Color Mixture Research Articles

Direct white-light from core-shell-like sphere with Sr3Mg-Si2O8: Eu2+, Mn2+ coated on Sr2SiO4:Eu2+

A method of color mixture for white light is presented with Sr3MgSi2O8:Eu2+, Mn2+ shell coated on Sr2SiO4:Eu2+ core by spray pyrolysis procedure. Upon near ultraviolet (NUV) excitation, a 550 nm band emission of Eu2+ from core host combines with the simultaneous emissions of Eu2+ at 457 nm and Mn2+ at 683 nm based on energy transfer in the shell lattice to generate warm white light with color rendering index (CRI) of 91. With such a core-shell-like structure, the re-absorption of blue light from shell layer can be effectively suppressed, and the chemical stability of the phosphor is verified experimentally to be superior to that of the Sr2SiO4:Eu2+. This new proposed phosphor provides great potential in the color mixture of blending-free phosphor converted white NUV light emitting diode (LED) devices.

Novel software for quantitative evaluation and graphical representation of masticatory efficiency

Blending of chewing gums of different colours is used in the clinical setting, as a simple and reliable means for the assessment of chewing efficiency. However, the available software is difficult to use in an everyday clinical setting, and there is no possibility of automated classification of the patient's chewing ability in a graph, to facilitate visualisation of the results and to evaluate potential chewing difficulties. The aims of this study were to test the validity of ViewGum - a novel image analysis software for the evaluation of boli derived from a two-colour mixing ability test - and to establish a baseline graph for the representation of the masticatory efficiency in a healthy population. Image analysis demonstrated significant hue variation decrease as the number of chewing cycles increased, indicating a higher degree of colour mixture. Standard deviation of hue (SDHue) was significantly different between all chewing cycles. Regression of the log-transformed values of the medians of SDHue on the number of chewing cycles showed a high statistically significant correlation (r² = 0.94, P < 0.01). ViewGum eliminates drawbacks of previous two-colour chewing gum test methods by the simplicity of its application. The newly developed ViewGum software provides speed, ease of use and immediate extraction of clinically useful conclusions to the already established method of chewing efficiency evaluation and is a valid adjunct for the evaluation of masticatory efficiency with two-colour chewing gum.

Corneal geometry: preprocessing the map of curvature before compressing

An algorithm to obtain a concise description of a map of corneal curvature is described in [Lenarduzzi, 2012]; here we enter into the details of its computational cost. In the current note we describe how to preprocess the map in order to correct the colors of some pixels: such pixels are mixture of colors from the palette (empty of pure black and pure white) with the pure white. The algorithm assigns one color of the palette to each one of such pixels.

Radiometric Calibration by Rank Minimization

We present a robust radiometric calibration framework that capitalizes on the transform invariant low-rank structure in the various types of observations, such as sensor irradiances recorded from a static scene with different exposure times, or linear structure of irradiance color mixtures around edges. We show that various radiometric calibration problems can be treated in a principled framework that uses a rank minimization approach. This framework provides a principled way of solving radiometric calibration problems in various settings. The proposed approach is evaluated using both simulation and real-world datasets and shows superior performance to previous approaches.

Erratum to: “Color asymmetry in 3D imaging: Influence on the viewing experience”

In theabove article, which appeared in volume 3, August 2012, reference 25 appeared as: R.W. Pridmore RW (2011) Complementary colors theory of color vision: physiology, color mixture, color constancy and color. Perception, 36:394–412. The wrong journal was cited, and the citation should read as follows: Pridmore RW (2011) Complementary colors theory of color vision: physiology, color mixture, color constancy and color perception. Color Research and Application, 36:394–412.

