 and of violet/ultraviolet sensitivity in birds suggest that avian ancestors had violet-sensitive vision. Additionally, we demonstrate an adaptive association between the RH2 opsin and the MC1R plumage color gene, suggesting that plumage coloration has been photic mediated. At the intra-avian level we observed some unique adaptive patterns. For example, barn owl showed early signs of pseudogenization in RH2, perhaps in response to nocturnal behavior, and penguins had amino acid deletions in RH2 sites responsible for the red shift and retinal binding. These patterns in the barn owl and penguins were convergent with adaptive strategies in nocturnal and aquatic mammals, respectively. We conclude that birds have evolved diverse opsin adaptations through gene loss, adaptive selection and coevolution with plumage coloration, and that differentiated selective patterns at the species level suggest novel photic pressures to influence evolutionary patterns of more-recent lineages.

  20. 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.

  1. Precision of synesthetic color matching resembles that for recollected colors rather than physical colors.

    Science.gov (United States)

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

    2012-10-01

    Grapheme-color synesthesia is an atypical condition in which individuals experience sensations of color when reading printed graphemes such as letters and digits. For some grapheme-color synesthetes, seeing a printed grapheme triggers a sensation of color, but hearing the name of a grapheme does not. This dissociation allowed us to compare the precision with which synesthetes are able to match their color experiences triggered by visible graphemes, with the precision of their matches for recalled colors based on the same graphemes spoken aloud. In six synesthetes, color matching for printed graphemes was equally variable relative to recalled experiences. In a control experiment, synesthetes and age-matched controls either matched the color of a circular patch while it was visible on a screen, or they judged its color from memory after it had disappeared. Both synesthetes and controls were more variable when matching from memory, and the variance of synesthetes' recalled color judgments matched that associated with their synesthetic judgments for visible graphemes in the first experiment. Results suggest that synesthetic experiences of color triggered by achromatic graphemes are analogous to recollections of color.

  2. Color Terms and Color Concepts

    Science.gov (United States)

    Davidoff, Jules

    2006-01-01

    In their lead articles, both Kowalski and Zimiles (2006) and O'Hanlon and Roberson (2006) declare a general relation between color term knowledge and the ability to conceptually represent color. Kowalski and Zimiles, in particular, argue for a priority for the conceptual representation in color term acquisition. The complexities of the interaction…

  3. Alternative Mating Tactics in Male Chameleons (Chamaeleo chamaeleon) Are Evident in Both Long-Term Body Color and Short-Term Courtship Pattern

    Science.gov (United States)

    Keren-Rotem, Tammy; Levy, Noga; Wolf, Lior; Bouskila, Amos; Geffen, Eli

    2016-01-01

    Alternative mating tactics in males of various taxa are associated with body color, body size, and social status. Chameleons are known for their ability to change body color following immediate environmental or social stimuli. In this study, we examined whether the differential appearance of male common chameleon during the breeding season is indeed an expression of alternative mating tactics. We documented body color of males and used computer vision techniques to classify images of individuals into discrete color patterns associated with seasons, individual characteristics, and social contexts. Our findings revealed no differences in body color and color patterns among males during the non-breeding season. However, during the breeding season males appeared in several color displays, which reflected body size, social status, and behavioral patterns. Furthermore, smaller and younger males resembled the appearance of small females. Consequently, we suggest that long-term color change in males during the breeding season reflects male alternative mating tactics. Upon encounter with a receptive female, males rapidly alter their appearance to that of a specific brief courtship display, which reflects their social status. The females, however, copulated indiscriminately in respect to male color patterns. Thus, we suggest that the differential color patterns displayed by males during the breeding season are largely aimed at inter-male signaling. PMID:27409771

  4. Alternative Mating Tactics in Male Chameleons (Chamaeleo chamaeleon Are Evident in Both Long-Term Body Color and Short-Term Courtship Pattern.

    Directory of Open Access Journals (Sweden)

    Tammy Keren-Rotem

    Full Text Available Alternative mating tactics in males of various taxa are associated with body color, body size, and social status. Chameleons are known for their ability to change body color following immediate environmental or social stimuli. In this study, we examined whether the differential appearance of male common chameleon during the breeding season is indeed an expression of alternative mating tactics. We documented body color of males and used computer vision techniques to classify images of individuals into discrete color patterns associated with seasons, individual characteristics, and social contexts. Our findings revealed no differences in body color and color patterns among males during the non-breeding season. However, during the breeding season males appeared in several color displays, which reflected body size, social status, and behavioral patterns. Furthermore, smaller and younger males resembled the appearance of small females. Consequently, we suggest that long-term color change in males during the breeding season reflects male alternative mating tactics. Upon encounter with a receptive female, males rapidly alter their appearance to that of a specific brief courtship display, which reflects their social status. The females, however, copulated indiscriminately in respect to male color patterns. Thus, we suggest that the differential color patterns displayed by males during the breeding season are largely aimed at inter-male signaling.

  5. Sex & vision I: Spatio-temporal resolution

    Directory of Open Access Journals (Sweden)

    Abramov Israel

    2012-09-01

    Full Text Available Abstract Background Cerebral cortex has a very large number of testosterone receptors, which could be a basis for sex differences in sensory functions. For example, audition has clear sex differences, which are related to serum testosterone levels. Of all major sensory systems only vision has not been examined for sex differences, which is surprising because occipital lobe (primary visual projection area may have the highest density of testosterone receptors in the cortex. We have examined a basic visual function: spatial and temporal pattern resolution and acuity. Methods We tested large groups of young adults with normal vision. They were screened with a battery of standard tests that examined acuity, color vision, and stereopsis. We sampled the visual system’s contrast-sensitivity function (CSF across the entire spatio-temporal space: 6 spatial frequencies at each of 5 temporal rates. Stimuli were gratings with sinusoidal luminance profiles generated on a special-purpose computer screen; their contrast was also sinusoidally modulated in time. We measured threshold contrasts using a criterion-free (forced-choice, adaptive psychophysical method (QUEST algorithm. Also, each individual’s acuity limit was estimated by fitting his or her data with a model and extrapolating to find the spatial frequency corresponding to 100% contrast. Results At a very low temporal rate, the spatial CSF was the canonical inverted-U; but for higher temporal rates, the maxima of the spatial CSFs shifted: Observers lost sensitivity at high spatial frequencies and gained sensitivity at low frequencies; also, all the maxima of the CSFs shifted by about the same amount in spatial frequency. Main effect: there was a significant (ANOVA sex difference. Across the entire spatio-temporal domain, males were more sensitive, especially at higher spatial frequencies; similarly males had significantly better acuity at all temporal rates. Conclusion As with other sensory systems

  6. Brightness, hue, and saturation in photopic vision: a result of luminance and wavelength in the cellular phase-grating optical 3D chip of the inverted retina

    Science.gov (United States)

    Lauinger, Norbert

    1994-10-01

    In photopic vision, two physical variables (luminance and wavelength) are transformed into three psychological variables (brightness, hue, and saturation). Following on from 3D grating optical explanations of aperture effects (Stiles-Crawford effects SCE I and II), all three variables can be explained via a single 3D chip effect. The 3D grating optical calculations are carried out using the classical von Laue equation and demonstrated using the example of two experimentally confirmed observations in human vision: saturation effects for monochromatic test lights between 485 and 510 nm in the SCE II and the fact that many test lights reverse their hue shift in the SCE II when changing from moderate to high luminances compared with that on changing from low to medium luminances. At the same time, information is obtained on the transition from the trichromatic color system in the retina to the opponent color system.

  7. Color Categories and Color Appearance

    Science.gov (United States)

    Webster, Michael A.; Kay, Paul

    2012-01-01

    We examined categorical effects in color appearance in two tasks, which in part differed in the extent to which color naming was explicitly required for the response. In one, we measured the effects of color differences on perceptual grouping for hues that spanned the blue-green boundary, to test whether chromatic differences across the boundary…

  8. Color Memory of University Students: Influence of Color Experience and Color Characteristic

    Science.gov (United States)

    Bynum, Carlisle; Epps, Helen H.; Kaya, Naz

    2006-01-01

    The ability to select a previously viewed color specimen from an array of specimens that differ in hue, value, or chroma varies among individuals, and may be related to one's basic color discrimination ability or to prior experience with color. This study investigated short-term color memory of 40 college students, 20 of whom were interior design…

  9. The CCH Vision Stimulation Program for Infants with Low Vision: Preliminary Results.

    Science.gov (United States)

    Leguire, L. E.; And Others

    1992-01-01

    This study evaluated the Columbus (Ohio) Children's Hospital vision stimulation program, involving in-home intervention with 15 visually impaired infants. Comparison with controls indicated benefits of appropriate vision stimulation in increasing the neural foundation for vision and visual-motor function in visually impaired infants. (Author/DB)

  10. Memory for color reactivates color processing region.

    Science.gov (United States)

    Slotnick, Scott D

    2009-11-25

    Memory is thought to be constructive in nature, where features processed in different cortical regions are synthesized during retrieval. In an effort to support this constructive memory framework, the present functional magnetic resonance imaging study assessed whether memory for color reactivated color processing regions. During encoding, participants were presented with colored and gray abstract shapes. During retrieval, old and new shapes were presented in gray and participants responded 'old-colored', 'old-gray', or 'new'. Within color perception regions, color memory related activity was observed in the left fusiform gyrus, adjacent to the collateral sulcus. A retinotopic mapping analysis indicated this activity occurred within color processing region V8. The present feature specific evidence provides compelling support for a constructive view of memory.

