Segmenting memory colours

OpenAIRE

Fredembach, Clément; Estrada, Francisco; Süsstrunk, Sabine

2008-01-01

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

Gamut Volume Index: a color preference metric based on meta-analysis and optimized colour samples.

Science.gov (United States)

Liu, Qiang; Huang, Zheng; Xiao, Kaida; Pointer, Michael R; Westland, Stephen; Luo, M Ronnier

2017-07-10

A novel metric named Gamut Volume Index (GVI) is proposed for evaluating the colour preference of lighting. This metric is based on the absolute gamut volume of optimized colour samples. The optimal colour set of the proposed metric was obtained by optimizing the weighted average correlation between the metric predictions and the subjective ratings for 8 psychophysical studies. The performance of 20 typical colour metrics was also investigated, which included colour difference based metrics, gamut based metrics, memory based metrics as well as combined metrics. It was found that the proposed GVI outperformed the existing counterparts, especially for the conditions where correlated colour temperatures differed.

Memory colour segmentation and classification using class-specific eigenregions

OpenAIRE

Fredembach, Clement; Estrada, Francisco; Süsstrunk, Sabine

2009-01-01

Memory colours refer to the colour of specific image regions that have the essential attribute of being perceived in a consistent manner by human observers. In colour correction-or rendering-tasks, this consistency implies that they have to be faithfully reproduced; their importance, in that respect, is greater than for other regions in an image. There are various schemes and attributes to detect memory colours, but the preferred method remains to segment the images into meaningful regions, a...

Coloured phase singularities

International Nuclear Information System (INIS)

Berry, M.V.

2002-01-01

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

Color Rendering Index Thermal Stability Improvement of Glass-Based Phosphor-Converted White Light-Emitting Diodes for Solid-State Lighting

Directory of Open Access Journals (Sweden)

Chun-Chin Tsai

2014-01-01

Full Text Available High color rendering index performance has been required for phosphor-converted warm-white light-emitting diodes (PC-WWLEDs in lighting industry. The characteristics of low-temperature fabricated phosphor (yellow: Ce3+:YAG, green: Tb3+:YAG, and red: CaAlClSiN3:Eu2+ doped glass were presented for applications to high color rendering index warm-white-light-emitting diodes. Color coordinates (x, y = (0.36, 0.29, quantum yield (QY = 55.6%, color rending index (CRI = 85.3, and correlated color temperature (CCT = 3923 K were characterized. Glass-based PC-WWLEDs was found able to maintain good thermal stability for long-time high-temperature operation. QY decay, CRI remenance, and chromaticity shift were also analyzed for glass- and silicone-based high-power PC-WLEDs by thermal aging at 150°C and 250°C for industrial test standard’s aging time 1008 hours. Better than the silicone’s, thermal stability of glass-based PC-WLEDs has been improved. The resulted high color rendering index (CRI glass phosphor potentially can be used as a phosphor layer for high-performance and low-cost PC-WLEDs used in next-generation indoor solid-state lighting applications.

Classifying Natural Waters with the Forel-Ule Colour Index System: Results, Applications, Correlations and Crowdsourcing

Directory of Open Access Journals (Sweden)

Shungudzemwoyo P. Garaba

2015-12-01

Full Text Available Societal awareness of changes in the environment and climate has grown rapidly, and there is a need to engage citizens in gathering relevant scientific information to monitor environmental changes due to recognition that citizens are a potential source of critical information. The apparent colour of natural waters is one aspect of our aquatic environment that is easy to detect and an essential complementary optical water quality indicator. Here we present the results and explore the utility of the Forel-Ule colour index (FUI scale as a proxy for different properties of natural waters. A FUI scale is used to distinguish the apparent colours of different natural surface water masses. Correlation analysis was completed in an effort to determine the constituents of natural waters related to FUI. Strong correlations with turbidity, Secchi-disk depth, and coloured dissolved organic material suggest the FUI is a good indicator of changes related to other constituents of water. The increase in the number of tools capable of determining the FUI colours, (i ocean colour remote sensing products; (ii a handheld scale; and (iii a mobile device app, make it a versatile relative measure of water quality. It has the potential to provide higher spatial and temporal resolution of data for a modernized classification of optical water quality. This FUI colour system has been favoured by several scientists in the last century because it is affordable and easy to use and provides indicative information about the colour of water and the water constituents producing that colour. It is therefore within the scope of a growing interest in the application and usefulness of basic measurement methodologies with the potential to provide timely benchmark information about the environment to the public, scientists and policymakers.

Classifying Natural Waters with the Forel-Ule Colour Index System: Results, Applications, Correlations and Crowdsourcing.

Science.gov (United States)

Garaba, Shungudzemwoyo P; Friedrichs, Anna; Voß, Daniela; Zielinski, Oliver

2015-12-18

Societal awareness of changes in the environment and climate has grown rapidly, and there is a need to engage citizens in gathering relevant scientific information to monitor environmental changes due to recognition that citizens are a potential source of critical information. The apparent colour of natural waters is one aspect of our aquatic environment that is easy to detect and an essential complementary optical water quality indicator. Here we present the results and explore the utility of the Forel-Ule colour index (FUI) scale as a proxy for different properties of natural waters. A FUI scale is used to distinguish the apparent colours of different natural surface water masses. Correlation analysis was completed in an effort to determine the constituents of natural waters related to FUI. Strong correlations with turbidity, Secchi-disk depth, and coloured dissolved organic material suggest the FUI is a good indicator of changes related to other constituents of water. The increase in the number of tools capable of determining the FUI colours, (i) ocean colour remote sensing products; (ii) a handheld scale; and (iii) a mobile device app, make it a versatile relative measure of water quality. It has the potential to provide higher spatial and temporal resolution of data for a modernized classification of optical water quality. This FUI colour system has been favoured by several scientists in the last century because it is affordable and easy to use and provides indicative information about the colour of water and the water constituents producing that colour. It is therefore within the scope of a growing interest in the application and usefulness of basic measurement methodologies with the potential to provide timely benchmark information about the environment to the public, scientists and policymakers.

Steady full colour white organic light-emitting devices consisting of an ultrathin red fluorescent layer

International Nuclear Information System (INIS)

Wen Wen; Yu Junsheng; Li Lu; Wang Jun; Jiang Yadong

2009-01-01

White organic light-emitting devices were fabricated using an ultrathin red fluorescent dye of 3-(dicyanomethylene)-5, 5-dimethyl-1-(4-dimethylamino-styryl)cyclohexene inserted in tris(8-quinolinolato) aluminium layer as a red and green emitting layer (EML) and a thin 4, 4'-bis(2, 2'-diphenylvinyl)-1, 1'-diphenyl (DPVBi) layer as blue EML. A maximum power efficiency of 2.4 lm W -1 at 5.5 V and a maximum luminance of 16 690 cd m -2 at 18.5 V were obtained. Pure white emission with a good colour rendering index of 80 was achieved as low as 5 V. The Commission Internationale de l'Eclairage (CIE) coordinates near (0.330, 0.300) show a slight variation of (-0.020, +0.002) in a wide range of voltages. The achievement of full colour white emission at low-operation voltages and high-colour stability is attributed to the confining emission zone function of the thin EML and direct carrier trapping in the ultrathin layer.

A new universal colour image fidelity metric

NARCIS (Netherlands)

Toet, A.; Lucassen, M.P.

2003-01-01

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

Photometric and Colorimeric Comparison of HDR and Spctrally Resolved Rendering Images

DEFF Research Database (Denmark)

Amdemeskel, Mekbib Wubishet; Soreze, Thierry Silvio Claude; Thorseth, Anders

2017-01-01

In this paper, we will demonstrate a comparison between measured colorimetric images, and simulated images from a physics based rendering engine. The colorimetric images are high dynamic range (HDR) and taken with a luminance and colour camera mounted on a goniometer. For the comparison, we have ...

Steady full colour white organic light-emitting devices consisting of an ultrathin red fluorescent layer

Energy Technology Data Exchange (ETDEWEB)

Wen Wen; Yu Junsheng; Li Lu; Wang Jun; Jiang Yadong [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China)], E-mail: jsyu@uestc.edu.cn

2009-01-07

White organic light-emitting devices were fabricated using an ultrathin red fluorescent dye of 3-(dicyanomethylene)-5, 5-dimethyl-1-(4-dimethylamino-styryl)cyclohexene inserted in tris(8-quinolinolato) aluminium layer as a red and green emitting layer (EML) and a thin 4, 4'-bis(2, 2'-diphenylvinyl)-1, 1'-diphenyl (DPVBi) layer as blue EML. A maximum power efficiency of 2.4 lm W{sup -1} at 5.5 V and a maximum luminance of 16 690 cd m{sup -2} at 18.5 V were obtained. Pure white emission with a good colour rendering index of 80 was achieved as low as 5 V. The Commission Internationale de l'Eclairage (CIE) coordinates near (0.330, 0.300) show a slight variation of (-0.020, +0.002) in a wide range of voltages. The achievement of full colour white emission at low-operation voltages and high-colour stability is attributed to the confining emission zone function of the thin EML and direct carrier trapping in the ultrathin layer.

Bi-layer non-doped small-molecular white organic light-emitting diodes with high colour stability

International Nuclear Information System (INIS)

Chen Shuming; Kwok, Hoi-Sing; Zhao Zujin; Tang Benzhong; Wang Zhiming; Lu Ping; Gao Zhao; Ma Yuguang

2011-01-01

Bi-layer non-doped white organic light-emitting diodes (WOLEDs) with hole-transporting layer 4-(4-(1,2,2-triphenylvinyl)phenyl)-7-(5-(4-(1,2,2-triphenylvinyl)phenyl) thiophen-2yl)benzo[c][1,2,5]thiadiazole (BTPETTD) as a red emitter and electron-transporting layer 4,4'-bis(1-phenyl-1H-phenanthro[9,10-d]imidazol-2-yl)biphenyl (DDPi) as a blue emitter are demonstrated. The blue emission is due to direct recombination of excitons in DPPi, while the red emission originates not only from the direct recombination of excitons in BTPETTD but also from a colour down-conversion process by absorbing blue emission and re-emitting red photons. The combination of blue emission and red emission yields an efficient and extremely stable white colour, regardless of driving voltages. In our demonstration, a bi-layer WOLED with an efficiency of 4.2 cd A -1 at 1000 cd m -2 , 1931 Commision International de L'Eclairage coordinates of (0.31, 0.31) and a high colour rendering index of 92 over a wide range of driving voltages is obtained.

Field-portable pixel super-resolution colour microscope.

Directory of Open Access Journals (Sweden)

Alon Greenbaum

Full Text Available Based on partially-coherent digital in-line holography, we report a field-portable microscope that can render lensfree colour images over a wide field-of-view of e.g., >20 mm(2. This computational holographic microscope weighs less than 145 grams with dimensions smaller than 17×6×5 cm, making it especially suitable for field settings and point-of-care use. In this lensfree imaging design, we merged a colorization algorithm with a source shifting based multi-height pixel super-resolution technique to mitigate 'rainbow' like colour artefacts that are typical in holographic imaging. This image processing scheme is based on transforming the colour components of an RGB image into YUV colour space, which separates colour information from brightness component of an image. The resolution of our super-resolution colour microscope was characterized using a USAF test chart to confirm sub-micron spatial resolution, even for reconstructions that employ multi-height phase recovery to handle dense and connected objects. To further demonstrate the performance of this colour microscope Papanicolaou (Pap smears were also successfully imaged. This field-portable and wide-field computational colour microscope could be useful for tele-medicine applications in resource poor settings.