Research on the Imaging Mechanism of Additive Color of Fluorescent Ink-Jet Ink

The formation of color images are generally divided into two methods: additive color imaging based on color light mixture and subtractive color imaging based on colorant mixture. Additive color imaging refers to the color image mixed by a certain percentage of the three primary color lights: red (R), green (G) and blue (B), such as LED display, cell phone screens, digital cameras and others. Subtractive color imaging refers to the color image generated by light mixture reflected by each colorant, due to some light of different wavelength in the white light separately absorbed by certain colorant after mixing a certain percentage of the three primary colorant: cyan (C), magenta (M) and yellow (Y). Inkjet, color laser printing, inkjet printing, etc. belong to the subtractive color imaging. Most commonly, printing also belongs to the subtractive color imaging. This thesis is based on the characteristics that fluorescent materials can produce colors under UV excitation, designing and preparing three fluorescent inkjet inks which can respectively produce red (R), green (G), blue (B) under UV light excitation, using inkjet printers to print color images, investigating the imaging mechanism of the additive color based on fluorescence inkjet printing, and observing the imaging results. The results show that color effect of monochrome image is good, and the color deviation is large after overlapping different colors.

Unsupervised Nosologic Imaging for Glioma Diagnosis

In this letter a novel approach to create nosologic images of the brain using magnetic resonance spectroscopic imaging (MRSI) data in an unsupervised way is presented. Different tissue patterns are identified from the MRSI data using nonnegative matrix factorization and are then coded as different primary colors (i.e. red, green, and blue) in an RGB image, so that mixed tissue regions are automatically visualized as mixtures of primary colors. The approach is useful in assisting glioma diagnosis, where several tissue patterns such as normal, tumor, and necrotic tissue can be present in the same voxel/spectrum. Error-maps based on linear least squares estimation are computed for each nosologic image to provide additional reliability information, which may help clinicians in decision making. Tests on in vivo MRSI data show the potential of this new approach.

Ultrathin Ca‐PO4‐CO3 Solid‐Solution Nanowires: A Controllable Synthesis and Full‐Color Emission by Rare‐Earth Doping

It was found that calcium carbonate (CaCO(3)) and hydroxyapatite (Ca(10)(OH)(2)(PO(4))(6)), which are two crucial constituents of the most abundant minerals in nature and very important bioinorganic components in the tissues of mineralizing organisms, can form solid solutions in a wide range of PO(4)(3-)/CO(3)(2-) (P/C) ratios at low temperature when prepared as ultrathin nanowire structures. This is due to the special reactivity of ultrasmall nanocrystals, which can effectively lower the synthetic temperature and promote the formation of solid solutions. The as-prepared ultrathin nanowires with suitable P/C ratios presented strong blue luminescence due to the existence of abundant defects strengthened by CO(3)(2-). If used as the matrix, the as-prepared ultrathin nanowires demonstrated bright green or red luminescent properties when doped with Tb(3+) or Eu(3+) ions, and simultaneously retained their original morphologies. These three kinds of fluorescent nanowires could reproduce a full range of luminescence colors based on additive color mixtures of the three primary colors (red, green, and blue). In addition, under the same reaction system, ultrafine rare-earth-doped (Ce(3+), Tb(3+), Eu(3+)) nanowires (about 1 nm in diameter) were synthesized by using a one-step hydrothermal process, which further pushed the size of the Ca-PO(4)-CO(3) nanobuilding blocks to one unit cell region. These ultrafine nanowires displayed excellent film-forming properties and the ability to absorb UV radiation.

Pretreatment Strategies for SERS Analysis of Indigo and Prussian Blue in Aged Painted Surfaces

Surface-enhanced Raman scattering (SERS) spectroscopy is increasingly applied to the identification of organic colorants in cultural heritage objects because vibrational fingerprints can be measured from microscopic samples. However, the development of SERS into a reliable, broad-spectrum method for art analysis requires the study of a wide variety of organic and inorganic colorants as well as colorant mixtures in paint. Here, we demonstrate reliable protocols for SERS-based identification of insoluble indigo, Prussian blue (PB), and mixtures thereof in aged painted surfaces. The use of simple salts and acids for sample pretreatment is evaluated. High-quality SERS spectra of PB and indigo are elucidated upon sample pretreatment with H(2)SO(4). In several cases, SERS spectra of the colorants could not be obtained without sample pretreatment. We demonstrate the use of H(2)SO(4) to solubilize PB as well as perform an in situ conversion of insoluble indigo to soluble indigo carmine (IC) on indigo, indigo oil paint, and actual samples from historic painted surfaces. A microscopic H(2)SO(4)-treated sample from the Portrait of Evelyn Byrd produced a SERS spectrum that is consistent with a mixture of PB and IC. To our knowledge, this work represents the first SERS spectrum of indigo in oil paint and the first simultaneous detection of a mixture of blue organic and inorganic colorants in a single art sample using SERS.