  11. Determination of connected components inthe analysis of homogeneous and detail zonesin color images

    Directory of Open Access Journals (Sweden)

    Cristina Pérez-Benito

    2018-02-01

    Full Text Available A model based on local graphs to classify pixels coming from at or detail regions of an image is presented. For each pixel a local graph is dened. Its structure will depend on the similarity between neighbouring pixels. Its features allow us to classify each image pixel as belonging to one type of region or the other. This classication is an essential pre-processing technique for many Computer Vision tools, such as smoothingor sharpening of digital color images.

  12. Color dependence with horizontal-viewing angle and colorimetric characterization of two displays using different backlighting

    Science.gov (United States)

    Castro, José J.; Pozo, Antonio M.; Rubiño, Manuel

    2013-11-01

    In this work we studied the color dependence with a horizontal-viewing angle and colorimetric characterization of two liquid-crystal displays (LCD) using two different backlighting: Cold Cathode Fluorescent Lamps (CCFLs) and light-emitting diodes (LEDs). The LCDs studied had identical resolution, size, and technology (TFT - thin film transistor). The colorimetric measurements were made with the spectroradiometer SpectraScan PR-650 following the procedure recommended in the European guideline EN 61747-6. For each display, we measured at the centre of the screen the chromaticity coordinates at horizontal viewing angles of 0, 20, 40, 60 and 80 degrees for the achromatic (A), red (R), green (G) and blue (B) channels. Results showed a greater color-gamut area for the display with LED backlight, compared with the CCFL backlight, showing a greater range of colors perceptible by human vision. This color-gamut area diminished with viewing angle for both displays. Higher differences between trends for viewing angles were observed in the LED-backlight, especially for the R- and G-channels, demonstrating a higher variability of the chromaticity coordinates with viewing angle. The best additivity was reached by the LED-backlight display (a lower error percentage). LED-backlight display provided better color performance of visualization.

  13. Health-related quality of life and binocular vision in patients with diplopia in acute-onset comitant esotropia with press-on prism improves

    Directory of Open Access Journals (Sweden)

    Qian Wang

    2017-11-01

    Full Text Available AIM: To assess the effect of press-on prisms in patients with acute-onset comitant esotropia and diplopia, focusing primarily on vision-related quality of life and binocular vision. METHODS: Retrospective case-series study. Totally 16 acute-onset comitant esotropia patients with diplopia who received treatment in the Huzhou Central Hospital were included in this study from March 2014 to March 2017. Vision-related quality of life before press-on prism correction and 1mo after press-on prism correction were performed with the Chinese version of the 25-item National Eye Institute Visual Functioning Questionnaire(CHI-NEI-VFQ-25. In each time of follow-up, we made a minute examination, includes worth four dot test and stereo tests. Data was statistically analyzed with paired sample t test, Chi-square test and Fisher's exact test. RESULTS: Except the degree of eye pain, color vision and perimetry, the indicators from CHI-NEI-VFQ-25 table including general health status, overall vision, mental health, social role difficulties, social functional, near activities, distant activities, independency and driving of acute-onset comitant esotropia patients with diplopia were obviously significant improved 1mo after press-on prism correction(PPCONCLUSION: Press-on prism correction may be helpful for binocular vision recovery in acute-onset comitant esotropia patients with diplopia, so as improve the vision-related quality of life.

  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. Using Vision System Technologies to Enable Operational Improvements for Low Visibility Approach and Landing Operations

    Science.gov (United States)

    Kramer, Lynda J.; Ellis, Kyle K. E.; Bailey, Randall E.; Williams, Steven P.; Severance, Kurt; Le Vie, Lisa R.; Comstock, James R.

    2014-01-01

    Flight deck-based vision systems, such as Synthetic and Enhanced Vision System (SEVS) technologies, have the potential to provide additional margins of safety for aircrew performance and enable the implementation of operational improvements for low visibility surface, arrival, and departure operations in the terminal environment with equivalent efficiency to visual operations. To achieve this potential, research is required for effective technology development and implementation based upon human factors design and regulatory guidance. This research supports the introduction and use of Synthetic Vision Systems and Enhanced Flight Vision Systems (SVS/EFVS) as advanced cockpit vision technologies in Next Generation Air Transportation System (NextGen) operations. Twelve air transport-rated crews participated in a motion-base simulation experiment to evaluate the use of SVS/EFVS in NextGen low visibility approach and landing operations. Three monochromatic, collimated head-up display (HUD) concepts (conventional HUD, SVS HUD, and EFVS HUD) and two color head-down primary flight display (PFD) concepts (conventional PFD, SVS PFD) were evaluated in a simulated NextGen Chicago O'Hare terminal environment. Additionally, the instrument approach type (no offset, 3 degree offset, 15 degree offset) was experimentally varied to test the efficacy of the HUD concepts for offset approach operations. The data showed that touchdown landing performance were excellent regardless of SEVS concept or type of offset instrument approach being flown. Subjective assessments of mental workload and situation awareness indicated that making offset approaches in low visibility conditions with an EFVS HUD or SVS HUD may be feasible.

  16. Agnosic vision is like peripheral vision, which is limited by crowding.

    Science.gov (United States)

    Strappini, Francesca; Pelli, Denis G; Di Pace, Enrico; Martelli, Marialuisa

    2017-04-01

    Visual agnosia is a neuropsychological impairment of visual object recognition despite near-normal acuity and visual fields. A century of research has provided only a rudimentary account of the functional damage underlying this deficit. We find that the object-recognition ability of agnosic patients viewing an object directly is like that of normally-sighted observers viewing it indirectly, with peripheral vision. Thus, agnosic vision is like peripheral vision. We obtained 14 visual-object-recognition tests that are commonly used for diagnosis of visual agnosia. Our "standard" normal observer took these tests at various eccentricities in his periphery. Analyzing the published data of 32 apperceptive agnosia patients and a group of 14 posterior cortical atrophy (PCA) patients on these tests, we find that each patient's pattern of object recognition deficits is well characterized by one number, the equivalent eccentricity at which our standard observer's peripheral vision is like the central vision of the agnosic patient. In other words, each agnosic patient's equivalent eccentricity is conserved across tests. Across patients, equivalent eccentricity ranges from 4 to 40 deg, which rates severity of the visual deficit. In normal peripheral vision, the required size to perceive a simple image (e.g., an isolated letter) is limited by acuity, and that for a complex image (e.g., a face or a word) is limited by crowding. In crowding, adjacent simple objects appear unrecognizably jumbled unless their spacing exceeds the crowding distance, which grows linearly with eccentricity. Besides conservation of equivalent eccentricity across object-recognition tests, we also find conservation, from eccentricity to agnosia, of the relative susceptibility of recognition of ten visual tests. These findings show that agnosic vision is like eccentric vision. Whence crowding? Peripheral vision, strabismic amblyopia, and possibly apperceptive agnosia are all limited by crowding, making it

  17. Sexing a sex-role-reversed species based on plumage: potential challenges in the red phalarope

    Directory of Open Access Journals (Sweden)

    Marie-Andrée Giroux

    2016-05-01

    Full Text Available Sex-role reversal, in which males care for offspring, can occur when mate competition is stronger between females than males. Secondary sex traits and mate attracting displays in sex-role-reversed species are usually more pronounced in females than in males. The red phalarope (Phalaropus fulicarius is a textbook example of a sex-role-reversed species. It is generally agreed that males are responsible for all incubation and parental care duties, whereas females typically desert males after having completed a clutch and may pair with new males to lay additional clutches. The breeding plumage of female red phalaropes is usually more brightly colored than male plumage, a reversed sexual dichromatism usually associated with sex-role reversal. Here, we confirm with PCR-based sexing that male red phalaropes can exhibit both the red body plumage typical of a female and the incubation behavior typical of a male. Our result, combined with previous observations of brightly colored red phalaropes incubating nests at the same arctic location (Igloolik Island, Nunavut, Canada, suggests that plumage dichromatism alone may not be sufficient to distinguish males from females in this breeding population of red phalaropes. This stresses the need for more systematic genetic sexing combined with standardized description of intersexual differences in red phalarope plumages. Determining whether such female-like plumage on males is a result of phenotypic plasticity or genetic variation could contribute to further understanding sex-role reversal strategies in the short Arctic summer.