高显色指数LED合成白光光源的研究%Study on LEDs Synthesized High Color Rendering Index White Light Source

Institute of Scientific and Technical Information of China (English)

胡奕彬; 庄其仁; 刘士伟; 赖传杜

2016-01-01

针对目前白光发光二极管(LED)照明灯具显色性不高的问题,基于测色法研究了LED合成白光显色指数的计算模型,根据参与合成的LED光源光谱及其数量,软件编程计算得出合成光源的色温、显色指数等参数.采用优化的遍历范围,将实验测量得到的冷、暖白光及单色LED的光谱导入程序进行模拟计算,得到不同色温下合成光源的显色指数最大值以及所对应的各种LED配比数量.结果表明,暖白光LED与红、绿、蓝LED合成可以获得色温L介于3500 K～12300 K、显色指数见介于92.0～97.7的白光;与红、绿、青LED合成可以获得Ra介于95.0～97.8的低色温白光(3500 K～4500 K).冷白光LED与红、绿、青LED合成可以获得Ra介于90.9～98.4的高色温白光(8200 K～13000 K).对理论计算的Tc=7803 K、Ra=97.29的LED配比进行实际制作,实验测量得到Tc=7992 K,Ra=97.1,理论计算结果与实验结果吻合.%Targeting poor color rendering property of current white light-emitting diode (LED) lamps,based on the colorimetry method,the calculation model for color rendering index of synthetic white light is studied and the parameters like color temperature and color rendering index of the synthetic LED light source are obtained based on the spectrum and quantity of light sources involved in the synthesis process.By using optimized traversal range,the spectra of cold and warm white light and single-color LEDs are imported into the program for simulating calculation,obtaining the maximum value of color rendering index of the synthesized light source under different color temperatures as well as corresponding matched quantity of various LEDs.The results show that the synthesis with warm white LEDs and red,green and blue LEDs can lead to white light whose color temperature falls in the range of 3500 K～12300 K and color rendering index Ra ranges between 92.0 and 97.7.The synthesis with warm white LEDs and red,green and bluish

Ultra-realistic 3-D imaging based on colour holography

International Nuclear Information System (INIS)

Bjelkhagen, H I

2013-01-01

A review of recent progress in colour holography is provided with new applications. Colour holography recording techniques in silver-halide emulsions are discussed. Both analogue, mainly Denisyuk colour holograms, and digitally-printed colour holograms are described and their recent improvements. An alternative to silver-halide materials are the panchromatic photopolymer materials such as the DuPont and Bayer photopolymers which are covered. The light sources used to illuminate the recorded holograms are very important to obtain ultra-realistic 3-D images. In particular the new light sources based on RGB LEDs are described. They show improved image quality over today's commonly used halogen lights. Recent work in colour holography by holographers and companies in different countries around the world are included. To record and display ultra-realistic 3-D images with perfect colour rendering are highly dependent on the correct recording technique using the optimal recording laser wavelengths, the availability of improved panchromatic recording materials and combined with new display light sources.

Semiconductive 3-D haloplumbate framework hybrids with high color rendering index white-light emission.

Science.gov (United States)

Wang, Guan-E; Xu, Gang; Wang, Ming-Sheng; Cai, Li-Zhen; Li, Wen-Hua; Guo, Guo-Cong

2015-12-01

Single-component white light materials may create great opportunities for novel conventional lighting applications and display systems; however, their reported color rendering index (CRI) values, one of the key parameters for lighting, are less than 90, which does not satisfy the demand of color-critical upmarket applications, such as photography, cinematography, and art galleries. In this work, two semiconductive chloroplumbate (chloride anion of lead(ii)) hybrids, obtained using a new inorganic-organic hybrid strategy, show unprecedented 3-D inorganic framework structures and white-light-emitting properties with high CRI values around 90, one of which shows the highest value to date.

Colour characteristics of winter wheat grits of different grain size

Directory of Open Access Journals (Sweden)

Horváth Zs. H.

2015-01-01

Full Text Available Nowadays, wheat has spread all over the world due to its extensive usability. The colour of wheat grits is very important for the milling and baking industry because it determines the colour of the products made from it. The instrumental colour measuring is used, first of all, for durum wheat. We investigated the relationship between colour characteristics and grain size in the case of different hard aestivum wheats. We determined the colour using the CIE (Commission Internationale de l’Eclairage 1976 L*, a*, b* colour system measured by MINOLTA CR-300 tristimulus colorimeter. After screening the colour of the wheat fractions of different grain size, grits was measured wet and dry. We determined the L*, a*, b* colour co-ordinates and the whiteness index, too. To evaluate the values we had obtained, we used analysis of variance and regression analysis. We pointed out that the colour of wheat grits of different grain size is dependent on the hardness index of wheat. The lightness co-ordinate (L* of grits of the harder wheat is smaller, while a* and b* co-ordinates are higher. We also found that while grain size rises, the L* co-ordinate decreases and a*, b* values increase in the case of every type of wheat. The colour of grits is determined by the colour of fractions of 250-400 μm in size, independently from the average grain size. The whiteness index and the L* colour co-ordinate have a linear relation (R2 = 0.9151; so, the determination of whiteness index is not necessary. The L* value right characterizes the whiteness of grits.

High colour purity single-phased full colour emitting white LED phosphor Sr2V2O7:Eu3+

International Nuclear Information System (INIS)

Zhou Zhi; Zhou Nan; He Zhangxing; Liu Suqin; Liu Younian; Tian Ziwei; Wang Nanfang; Mao Zhiyong; Hintzen, H T

2013-01-01

Single-phased white-light-emitting phosphor Sr 2 V 2 O 7 :Eu 3+ was successfully synthesized by the solid-state method. The result of x-ray diffraction analysis indicated that the obtained phosphor has the same crystal structure as that of Sr 2 V 2 O 7 . The synthesized Sr 2 V 2 O 7 :Eu 3+ was combined with near-UV light (365 nm) chips and then assembled into ligtht-emitting diodes (LED) devices, which generated white light with colour coordinates of (0.324, 0.317). The white light was generated from yellow-green and red emissions, which should be attributed to the host Sr 2 V 2 O 7 and dopant Eu ions, respectively. The effects of the concentration of Eu ions and charge compensation on the emission intensity were carefully investigated. The results show that the energy migrates from the host to the dopant and also that Li 2 CO 3 should be the best charge compensator for this single-phased phosphor. In addition, the colour rendering index and luminescence efficiency of the fabricated LED devices with Sr 1.90 V 2 O 7 :0.10Eu 3+ phosphor were 91 and 32 lm W -1 , respectively, suggesting that Sr 1.90 V 2 O 7 :0.10Eu 3+ phosphor is a potential candidate for the phosphor-converted white-light-emitting diodes with near-UV chips.

Color design model of high color rendering index white-light LED module.

Science.gov (United States)

Ying, Shang-Ping; Fu, Han-Kuei; Hsieh, Hsin-Hsin; Hsieh, Kun-Yang

2017-05-10

The traditional white-light light-emitting diode (LED) is packaged with a single chip and a single phosphor but has a poor color rendering index (CRI). The next-generation package comprises two chips and a single phosphor, has a high CRI, and retains high luminous efficacy. This study employs two chips and two phosphors to improve the diode's color tunability with various proportions of two phosphors and various densities of phosphor in the silicone used. A color design model is established for color fine-tuning of the white-light LED module. The maximum difference between the measured and color-design-model simulated CIE 1931 color coordinates is approximately 0.0063 around a correlated color temperature (CCT) of 2500 K. This study provides a rapid method to obtain the color fine-tuning of a white-light LED module with a high CRI and luminous efficacy.

Formulating CdSe quantum dots for white light-emitting diodes with high color rendering index

International Nuclear Information System (INIS)

Li, Fei; Li, Wan-Nan; Fu, Shao-Yun; Xiao, Hong-Mei

2015-01-01

Generation of white light using CdSe quantum dots (QDs) alone presents exciting possibilities for solid state lighting technology. In this work, Cd(Ac) 2 ·2H 2 O and Na 2 SeSO 3 are used as precursors to synthesize CdSe-QDs with an average diameter ranging from 2.77 to 4.65 nm at the low temperature from 60 to 180 °C. Smaller CdSe-QDs with an average diameter of 2.29 nm are got by an oxidation etching process using H 2 O 2 as oxidant. The structural and optical properties of these QDs are investigated and proper formulation of CdSe QDs with various sizes is carefully designed to achieve white light with a high color rendering index (CRI). It is observed for the first time that the as-prepared white light-emitting diodes from single CdSe-QDs show the Commission Inernationale del’Eclairage coordinate (CIE) of (0.30,0.34) very close to that (0.33,0.33) of pure white light and a high CRI of 84. Owing to these advantages, the as-prepared white light-emitting diodes from a single compound are promising for lighting applications. - Highlights: • CdSe-quantum dots (QDs) with a continuously changing size from 2.31 to 4.74 nm are prepared. • The obtained CdSe-QDs emit lights with tunable colors in the whole visible range. • The obtained mixture sample generates white light with a high color rendering index of 84. • The sample yields white light with the CIE coordinate (0.30, 0.34) very close to that of pure white light

ON f-EDGE COVER-COLOURING OF SIMPLE GRAPHS

Institute of Scientific and Technical Information of China (English)

Song Huimin; Liu Guizhen

2005-01-01

An f-edge cover-colouring of a graph G = (V, E) is an assignment of colours to the edges of G such that every colour appears at each vertex υ∈ V at least f(υ) times.The maximum number of colours needed to f-edge cover colour G is called the f-edge cover chromatic index of G, denoted by χfc(G). This paper gives that min[d(ν)-1/f(ν)] ≤χfc(G) ≤min[d(υ)/f(υ)].

Physically based rendering from theory to implementation

CERN Document Server

Pharr, Matt

2010-01-01

"Physically Based Rendering, 2nd Edition" describes both the mathematical theory behind a modern photorealistic rendering system as well as its practical implementation. A method - known as 'literate programming'- combines human-readable documentation and source code into a single reference that is specifically designed to aid comprehension. The result is a stunning achievement in graphics education. Through the ideas and software in this book, you will learn to design and employ a full-featured rendering system for creating stunning imagery. This book features new sections on subsurface scattering, Metropolis light transport, precomputed light transport, multispectral rendering, and much more. It includes a companion site complete with source code for the rendering system described in the book, with support for Windows, OS X, and Linux. Code and text are tightly woven together through a unique indexing feature that lists each function, variable, and method on the page that they are first described.

True Yellow Light-Emitting Diodes as Phosphor for Tunable Color-Rendering Index Laser-Based White Light

KAUST Repository

Janjua, Bilal; Ng, Tien Khee; Zhao, Chao; Prabaswara, Aditya; Consiglio, Giuseppe Bernardo; Priante, Davide; Shen, Chao; Elafandy, Rami T.; Anjum, Dalaver H.; Alhamoud, Abdullah A.; Alatawi, Abdullah A.; Yang, Yang; Alyamani, Ahmed Y.; El-Desouki, Munir M.; Ooi, Boon S.

2016-01-01

An urgent challenge for the lighting research community is the lack of efficient optical devices emitting in between 500 and 600 nm, resulting in the “green-yellow gap”. In particular, true green (∼555 nm) and true yellow (∼590 nm), along with blue and red, constitute four technologically important colors. The III-nitride material system, being the most promising choice of platform to bridge this gap, still suffers from high dislocation density and poor crystal quality in realizing high-power, efficient devices. Particularly, the high polarization fields in the active region of such 2D quantum confined structures prevent efficient recombination of carriers. Here we demonstrate a true yellow nanowire (NW) light emitting diode (LED) with peak emission of 588 nm at 29.5 A/cm2 (75 mA in a 0.5 × 0.5 mm2 device) and a low turn-on voltage of ∼2.5 V, while having an internal quantum efficiency of 39%, and without “efficiency droop” up to an injection current density of 29.5 A/cm2. By mixing yellow light from a NW LED in reflective configuration with that of a red, green, and blue laser diode (LD), white light with a correlated color temperature of ∼6000 K and color-rendering index of 87.7 was achieved. The nitride-NW-based device offers a robust, long-term stability for realizing yellow light emitters for tunable color-rendering index solid-state lighting, on a scalable, low-cost, foundry-compatible titanium/silicon substrate, suitable for industry uptake.

True Yellow Light-Emitting Diodes as Phosphor for Tunable Color-Rendering Index Laser-Based White Light

KAUST Repository

Janjua, Bilal

2016-10-11

An urgent challenge for the lighting research community is the lack of efficient optical devices emitting in between 500 and 600 nm, resulting in the “green-yellow gap”. In particular, true green (∼555 nm) and true yellow (∼590 nm), along with blue and red, constitute four technologically important colors. The III-nitride material system, being the most promising choice of platform to bridge this gap, still suffers from high dislocation density and poor crystal quality in realizing high-power, efficient devices. Particularly, the high polarization fields in the active region of such 2D quantum confined structures prevent efficient recombination of carriers. Here we demonstrate a true yellow nanowire (NW) light emitting diode (LED) with peak emission of 588 nm at 29.5 A/cm2 (75 mA in a 0.5 × 0.5 mm2 device) and a low turn-on voltage of ∼2.5 V, while having an internal quantum efficiency of 39%, and without “efficiency droop” up to an injection current density of 29.5 A/cm2. By mixing yellow light from a NW LED in reflective configuration with that of a red, green, and blue laser diode (LD), white light with a correlated color temperature of ∼6000 K and color-rendering index of 87.7 was achieved. The nitride-NW-based device offers a robust, long-term stability for realizing yellow light emitters for tunable color-rendering index solid-state lighting, on a scalable, low-cost, foundry-compatible titanium/silicon substrate, suitable for industry uptake.