Genotyping Antirrhinum commercial varieties using miniature inverted-repeat transposable elements (MITEs)

A special challenge for variety fingerprinting arises in ornamentals sold as population mixture or F1 hybrids displaying colour combinations. We developed a fingerprint protocol for snapdragon (Antirrhinum spp.) commercial plant material based on mapped miniature inverted-repeat transposable elements. We used 15 MITEs-based markers to discriminate two laboratory inbred lines 165E and Sippe 50 and twelve commercial varieties including six sold as colour mixtures, out of which three were F1 hybrid varieties, three were population mixtures and three single coloured. As MITEs share a common sequence the number of primers was reduced over 33% compared to regular primer pairs. In spite of the obvious variability, we found single markers homozygote for a given variety, and as expected, several heterozygote markers. We developed a dichotomic amplification protocol that allows unambiguous identification of snapdragon varieties thus showing that all varieties have a unique pattern of MITEs marker amplification that allows the reliable genotyping of these ornamental cultivars. Distinctiveness, uniformity and stability of ornamental F1 hybrid varieties can be established using these molecular markers.

Helical structure of complementary colors' relative spectral distribution function

I report a curious double helix in psychophysical data. As recently reported, color complementarism structures at least 40 functional roles in vision including all Red-, Green-, Blue-peaked functions (e.g., color matching functions, Helmholtz–Kohlrausch effect, saturation discrimination, lightness discrimination, and wavelength discrimination). These can be modeled from the relative spectral power distribution (SPD) function of complementary colors (at requisite power ratios to neutralize complements). So, the SPDs three-dimensional (3D) structure is of interest. Extended to the hue cycle, the SPD is plotted in a rectilinear graph of wavelength versus wavelength with radiance vertical to the plane. In this rectilinear color mixture space, the white locus representing the illuminant chromaticity is not a single point (representing the junction of complementary pairs of wavelengths) but a sinusoidal curve whose 3D structure is a double helix, representing an SPD and its complementary SPD. The structure's purpose is possibly to store and access global complementary colors data across illuminants. © 2012 Wiley Periodicals, Inc. Col Res Appl, 38, 292–296, 2013

Determination of Synthetic Food Colorants in Water-Soluble Beverages Individually by HPLC and Totally by Ce(IV)-Oxidative Spectrophotometry

Food colorants are an important class of food additives that give the first impression to consumers about the quality of food. Ce(IV)-reducing antioxidant capacity assay originally developed in our laboratories was adapted to the determination of synthetic food colorants for the first time. This method allowing for total antioxidant capacity assay of dietary polyphenols, flavonoids, and ascorbic acid in plant extracts is based on the room temperature oxidation of antioxidant compounds with Ce(IV) sulfate in dilute H2SO4 solution and measurement of the absorbance of unreacted Ce(IV) at 320 nm. The results of the proposed method were correlated with high-performance liquid chromatography (HPLC) findings. Individual standard solutions, synthetic mixtures of synthetic colorants, and colorant extracts were identified and quantified with HPLC on a C18 column equipped with a diode array detector, and slight modifications on the existing HPLC method were made to analyze synthetic colorant mixtures. This work proposes Ce(IV)-oxidative spectrophotometry as a complementary technique to HPLC in the analysis of food colorants.

Combining Kalman Filter with Mixture Color Model Tracking of Pallet Image

In this paper, we propose combining the mixture color model with Kalman filter method. The purpose is to enable forklifts to search for pallets, but it is able to meet fully automated system with real-time. We focused on pallets for image feature and tracking. First, we manually segmented 30 pallet images and statistics of the best color threshold, this method must find the threshold of different color space and mixture of two important color spaces containing HSV and YCbCr, we extracted the H and the Cb composition mixtures to find the best color threshold, and using a combination of Kalman filter(KF) and the color model method to track pallet images, we then used the logic function to keep our information after obtaining the color image segmentation, the noise of the image must be removed, this algorithm can be used on video sequences efficiently. Finally, experimental results show that the method has effective tracking pallet images in the video sequences.