  18. Using Single Colors and Color Pairs to Communicate Basic Tastes II: Foreground-Background Color Combinations.

    Science.gov (United States)

    Woods, Andy T; Marmolejo-Ramos, Fernando; Velasco, Carlos; Spence, Charles

    2016-01-01

    People associate basic tastes (e.g., sweet, sour, bitter, and salty) with specific colors (e.g., pink or red, green or yellow, black or purple, and white or blue). In the present study, we investigated whether a color bordered by another color (either the same or different) would give rise to stronger taste associations relative to a single patch of color. We replicate previous findings, highlighting the existence of a robust crossmodal correspondence between individual colors and basic tastes. On occasion, color pairs were found to communicate taste expectations more consistently than were single color patches. Furthermore, and in contrast to a recent study in which the color pairs were shown side-by-side, participants took no longer to match the color pairs with tastes than the single colors (they had taken twice as long to respond to the color pairs in the previous study). Possible reasons for these results are discussed, and potential applications for the results, and for the testing methodology developed, are outlined.

  19. Peripheral vision of youths with low vision: motion perception, crowding, and visual search.

    Science.gov (United States)

    Tadin, Duje; Nyquist, Jeffrey B; Lusk, Kelly E; Corn, Anne L; Lappin, Joseph S

    2012-08-24

    Effects of low vision on peripheral visual function are poorly understood, especially in children whose visual skills are still developing. The aim of this study was to measure both central and peripheral visual functions in youths with typical and low vision. Of specific interest was the extent to which measures of foveal function predict performance of peripheral tasks. We assessed central and peripheral visual functions in youths with typical vision (n = 7, ages 10-17) and low vision (n = 24, ages 9-18). Experimental measures used both static and moving stimuli and included visual crowding, visual search, motion acuity, motion direction discrimination, and multitarget motion comparison. In most tasks, visual function was impaired in youths with low vision. Substantial differences, however, were found both between participant groups and, importantly, across different tasks within participant groups. Foveal visual acuity was a modest predictor of peripheral form vision and motion sensitivity in either the central or peripheral field. Despite exhibiting normal motion discriminations in fovea, motion sensitivity of youths with low vision deteriorated in the periphery. This contrasted with typically sighted participants, who showed improved motion sensitivity with increasing eccentricity. Visual search was greatly impaired in youths with low vision. Our results reveal a complex pattern of visual deficits in peripheral vision and indicate a significant role of attentional mechanisms in observed impairments. These deficits were not adequately captured by measures of foveal function, arguing for the importance of independently assessing peripheral visual function.

  20. Fluorescein isothiocyanate and rhodamine B dye encapsulated mesoporous SiO2 for applications of blue LED excited white LED

    Science.gov (United States)

    Das, Sourav; Manam, J.

    2018-05-01

    In this work, the fluorescein isothiocyanate (FITC) and rhodamine B (RhB) dyes were encapsulated in mesoporous silica nanoparticles (MSNp). The MSNp-FITC-RhB nanohybrids phosphor showed a dichromatic PL emission at green region and orange region when excited at 460 nm. A Forster Resonance Energy Transfer (FRET) was observed from FITC to RhB. The materials were further characterized by XRD, FTIR, TEM, and temperature dependent photoluminescence. The CIE coordinates were tuned from greenish yellow to the orange region and quantum yield was reached 52.04% based on FRET. So by combining the MSNp-FITC-RhB nanohybrids phosphor with the blue LED chip, the white light emission with flexible Color Correlated Temperature and improved Color Rendering Index can be obtained.

  1. Vision restoration after brain and retina damage: the "residual vision activation theory".

    Science.gov (United States)

    Sabel, Bernhard A; Henrich-Noack, Petra; Fedorov, Anton; Gall, Carolin

    2011-01-01

    Vision loss after retinal or cerebral visual injury (CVI) was long considered to be irreversible. However, there is considerable potential for vision restoration and recovery even in adulthood. Here, we propose the "residual vision activation theory" of how visual functions can be reactivated and restored. CVI is usually not complete, but some structures are typically spared by the damage. They include (i) areas of partial damage at the visual field border, (ii) "islands" of surviving tissue inside the blind field, (iii) extrastriate pathways unaffected by the damage, and (iv) downstream, higher-level neuronal networks. However, residual structures have a triple handicap to be fully functional: (i) fewer neurons, (ii) lack of sufficient attentional resources because of the dominant intact hemisphere caused by excitation/inhibition dysbalance, and (iii) disturbance in their temporal processing. Because of this resulting activation loss, residual structures are unable to contribute much to everyday vision, and their "non-use" further impairs synaptic strength. However, residual structures can be reactivated by engaging them in repetitive stimulation by different means: (i) visual experience, (ii) visual training, or (iii) noninvasive electrical brain current stimulation. These methods lead to strengthening of synaptic transmission and synchronization of partially damaged structures (within-systems plasticity) and downstream neuronal networks (network plasticity). Just as in normal perceptual learning, synaptic plasticity can improve vision and lead to vision restoration. This can be induced at any time after the lesion, at all ages and in all types of visual field impairments after retinal or brain damage (stroke, neurotrauma, glaucoma, amblyopia, age-related macular degeneration). If and to what extent vision restoration can be achieved is a function of the amount of residual tissue and its activation state. However, sustained improvements require repetitive

  2. 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.

  3. Colorism/Neo-Colorism

    Science.gov (United States)

    Snell, Joel

    2017-01-01

    There are numerous aspects to being non-Caucasian that may not be known by Whites. Persons of color suggest folks who are African, South Americans, Native Americans, Biracial, Asians and others. The question is what do these individuals feel relative to their color and facial characteristics. Eugene Robinson suggest that the future favorable color…

  4. 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.

  5. Foreword to the theme issue on geospatial computer vision

    Science.gov (United States)

    Wegner, Jan Dirk; Tuia, Devis; Yang, Michael; Mallet, Clement

    2018-06-01

    Geospatial Computer Vision has become one of the most prevalent emerging fields of investigation in Earth Observation in the last few years. In this theme issue, we aim at showcasing a number of works at the interface between remote sensing, photogrammetry, image processing, computer vision and machine learning. In light of recent sensor developments - both from the ground as from above - an unprecedented (and ever growing) quantity of geospatial data is available for tackling challenging and urgent tasks such as environmental monitoring (deforestation, carbon sequestration, climate change mitigation), disaster management, autonomous driving or the monitoring of conflicts. The new bottleneck for serving these applications is the extraction of relevant information from such large amounts of multimodal data. This includes sources, stemming from multiple sensors, that exhibit distinct physical nature of heterogeneous quality, spatial, spectral and temporal resolutions. They are as diverse as multi-/hyperspectral satellite sensors, color cameras on drones, laser scanning devices, existing open land-cover geodatabases and social media. Such core data processing is mandatory so as to generate semantic land-cover maps, accurate detection and trajectories of objects of interest, as well as by-products of superior added-value: georeferenced data, images with enhanced geometric and radiometric qualities, or Digital Surface and Elevation Models.

  6. Luminance contours can gate afterimage colors and "real" colors.

    Science.gov (United States)

    Anstis, Stuart; Vergeer, Mark; Van Lier, Rob

    2012-09-06

    It has long been known that colored images may elicit afterimages in complementary colors. We have already shown (Van Lier, Vergeer, & Anstis, 2009) that one and the same adapting image may result in different afterimage colors, depending on the test contours presented after the colored image. The color of the afterimage depends on two adapting colors, those both inside and outside the test. Here, we further explore this phenomenon and show that the color-contour interactions shown for afterimage colors also occur for "real" colors. We argue that similar mechanisms apply for both types of stimulation.

  7. 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.