Effect of Window Glazing on Colour Quality of Transmitted Daylight

Directory of Open Access Journals (Sweden)

Rajendra Dangol

2017-12-01

Full Text Available In this study, the colour quality of the daylight transmitted through different window glazing types is evaluated. The analysis considered four different types of window glazing: laminated, monolithic, coated and applied film glazing ranging in luminous transmittance from around 0.97 to <0.1. The spectral transmittance data of different window glazing types are taken from the International Glazing Data Base (IGDB, which is maintained by Lawrence Berkeley National Laboratories (LBNL. The study showed that the CIE CRI does not always seem to be the suitable method to predict the colour quality of daylight in building for particular situations. However, in the context of this study, the prediction of colour rendering properties of window glazing by other metrics such as Colour Quality Scale (version 9, Memory CRI, Ra,D65 (adjusted CRI metric with D65 as the reference illuminant performed better. For most of the daylit situations inside the building, the chromaticity difference criterion was not met. Judging the colour quality of such situations requires different method.

10 CFR Appendix R to Subpart B of... - Uniform Test Method for Measuring Average Lamp Efficacy (LE), Color Rendering Index (CRI), and...

Science.gov (United States)

2010-01-01

... (LE), Color Rendering Index (CRI), and Correlated Color Temperature (CCT) of Electric Lamps R Appendix R to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. R Appendix R to Subpart B of Part...

The original colours of fossil beetles.

Science.gov (United States)

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

2012-03-22

Structural colours, the most intense, reflective and pure colours in nature, are generated when light is scattered by complex nanostructures. Metallic structural colours are widespread among modern insects and can be preserved in their fossil counterparts, but it is unclear whether the colours have been altered during fossilization, and whether the absence of colours is always real. To resolve these issues, we investigated fossil beetles from five Cenozoic biotas. Metallic colours in these specimens are generated by an epicuticular multi-layer reflector; the fidelity of its preservation correlates with that of other key cuticular ultrastructures. Where these other ultrastructures are well preserved in non-metallic fossil specimens, we can infer that the original cuticle lacked a multi-layer reflector; its absence in the fossil is not a preservational artefact. Reconstructions of the original colours of the fossils based on the structure of the multi-layer reflector show that the preserved colours are offset systematically to longer wavelengths; this probably reflects alteration of the refractive index of the epicuticle during fossilization. These findings will allow the former presence, and original hue, of metallic structural colours to be identified in diverse fossil insects, thus providing critical evidence of the evolution of structural colour in this group.

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

Science.gov (United States)

Granzier, Jeroen J M; Gegenfurtner, Karl R

2012-01-01

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

Performance of different metrics proposed to CIE TC 1-91

NARCIS (Netherlands)

Bhusal, P.; Dangol, R.

2017-01-01

The main aim of the article is to find out the performance of different metrics proposed to CIE TC 1-91. Currently, six different indexes have been proposed to CIE TC 1-91: Colour Quality Scale (CQS), Feeling of Contrast Index (FCI), Memory colour rendering index (MCRI), Preference of skin (PS),

Crystal structure and luminescence properties of (Ca{sub 2.94-x}Lu{sub x}Ce{sub 0.06})(Sc{sub 2-y}Mg{sub y})Si{sub 3}O{sub 12} phosphors for white LEDs with excellent colour rendering and high luminous efficiency

Energy Technology Data Exchange (ETDEWEB)

Liu Yongfu; Zhang Xia; Hao Zhendong; Lu Wei; Liu Xingyuan; Zhang Jiahua [Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 Eastern South Lake Road, Changchun 130033 (China); Wang Xiaojun, E-mail: zhangjh@ciomp.ac.cn [Department of Physics, Georgia Southern University, Statesboro, GA 30460 (United States)

2011-02-23

Lu-modified (Ca{sub 2.94-x}Lu{sub x}Ce{sub 0.06})(Sc{sub 2-y}Mg{sub y})Si{sub 3}O{sub 12} (CLSMS : Ce{sup 3+}) yellow emitting phosphors are prepared by a solid-state reaction. Controllable luminescent intensity and emitting colour are studied as a function of Lu and Mg contents. Fixing the Mg content to be 1, the effect of Lu content on crystal phase formation, luminescence properties and temperature characteristics is studied. It is revealed that the Lu-induced luminescent enhancement is the result of an increase in absorbance of Ce{sup 3+} rather than the internal quantum efficiency. Intense and broadband emission is realized by controlling the Lu content to obtain a pure CLSMS crystal phase. The maximum luminescence intensity is obtained at x = 0.54, which is as high as 156% of the Lu-free phosphor. The Lu-containing phosphor also exhibits better temperature characteristics for its big activation energy (0.20 eV) than the Lu-free one (0.18 eV). Combining the present phosphor with a blue light-emitting diode (LED) chip, a white LED with an excellent colour rendering index R{sub a} of 86 and a high luminous efficiency of 86 lm W{sup -1} is obtained. The results of the present study demonstrate that the CLSMS : Ce{sup 3+} phosphors show a good performance and are attractive candidates for commercial applications when used in white LEDs.

Effects of Memory Colour on Colour Constancy for Unknown Coloured Objects

Directory of Open Access Journals (Sweden)

Jeroen J M Granzier

2012-04-01

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

Effects of memory colour on colour constancy for unknown coloured objects

OpenAIRE

Granzier, Jeroen J M; Gegenfurtner, Karl R

2012-01-01

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

Methods for Determining Organic Matter and Colour in Water

Directory of Open Access Journals (Sweden)

Ramunė Albrektienė

2011-02-01

Full Text Available The article examines different methods for determining organic matter and colour in water. Most of organic compounds in water have a humic substance. These substances frequently form complexes with iron. Humic matter gives water a yellow-brownish colour. Water filtration through conventional sand filters does not remove colour and organic compounds, and therefore complicated water treatment methods shall be applied. The methods utilized for organic matter determination in water included research on total organic carbon, permanganate index and the bichromate number of UV absorption of 254 nm wave length. The obtained results showed the greatest dependence between water colour and permanganate index. However, UV adsorption could be used for organic matter determination during the operation of a water treatment plant and the start-up of plants as easy and fast methods.Article in Lithuanian

Effect of Pre-Drying and Hydrocolloid Type on Colour and Textural ...

African Journals Online (AJOL)

The effect of pre-drying and coating on colour and texture of yam chips were investigated. The colour parameters studied were lightness index (L*), hue angle (h) and browning index (BI). Peak force (PF) of penetration was observed for texture. Coating pick-up (amount of coating adhering to the samples) prior to frying was ...

Red carbon dots-based phosphors for white light-emitting diodes with color rendering index of 92.

Science.gov (United States)

Zhai, Yuechen; Wang, Yi; Li, Di; Zhou, Ding; Jing, Pengtao; Shen, Dezhen; Qu, Songnan

2018-05-29

Exploration of solid-state efficient red emissive carbon dots (CDs) phosphors is strongly desired for the development of high performance CDs-based white light-emitting diodes (WLEDs). In this work, enhanced red emissive CDs-based phosphors with photoluminescence quantum yields (PLQYs) of 25% were prepared by embedding red emissive CDs (PLQYs of 23%) into polyvinyl pyrrolidone (PVP). Because of the protection of PVP, the phosphors could preserve strong luminescence under long-term UV excitation or being mixed with conventional packaging materials. By applying the red emissive phosphors as the color conversion layer, WLEDs with high color rendering index of 92 and color coordinate of (0.33, 0.33) are fabricated. Copyright © 2018 Elsevier Inc. All rights reserved.

The genetics of eye colours in an Italian population measured with an objective method for eye colour quantification

DEFF Research Database (Denmark)

Pietroni, C.; Andersen, J.D.; Johansen, P.

2013-01-01

Brown and blue eye colours are primarily explained by the single nucleotide polymorphism (SNP) HERC2 rs12913832. However, the genetics of eye colours that appear to be neither blue nor brown are not well understood. In this study, 230 unrelated Italian individuals were typed for 32 SNP loci...... in the iris region and calculated a Pixel Index of the Eye (PIE-score) that described the eye colours quantitatively. The PIE-score ranged from _1 to 1 (brown to blue). We investigated the association of the PIE-scores extracted from the eye images with the genotypes of the 32 pigmentary SNPs. We observed...

Colour dielectric model of the proton

International Nuclear Information System (INIS)

Jen, P.K.; Pradhan, T.

1984-01-01

A model of the proton with its constituent quarks bound in a colour polarizable medium with dielectric constant varying as (a/r - b 2 ) from a fixed centre, is presented. The Dirac equation modified by the colour polarization is solved and the analytic expression for the wavefunction of the quarks obtained shows that quarks with higher energy lie closer to the fixed centre. The energy spectrum is equispaced without any continuum. A semiclassical approximation scheme yields closed orbits for quarks which have smaller size for higher energies and no orbits with size bigger than a certain maximum, thereby rendering the quarks permanently confined. The wavefunctions of the three quarks constituting the proton are used to calculate physical parameters of the proton such as its mass, charge radius and weak coupling constant which with suitable choice of the constants a and b appearing in the dielectric constant agree fairly well with experimental results. (author)

Cloud-based Monte Carlo modelling of BSSRDF for the rendering of human skin appearance (Conference Presentation)

Science.gov (United States)

Doronin, Alexander; Rushmeier, Holly E.; Meglinski, Igor; Bykov, Alexander V.

2016-03-01

We present a new Monte Carlo based approach for the modelling of Bidirectional Scattering-Surface Reflectance Distribution Function (BSSRDF) for accurate rendering of human skin appearance. The variations of both skin tissues structure and the major chromophores are taken into account correspondingly to the different ethnic and age groups. The computational solution utilizes HTML5, accelerated by the graphics processing units (GPUs), and therefore is convenient for the practical use at the most of modern computer-based devices and operating systems. The results of imitation of human skin reflectance spectra, corresponding skin colours and examples of 3D faces rendering are presented and compared with the results of phantom studies.

Parallel rendering

Science.gov (United States)

Crockett, Thomas W.

1995-01-01

This article provides a broad introduction to the subject of parallel rendering, encompassing both hardware and software systems. The focus is on the underlying concepts and the issues which arise in the design of parallel rendering algorithms and systems. We examine the different types of parallelism and how they can be applied in rendering applications. Concepts from parallel computing, such as data decomposition, task granularity, scalability, and load balancing, are considered in relation to the rendering problem. We also explore concepts from computer graphics, such as coherence and projection, which have a significant impact on the structure of parallel rendering algorithms. Our survey covers a number of practical considerations as well, including the choice of architectural platform, communication and memory requirements, and the problem of image assembly and display. We illustrate the discussion with numerous examples from the parallel rendering literature, representing most of the principal rendering methods currently used in computer graphics.

Memory colours affect colour appearance.

Science.gov (United States)

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

2016-01-01

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

Association of Sun Exposure, Skin Colour and Body Mass Index with Vitamin D Status in Individuals Who Are Morbidly Obese.

Science.gov (United States)

Dix, Clare F; Bauer, Judith D; Martin, Ian; Rochester, Sharon; Duarte Romero, Briony; Prins, Johannes B; Wright, Olivia R L

2017-10-04

Vitamin D deficiency is a common issue, particularly in obese populations, and is tested by assessing serum 25(OH)D concentrations. This study aimed to identify factors that contribute to the vitamin D status in fifty morbidly obese individuals recruited prior to bariatric surgery. Data collected included serum 25(OH)D concentrations, dietary and supplement intake of vitamin D, sun exposure measures, skin colour via spectrophotometry, and genotype analysis of several single nucleotide polymorphisms in the vitamin D metabolism pathway. Results showed a significant correlation between serum 25(OH)D concentrations and age, and serum 25(OH)D and ITAC score (natural skin colour). Natural skin colour accounted for 13.5% of variation in serum 25(OH)D, with every 10° increase in ITAC score (i.e., lighter skin) leading to a 9 nmol/L decrease in serum 25(OH)D. Multiple linear regression using age, ITAC score, and average UV index in the three months prior to testing, significantly predicted serum 25(OH)D concentrations ( R ² = 29.7%). Single nucleotide polymorphisms for all vitamin D genes tested, showed lower serum 25(OH)D for those with the rare genotype compared to the common genotype; this was most pronounced for fok1 and rs4588 , where those with the rare genotype were insufficient (vitamin D status in individuals with morbid obesity requires testing of 25(OH)D, but potential risk factors for this population include natural skin colour and age.

