172 research outputs found

    Colorizing Color Images

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    This paper describes a method of improving the quality of the color in color images by colorizing them. In particular, color quality may suffer from improper white balance and other factors such as inadequate camera characterization. Colorization generally refers to the problem of turning a luminance image into a realistic looking color image and impressive results have been reported in the computer vision literature. Based on the assumption that if colorization can successfully predict colors from luminance data alone then it should certainly be able to predict colors from color data, the proposed method employs colorization to ‘color’ color images. Tests show that the proposed method quite effectively removes color casts—including spatially varying color casts—created by changes in the illumination. The colorization method itself is based on training a deep neural network to learn the connection between the colors in an improperly balanced image and those in a properly balanced one. Unlike many traditional white-balance methods, the proposed method is image-inimage- out and does not explicitly estimate the chromaticity of the illumination nor apply a von-Kries-type adaptation step. The colorization method is also spatially varying and so handles spatially varying illumination conditions without further modification

    A Colour Rendering Index for Dichromats

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    We propose a method of evaluating the colour rendering quality of light sources tailored to dichromatic vision. To the best of our knowledge, the proposed color rendering index (CRI) is the first such index to be specifically designed for dichromats. Previous CRIs have been defined only for trichromats and they generally rely on measuring ΔE colour differences in a standardized uniform colour space such as CAM02-UCS. Since these spaces are defined only for trichromatic colour vision these methods do not generalize to the case of dichromatic colour vision. The proposed dichromat CRI is based on the metamer mismatch index, which applies to both the trichromatic and dichromatic cases

    Object Recognition and Pose Estimation across Illumination Changes

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    In this paper, we present a new algorithm for color-based object recognition that detects objects and estimates their pose (position and orientation) in cluttered scenes observed under uncontrolled illumination conditions. As with so many other color-based object-recognition algorithms, color histograms are also fundamental to our approach; however, we use histograms obtained from overlapping subwindows, rather than the entire image. Furthermore, each local histogram is normalized using greyworld normalization in order to be as less sensitive to illumination as possible. An object from a database of prototype objects is identified and located in an input image by matching the subwindow contents. The prototype is detected in the input whenever many good histogram matches are found between the subwindows of the input image and those of the prototype. In essence, normalized color histograms of subwindows are the local features being matched. Once an object has been recognized, its 2D pose is found by approximating the geometrical transformation most consistently mapping the locations of prototype’s subwindows to their matched subwindow locations in the input image

    Optimum Sensors for ‘Chromaticity’ Constancy in the Pixel

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    The evolution of drug resistance in clinical isolates of Candida albicans

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    Candida albicans is both a member of the healthy human microbiome and a major pathogen in immunocompromised individuals. Infections are typically treated with azole inhibitors of ergosterol biosynthesis often leading to drug resistance. Studies in clinical isolates have implicated multiple mechanisms in resistance, but have focused on large-scale aberrations or candidate genes, and do not comprehensively chart the genetic basis of adaptation. Here, we leveraged next-generation sequencing to analyze 43 isolates from 11 oral candidiasis patients. We detected newly selected mutations, including single-nucleotide polymorphisms (SNPs), copy-number variations and loss-of-heterozygosity (LOH) events. LOH events were commonly associated with acquired resistance, and SNPs in 240 genes may be related to host adaptation. Conversely, most aneuploidies were transient and did not correlate with drug resistance. Our analysis also shows that isolates also varied in adherence, filamentation, and virulence. Our work reveals new molecular mechanisms underlying the evolution of drug resistance and host adaptation.National Science Foundation (U.S.). Graduate Research Fellowship ProgramHoward Hughes Medical InstituteHelen Hay Whitney Foundation (Postdoctoral Fellowship)Alfred P. Sloan FoundationNational Institutes of Health (U.S.) (Grant 8DP1CA174427)National Institutes of Health (U.S.) (Grant 2R01CA119176-01

    Fruit crops: a summary of research, 1998

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    Pesticide deposition in orchards: effects of pesticide type, tree canopy, timing, cultivar, and leaf type / Franklin R. Hall, Jane A. Cooper, and David C. Ferree -- The influence of a synthetic foraging attractant, Bee-Scentâ„¢, on the number of honey bees visiting apple blossoms and on subsequent fruit production / James E. Tew and David C. Ferree -- The reliability of three traps vs. a single trap for determining population levels of codling moth in commercial northern Ohio apple orchards / Ted W. Gastier -- Evaluation of an empirical model for predicting sooty blotch and flyspeck of apples in Ohio / Michael A. Ellis, Laurence V. Madden, and L. Lee Wilson -- Influence of pesticides and water stress on photosynthesis and transpiration of apple / David C. Ferree, Franklin R. Hall, Charles R. Krause, Bruce R. Roberts, and Ross D. Brazee -- Influence of temporary bending and heading on branch development and flowering of vigorous young apple trees / David C. Ferree and John C. Schmid -- The effect of apple fruit bruising on total returns / Richard C. Funt, Ewen A. Cameron, and Nigel H. Banks -- Yield, berry quality, and economics of mechanical berry harvest in Ohio / Richard C. Funt, Thomas E. Wall, and Joseph C. Scheerens -- Monitoring flower thrips activities in strawberry fields at two Ohio locations / Roger N. Williams, M. Sean Ellis, Dan S. Fickle, and Carl M. Pelland -- Cluster thinning effects on fruit weight, juice quality, and fruit skin characteristics in 'Reliance' grapes / Yu Gao and Garth A. Cahoon -- Effects of various fungicide programs on powdery mildew control, percent berry sugar, yield, and vine vigor of 'Concord' grapes in Ohio / Michael A. Ellis, Laurence V. Madden, L. Lee Wilson, and Gregory R. Johns -- Influence of growth regulators, cropping, and number on replacement trunks of winter-injured 'Vidal Blanc' grapes / David C. Ferree, David M. Scurlock, and Rick Evans -- Effect of new herbicides on tissue-cultured black raspberry plants / Richard C. Funt, Thomas E. Wall, and B. Dale Stokes -- Investigating the relationship between vine vigor and berry set of field-grown 'Seyval Blanc' grapevines / Steven J. McArtney and David C. Ferree -- Summary of Ohio Fruit Growers Society apple cider competition, 1993-1997 / Winston Bash and Diane Mille
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