  8. Color picture drawings without form and eye movements: a case report of visual form agnosia in a girl.

    Science.gov (United States)

    Kaga, Kimitaka; Shindo, Mitsuko

    2012-04-01

    The case of an 8-year-old girl who manifested cortical blindness and whose color drawings of faces and objects were without outlines is reported. Her birth was uneventful. When she was 10 months old, she fell down to the floor from a chair, resulting in a subarachnoidal hemorrhage. A repeat brain MRI revealed localized lesions in the visual cortices in the right and left hemispheres. As she grew older she was found to have visual imperceptions. She was found to have difficulties in learning visually the names of objects with form and letters, and in recognizing faces of her family. However, she was able to discriminate well the colors of faces and objects and learn easily the names of the objects with form by touching. She seemed to utilize subcortical vision for seeing colors of faces and objects.

  9. Research on robot navigation vision sensor based on grating projection stereo vision

    Science.gov (United States)

    Zhang, Xiaoling; Luo, Yinsheng; Lin, Yuchi; Zhu, Lei

    2016-10-01

    A novel visual navigation method based on grating projection stereo vision for mobile robot in dark environment is proposed. This method is combining with grating projection profilometry of plane structured light and stereo vision technology. It can be employed to realize obstacle detection, SLAM (Simultaneous Localization and Mapping) and vision odometry for mobile robot navigation in dark environment without the image match in stereo vision technology and without phase unwrapping in the grating projection profilometry. First, we research the new vision sensor theoretical, and build geometric and mathematical model of the grating projection stereo vision system. Second, the computational method of 3D coordinates of space obstacle in the robot's visual field is studied, and then the obstacles in the field is located accurately. The result of simulation experiment and analysis shows that this research is useful to break the current autonomous navigation problem of mobile robot in dark environment, and to provide the theoretical basis and exploration direction for further study on navigation of space exploring robot in the dark and without GPS environment.

  10. Using Single Colors and Color Pairs to Communicate Basic Tastes II: Foreground–Background Color Combinations

    Science.gov (United States)

    Marmolejo-Ramos, Fernando; Velasco, Carlos; Spence, Charles

    2016-01-01

    People associate basic tastes (e.g., sweet, sour, bitter, and salty) with specific colors (e.g., pink or red, green or yellow, black or purple, and white or blue). In the present study, we investigated whether a color bordered by another color (either the same or different) would give rise to stronger taste associations relative to a single patch of color. We replicate previous findings, highlighting the existence of a robust crossmodal correspondence between individual colors and basic tastes. On occasion, color pairs were found to communicate taste expectations more consistently than were single color patches. Furthermore, and in contrast to a recent study in which the color pairs were shown side-by-side, participants took no longer to match the color pairs with tastes than the single colors (they had taken twice as long to respond to the color pairs in the previous study). Possible reasons for these results are discussed, and potential applications for the results, and for the testing methodology developed, are outlined. PMID:27708752

  11. Research of image retrieval technology based on color feature

    Science.gov (United States)

    Fu, Yanjun; Jiang, Guangyu; Chen, Fengying

    2009-10-01

    make rotating and translation does not change. The HSV color space is used to show color characteristic of image, which is suitable to the visual characteristic of human. Taking advance of human's feeling to color, it quantifies color sector with unequal interval, and get characteristic vector. Finally, it matches the similarity of image with the algorithm of the histogram intersection and the partition-overall histogram. Users can choose a demonstration image to show inquired vision require, and also can adjust several right value through the relevance-feedback method to obtain the best result of search.An image retrieval system based on these approaches is presented. The result of the experiments shows that the image retrieval based on partition-overall histogram can keep the space distribution information while abstracting color feature efficiently, and it is superior to the normal color histograms in precision rate while researching. The query precision rate is more than 95%. In addition, the efficient block expression will lower the complicate degree of the images to be searched, and thus the searching efficiency will be increased. The image retrieval algorithms based on the partition-overall histogram proposed in the paper is efficient and effective.

  12. Color adaptation induced from linguistic description of color.

    Directory of Open Access Journals (Sweden)

    Liling Zheng

    Full Text Available Recent theories propose that language comprehension can influence perception at the low level of perceptual system. Here, we used an adaptation paradigm to test whether processing language caused color adaptation in the visual system. After prolonged exposure to a color linguistic context, which depicted red, green, or non-specific color scenes, participants immediately performed a color detection task, indicating whether they saw a green color square in the middle of a white screen or not. We found that participants were more likely to perceive the green color square after listening to discourses denoting red compared to discourses denoting green or conveying non-specific color information, revealing that language comprehension caused an adaptation aftereffect at the perceptual level. Therefore, semantic representation of color may have a common neural substrate with color perception. These results are in line with the simulation view of embodied language comprehension theory, which predicts that processing language reactivates the sensorimotor systems that are engaged during real experience.

  13. Peripheral Vision of Youths with Low Vision: Motion Perception, Crowding, and Visual Search

    Science.gov (United States)

    Tadin, Duje; Nyquist, Jeffrey B.; Lusk, Kelly E.; Corn, Anne L.; Lappin, Joseph S.

    2012-01-01

    Purpose. Effects of low vision on peripheral visual function are poorly understood, especially in children whose visual skills are still developing. The aim of this study was to measure both central and peripheral visual functions in youths with typical and low vision. Of specific interest was the extent to which measures of foveal function predict performance of peripheral tasks. Methods. We assessed central and peripheral visual functions in youths with typical vision (n = 7, ages 10–17) and low vision (n = 24, ages 9–18). Experimental measures used both static and moving stimuli and included visual crowding, visual search, motion acuity, motion direction discrimination, and multitarget motion comparison. Results. In most tasks, visual function was impaired in youths with low vision. Substantial differences, however, were found both between participant groups and, importantly, across different tasks within participant groups. Foveal visual acuity was a modest predictor of peripheral form vision and motion sensitivity in either the central or peripheral field. Despite exhibiting normal motion discriminations in fovea, motion sensitivity of youths with low vision deteriorated in the periphery. This contrasted with typically sighted participants, who showed improved motion sensitivity with increasing eccentricity. Visual search was greatly impaired in youths with low vision. Conclusions. Our results reveal a complex pattern of visual deficits in peripheral vision and indicate a significant role of attentional mechanisms in observed impairments. These deficits were not adequately captured by measures of foveal function, arguing for the importance of independently assessing peripheral visual function. PMID:22836766

  14. 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).

  15. 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 ...

  16. Shift Colors

    Science.gov (United States)

    Publications & News Shift Colors Pages default Sign In NPC Logo Banner : Shift Colors Search Navy Personnel Command > Reference Library > Publications & News > Shift Colors Top Link Bar Navy Personnel Library Expand Reference Library Quick Launch Shift Colors Shift Colors Archives Mailing Address How to

  17. Review: Familiarity to Vision Rehabilitation Process

    Directory of Open Access Journals (Sweden)

    Nasser Sadegh-Pour

    2006-10-01

    Full Text Available Considering the numbers of low vision patients who have been visited and treated in eye clinics, sometimes there is no exact treatment to increase their visual acuity. Therefore, the necessity to pay attention to vision rehabilitation for them is strongly felt. The aims of this essay are to define vision rehabilitation and its process in relevant centers (called Low Vision Clinic.The statistic of low vision people is reported and the method of collecting data is described. Standard definition, causes of low vision and related diseases (congenital, heredity, acquired… are explained. In addition, low vision aids and role of test and prescription are discussed. Sometimes ophthalmologists and optometrists can not exactly cure patient to raise their V.A because there is no treatment or drug or ordinary glasses. In these cases the clients should refer to low vision clinic and visit low vision specialist on vision rehabilitation process. After primary evaluation they are tested completely and at the end are prescribed proper low vision aid and also provided with advice in relation to career, education role and training techniques especially in children. At the last part of present dissertation, some examples are provided to show effectiveness of vision rehabilitation and low vision aid among the clients in different countries.

  18. Natural Colorants: Food Colorants from Natural Sources.

    Science.gov (United States)

    Sigurdson, Gregory T; Tang, Peipei; Giusti, M Mónica

    2017-02-28

    The color of food is often associated with the flavor, safety, and nutritional value of the product. Synthetic food colorants have been used because of their high stability and low cost. However, consumer perception and demand have driven the replacement of synthetic colorants with naturally derived alternatives. Natural pigment applications can be limited by lower stability, weaker tinctorial strength, interactions with food ingredients, and inability to match desired hues. Therefore, no single naturally derived colorant can serve as a universal alternative for a specified synthetic colorant in all applications. This review summarizes major environmental and biological sources for natural colorants as well as nature-identical counterparts. Chemical characteristics of prevalent pigments, including anthocyanins, carotenoids, betalains, and chlorophylls, are described. The possible applications and hues (warm, cool, and achromatic) of currently used natural pigments, such as anthocyanins as red and blue colorants, and possible future alternatives, such as purple violacein and red pyranoanthocyanins, are also discussed.