An Image-Based Gamut Analysis of Translucent Digital Ceramic Prints for Coloured Photovoltaic Modules

Directory of Open Access Journals (Sweden)

Roland Schregle

2018-02-01

Full Text Available Colouring the frontglass of photovoltaic (PV modules via digital ceramic printing aids in concealing the PV modules when integrated into existing building façades as building-integrated photovoltaics (BIPV, while admitting sufficient light to produce electricity. This promotes the visual acceptance and adoption of PV modules as a source of renewable energy in urban environments. The effective colour of the PV laminate is a combination of the transparent colour on glass and the colour of the PV cells. This colour should ideally match the architect’s visual expectations in terms of fidelity, but also in terms of relative PV efficiency as a function of print density. In practice, these requirements are often contradictory, particularly for vivid colours, and the visual results may deviate significantly. This paper presents an objective analysis of how colours appear on ceramically printed frontglass when laminated with a PV module, using an image-based colour acquisition process. Given a set of 1044 nominal colours uniformly distributed in the RGB colour space, each printed in 10 opacities, we quantify the range of effective colours observed when printed on glass and combined with a PV module, and their deviation from the nominals. Our results confirm that the effective colour gamuts are significantly constrained and skewed, depending on the ink volume and glass finish used for printing. In particular, blue–magenta hues cannot be reliably rendered with this process. These insights can serve as guidelines for selecting target colours for BIPV that can be well approximated in practice.

Enhancement of Color Rendering Index for White Light LED Lamps by Red Y2O3:EU3+ Phosphor

Directory of Open Access Journals (Sweden)

Tran Hoang Quang Minh

2016-01-01

Full Text Available We present an application of the red Y2O3:Eu3+ dopant phosphor compound for reaching the color rendering index as high as 86. The Multi-Chip White LED lamps (MCW-LEDs with high Correlated Color Temperatures (CCTs including 7000 K and 8500 K are employed in this study. Besides, the impacts of the Y2O3:Eu3+ phosphor on the attenuation of light through phosphor layers of the various packages is also demonstrated based on the Beer-Lambert law. Simulation results provide important conclusion for selecting and developing the phosphor materials in MCW-LEDs manufacturing.

A simplified method for generation of pseudo natural colours from colour infrared aerial photos

DEFF Research Database (Denmark)

Knudsen, Thomas; Olsen, Brian Pilemann

mapping methods. The method presented is a dramatic simplification of a recently published method, going from a 7 step to a 2 step procedure. The first step is a classification of the input image into 4 domains, based on simple thresholding of a vegetation index and a saturation measure for each pixel....... In the second step the blue colour component is estimated using tailored models for each domain. Green and red colour components are taken directly fron the CIR photo. The visual impression of the results from the 2 step method is only slightly inferior to the original 7 step method. The implementation, however...

The effect of gamma irradiation on the degree of ripening of mango by comparing the parameter of colour index, texture firmness and pH value

International Nuclear Information System (INIS)

Muhammad Hafiz Hanafi

2012-01-01

This study was carried out to determine the effect of low dose gamma irradiation on the ripening degree of cv Chokanan mangoes through the comparison of colour index changes, texture firmness and pH value. Harvested mature mango was studied through the storage period for 14 days. Dose level used were 0.00 kGy (control), 0.25 kGy, 0.50 kGy, 0.75 kGy and 1.00 kGy of gamma cell 220. All fruits were wrapped using plastic after irradiated. There was no change in 0 day. However, there are changes in colour index, firmness and pH value of fruits in after 3 days. Dose of 0.75 kGy and 1.00 kGy gave positive effect to storage extension period and rate deceleration compared to 0.00 kGy (control), 0.25 kGy and 0.50 kGy. After 10 days storage, 0.00, 0.25 and 0.50 kGy of fruits became rot which affects quality of organoleptic. Whereas 0.75 and 1.00 kGy still retained organoleptic quality . When the ripening rate of fruit was fast, this would lead to faster of the colour change. The firmness value of fruit became decrease and the value of pH was increase. (author)

Antireflective sub-wavelength structures for improvement of the extraction efficiency and color rendering index of monolithic white light-emitting diode

DEFF Research Database (Denmark)

Ou, Yiyu; Corell, Dennis Dan; Dam-Hansen, Carsten

2011-01-01

We have theoretically investigated the influence of antireflective sub-wavelength structures on a monolithic white light-emitting diode (LED). The simulation is based on the rigorous coupled wave analysis (RCWA) algorithm, and both cylinder and moth-eye structures have been studied in the work. Our...... simulation results show that a moth-eye structure enhances the light extraction efficiency over the entire visible light range with an extraction efficiency enhancement of up to 26 %. Also for the first time to our best knowledge, the influence of sub-wavelength structures on both the color rendering index...

Colour evaluation of a phycobiliprotein-rich extract obtained from Nostoc PCC9205 in acidic solutions and yogurt.

Science.gov (United States)

de O Moreira, Isabela; Passos, Thaís S; Chiapinni, Claudete; Silveira, Gabrielle K; Souza, Joana C M; Coca-Vellarde, Luis Guillermo; Deliza, Rosires; de Lima Araújo, Kátia G

2012-02-01

Phycobiliproteins are coloured proteins produced by cyanobacteria, which have several applications because of their colour properties. However, there is no available information about the colour stability of phycobiliproteins from Nostoc sp. in food systems. The aim of this work was to study the colour stability of a purple-coloured phycobiliprotein-rich extract from the cyanobacterium Nostoc PCC9205 in acidic solutions and yogurt. Variations of pH for Nostoc PCC9205 extract have shown stability for the L* (lightness) and a* (redness) indexes in the range 1.0-7.0. The b* index (blueness), however, increased at pH values below 4.0, indicating loss of the blue colour. The Nostoc PCC9205 extract was used as colorant in yogurt (pH 4.17) stored for 60 days. Instrumental colour analysis showed no changes for the L* and a* indexes during storage, whereas the b* index changed after 20 days of storage. A multiple comparison test showed colour instability after 20 days of storage. A hedonic scale test performed on the 60th day of storage showed acceptability of the product. The red component of the phycobiliprotein-rich extract from Nostoc PCC9205 presented an improved stability in acidic media and yogurt compared with the blue component of this extract. Copyright © 2011 Society of Chemical Industry.

Afrikaans as an index of identity among Western Cape Coloured ...

African Journals Online (AJOL)

katevg

shift in two semi-urban Western Cape Coloured communities; in particular, ... as the workplace and in the church), with Afrikaans being used almost ... language use, on the one hand, and ongoing psychological, social or cultural processes, ...

Performance of different metrics proposed to CIE TC 1-91

Directory of Open Access Journals (Sweden)

Pramod Bhusal

2017-12-01

Full Text Available The main aim of the article is to find out the performance of different metrics proposed to CIE TC 1-91. Currently, six different indexes have been proposed to CIE TC 1-91: Colour Quality Scale (CQS, Feeling of Contrast Index (FCI, Memory colour rendering index (MCRI, Preference of skin (PS, Relative gamut area index (RGAI and Illuminating Engineering society Method for evaluating light source colour rendition (IES TM-30. The evaluation and analysis are based on previously conducted experiment in lighting booth. The analysis showed the area based metric FCI was good subjective preference indicator. The subjective preference was measured in terms of naturalness of objects, colourfulness of colour checker chart, and the visual appearance of the lit scene in the booth.

Association of Sun Exposure, Skin Colour and Body Mass Index with Vitamin D Status in Individuals Who Are Morbidly Obese

Directory of Open Access Journals (Sweden)

Clare F. Dix

2017-10-01

Full Text Available Vitamin D deficiency is a common issue, particularly in obese populations, and is tested by assessing serum 25(OHD concentrations. This study aimed to identify factors that contribute to the vitamin D status in fifty morbidly obese individuals recruited prior to bariatric surgery. Data collected included serum 25(OHD concentrations, dietary and supplement intake of vitamin D, sun exposure measures, skin colour via spectrophotometry, and genotype analysis of several single nucleotide polymorphisms in the vitamin D metabolism pathway. Results showed a significant correlation between serum 25(OHD concentrations and age, and serum 25(OHD and ITAC score (natural skin colour. Natural skin colour accounted for 13.5% of variation in serum 25(OHD, with every 10° increase in ITAC score (i.e., lighter skin leading to a 9 nmol/L decrease in serum 25(OHD. Multiple linear regression using age, ITAC score, and average UV index in the three months prior to testing, significantly predicted serum 25(OHD concentrations (R2 = 29.7%. Single nucleotide polymorphisms for all vitamin D genes tested, showed lower serum 25(OHD for those with the rare genotype compared to the common genotype; this was most pronounced for fok1 and rs4588, where those with the rare genotype were insufficient (<50 nmol/L, and those with the common genotype were sufficient (≥50 nmol/L. Assessing vitamin D status in individuals with morbid obesity requires testing of 25(OHD, but potential risk factors for this population include natural skin colour and age.

Colorimetry and efficiency of white LEDs: Spectral width dependence

Energy Technology Data Exchange (ETDEWEB)

Taylor, Elaine; Edwards, Paul R.; Martin, Robert W. [Department of Physics, SUPA, Strathclyde University, Glasgow (United Kingdom)

2012-03-15

The potential colour rendering capability and efficiency of white LEDs constructed by a combination of individual red, green and blue (RGB) LEDs are analysed. The conventional measurement of colour rendering quality, the colour rendering index (CRI), is used as well as a recently proposed colour quality scale (CQS), designed to overcome some of the limitations of CRI when narrow-band emitters are being studied. The colour rendering performance is maximised by variation of the peak emission wavelength and relative intensity of the component LEDs, with the constraint that the spectral widths follow those measured in actual devices. The highest CRI achieved is 89.5, corresponding to a CQS value of 79, colour temperature of 3800 K and a luminous efficacy of radiation (LER) of 365 lm/W. By allowing the spectral width of the green LED to vary the CRI can be raised to 90.9, giving values of 82.5 and 370 lm/W for the CQS and LER, respectively. The significance of these values are discussed in terms of optimising the possible performance of RGB LEDs. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Afrikaans as an index of identity among Western Cape Coloured ...

African Journals Online (AJOL)

... in the intimate domains. It appears that Afrikaans remains a strong marker of identity in the two semi-urban Western Cape Coloured communities, despite English largely being regarded as the language of upward socioeconomic mobility. Keywords: language shift, language maintenance, language attitudes, bilingualism ...

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

Science.gov (United States)

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

2016-01-01

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

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

Science.gov (United States)

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

2016-01-01

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

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

Directory of Open Access Journals (Sweden)

Lewis Forder

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

Non-binary Colour Modulation for Display Device Based on Phase Change Materials

Science.gov (United States)

Ji, Hong-Kai; Tong, Hao; Qian, Hang; Hui, Ya-Juan; Liu, Nian; Yan, Peng; Miao, Xiang-Shui

2016-12-01

A reflective-type display device based on phase change materials is attractive because of its ultrafast response time and high resolution compared with a conventional display device. This paper proposes and demonstrates a unique display device in which multicolour changing can be achieved on a single device by the selective crystallization of double layer phase change materials. The optical contrast is optimized by the availability of a variety of film thicknesses of two phase change layers. The device exhibits a low sensitivity to the angle of incidence, which is important for display and colour consistency. The non-binary colour rendering on a single device is demonstrated for the first time using optical excitation. The device shows the potential for ultrafast display applications.

Non-binary Colour Modulation for Display Device Based on Phase Change Materials.

Science.gov (United States)

Ji, Hong-Kai; Tong, Hao; Qian, Hang; Hui, Ya-Juan; Liu, Nian; Yan, Peng; Miao, Xiang-Shui

2016-12-19

A reflective-type display device based on phase change materials is attractive because of its ultrafast response time and high resolution compared with a conventional display device. This paper proposes and demonstrates a unique display device in which multicolour changing can be achieved on a single device by the selective crystallization of double layer phase change materials. The optical contrast is optimized by the availability of a variety of film thicknesses of two phase change layers. The device exhibits a low sensitivity to the angle of incidence, which is important for display and colour consistency. The non-binary colour rendering on a single device is demonstrated for the first time using optical excitation. The device shows the potential for ultrafast display applications.