Semi-automatic Coloration Based on Color Mixture for Sankey Diagram

Semi-automatic Coloration Based on Color Mixture for Sankey Diagram

A new approach for color image segmentation based on color mixture

The aim of this paper is to propose a new methodology for color image segmentation. We have developed an image processing technique, based on color mixture, considering how painters do to overlap layers of various hues of paint on creating oil paintings. We also have evaluated the distribution of cones in the human retina for the interpretation of these colors, and we have proposed a schema for the color mixture weight. This method expresses the mixture of black, blue, green, cyan, red, magenta, yellow and white colors quantified by the binary weight of the color that makes up the pixels of an RGB image with 8 bits per channel. The color mixture generates planes that intersect the RGB cube, defining the HSM (Hue, Saturation, Mixture) color space. The position of these planes inside the RGB cube is modeled, based on the distribution of r, g and b cones of the human retina. To demonstrate the applicability of the proposed methodology, we present in this paper, the segmentation of “human skin” or “non-skin” pixels in digital color images. The performance of the color mixture was analyzed by a Gaussian distribution in the HSM, HSV and YCbCr color spaces. The method is compared with other skin/non-skin classifiers. The results demonstrate that our approach surpassed the performance of all compared methodologies. The main contributions of this paper are related to a new way for interpreting color of binary images, taking into account the bit-plane levels and the application in image processing techniques.

Optic Visualization of Auricular Nerves and Blood Vessels: Optimisation and Validation

Auricular blood vessels can be visualized by transillumination of the auricular tissue. The optimisation and validation of the optic visualization are the main subject of this work. Since blood vessels and nerve fibers can be found along one another, the transillumination reveals locations of auricular nerves to unaided human eye. The visualization of the nerves is needed by physicians to precisely insert needles into the auricle for electrical stimulation of auricular nerves. The stimulation is applied to relieve chronic pain and normalize vital physiological parameters. Theoretical approaches are shortly considered which are related to light absorption coefficients of different auricular tissue types and coefficient changes over wavelength. The theory predicts optimal optical contrasts if green and blue colors of light are applied. An experimental validation has been carried out using a novel transillumination device, a finger thimble, among young and elderly, male and female; in total 22 volunteers. Complementary experimental approaches have confirmed theoretical reasoning and have been used to optimize the optical contrast and applied color mixture even further.

Complementary colors theory of color vision: Physiology, color mixture, color constancy and color perception

AbstractI describe complementary colors' physiology and functional roles in color vision, in a three‐stage theory (receptor, opponent color, and complementary color stages). 40 specific roles include the complementary structuring of: S and L cones, opponent single cells, cardinal directions, hue cycle structure, hue constancy, trichromatic color mixture, additive/subtractive primaries, two unique hues, color mixture space, uniform hue difference, lightness‐, saturation‐, and wavelength/hue‐discrimination, spectral sensitivity, chromatic adaptation, metamerism, chromatic induction, Helson‐Judd effect, colored shadows, color rendering, warm‐cool colors, brilliance, color harmony, Aristotle's flight of colors, white‐black responsivity, Helmholtz‐Kohlrausch effect, rainbows/halos/glories, dichromatism, spectral‐sharpening, and trimodality of functions (RGB peaks, CMY troughs whose complementarism adapts functions to illuminant). The 40 specific roles fall into 3 general roles: color mixture, color constancy, and color perception. Complementarism evidently structures much of the visual process. Its physiology is evident in complementarism of cones, and opponent single cells in retina, LGN, and cortex. Genetics show our first cones were S and L, which are complementary in daylight D65, giving a standard white to aid chromatic adaptation. M cone later split from L to oppose the nonspectral (red and purple) hues mixed from S+L. Response curves and wavelength peaks of cones L, S, and (S+L), M, closely resemble, and lead to, those of opponent‐color chromatic responses y, b, and r, g, a bimodal system whose summation gives spectral‐sharpened trimodal complementarism (RGB peaks, CMY troughs). Spectral sharpening demands a post‐receptoral, post‐opponent‐colors location, hence a third stage. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2011