  19. The ontology of vision. The invisible, consciousness of Living matter.

    Directory of Open Access Journals (Sweden)

    Giorgia eFiorio

    2016-02-01

    Full Text Available If I close my eyes, the absence of light activates the peripheral cells devoted to the perception of darkness. The awareness of ‘seeing oneself seeing’ is in its essence a thought, one that is internal to the vision and previous to any object of sight. To this amphibious faculty, the diaphanous color of darkness, Aristotle assigns the principle of knowledge. Vision is a whole perceptual system, not a channel of sense. Functions of vision are interweaved to the texture of human interaction within a terrestrial environment that is in turn contained into the cosmic order. Within the internal resonance of a double reflection, the living being is the transitive host between two orders of scale, both bigger and smaller than the individual and unity. In the perceptual integrative system of human vision, the convergence-divergence of the corporeal presence and the diffraction of its own appearance is the margin. The sensation of being no longer coincides with the breath of life, it does not seems ‘real’ without the trace of some visible evidence and its simultaneous ‘sharing.’ Without a shadow, without an imprint, and destined for multiple invisible witnesses, the numeric copia of the physical presence inhabits the transient memory of our electronic prostheses. A rudimentary ‘visuality’ replaces tangible experience dissipating its meaning and the awareness of being alive. Transversal to the civilizations of the ancient world, through different orders of function and status, the anthropomorphic figuration of archaic sculpture questions the idea of Being. Ancient statues do not appear in order to be visible as artworks, but rather to exist. The awareness of human finiteness seals the compulsion to ‘give body’ to an invisible apparition that shapes the figuration of Being as the corporeal expression of an ontogenetic waking of human consciousness.Subject and object, the term humanum fathoms the relationship between matter and its living

  20. Profile of Low Vision Population Attending Low Vision Clinic in a Peripheral Eye Hospital in Nepal

    OpenAIRE

    Safal Khanal, BOptom; Pekila Lama, MD

    2013-01-01

    Background: Blindness and low vision are major causes of morbidity and constitute a significant public health problem, both detrimental to the quality of life for the individual and an economic burden on the individual, family, and society in general. People with low vision have the potential for enhancement of functional vision if they receive the appropriate low vision services. The present study aims to determine the profile of the low vision population attending a low vision clinic at a p...

  1. Learning from vision-to-touch is different than from touch-to-vision.

    Directory of Open Access Journals (Sweden)

    Dagmar A Wismeijer

    2012-11-01

    Full Text Available We studied whether vision can teach touch to the same extent as touch seems to teach vision. In a 2 x 2 between-participants learning study, we artificially correlated visual gloss cues with haptic compliance cues. In two "natural" tasks, we tested whether visual gloss estimations have an influence on haptic estimations of softness and vice versa. In two "new" tasks, in which participants were either asked to haptically judge glossiness or to visually judge softness, we investigated how perceptual estimates transfer from one sense to the other. Our results showed that vision does not teach touch as efficient as touch seems to teach vision.

  2. Colors, colored overlays, and reading skills

    Directory of Open Access Journals (Sweden)

    Arcangelo eUccula

    2014-07-01

    Full Text Available In this article, we are concerned with the role of colors in reading written texts. It has been argued that colored overlays applied above written texts positively influence both reading fluency and reading speed. These effects would be particularly evident for those individuals affected by the so called Meares-Irlen syndrome, i.e. who experience eyestrain and/or visual distortions – e.g. color, shape or movement illusions – while reading. This condition would interest the 12-14% of the general population and up to the 46% of the dyslexic population. Thus, colored overlays have been largely employed as a remedy for some aspects of the difficulties in reading experienced by dyslexic individuals, as fluency and speed. Despite the wide use of colored overlays, how they exert their effects has not been made clear yet. Also, according to some researchers, the results supporting the efficacy of colored overlays as a tool for helping readers are at least controversial. Furthermore, the very nature of the Meares-Irlen syndrome has been questioned. Here we provide a concise, critical review of the literature.

  3. Precision of Synesthetic Color Matching Resembles That for Recollected Colors Rather than Physical Colors

    Science.gov (United States)

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

    2012-01-01

    Grapheme-color synesthesia is an atypical condition in which individuals experience sensations of color when reading printed graphemes such as letters and digits. For some grapheme-color synesthetes, seeing a printed grapheme triggers a sensation of color, but "hearing" the name of a grapheme does not. This dissociation allowed us to…

  4. 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.

  5. Generating high gray-level resolution monochrome displays with conventional computer graphics cards and color monitors.

    Science.gov (United States)

    Li, Xiangrui; Lu, Zhong-Lin; Xu, Pengjing; Jin, Jianzhong; Zhou, Yifeng

    2003-11-30

    Display systems based on conventional computer graphics cards are capable of generating images with about 8-bit luminance resolution. However, most vision experiments require more than 12 bits of luminance resolution. Pelli and Zhang [Spatial Vis. 10 (1997) 443] described a video attenuator for generating high luminance resolution displays on a monochrome monitor, or for driving just the green gun of a color monitor. Here we show how to achieve a white display by adding video amplifiers to duplicate the monochrome signal to drive all three guns of any color monitor. Because of the lack of the availability of high quality monochrome monitors, our method provides an inexpensive way to achieve high-resolution monochromatic displays using conventional, easy-to-get equipment. We describe the design principles, test results, and a few additional functionalities.

  6. Low Vision Rehabilitation and Diabetic Retinopathy

    International Nuclear Information System (INIS)

    Khan, Sarfaraz A.

    2007-01-01

    Diabetic retinopathy is emerging as a major cause of blindness. Diabetic retinopathy calls for a multidisciplinary to the patients. Management of the patient requires a team work by the internist, diabetologist, dietician, ophthalmologist and low vision therapist. Diabetic retinopathy very often results in vision loss. It is important for ophthalmologist to recognize the importance of low vision rehabilitation in formulating appropriate treatment strategies. People with low vision loss due to diabetic retinopathy usually experience difficulty in daily life. Most people with diabetic retinopathy (who have remaining useful vision) can be helped with low vision devices. However, often one low vision device may not be suitable for all purposes. A comprehensive low vision evaluation is required to assess the person's current visual status, identify the goals and the visual needs, and then design an individualized vision rehabilitation program to meet these needs. (author)

  7. Color Analysis

    Science.gov (United States)

    Wrolstad, Ronald E.; Smith, Daniel E.

    Color, flavor, and texture are the three principal quality attributes that determine food acceptance, and color has a far greater influence on our judgment than most of us appreciate. We use color to determine if a banana is at our preferred ripeness level, and a discolored meat product can warn us that the product may be spoiled. The marketing departments of our food corporations know that, for their customers, the color must be "right." The University of California Davis scorecard for wine quality designates four points out of 20, or 20% of the total score, for color and appearance (1). Food scientists who establish quality control specifications for their product are very aware of the importance of color and appearance. While subjective visual assessment and use of visual color standards are still used in the food industry, instrumental color measurements are extensively employed. Objective measurement of color is desirable for both research and industrial applications, and the ruggedness, stability, and ease of use of today's color measurement instruments have resulted in their widespread adoption.

  8. Color Memory

    OpenAIRE

    Pate, Monica; Raclariu, Ana-Maria; Strominger, Andrew

    2017-01-01

    A transient color flux across null infinity in classical Yang-Mills theory is considered. It is shown that a pair of test `quarks' initially in a color singlet generically acquire net color as a result of the flux. A nonlinear formula is derived for the relative color rotation of the quarks. For weak color flux the formula linearizes to the Fourier transform of the soft gluon theorem. This color memory effect is the Yang-Mills analog of the gravitational memory effect.

  9. Color Algebras

    Science.gov (United States)

    Mulligan, Jeffrey B.

    2017-01-01

    A color algebra refers to a system for computing sums and products of colors, analogous to additive and subtractive color mixtures. The difficulty addressed here is the fact that, because of metamerism, we cannot know with certainty the spectrum that produced a particular color solely on the basis of sensory data. Knowledge of the spectrum is not required to compute additive mixture of colors, but is critical for subtractive (multiplicative) mixture. Therefore, we cannot predict with certainty the multiplicative interactions between colors based solely on sensory data. There are two potential applications of a color algebra: first, to aid modeling phenomena of human visual perception, such as color constancy and transparency; and, second, to provide better models of the interactions of lights and surfaces for computer graphics rendering.