FUZZY RIPENING MANGO INDEX USING RGB COLOUR SENSOR MODEL

OpenAIRE

Ab Razak Mansor; Mahmod Othman; Mohd Nazari Abu Bakar; Khairul Adilah Ahmad; Tajul Rosli Razak

2014-01-01

Currently, the mango ripeness classification is determined manually by human graders according to a particular procedure. This method is inconsistent and subjective in nature because each grader has different techniques. Thus, it affects the quantity and quality of the mango fruit that can be marketed. In this project, a new model for classifying mango fruit is developed using the fuzzy logic RGB sensor colour model build in the MATLAB software. The grading system was programme...

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

Science.gov (United States)

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

2008-01-15

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

Colour in flux: describing and printing colour in art

Science.gov (United States)

Parraman, Carinna

2008-01-01

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

Specifying colours for colour vision testing using computer graphics.

Science.gov (United States)

Toufeeq, A

2004-10-01

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

Colour discrimination of dental professionals and colour deficient laypersons.

Science.gov (United States)

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

2011-12-01

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

Colour simplicity

OpenAIRE

du Preez, Warren

2017-01-01

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

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

OpenAIRE

Hårleman, Maud

2007-01-01

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

Does Colour Preference Have a Role in Colour Term Acquisition?

Science.gov (United States)

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

2009-01-01

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

The Global Solar UV Index used in the United Kingdom

International Nuclear Information System (INIS)

New, C.; Driscoll, C.M.H.; Kitchen, K.; Miners, B.

2000-01-01

Weather forecast bulletins on television, radio and in the newspapers in the UK now include advice about the strength of the ultraviolet (UV) radiation from the sun in terms of the Global Solar UV Index. A numerical scale of 1 to 20 is used to quote the Index for anywhere in the world and the Index addresses all ethnic groups. The Index replaces the sunburn warning system. The daily UV Index is calculated by the Met. Office from documented UV radiation levels and current atmospheric data and takes into account cloud cover forecast. Armed with the knowledge of the UV Index the public will be able to assess their personal risk of sun damage at home or abroad depending on their natural skin colour. Four categories of skin colour are identified with the Index; white skin that sunburns easily, white skin that tans readily, brown skin and black skin. A colour-coded rating from low to very high is used to identify personal risk with these skin colour categories. The Global UV Index forms an important part of the 'Sun Safety Code' developed by health organisations within the UK. (author)

The Global Solar UV Index used in the United Kingdom

Energy Technology Data Exchange (ETDEWEB)

New, C.; Driscoll, C.M.H.; Kitchen, K.; Miners, B

2000-07-01

Weather forecast bulletins on television, radio and in the newspapers in the UK now include advice about the strength of the ultraviolet (UV) radiation from the sun in terms of the Global Solar UV Index. A numerical scale of 1 to 20 is used to quote the Index for anywhere in the world and the Index addresses all ethnic groups. The Index replaces the sunburn warning system. The daily UV Index is calculated by the Met. Office from documented UV radiation levels and current atmospheric data and takes into account cloud cover forecast. Armed with the knowledge of the UV Index the public will be able to assess their personal risk of sun damage at home or abroad depending on their natural skin colour. Four categories of skin colour are identified with the Index; white skin that sunburns easily, white skin that tans readily, brown skin and black skin. A colour-coded rating from low to very high is used to identify personal risk with these skin colour categories. The Global UV Index forms an important part of the 'Sun Safety Code' developed by health organisations within the UK. (author)

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

Science.gov (United States)

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

2007-10-01

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

Colour scheme an exploration of the indeterminate space of colour

OpenAIRE

Varga, Tania Elke

2017-01-01

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

RenderToolbox3: MATLAB tools that facilitate physically based stimulus rendering for vision research.

Science.gov (United States)

Heasly, Benjamin S; Cottaris, Nicolas P; Lichtman, Daniel P; Xiao, Bei; Brainard, David H

2014-02-07

RenderToolbox3 provides MATLAB utilities and prescribes a workflow that should be useful to researchers who want to employ graphics in the study of vision and perhaps in other endeavors as well. In particular, RenderToolbox3 facilitates rendering scene families in which various scene attributes and renderer behaviors are manipulated parametrically, enables spectral specification of object reflectance and illuminant spectra, enables the use of physically based material specifications, helps validate renderer output, and converts renderer output to physical units of radiance. This paper describes the design and functionality of the toolbox and discusses several examples that demonstrate its use. We have designed RenderToolbox3 to be portable across computer hardware and operating systems and to be free and open source (except for MATLAB itself). RenderToolbox3 is available at https://github.com/DavidBrainard/RenderToolbox3.

Rethinking Colour Constancy.

Directory of Open Access Journals (Sweden)

Alexander D Logvinenko

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

Rethinking Colour Constancy.

Science.gov (United States)

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

2015-01-01

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

Developmental colour agnosia.

Science.gov (United States)

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

2007-08-01

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

Colour tuning in white hybrid inorganic/organic light-emitting diodes

International Nuclear Information System (INIS)

Bruckbauer, Jochen; Brasser, Catherine; Edwards, Paul R; Martin, Robert W; Findlay, Neil J; Skabara, Peter J; Wallis, David J

2016-01-01

White hybrid inorganic/organic light-emitting diodes (LEDs) were fabricated by combining a novel organic colour converter with a blue inorganic LED. An organic small molecule was specifically synthesised to act as down-converter. The characteristics of the white colour were controlled by changing the concentration of the organic molecule based on the BODIPY unit, which was embedded in a transparent matrix, and volume of the molecule and encapsulant mixture. The concentration has a critical effect on the conversion efficiency, i.e. how much of the absorbed blue light is converted into yellow light. With increasing concentration the conversion efficiency decreases. This quenching effect is due to aggregation of the organic molecule at higher concentrations. Increasing the deposited amount of the converter does not increase the yellow emission despite more blue light being absorbed. Degradation of the organic converter was also observed during a period of 15 months from LED fabrication. Angular-dependent measurements revealed slight deviation from a Lambertian profile for the blue and yellow emission peaks leading to a small change in ‘whiteness’ with emission angle. Warm white and cool white light with correlated colour temperatures of 2770 K and 7680 K, respectively, were achieved using different concentrations of the converter molecule. Although further work is needed to improve the lifetime and poor colour rendering, these hybrid LEDs show promising results as an alternative approach for generating white LEDs compared with phosphor-based white LEDs. (paper)

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

Directory of Open Access Journals (Sweden)

Derek H. Arnold

2011-05-01

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

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

Science.gov (United States)

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

2010-06-01

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

New model for colour kinetics of plum under infrared vacuum condition and microwave drying.

Science.gov (United States)

Chayjan, Reza Amiri; Alaei, Behnam

2016-01-01

Quality of dried foods is affected by the drying method and physiochemical changes in tissue. The drying method affects properties such as colour. The colour of processed food is one of the most important quality indices and plays a determinant role in consumer acceptability of food materials and the processing method. The colour of food materials can be used as an indirect factor to determine changes in quality, since it is simpler and faster than chemical methods. The study focused on the kinetics of colour changes of plum slices, under infrared vacuum and microwave conditions. Drying the samples was implemented at the absolute pressures of 20 and 60 kPa, drying temperatures of 50 and 60°C and microwave power of 90, 270, 450 and 630 W. Colour changes were quantified by the tri-stimulus L* (whiteness/darkness), a* (redness/greenness) and b* (yellowness/blueness) model, which is an international standard for color measurement developed by the Commission Internationale d'Eclairage (CIE). These values were also used to calculate total colour change (∆E), chroma, hue angle, and browning index (BI). A new model was used for mathematical modelling of colour change kinetics. The drying process changed the colour parameters of L*, a*, and b*, causing a colour shift toward the darker region. The values of L* and hue angle decreased, whereas the values of a*, b*, ∆E, chroma and browning index increased during exposure to infrared vacuum conditions and microwave drying. Comparing the results obtained using the new model with two conventional models of zero-order and first-order kinetics indicated that the new model presented more compatibility with the data of colour kinetics for all colour parameters and drying conditions. All kinetic changes in colour parameters can be explained by the new model presented in this study. The hybrid drying system included infrared vacuum conditions and microwave power for initial slow drying of plum slices and provided the desired

High color rendering index white organic light-emitting diode using levofloxacin as blue emitter

International Nuclear Information System (INIS)

Miao Yan-Qin; Zhang Ai-Qin; Li Yuan-Hao; Wang Hua; Jia Hu-Sheng; Liu Xu-Guang; Gao Zhi-Xiang; Tsuboi Taijuf

2015-01-01

Levofloxacin (LOFX), which is well-known as an antibiotic medicament, was shown to be useful as a 452-nm blue emitter for white organic light-emitting diodes (OLEDs). In this paper, the fabricated white OLED contains a 452-nm blue emitting layer (thickness of 30 nm) with 1 wt% LOFX doped in CBP (4,4’-bis(carbazol-9-yl)biphenyl) host and a 584-nm orange emitting layer (thickness of 10 nm) with 0.8 wt% DCJTB (4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7, 7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran) doped in CBP, which are separated by a 20-nm-thick buffer layer of TPBi (2,2’,2”-(benzene-1,3,5-triyl)-tri(1-phenyl-1H-benzimidazole). A high color rendering index (CRI) of 84.5 and CIE chromaticity coordinates of (0.33, 0.32), which is close to ideal white emission CIE (0.333, 0.333), are obtained at a bias voltage of 14 V. Taking into account that LOFX is less expensive and the synthesis and purification technologies of LOFX are mature, these results indicate that blue fluorescence emitting LOFX is useful for applications to white OLEDs although the maximum current efficiency and luminance are not high. The present paper is expected to become a milestone to using medical drug materials for OLEDs. (paper)

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

International Nuclear Information System (INIS)

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

2008-01-01

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

Recolouring-resistant colourings

DEFF Research Database (Denmark)

Pedersen, A. S.; Rautenbach, D.

2011-01-01

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

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

Directory of Open Access Journals (Sweden)

Duncan Tamsett

2016-03-01

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

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

Science.gov (United States)

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

2014-11-01

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

Improved image retrieval based on fuzzy colour feature vector

Science.gov (United States)

Ben-Ahmeida, Ahlam M.; Ben Sasi, Ahmed Y.

2013-03-01

One of Image indexing techniques is the Content-Based Image Retrieval which is an efficient way for retrieving images from the image database automatically based on their visual contents such as colour, texture, and shape. In this paper will be discuss how using content-based image retrieval (CBIR) method by colour feature extraction and similarity checking. By dividing the query image and all images in the database into pieces and extract the features of each part separately and comparing the corresponding portions in order to increase the accuracy in the retrieval. The proposed approach is based on the use of fuzzy sets, to overcome the problem of curse of dimensionality. The contribution of colour of each pixel is associated to all the bins in the histogram using fuzzy-set membership functions. As a result, the Fuzzy Colour Histogram (FCH), outperformed the Conventional Colour Histogram (CCH) in image retrieving, due to its speedy results, where were images represented as signatures that took less size of memory, depending on the number of divisions. The results also showed that FCH is less sensitive and more robust to brightness changes than the CCH with better retrieval recall values.

Measuring colour rivalry suppression in amblyopia.

Science.gov (United States)

Hofeldt, T S; Hofeldt, A J

1999-11-01

To determine if the colour rivalry suppression is an index of the visual impairment in amblyopia and if the stereopsis and fusion evaluator (SAFE) instrument is a reliable indicator of the difference in visual input from the two eyes. To test the accuracy of the SAFE instrument for measuring the visual input from the two eyes, colour rivalry suppression was measured in six normal subjects. A test neutral density filter (NDF) was placed before one eye to induce a temporary relative afferent defect and the subject selected the NDF before the fellow eye to neutralise the test NDF. In a non-paediatric private practice, 24 consecutive patients diagnosed with unilateral amblyopia were tested with the SAFE. Of the 24 amblyopes, 14 qualified for the study because they were able to fuse images and had no comorbid disease. The relation between depth of colour rivalry suppression, stereoacuity, and interocular difference in logMAR acuity was analysed. In normal subjects, the SAFE instrument reversed temporary defects of 0.3 to 1. 8 log units to within 0.6 log units. In amblyopes, the NDF to reverse colour rivalry suppression was positively related to interocular difference in logMAR acuity (beta=1.21, psuppression as measured with the SAFE was found to agree closely with the degree of visual acuity impairment in non-paediatric patients with amblyopia.