Selective color transferring via ellipsoid color mixture map

Color transfer among images is a natural phenomenon and important research topic in interactive graphics and augmented environments. Most of the conventional methods need complex user interactions and difficult image segmentation. Motivated for the intuitive use of color editing tools, this paper presents a simple but effective ellipsoid color mixture map to realize selective color transfers. Our approach proposes ellipsoid hulls to represent color statistics of the images. Based on the window-click input, the system computes the ellipsoid hulls of the source and target images respectively. The color mixture map is generated to determine the blending weight of pixels in the output image, according to the color and distance information instead of using image segmentation. By mixing the images using the color mixture map, the final results we produce have the source color selected realistically spreading on the structures related to the target window. Our selective color transferring approach is efficient and simple to use, and widely applicable for images and also video sequences without the need of addition interaction. Our experimental results have showed the high-quality visual effects and efficiency of image/video color transfers.

Re-evaluation of synthetic colours: State of the art

Food colours are used in foodstuffs such as soft drinks, bakeryproducts, desserts, sauces and confectionery to make them visually appealing to consumers. The most common synthetic food colours are mono-, di- and tri-azo dyes; triarylmethyl, quinoline, xanthene and indigoid structures are also used. Safety assessmentsof food colours date back many years, and consequently the 45 currently permitted food colours are undergoing re-evaluation by the European Food Safety Authority's (EFSA) Scientific Panel on Additives and Nutrient Sources in Food (ANS). This talk describes the re-evaluation of the synthetic food colours. The results to date have indicated some gaps in the toxicological data, particularly in relation to reproductive toxicity. EFSA has lowered the Acceptable Daily Intake (ADI) for several of these colours, and the authorisation for the colour Red 2G was withdrawn because of concerns regarding genotoxicity and carcinogenicity. The re-evaluation of six of the synthetic colours, Tartrazine (E102), Quinoline Yellow (E104), Sunset Yellow FCF (E110), Azorubine/Carmoisine (E122), Ponceau 4R (E124)and Allura Red AC (E129) was prioritised after a study published in 2008 by Southampton University linked consumption of these colours with hyperactivity in children. The ANS Panel concluded that the study provided limited evidence that certain mixtures of these food colours could have a small effect on some children's activity and attention, but overall the study did not justify changing the ADIs for the individual colours involved. However the Panel considered that the ADIs for Ponceau 4R, Quinoline Yellow and Sunset Yellow should be lowered, on different toxicological grounds.

Solving the puzzle of attention deficit hyperactivity disorder

Helping a child with attention deficit hyperactivity disorder (ADHD) is like solving a jigsaw puzzle with many pieces: you have to identify the out-of-place pieces, then fit them in and complete the puzzle. These “pieces” include cognitive therapy, special education, strategies to improve sleep, medication, environmental toxins, and nutritional interventions. To identify the nutritional pieces, two questions should be asked. 1) Are there nutrients this child is not consuming in large enough amounts in the diet, like zinc, iron, and omega-3 fatty acids? 2) Are there foods or food additives in the diet that the child needs to avoid because they increase symptoms of ADHD? For the last 35 years, researchers have studied the effects of artificial food dyes (AFDs) on the behavior of children with symptoms of ADHD. Some of these studies are well reviewed by Kanarek in the present issue of this journal and by Stevens et al. elsewhere (2011).1 Although animal studies were beyond the scope of Kanarek's review, there have been some interesting studies of the effects of artificial food dyes on animal behavior. For example, Shaywitz and Goldenring2 studied the effects of a mixture of artificial colors on rats and found significant increases in motor activity ( P < 0.001) and a reduction of activity habituation ( P < 0.001) in rats dosed with a mixture of the dyes.2 Several years later, Goldenring et al.3 administered sulfanilic acid, a major metabolite … [↵][1] LJ Stevens , Department of Foods & Nutrition, Purdue University, 700 W. State Street G-1, West Lafayette, Indiana 47907, USA. E-mail: stevens5{at}purdue.edu, Phone: 1-765-447-4570, Fax: 1-765-494-0906. [1]: #xref-corresp-1-1