  10. 3-D vision and figure-ground separation by visual cortex.

    Science.gov (United States)

    Grossberg, S

    1994-01-01

    A neural network theory of three-dimensional (3-D) vision, called FACADE theory, is described. The theory proposes a solution of the classical figure-ground problem for biological vision. It does so by suggesting how boundary representations and surface representations are formed within a boundary contour system (BCS) and a feature contour system (FCS). The BCS and FCS interact reciprocally to form 3-D boundary and surface representations that are mutually consistent. Their interactions generate 3-D percepts wherein occluding and occluded object parts are separated, completed, and grouped. The theory clarifies how preattentive processes of 3-D perception and figure-ground separation interact reciprocally with attentive processes of spatial localization, object recognition, and visual search. A new theory of stereopsis is proposed that predicts how cells sensitive to multiple spatial frequencies, disparities, and orientations are combined by context-sensitive filtering, competition, and cooperation to form coherent BCS boundary segmentations. Several factors contribute to figure-ground pop-out, including: boundary contrast between spatially contiguous boundaries, whether due to scenic differences in luminance, color, spatial frequency, or disparity; partially ordered interactions from larger spatial scales and disparities to smaller scales and disparities; and surface filling-in restricted to regions surrounded by a connected boundary. Phenomena such as 3-D pop-out from a 2-D picture, Da Vinci stereopsis, 3-D neon color spreading, completion of partially occluded objects, and figure-ground reversals are analyzed. The BCS and FCS subsystems model aspects of how the two parvocellular cortical processing streams that join the lateral geniculate nucleus to prestriate cortical area V4 interact to generate a multiplexed representation of Form-And-Color-And-DEpth, or FACADE, within area V4. Area V4 is suggested to support figure-ground separation and to interact with

  11. Beauty and cuteness in peripheral vision

    Science.gov (United States)

    Kuraguchi, Kana; Ashida, Hiroshi

    2015-01-01

    Guo et al. (2011) showed that attractiveness was detectable in peripheral vision. Since there are different types of attractiveness (Rhodes, 2006), we investigated how beauty and cuteness are detected in peripheral vision with a brief presentation. Participants (n = 45) observed two Japanese female faces for 100 ms, then were asked to respond which face was more beautiful (or cuter). The results indicated that both beauty and cuteness were detectable in peripheral vision, but not in the same manner. Discrimination rates for judging beauty were invariant in peripheral and central vision, while discrimination rates for judging cuteness declined in peripheral vision as compared with central vision. This was not explained by lower resolution in peripheral vision. In addition, for male participants, it was more difficult to judge cuteness than beauty in peripheral vision, thus suggesting that gender differences can have a certain effect when judging cuteness. Therefore, central vision might be suitable for judging cuteness while judging beauty might not be affected by either central or peripheral vision. This might be related with the functional difference between beauty and cuteness. PMID:25999883

  12. Color-Blind Racism, Color-Blind Theology, and Church Practices

    Science.gov (United States)

    Hearn, Mark

    2009-01-01

    Color-blind racism develops when persons ignore color in people and see them simply as individuals. As persons of color in racialized societies such as the United States are unequally treated on account of their color, the issue becomes a matter of faith and religious experience as religious leaders and educators, who disregard color, overlook…

  13. Efficacy of vision therapy in children with learning disability and associated binocular vision anomalies.

    Science.gov (United States)

    Hussaindeen, Jameel Rizwana; Shah, Prerana; Ramani, Krishna Kumar; Ramanujan, Lalitha

    To report the frequency of binocular vision (BV) anomalies in children with specific learning disorders (SLD) and to assess the efficacy of vision therapy (VT) in children with a non-strabismic binocular vision anomaly (NSBVA). The study was carried out at a centre for learning disability (LD). Comprehensive eye examination and binocular vision assessment was carried out for 94 children (mean (SD) age: 15 (2.2) years) diagnosed with specific learning disorder. BV assessment was done for children with best corrected visual acuity of ≥6/9 - N6, cooperative for examination and free from any ocular pathology. For children with a diagnosis of NSBVA (n=46), 24 children were randomized to VT and no intervention was provided to the other 22 children who served as experimental controls. At the end of 10 sessions of vision therapy, BV assessment was performed for both the intervention and non-intervention groups. Binocular vision anomalies were found in 59 children (62.8%) among which 22% (n=13) had strabismic binocular vision anomalies (SBVA) and 78% (n=46) had a NSBVA. Accommodative infacility (AIF) was the commonest of the NSBVA and found in 67%, followed by convergence insufficiency (CI) in 25%. Post-vision therapy, the intervention group showed significant improvement in all the BV parameters (Wilcoxon signed rank test, p<0.05) except negative fusional vergence. Children with specific learning disorders have a high frequency of binocular vision disorders and vision therapy plays a significant role in improving the BV parameters. Children with SLD should be screened for BV anomalies as it could potentially be an added hindrance to the reading difficulty in this special population. Copyright © 2017 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

  14. A conceptual lemon: theta burst stimulation to the left anterior temporal lobe untangles object representation and its canonical color.

    Science.gov (United States)

    Chiou, Rocco; Sowman, Paul F; Etchell, Andrew C; Rich, Anina N

    2014-05-01

    Object recognition benefits greatly from our knowledge of typical color (e.g., a lemon is usually yellow). Most research on object color knowledge focuses on whether both knowledge and perception of object color recruit the well-established neural substrates of color vision (the V4 complex). Compared with the intensive investigation of the V4 complex, we know little about where and how neural mechanisms beyond V4 contribute to color knowledge. The anterior temporal lobe (ATL) is thought to act as a "hub" that supports semantic memory by integrating different modality-specific contents into a meaningful entity at a supramodal conceptual level, making it a good candidate zone for mediating the mappings between object attributes. Here, we explore whether the ATL is critical for integrating typical color with other object attributes (object shape and name), akin to its role in combining nonperceptual semantic representations. In separate experimental sessions, we applied TMS to disrupt neural processing in the left ATL and a control site (the occipital pole). Participants performed an object naming task that probes color knowledge and elicits a reliable color congruency effect as well as a control quantity naming task that also elicits a cognitive congruency effect but involves no conceptual integration. Critically, ATL stimulation eliminated the otherwise robust color congruency effect but had no impact on the numerical congruency effect, indicating a selective disruption of object color knowledge. Neither color nor numerical congruency effects were affected by stimulation at the control occipital site, ruling out nonspecific effects of cortical stimulation. Our findings suggest that the ATL is involved in the representation of object concepts that include their canonical colors.

  15. Evaluation of Synthetic Vision Display Concepts for Improved Awareness in Unusual Attitude Recovery Scenarios

    Science.gov (United States)

    Nicholas, Stephanie

    2016-01-01

    A recent study conducted by the Commercial Aviation Safety Team (CAST) determined 40 percent of all fixed-wing fatal accidents, between 2001 and 2011, were caused by Loss-of-Control (LOC) in flight (National Transportation Safety Board, 2015). Based on their findings, CAST recommended manufacturers develop and implement virtual day-visual meteorological conditions (VMC) display systems, such as synthetic vision or equivalent systems (CAST, 2016). In a 2015 simulation study conducted at NASA Langley Research Center (LaRC), researchers gathered to test and evaluate virtual day-VMC displays under realistic flight operation scenarios capable of inducing reduced attention states in pilots. Each display concept was evaluated to determine its efficacy to improve attitude awareness. During the experiment, Evaluation Pilots (EPs) were shown the following three display concepts on the Primary Flight Display (PFD): Baseline, Synthetic Vision (SV) with color gradient, and SV with texture. The baseline configuration was a standard, conventional 'blue over brown' display. Experiment scenarios were simulated over water to evaluate Unusual Attitude (UA) recovery over 'featureless terrain' environments. Thus, the SV with color gradient configuration presented a 'blue over blue' display with a linear blue color progression, to differentiate attitude changes between sky and ocean. The SV with texture configuration presented a 'blue over blue' display with a black checkerboard texture atop a synthetic ocean. These displays were paired with a Background Attitude Indicator (BAI) concept. The BAI was presented across all four Head-Down Displays (HDDs), displaying a wide field-of-view blue-over-blue attitude indicator. The BAI aligned with the PFD and showed through the background of the navigation displays with opaque transparency. Each EP participated in a two-part experiment series with a total seventy-five trial runs: Part I included a set of twenty-five Unusual Attitude Recovery (UAR

  16. Synthetic vision to augment sensor based vision for remotely piloted vehicles

    NARCIS (Netherlands)

    Tadema, J.; Koeners, J.; Theunissen, E.