Video-based rendering

CERN Document Server

Magnor, Marcus A

2005-01-01

Driven by consumer-market applications that enjoy steadily increasing economic importance, graphics hardware and rendering algorithms are a central focus of computer graphics research. Video-based rendering is an approach that aims to overcome the current bottleneck in the time-consuming modeling process and has applications in areas such as computer games, special effects, and interactive TV. This book offers an in-depth introduction to video-based rendering, a rapidly developing new interdisciplinary topic employing techniques from computer graphics, computer vision, and telecommunication en

Is colour cognitive?

Science.gov (United States)

Skorupski, Peter; Chittka, Lars

2011-03-01

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

Plasmonic colour generation

DEFF Research Database (Denmark)

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

2016-01-01

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

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

Science.gov (United States)

Mecklenbräuker, S; Hupbach, A; Wippich, W

2001-11-01

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

Colour Studies

African Journals Online (AJOL)

DR Nneka

2015-04-14

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

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

OpenAIRE

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

2011-01-01

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

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

Science.gov (United States)

Delhey, Kaspar

2015-01-01

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

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

International Nuclear Information System (INIS)

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

2001-01-01

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

Colour printing techniques

OpenAIRE

Parraman, C.

2017-01-01

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

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

International Nuclear Information System (INIS)

Dolejsi, J.; Huefner, J.

1992-01-01

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

Colour computer-generated holography for point clouds utilizing the Phong illumination model.

Science.gov (United States)

Symeonidou, Athanasia; Blinder, David; Schelkens, Peter

2018-04-16

A technique integrating the bidirectional reflectance distribution function (BRDF) is proposed to generate realistic high-quality colour computer-generated holograms (CGHs). We build on prior work, namely a fast computer-generated holography method for point clouds that handles occlusions. We extend the method by integrating the Phong illumination model so that the properties of the objects' surfaces are taken into account to achieve natural light phenomena such as reflections and shadows. Our experiments show that rendering holograms with the proposed algorithm provides realistic looking objects without any noteworthy increase to the computational cost.

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

Science.gov (United States)

Battersby, Paul D; Battersby, Stephen J

2015-03-01

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

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

NARCIS (Netherlands)

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

2007-01-01

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

High-Efficiency and High-Color-Rendering-Index Semitransparent Polymer Solar Cells Induced by Photonic Crystals and Surface Plasmon Resonance.

Science.gov (United States)

Shen, Ping; Wang, Guoxin; Kang, Bonan; Guo, Wenbin; Shen, Liang

2018-02-21

Semitransparent polymer solar cells (ST-PSCs) show attractive potential in power-generating windows or building-integrated photovoltaics. However, the development of ST-PSCs is lagging behind opaque PSCs because of the contradiction between device efficiency and transmission. Herein, Ag/Au alloy nanoparticles and photonic crystals (PCs) were simultaneously introduced into ST-PSCs, acting compatibly as localized surface plasmon resonances and distributed Bragg reflectors to enhance light absorption and transmission. As a result, ST-PSCs based on a hybrid PTB7-Th:PC 71 BM active layer contribute an efficiency as high as 7.13 ± 0.15% and an average visible transmission beyond 20%, which are superior to most of the reported results. Furthermore, PCs can partly compensate valley range of transmission by balancing reflection and transmission regions, yielding a high color rendering index of 95. We believe that the idea of two light management methods compatibly enhancing the performance of ST-PSCs can offer a promising path to develop photovoltaic applications.

Two-dimensional Fourier analysis of the spongy medullary keratin of structurally coloured feather barbs

Science.gov (United States)

Prum, R. O.; Torres, R.; Williamson, S.; Dyck, J.

1999-01-01

We conducted two-dimensional (2D) discrete Fourier analyses of the spatial variation in refractive index of the spongy medullary keratin from four different colours of structurally coloured feather barbs from three species of bird: the rose-faced lovebird, Agapornis roseicollis (Psittacidae), the budgerigar, Melopsittacus undulatus (Psittacidae), and the Gouldian finch, Poephila guttata (Estrildidae). These results indicate that the spongy medullary keratin is a nanostructured tissue that functions as an array of coherent scatterers. The nanostructure of the medullary keratin is nearly uniform in all directions. The largest Fourier components of spatial variation in refractive index in the tissue are of the appropriate size to produce the observed colours by constructive interference alone. The peaks of the predicted reflectance spectra calculated from the 2D Fourier power spectra are congruent with the reflectance spectra measured by using microspectrophotometry. The alternative physical models for the production of these colours, the Rayleigh and Mie theories, hypothesize that medullary keratin is an incoherent array and that scattered waves are independent in phase. This assumption is falsified by the ring-like Fourier power spectra of these feathers, and the spacing of the scattering air vacuoles in the medullary keratin. Structural colours of avian feather barbs are produced by constructive interference of coherently scattered light waves from the optically heterogeneous matrix of keratin and air in the spongy medullary layer.

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

Science.gov (United States)

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

2008-01-01

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

Colour Blocking: Disregarding Traditional Artistic Colour Harmonies ...

African Journals Online (AJOL)

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

Real-time colouring and filtering with graphics shaders

Science.gov (United States)

Vohl, D.; Fluke, C. J.; Barnes, D. G.; Hassan, A. H.

2017-11-01

Despite the popularity of the Graphics Processing Unit (GPU) for general purpose computing, one should not forget about the practicality of the GPU for fast scientific visualization. As astronomers have increasing access to three-dimensional (3D) data from instruments and facilities like integral field units and radio interferometers, visualization techniques such as volume rendering offer means to quickly explore spectral cubes as a whole. As most 3D visualization techniques have been developed in fields of research like medical imaging and fluid dynamics, many transfer functions are not optimal for astronomical data. We demonstrate how transfer functions and graphics shaders can be exploited to provide new astronomy-specific explorative colouring methods. We present 12 shaders, including four novel transfer functions specifically designed to produce intuitive and informative 3D visualizations of spectral cube data. We compare their utility to classic colour mapping. The remaining shaders highlight how common computation like filtering, smoothing and line ratio algorithms can be integrated as part of the graphics pipeline. We discuss how this can be achieved by utilizing the parallelism of modern GPUs along with a shading language, letting astronomers apply these new techniques at interactive frame rates. All shaders investigated in this work are included in the open source software shwirl (Vohl 2017).

Colour perception in ADHD

NARCIS (Netherlands)

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

2006-01-01

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

Conservation of old renderings - the consolidation of rendering with loss of cohesion

Directory of Open Access Journals (Sweden)

Martha Tavares

2008-01-01

Full Text Available The study of external renderings in the scope of conservation and restoration has acquired in the last years great methodological, scientific and technical advances. These renderings are important elements of the built structure, for besides possessing a protection function, they possess often a decorative function of great relevance for the image of the monument. The maintenance of these renderings implies the conservation of traditional constructive techniques and the use of compatible materials, as similar to the originals as possible. The main objective of this study is to define a methodology of conservative restoration using strategies of maintenance of renderings and traditional constructive techniques. The minimum intervention principle is maintained as well as the use of materials compatible with the original ones. This paper describes the technique and products used for the consolidation of the loss of cohesion. The testing campaign was developed under controlled conditions, in laboratory, and in situ in order to evaluate their efficacy for the consolidation of old renders. A set of tests is presented to evaluate the effectiveness of the process. The results are analysed and a reflection is added referring to the applicability of these techniques. Finally the paper presents a proposal for further research.

Effect of glucocorticosteroid injections in tennis elbow verified on colour Doppler ultrasonography: evidence of inflammation

DEFF Research Database (Denmark)

Torp-Pedersen, T.E.; Torp-Pedersen, S.T.; Qvistgaard, E.

2008-01-01

were evaluated at baseline before the injection and at 2 weeks of follow-up. Outcome measures were changes in pain score and US parameters (resistive index (RI) and the amount of colour within the CEO). Prognosticators for outcome were: use of computer mouse, symptom duration, elbow strain, RI, colour...... fraction, Likert pain score, pain at rest, pain during activity, age, height, weight, disease in dominant versus nondominant arm. RESULTS: All but one patient experienced improvement of general elbow pain perception at follow-up at 2 weeks. In parallel, Doppler US showed significant reduction in colour...

COLOUR THEREPY-BOON TO MANKIND

OpenAIRE

Dr.Sajan Kurien Mathew

2017-01-01

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

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

Science.gov (United States)

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

2018-08-01

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

A two-metric proposal to specify the color-rendering properties of light sources for retail lighting

Science.gov (United States)

Freyssinier, Jean Paul; Rea, Mark

2010-08-01

Lighting plays an important role in supporting retail operations, from attracting customers, to enabling the evaluation of merchandise, to facilitating the completion of the sale. Lighting also contributes to the identity, comfort, and visual quality of a retail store. With the increasing availability and quality of white LEDs, retail lighting specifiers are now considering LED lighting in stores. The color rendering of light sources is a key factor in supporting retail lighting goals and thus influences a light source's acceptance by users and specifiers. However, there is limited information on what consumers' color preferences are, and metrics used to describe the color properties of light sources often are equivocal and fail to predict preference. The color rendering of light sources is described in the industry solely by the color rendering index (CRI), which is only indirectly related to human perception. CRI is intended to characterize the appearance of objects illuminated by the source and is increasingly being challenged because new sources are being developed with increasingly exotic spectral power distributions. This paper discusses how CRI might be augmented to better use it in support of the design objectives for retail merchandising. The proposed guidelines include the use of gamut area index as a complementary metric to CRI for assuring good color rendering.

Colour Perception in ADHD

Science.gov (United States)

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

2006-01-01

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

Colour and magnetic monopoles

International Nuclear Information System (INIS)

Corrigan, E.; Olive, D.

1976-01-01

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

Colour perception in ADHD

OpenAIRE

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

2006-01-01

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

Colourful FKS subtraction

CERN Document Server

Frixione, Stefano

2011-01-01

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

The colours of CERN

CERN Multimedia

Laëtitia Pedroso

2010-01-01

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

Subjective estimates of colour attributes for surface colours

NARCIS (Netherlands)

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

1970-01-01

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

Object Knowledge Modulates Colour Appearance

Directory of Open Access Journals (Sweden)

Christoph Witzel

2011-01-01

Full Text Available We investigated the memory colour effect for colour diagnostic artificial objects. Since knowledge about these objects and their colours has been learned in everyday life, these stimuli allow the investigation of the influence of acquired object knowledge on colour appearance. These investigations are relevant for questions about how object and colour information in high-level vision interact as well as for research about the influence of learning and experience on perception in general. In order to identify suitable artificial objects, we developed a reaction time paradigm that measures (subjective colour diagnosticity. In the main experiment, participants adjusted sixteen such objects to their typical colour as well as to grey. If the achromatic object appears in its typical colour, then participants should adjust it to the opponent colour in order to subjectively perceive it as grey. We found that knowledge about the typical colour influences the colour appearance of artificial objects. This effect was particularly strong along the daylight axis.

Object knowledge modulates colour appearance

Science.gov (United States)

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

2011-01-01

We investigated the memory colour effect for colour diagnostic artificial objects. Since knowledge about these objects and their colours has been learned in everyday life, these stimuli allow the investigation of the influence of acquired object knowledge on colour appearance. These investigations are relevant for questions about how object and colour information in high-level vision interact as well as for research about the influence of learning and experience on perception in general. In order to identify suitable artificial objects, we developed a reaction time paradigm that measures (subjective) colour diagnosticity. In the main experiment, participants adjusted sixteen such objects to their typical colour as well as to grey. If the achromatic object appears in its typical colour, then participants should adjust it to the opponent colour in order to subjectively perceive it as grey. We found that knowledge about the typical colour influences the colour appearance of artificial objects. This effect was particularly strong along the daylight axis. PMID:23145224

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

Science.gov (United States)

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

1978-01-01

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

Optimal colour quality of LED clusters based on memory colours.