    2006-01-01

    In the past fifteen years, several research programs have demonstrated potential advantages of synthetic vision technology for manned aviation. More recently, some research programs have focused on integrating synthetic vision technology into control stations for remotely controlled aircraft. The

  17. 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.

  18. Interference, reduced action, and trajectories

    OpenAIRE

    Floyd, Edward R.

    2006-01-01

    Instead of investigating the interference between two stationary, rectilinear wave functions in a trajectory representation by examining the two rectilinear wave functions individually, we examine a dichromatic wave function that is synthesized from the two interfering wave functions. The physics of interference is contained in the reduced action for the dichromatic wave function. As this reduced action is a generator of the motion for the dichromatic wave function, it determines the dichroma...

  19. Robust object tracking combining color and scale invariant features

    Science.gov (United States)

    Zhang, Shengping; Yao, Hongxun; Gao, Peipei

    2010-07-01

    Object tracking plays a very important role in many computer vision applications. However its performance will significantly deteriorate due to some challenges in complex scene, such as pose and illumination changes, clustering background and so on. In this paper, we propose a robust object tracking algorithm which exploits both global color and local scale invariant (SIFT) features in a particle filter framework. Due to the expensive computation cost of SIFT features, the proposed tracker adopts a speed-up variation of SIFT, SURF, to extract local features. Specially, the proposed method first finds matching points between the target model and target candidate, than the weight of the corresponding particle based on scale invariant features is computed as the the proportion of matching points of that particle to matching points of all particles, finally the weight of the particle is obtained by combining weights of color and SURF features with a probabilistic way. The experimental results on a variety of challenging videos verify that the proposed method is robust to pose and illumination changes and is significantly superior to the standard particle filter tracker and the mean shift tracker.

  20. Experimental Study on Color Durability of Color Asphalt Pavement

    Science.gov (United States)

    Ning, Shi; Huan, Su

    2017-06-01

    Aiming at the poor Color durability and the lack of research on Color asphalt pavement, spraying an anti-tire trace seal resin emulsion on the surface, a Color durable asphalt pavement was proposed. After long-term rolling and long-term aging test, the Color durability was evaluated by RGB function in Photoshop and trace residue rate formula. Test results proved that the Evaluation method was simple and effective. After long-term rolling, the Color of the road surface tends to a constant value. Spraying the emulsion on the road surface can resist tire traces. After long-term aging test, the resistance to tire traces was increased by 26.6% compared with the conventional type, while the former was 44.1% higher than the latter without long-term aging. The Color durable asphalt pavement can effectively improve the ability of Color asphalt pavement to resist tire traces, and significantly improve the Color durability of Color asphalt pavement.

  1. What You Should Know (Low Vision)

    Science.gov (United States)

    ... Cataract Diabetic retinopathy Glaucoma Macular degeneration What is low vision? When you have low vision, eyeglasses, contact lenses, ... eyesight. How do I know if I have low vision? Below are some signs of low vision. Even ...

  2. Tree Colors: Color Schemes for Tree-Structured Data.

    Science.gov (United States)

    Tennekes, Martijn; de Jonge, Edwin

    2014-12-01

    We present a method to map tree structures to colors from the Hue-Chroma-Luminance color model, which is known for its well balanced perceptual properties. The Tree Colors method can be tuned with several parameters, whose effect on the resulting color schemes is discussed in detail. We provide a free and open source implementation with sensible parameter defaults. Categorical data are very common in statistical graphics, and often these categories form a classification tree. We evaluate applying Tree Colors to tree structured data with a survey on a large group of users from a national statistical institute. Our user study suggests that Tree Colors are useful, not only for improving node-link diagrams, but also for unveiling tree structure in non-hierarchical visualizations.

  3. Illuminant color estimation based on pigmentation separation from human skin color

    Science.gov (United States)

    Tanaka, Satomi; Kakinuma, Akihiro; Kamijo, Naohiro; Takahashi, Hiroshi; Tsumura, Norimichi

    2015-03-01

    Human has the visual system called "color constancy" that maintains the perceptive colors of same object across various light sources. The effective method of color constancy algorithm was proposed to use the human facial color in a digital color image, however, this method has wrong estimation results by the difference of individual facial colors. In this paper, we present the novel color constancy algorithm based on skin color analysis. The skin color analysis is the method to separate the skin color into the components of melanin, hemoglobin and shading. We use the stationary property of Japanese facial color, and this property is calculated from the components of melanin and hemoglobin. As a result, we achieve to propose the method to use subject's facial color in image and not depend on the individual difference among Japanese facial color.

  4. [Surgical treatment of advanced retinopathy of prematurity--last chance for vision. Report 2. Analysis of functional results].

    Science.gov (United States)

    Baranov, A V; Troianovskiĭ, R L

    2012-01-01

    Functional results of staged surgical treatment of advanced retinopathy of prematurity (ROP) are analyzed between 2005 and 2010 in ophthalmologic department of city children's hospital ( St. Petersburg). A total of 154 children (303 eyes) were operated. The assessment of visual functions was performed using proposed original method. Subject vision was achieved in 65% of 20 eyes (6,6%) with 4B stage ROP. Fair anatomic results were achieved in 131 eyes of children with 5 stage ROP (283 eyes), light perception was preserved in 52 eyes (39,7%), capability to distinguish large objects appeared in 40 eyes (30,5%) and subject vision developed in 39 eyes (29,8%). Correlation between visual functions and environmental conditions was found, in particular presence or absence of long-term period of training in color and individual objects distinguishing. In a group of children training resulted in achievement of fair functions (subject vision, capability to distinguish large objects) in 81,2% of patients, where as in a group without training the same capabilities developed in 31,8% of cases only. Functional outcomes were also found to depend on CNS condition and time of surgery.

  5. Vision Problems in Homeless Children.

    Science.gov (United States)

    Smith, Natalie L; Smith, Thomas J; DeSantis, Diana; Suhocki, Marissa; Fenske, Danielle

    2015-08-01

    Vision problems in homeless children can decrease educational achievement and quality of life. To estimate the prevalence and specific diagnoses of vision problems in children in an urban homeless shelter. A prospective series of 107 homeless children and teenagers who underwent screening with a vision questionnaire, eye chart screening (if mature enough) and if vision problem suspected, evaluation by a pediatric ophthalmologist. Glasses and other therapeutic interventions were provided if necessary. The prevalence of vision problems in this population was 25%. Common diagnoses included astigmatism, amblyopia, anisometropia, myopia, and hyperopia. Glasses were required and provided for 24 children (22%). Vision problems in homeless children are common and frequently correctable with ophthalmic intervention. Evaluation by pediatric ophthalmologist is crucial for accurate diagnoses and treatment. Our system of screening and evaluation is feasible, efficacious, and reproducible in other homeless care situations.

  6. Learning from vision-to-touch is different than learning from touch-to-vision.

    Science.gov (United States)

    Wismeijer, Dagmar A; Gegenfurtner, Karl R; Drewing, Knut

    2012-01-01

    We studied whether vision can teach touch to the same extent as touch seems to teach vision. In a 2 × 2 between-participants learning study, we artificially correlated visual gloss cues with haptic compliance cues. In two "natural" tasks, we tested whether visual gloss estimations have an influence on haptic estimations of softness and vice versa. In two "novel" tasks, in which participants were either asked to haptically judge glossiness or to visually judge softness, we investigated how perceptual estimates transfer from one sense to the other. Our results showed that vision does not teach touch as efficient as touch seems to teach vision.

  7. 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...

  8. 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.

  9. 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.

  10. INFRARED COLOR-COLOR DIAGRAMS FOR AGB STARS

    Directory of Open Access Journals (Sweden)

    Kyung-Won Suh

    2007-09-01

    Full Text Available We present infrared color-color diagrams of AGB stars from the observations at near and mid infrared bands. We compile the observations for hundreds of OH/IR stars and carbon stars using the data from the Midcourse Space Experiment (MSX, the two micron sky survey (2MASS, and the IRAS point source catalog (PSC. We compare the observations with the theoretical evolutionary tracks of AGB stars. From the new observational data base and the theoretical evolution tracks, we discuss the meaning of the infrared color-color diagrams at different wavelengths.

  11. FLORA™: Phase I development of a functional vision assessment for prosthetic vision users.

    Science.gov (United States)

    Geruschat, Duane R; Flax, Marshall; Tanna, Nilima; Bianchi, Michelle; Fisher, Andy; Goldschmidt, Mira; Fisher, Lynne; Dagnelie, Gislin; Deremeik, Jim; Smith, Audrey; Anaflous, Fatima; Dorn, Jessy

    2015-07-01

    Research groups and funding agencies need a functional assessment suitable for an ultra-low vision population to evaluate the impact of new vision-restoration treatments. The purpose of this study was to develop a pilot assessment to capture the functional visual ability and well-being of subjects whose vision has been partially restored with the Argus II Retinal Prosthesis System. The Functional Low-Vision Observer Rated Assessment (FLORA) pilot assessment involved a self-report section, a list of functional visual tasks for observation of performance and a case narrative summary. Results were analysed to determine whether the interview questions and functional visual tasks were appropriate for this ultra-low vision population and whether the ratings suffered from floor or ceiling effects. Thirty subjects with severe to profound retinitis pigmentosa (bare light perception or worse in both eyes) were enrolled in a clinical trial and implanted with the Argus II System. From this population, 26 subjects were assessed with the FLORA. Seven different evaluators administered the assessment. All 14 interview questions were asked. All 35 tasks for functional vision were selected for evaluation at least once, with an average of 20 subjects being evaluated for each test item. All four rating options—impossible (33 per cent), difficult (23 per cent), moderate (24 per cent) and easy (19 per cent)—were used by the evaluators. Evaluators also judged the amount of vision they observed the subjects using to complete the various tasks, with 'vision only' occurring 75 per cent on average with the System ON, and 29 per cent with the System OFF. The first version of the FLORA was found to contain useful elements for evaluation and to avoid floor and ceiling effects. The next phase of development will be to refine the assessment and to establish reliability and validity to increase its value as an assessment tool for functional vision and well-being. © 2015 The Authors. Clinical

  12. Color digital halftoning taking colorimetric color reproduction into account

    Science.gov (United States)

    Haneishi, Hideaki; Suzuki, Toshiaki; Shimoyama, Nobukatsu; Miyake, Yoichi

    1996-01-01

    Taking colorimetric color reproduction into account, the conventional error diffusion method is modified for color digital half-toning. Assuming that the input to a bilevel color printer is given in CIE-XYZ tristimulus values or CIE-LAB values instead of the more conventional RGB or YMC values, two modified versions based on vector operation in (1) the XYZ color space and (2) the LAB color space were tested. Experimental results show that the modified methods, especially the method using the LAB color space, resulted in better color reproduction performance than the conventional methods. Spatial artifacts that appear in the modified methods are presented and analyzed. It is also shown that the modified method (2) with a thresholding technique achieves a good spatial image quality.

  13. 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

  14. Color preferences change after experience with liked/disliked colored objects.

    Science.gov (United States)

    Strauss, Eli D; Schloss, Karen B; Palmer, Stephen E

    2013-10-01

    How are color preferences formed, and can they be changed by affective experiences with correspondingly colored objects? We examined these questions by testing whether affectively polarized experiences with images of colored objects would cause changes in color preferences. Such changes are implied by the ecological valence theory (EVT), which posits that color preferences are determined by people's average affective responses to correspondingly colored objects (Palmer & Schloss, Proceedings of the National Academy of Sciences, 107, 8877-8882, 2010). Seeing images of strongly liked (and disliked) red and green objects, therefore, should lead to increased (and decreased) preferences for correspondingly colored red and green color patches. Experiment 1 showed that this crossover interaction did occur, but only if participants were required to evaluate their preferences for the colored objects when they saw them. Experiment 2 showed that these overall changes decreased substantially over a 24-h delay, but the degree to which the effect lasted for individuals covaried with the magnitude of the effects immediately after object exposure. Experiment 3 demonstrated a similar, but weaker, effect of affectively biased changes in color preferences when participants did not see, but only imagined, the colored objects. The overall pattern of results indicated that color preferences are not fixed, but rather are shaped by affective experiences with colored objects. Possible explanations for the observed changes in color preferences were considered in terms of associative learning through evaluative conditioning and/or priming of prior knowledge in memory.

  15. Influence of color word availability on the Stroop color-naming effect.

    Science.gov (United States)

    Kim, Hyosun; Cho, Yang Seok; Yamaguchi, Motonori; Proctor, Robert W

    2008-11-01

    Three experiments tested whether the Stroop color-naming effect is a consequence of word recognition's being automatic or of the color word's capturing visual attention. In Experiment 1, a color bar was presented at fixation as the color carrier, with color and neutral words presented in locations above or below the color bar; Experiment 2 was similar, except that the color carrier could occur in one of the peripheral locations and the color word at fixation. The Stroop effect increased as display duration increased, and the Stroop dilution effect (a reduced Stroop effect when a neutral word is also present) was an approximately constant proportion of the Stroop effect at all display durations, regardless of whether the color bar or color word was at fixation. In Experiment 3, the interval between the onsets of the to-be-named color and the color word was manipulated. The Stroop effect decreased with increasing delay of the color word onset, but the absolute amount of Stroop dilution produced by the neutral word increased. This study's results imply that an attention shift from the color carrier to the color word is an important factor modulating the size of the Stroop effect.

  16. Impact of low vision services on the quality of life of low vision patients in Ghana

    Directory of Open Access Journals (Sweden)

    Godwin O. Ovenseri-Ogbomo

    2016-03-01

    Full Text Available Patients’ perspectives on the impact of clinical interventions have been recognised as critical elements in patient care. Quality-of-life instruments are designed to measure these perspectives. We used the National Eye Institute’s 25-item Visual Function Questionnaire (NEI VFQ to measure the impact of optical low vision devices on the quality of life of 22 low vision patients who obtained and were using low vision devices from a secondary low vision clinic in the Eastern Region, Ghana. The study employed a pre- and post-intervention technique. We found statistically significant improvements in measured visual acuity and NEI VFQ scores in 8 of the 10 domains evaluated. We conclude that optical low vision devices have a positive impact on the quality of life of low vision patients in Ghana. Keywords: low vision; quality of life; visual acuity; visual impairment; Ghana

  17. Representing Color Ensembles.

    Science.gov (United States)

    Chetverikov, Andrey; Campana, Gianluca; Kristjánsson, Árni

    2017-10-01

    Colors are rarely uniform, yet little is known about how people represent color distributions. We introduce a new method for studying color ensembles based on intertrial learning in visual search. Participants looked for an oddly colored diamond among diamonds with colors taken from either uniform or Gaussian color distributions. On test trials, the targets had various distances in feature space from the mean of the preceding distractor color distribution. Targets on test trials therefore served as probes into probabilistic representations of distractor colors. Test-trial response times revealed a striking similarity between the physical distribution of colors and their internal representations. The results demonstrate that the visual system represents color ensembles in a more detailed way than previously thought, coding not only mean and variance but, most surprisingly, the actual shape (uniform or Gaussian) of the distribution of colors in the environment.

  18. Online prediction of organileptic data for snack food using color images

    Science.gov (United States)

    Yu, Honglu; MacGregor, John F.

    2004-11-01

    In this paper, a study for the prediction of organileptic properties of snack food in real-time using RGB color images is presented. The so-called organileptic properties, which are properties based on texture, taste and sight, are generally measured either by human sensory response or by mechanical devices. Neither of these two methods can be used for on-line feedback control in high-speed production. In this situation, a vision-based soft sensor is very attractive. By taking images of the products, the samples remain untouched and the product properties can be predicted in real time from image data. Four types of organileptic properties are considered in this study: blister level, toast points, taste and peak break force. Wavelet transform are applied on the color images and the averaged absolute value for each filtered image is used as texture feature variable. In order to handle the high correlation among the feature variables, Partial Least Squares (PLS) is used to regress the extracted feature variables against the four response variables.

  19. Luminance contours can gate afterimage colors and 'real' colors

    NARCIS (Netherlands)

    Anstis, S.; Vergeer, M.L.T.; Lier, R.J. van

    2012-01-01

    It has long been known that colored images may elicit afterimages in complementary colors. We have already shown (Van Lier, Vergeer, & Anstis, 2009) that one and the same adapting image may result in different afterimage colors, depending on the test contours presented after the colored image. The

  20. Digital color imaging

    CERN Document Server

    Fernandez-Maloigne, Christine; Macaire, Ludovic

    2013-01-01

    This collective work identifies the latest developments in the field of the automatic processing and analysis of digital color images.For researchers and students, it represents a critical state of the art on the scientific issues raised by the various steps constituting the chain of color image processing.It covers a wide range of topics related to computational color imaging, including color filtering and segmentation, color texture characterization, color invariant for object recognition, color and motion analysis, as well as color image and video indexing and retrieval. <