Science.gov (United States)

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

2011-03-28

The spectral power distributions of tri- and tetrachromatic clusters of Light-Emitting-Diodes, composed of simulated and commercially available LEDs, were optimized with a genetic algorithm to maximize the luminous efficacy of radiation and the colour quality as assessed by the memory colour quality metric developed by the authors. The trade-off of the colour quality as assessed by the memory colour metric and the luminous efficacy of radiation was investigated by calculating the Pareto optimal front using the NSGA-II genetic algorithm. Optimal peak wavelengths and spectral widths of the LEDs were derived, and over half of them were found to be close to Thornton's prime colours. The Pareto optimal fronts of real LED clusters were always found to be smaller than those of the simulated clusters. The effect of binning on designing a real LED cluster was investigated and was found to be quite large. Finally, a real LED cluster of commercially available AlGaInP, InGaN and phosphor white LEDs was optimized to obtain a higher score on memory colour quality scale than its corresponding CIE reference illuminant.

Cadmium colours: composition and properties

International Nuclear Information System (INIS)

Paulus, J.; Knuutinen, U.

2004-01-01

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

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

Science.gov (United States)

He, Xun; Franklin, Anna

2017-01-01

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

Rendering of Gemstones

OpenAIRE

Krtek, Lukáš

2012-01-01

The distinctive appearance of gemstones is caused by the way light reflects and refracts multiple times inside of them. The goal of this thesis is to design and implement an application for photorealistic rendering of gems. The most important effects we aim for are realistic dispersion of light and refractive caustics. For rendering we use well-known algorithm of path tracing with an experimental modification for faster computation of caustic effects. In this thesis we also design and impleme...

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

Science.gov (United States)

Phillips, Peter L.

1985-05-01

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

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

Science.gov (United States)

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

2016-01-01

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

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

OpenAIRE

Berggren, Nick; Eimer, Martin

2016-01-01

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

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

NARCIS (Netherlands)

Lucassen, M.P.

2002-01-01

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

Transformative Rendering of Internet Resources

Science.gov (United States)

2012-10-01

using either the Firefox or Google Chrome rendering engine. The rendering server then captures a screen shot of the page and creates code that positions...be compromised at web pages the hackers had built for that hacking competition to exploit that particular OS /browser configuration. During...of risk with no benefit. They include: - The rendering server is hosted on a Linux-based operating system ( OS ). The OS is much more secure than the

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

Science.gov (United States)

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

2016-01-01

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

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

Directory of Open Access Journals (Sweden)

Domicele Jonauskaite

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

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

Science.gov (United States)

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

2016-01-01

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

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

Science.gov (United States)

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

2014-01-01

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

Computational colour science using MATLAB

CERN Document Server

Westland, Stephen; Cheung, Vien

2012-01-01

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

About Coloured Cold Asphaltic Mixtures

Directory of Open Access Journals (Sweden)

Loredana Judele

2008-01-01

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

High color rendering index white organic light-emitting diode using levofloxacin as blue emitter

Science.gov (United States)

Miao, Yan-Qin; Gao, Zhi-Xiang; Zhang, Ai-Qin; Li, Yuan-Hao; Wang, Hua; Jia, Hu-Sheng; Liu, Xu-Guang; Tsuboi, Taijuf

2015-05-01

Levofloxacin (LOFX), which is well-known as an antibiotic medicament, was shown to be useful as a 452-nm blue emitter for white organic light-emitting diodes (OLEDs). In this paper, the fabricated white OLED contains a 452-nm blue emitting layer (thickness of 30 nm) with 1 wt% LOFX doped in CBP (4,4’-bis(carbazol-9-yl)biphenyl) host and a 584-nm orange emitting layer (thickness of 10 nm) with 0.8 wt% DCJTB (4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran) doped in CBP, which are separated by a 20-nm-thick buffer layer of TPBi (2,2’,2”-(benzene-1,3,5-triyl)-tri(1-phenyl-1H-benzimidazole). A high color rendering index (CRI) of 84.5 and CIE chromaticity coordinates of (0.33, 0.32), which is close to ideal white emission CIE (0.333, 0.333), are obtained at a bias voltage of 14 V. Taking into account that LOFX is less expensive and the synthesis and purification technologies of LOFX are mature, these results indicate that blue fluorescence emitting LOFX is useful for applications to white OLEDs although the maximum current efficiency and luminance are not high. The present paper is expected to become a milestone to using medical drug materials for OLEDs. Project supported by the Program for New Century Excellent Talents in University of Ministry of Education of China (Grant No. NCET-13-0927), the International Science & Technology Cooperation Program of China (Grant No. 2012DFR50460), the National Natural Science Foundation of China (Grant Nos. 21101111 and 61274056), and the Shanxi Provincial Key Innovative Research Team in Science and Technology, China (Grant No. 2012041011).

Topographical coloured plasmonic coins

OpenAIRE

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

2016-01-01

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

Molluscan shell colour.

Science.gov (United States)

Williams, Suzanne T

2017-05-01

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

Colour for Behavioural Success

Science.gov (United States)

Reeves, Adam

2018-01-01

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

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

Science.gov (United States)

Rohde, Katja; Papiorek, Sarah; Lunau, Klaus

2013-03-01

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

Regional ocean-colour chlorophyll algorithms for the Red Sea

KAUST Repository

Brewin, Robert J.W.

2015-05-18

The Red Sea is a semi-enclosed tropical marine ecosystem that stretches from the Gulf of Suez and Gulf of Aqaba in the north, to the Gulf of Aden in the south. Despite its ecological and economic importance, its biological environment is relatively unexplored. Satellite ocean-colour estimates of chlorophyll concentration (an index of phytoplankton biomass) offer an observational platform to monitor the health of the Red Sea. However, little is known about the optical properties of the region. In this paper, we investigate the optical properties of the Red Sea in the context of satellite ocean-colour estimates of chlorophyll concentration. Making use of a new merged ocean-colour product, from the European Space Agency (ESA) Climate Change Initiative, and in situ data in the region, we test the performance of a series of ocean-colour chlorophyll algorithms. We find that standard algorithms systematically overestimate chlorophyll when compared with the in situ data. To investigate this bias we develop an ocean-colour model for the Red Sea, parameterised to data collected during the Tara Oceans expedition, that estimates remote-sensing reflectance as a function of chlorophyll concentration. We used the Red Sea model to tune the standard chlorophyll algorithms and the overestimation in chlorophyll originally observed was corrected. Results suggest that the overestimation was likely due to an excess of CDOM absorption per unit chlorophyll in the Red Sea when compared with average global conditions. However, we recognise that additional information is required to test the influence of other potential sources of the overestimation, such as aeolian dust, and we discuss uncertainties in the datasets used. We present a series of regional chlorophyll algorithms for the Red Sea, designed for a suite of ocean-colour sensors, that may be used for further testing.

The handicap of abnormal colour vision.

Science.gov (United States)

Cole, Barry L

2004-07-01

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

Specific deficit of colour-colour short-term memory binding in sporadic and familial Alzheimer's disease.

Science.gov (United States)

Parra, Mario A; Sala, Sergio Della; Abrahams, Sharon; Logie, Robert H; Méndez, Luis Guillermo; Lopera, Francisco

2011-06-01

Short-term memory binding of visual features which are processed across different dimensions (shape-colour) is impaired in sporadic Alzheimer's disease, familial Alzheimer's disease, and in asymptomatic carriers of familial Alzheimer's disease. This study investigated whether Alzheimer's disease also impacts on within-dimension binding processes. The study specifically explored whether visual short-term memory binding of features of the same type (colour-colour) is sensitive to Alzheimer's disease. We used a neuropsychological battery and a short-term memory binding task to assess patients with sporadic Alzheimer's disease (Experiment 1), familial Alzheimer's disease (Experiment 2) due to the mutation E280A of the Presenilin-1 gene and asymptomatic carriers of the mutation. The binding task assessed change detection within arrays of unicoloured objects (Colour Only) or bicoloured objects the colours of which had to be remembered separately (Unbound Colours) or together (Bound Colours). Performance on the Bound Colours condition (1) explained the largest proportion of variance between patients (sporadic and familial Alzheimer's disease), (2) combined more sensitivity and specificity for the disease than other more traditional neuropsychological tasks, (3) identified asymptomatic carriers of the mutation even when traditional neuropsychological measures and other measures of short-term memory did not and, (4) contrary to shape-colour binding, correlated with measures of hippocampal functions. Colour-colour binding and shape-colour binding both appear to be sensitive to AD even though they seem to rely on different brain mechanisms. Copyright © 2011 Elsevier Ltd. All rights reserved.

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

CERN Document Server

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

2004-01-01

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

Colour Reproduction on Tablet Devices

Directory of Open Access Journals (Sweden)

Vladimir Zorić

2014-07-01

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

Pulsed operation of high-pressure-sodium discharge lamps

International Nuclear Information System (INIS)

Guenther, K.; Kloss, H.G.; Lehmann, T.; Radtke, R.; Serick, F.

1990-01-01

Results of spectral and photometric measurements are presented for pulsed operated high-pressure-sodium lamps. Choosing for the colour temperature a value of 3000 K, the output spectrum was optimized with respect to colour rendition and lamp efficacy taking the pulse parameters, the sodium mole fraction, and the cold spot temperature as quantities to be varied. For the nominal rating of 70 W a maximum lamp efficacy of 70 lm/W and a colour rendering index of 40 can be obtained. Further improvements of the colour rendition require an enhanced sodium vapour pressure which can be achieved by operating the lamp at rised cold spot temperature. (orig.)

Pulsed operation of high-pressure-sodium discharge lamps

Energy Technology Data Exchange (ETDEWEB)

Guenther, K; Kloss, H G; Lehmann, T [Zentrum fuer Forschung und Technologie, Berlin (Germany, F.R.); Radtke, R; Serick, F [Zentralinstitut fuer Elektronenphysik, Berlin (Germany, F.R.)

1990-01-01

Results of spectral and photometric measurements are presented for pulsed operated high-pressure-sodium lamps. Choosing for the colour temperature a value of 3000 K, the output spectrum was optimized with respect to colour rendition and lamp efficacy taking the pulse parameters, the sodium mole fraction, and the cold spot temperature as quantities to be varied. For the nominal rating of 70 W a maximum lamp efficacy of 70 lm/W and a colour rendering index of 40 can be obtained. Further improvements of the colour rendition require an enhanced sodium vapour pressure which can be achieved by operating the lamp at rised cold spot temperature. (orig.).

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

Science.gov (United States)

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

2016-07-29

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

Distributed rendering for multiview parallax displays

Science.gov (United States)

Annen, T.; Matusik, W.; Pfister, H.; Seidel, H.-P.; Zwicker, M.

2006-02-01

3D display technology holds great promise for the future of television, virtual reality, entertainment, and visualization. Multiview parallax displays deliver stereoscopic views without glasses to arbitrary positions within the viewing zone. These systems must include a high-performance and scalable 3D rendering subsystem in order to generate multiple views at real-time frame rates. This paper describes a distributed rendering system for large-scale multiview parallax displays built with a network of PCs, commodity graphics accelerators, multiple projectors, and multiview screens. The main challenge is to render various perspective views of the scene and assign rendering tasks effectively. In this paper we investigate two different approaches: Optical multiplexing for lenticular screens and software multiplexing for parallax-barrier displays. We describe the construction of large-scale multi-projector 3D display systems using lenticular and parallax-barrier technology. We have developed different distributed rendering algorithms using the Chromium stream-processing framework and evaluate the trade-offs and performance bottlenecks. Our results show that Chromium is well suited for interactive rendering on multiview parallax displays.

CdSe white quantum dots-based white light-emitting diodes with high color rendering index

Science.gov (United States)

Su, Yu-Sheng; Hsiao, Chih-Chun; Chung, Shu-Ru

2016-09-01

A white light emission CdSe quantum dots (QDs) can be prepared by chemical route under 180°C. An organic oleic acid (OA) is used to react with CdO to form Cd-OA complex. Hexadecylamine (HDA) and 1-Octadecene (ODE) were used as co-surfactants. By controlling the reaction time, a white light emission CdSe QDs can be obtained after reacts for 3 to 10 min. The luminescence spectra compose two obvious emission peaks and entire visible light ranges from 400 to 650 nm. Based on TEM measurement result, spherical morphologies with particle size 2.39+/-0.27 nm can be obtained. The quantum yields (QYs) of white CdSe QD are between 20 and 60 %, which depends on reaction time. A white CdSe QDs were mixed with UV cured gel (OPAS-226) with weight ratios 50.0 wt. %, and putted the mixture into reflective cup (3020, 13 mil) as convert type. The white LEDs have controllable CIE coordinates and correlated color temperature (CCT). The luminous efficacy of the device is less than 3 lm/W, but the color rendering index (CRI) for all devices are higher than 80. Since the luminous efficacy of hybrid devices has a direct dependence on the external QY of the UV-LED as well, the luminous efficacy can be improved by well dispersion of CdSe QDs in UV gel matrix and using optimized LED chips. Therefore, in this study, we provide a new and simple method to prepare high QY of white CdSe QDs and its have a potential to applicate in solid-state lighting.

Neural correlates of imagined and synaesthetic colours.

Science.gov (United States)

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

2006-01-01

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

Sketchy Rendering for Information Visualization

NARCIS (Netherlands)

Wood, Jo; Isenberg, Petra; Isenberg, Tobias; Dykes, Jason; Boukhelifa, Nadia; Slingsby, Aidan

2012-01-01

We present and evaluate a framework for constructing sketchy style information visualizations that mimic data graphics drawn by hand. We provide an alternative renderer for the Processing graphics environment that redefines core drawing primitives including line, polygon and ellipse rendering. These

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

International Nuclear Information System (INIS)

Ramachandran, R.

1979-01-01

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

The role of colour flow Doppler in the investigation of the salivary gland tumour

International Nuclear Information System (INIS)

Bradley, M.J.; Durham, L.H.; Lancer, J.M.

2000-01-01

AIMS: Ultrasound is a highly effective imaging technique to determine salivary gland tumours and may help to identify many benign lesions. The aim of this study is to evaluate whether colour Doppler is able to further differentiate the malignant tumour. METHODS: Fifty-six patients with salivary gland lesions were prospectively assessed using ultrasound imaging with colour flow and power Doppler. The peak systolic velocity (PSV) was measured and the pulsatility index (PI) and resistive index (RI) calculations were performed on the pulsed wave traces. The real time ultrasound morphology and the Doppler information were correlated with the histology. RESULTS: In 18 of the 56 patients, no internal colour flow or power Doppler changes could be detected. The real time ultrasound morphology diagnosed benign disease with sensitivity of 89.7% with specificity of 57.1%. The positive predictive value was 93.6%. There were no significant differences in the colour Doppler appearances in terms of vessel type or intratumour distribution which could separate benign from malignant conditions. However, there was statistical discrimination for PI and RI values (P = 0.0006, P = 0.0002, respectively). No malignant lesions were seen when the PI was less than 1.8 and RI was less than 0.8. The PSV was elevated in several cases (> 50 cm per s) but there was no statistical correlation with malignancy. CONCLUSION: The risk of malignancy increases by a third when the colour Doppler demonstrates increased intratumour vascular resistance (RI > 0.8 and PI > 1.8), with positive predictive value of 97.3% (sensitivity 75.5%, specificity 85.7%). Bradley, M.J. (2000). Clinical Radiology 55, 759-762

COLOURFUL DIET FOR GOOD HEALTH

OpenAIRE

Vandana Gupta

2017-01-01

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

Disruptive colouration and perceptual grouping.

Science.gov (United States)

Espinosa, Irene; Cuthill, Innes C

2014-01-01

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

Disruptive colouration and perceptual grouping.

Directory of Open Access Journals (Sweden)

Irene Espinosa

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

Colour and Organization Studies

DEFF Research Database (Denmark)

Beyes, Timon

2017-01-01

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

Colour mixing based on daylight

International Nuclear Information System (INIS)

Meyn, Jan-Peter

2008-01-01

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

Colour Mixing Based on Daylight

Science.gov (United States)

Meyn, Jan-Peter

2008-01-01

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

Colour variations in the GRB 120327A afterglow

Science.gov (United States)

Melandri, A.; Covino, S.; Zaninoni, E.; Campana, S.; Bolmer, J.; Cobb, B. E.; Gorosabel, J.; Kim, J.-W.; Kuin, P.; Kuroda, D.; Malesani, D.; Mundell, C. G.; Nappo, F.; Sbarufatti, B.; Smith, R. J.; Steele, I. A.; Topinka, M.; Trotter, A. S.; Virgili, F. J.; Bernardini, M. G.; D'Avanzo, P.; D'Elia, V.; Fugazza, D.; Ghirlanda, G.; Gomboc, A.; Greiner, J.; Guidorzi, C.; Haislip, J. B.; Hanayama, H.; Hanlon, L.; Im, M.; Ivarsen, K. M.; Japelj, J.; Jelínek, M.; Kawai, N.; Kobayashi, S.; Kopac, D.; LaCluyzé, A. P.; Martin-Carrillo, A.; Murphy, D.; Reichart, D. E.; Salvaterra, R.; Salafia, O. S.; Tagliaferri, G.; Vergani, S. D.

2017-10-01

Aims: We present a comprehensive temporal and spectral analysis of the long Swift GRB 120327A afterglow data to investigate possible causes of the observed early-time colour variations. Methods: We collected data from various instruments and telescopes in X-ray, ultraviolet, optical, and near-infrared bands, and determined the shapes of the afterglow early-time light curves. We studied the overall temporal behaviour and the spectral energy distributions from early to late times. Results: The ultraviolet, optical, and near-infrared light curves can be modelled with a single power-law component between 200 and 2 × 104 s after the burst event. The X-ray light curve shows a canonical steep-shallow-steep behaviour that is typical of long gamma-ray bursts. At early times a colour variation is observed in the ultraviolet/optical bands, while at very late times a hint of a re-brightening is visible. The observed early-time colour change can be explained as a variation in the intrinsic optical spectral index, rather than an evolution of the optical extinction. Table 2 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/607/A29

Colour Perception in Ancient World

Science.gov (United States)

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

2017-11-01

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

The twelve colourful stones

International Nuclear Information System (INIS)

Doria, R.M.

1983-01-01

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

Supervised Object Class Colour Normalisation

DEFF Research Database (Denmark)

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

2013-01-01

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

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

OpenAIRE

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

2012-01-01

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

Colour-scent associations in a tropical orchid: three colours but two odours.

Science.gov (United States)

Delle-Vedove, Roxane; Juillet, Nicolas; Bessière, Jean-Marie; Grison, Claude; Barthes, Nicolas; Pailler, Thierry; Dormont, Laurent; Schatz, Bertrand

2011-06-01

Colour and scent are the major pollinator attractants to flowers, and their production may be linked by shared biosynthetic pathways. Species with polymorphic floral traits are particularly relevant to study the joint evolution of floral traits. We used in this study the tropical orchid Calanthe sylvatica from Réunion Island. Three distinct colour varieties are observed, presenting lilac, white or purple flowers, and named respectively C. sylvaticavar.lilacina (hereafter referred as var. lilacina), C. sylvaticavar. alba (var. alba) and C. sylvatica var. purpurea (var. purpurea). We investigated the composition of the floral scent produced by these colour varieties using the non-invasive SPME technique in the wild. Scent emissions are dominated by aromatic compounds. Nevertheless, the presence of the terpenoid (E)-4,8-dimethylnona-1,3,7-triène (DMNT) is diagnostic of var. purpurea, with the volatile organic compounds (VOC) produced by some individuals containing up to 60% of DMNT. We evidence specific colour-scent associations in C. sylvatica, with two distinct scent profiles in the three colour varieties: the lilacina-like profile containing no or very little DMNT (2%). Calanthe sylvatica var. alba individuals group with one or the other scent profile independently of their population of origin. We suggest that white-flowered individuals have evolved at least twice, once from var. lilacina and at least once from var. purpurea after the colonisation of la Réunion. White-flowered individuals may have been favoured by the particular pollinator fauna characterising the island. These flowering varieties of C. sylvatica, which display three colours but two scents profiles prove that colour is not always a good indicator of odour and that colour-scent associations may be complex, depending on pollination ecology of the populations concerned. Copyright © 2011 Elsevier Ltd. All rights reserved.

Fabrication of CuInS2/ZnS quantum dots-based white light-emitting diodes with high color rendering index

Science.gov (United States)

Hsiao, Chih-Chun; Su, Yu-Sheng; Chung, Shu-Ru

2017-09-01

Among solid-state lighting technology, phosphor-converted white light-emitting diodes (pc-WLEDs) are excellent candidates to replace incandescent lamps for their merit of high energy conservation, long lifetime, high luminous efficiency as well as polarized emissions. Semiconductor quantum dots (QDs) are emerging color tunable emissive light converters. They have shown significant promise as light emitters, as solar cells, and in biological imaging. It has been demonstrated that the pc-WLED devices integrated with red emissive ZnCdSe QDs show improved color rendering index of device. However, cadmium-based QDs have limited future owing to the well-known toxicity. Recently, non-cadmium luminescence materials, i.e. CuInS2-based QDs, are investigated as desirable low toxic alternatives. Particularly, CuInS2-based QDs exhibit very broad emissions spectra with full width at half maximum (FWHM) of 100-120 nm, large Stokes shifts of 200 300 meV and finely-tunable emissions. In order to adjust emission wavelengths and improved quantum yield (QY), CuInS2/ZnS (CIS/ZnS) core/shell structure was introduced. Therefore, CIS/ZnS QDs have been extensively investigated and be used as color converter in solid-state lighting. Synthesis and application of CuInS2/ZnS core/shell QDs are conducted using a hot injection route. CIS/ZnS core/shell QDs with molar ratio of Cu:In equal to 1:4 are prepared. For WLED fabrication, the CIS/ZnS QD is dispersed in toluene first, and then it is blended with transparent acrylic-based UV resin. Subsequently, the commercial green-emitting Lu3Al5O12: Ce3+ (LuAG) phosphors are mixed with QDs-resin mixture. After that, the QDs-phosphors-resin mixtures are put in the oven at 140 °C for 1 h to evaporate the toluene. Subsequently, the homogeneous QDs-phosphors-resin mixture is dropped on the top of a blue LED chip (InGaN). Then, the device is cured by 400 W UV light to form WLED. The emission wavelength of CIS/ZnS QD exhibits yellow region of 552 nm with QY

Real-time photorealistic stereoscopic rendering of fire

Science.gov (United States)

Rose, Benjamin M.; McAllister, David F.

2007-02-01

We propose a method for real-time photorealistic stereo rendering of the natural phenomenon of fire. Applications include the use of virtual reality in fire fighting, military training, and entertainment. Rendering fire in real-time presents a challenge because of the transparency and non-static fluid-like behavior of fire. It is well known that, in general, methods that are effective for monoscopic rendering are not necessarily easily extended to stereo rendering because monoscopic methods often do not provide the depth information necessary to produce the parallax required for binocular disparity in stereoscopic rendering. We investigate the existing techniques used for monoscopic rendering of fire and discuss their suitability for extension to real-time stereo rendering. Methods include the use of precomputed textures, dynamic generation of textures, and rendering models resulting from the approximation of solutions of fluid dynamics equations through the use of ray-tracing algorithms. We have found that in order to attain real-time frame rates, our method based on billboarding is effective. Slicing is used to simulate depth. Texture mapping or 2D images are mapped onto polygons and alpha blending is used to treat transparency. We can use video recordings or prerendered high-quality images of fire as textures to attain photorealistic stereo.

Ultrasonic colour Doppler imaging

DEFF Research Database (Denmark)

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

2011-01-01

Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue...... anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been...... vectors. This review briefly introduces the principles behind colour Doppler imaging and describes some clinical applications. It then describes the basic components of conventional colour Doppler systems and the methods used to derive velocity information from the ultrasound signal. Next, a number of new...

Colour schemes

DEFF Research Database (Denmark)

van Leeuwen, Theo

2013-01-01

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

Colour application on mammography image segmentation

Science.gov (United States)

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

2017-09-01

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

Colour isomers in quark material

International Nuclear Information System (INIS)

Hoegaasen, H.

1981-01-01

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

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

OpenAIRE

Nacher-Garcia, C.

2016-01-01

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

Graph Colouring Algorithms

DEFF Research Database (Denmark)

Husfeldt, Thore

2015-01-01

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

Phase shifting white light interferometry using colour CCD for optical metrology and bio-imaging applications

Science.gov (United States)

Upputuri, Paul Kumar; Pramanik, Manojit

2018-02-01

Phase shifting white light interferometry (PSWLI) has been widely used for optical metrology applications because of their precision, reliability, and versatility. White light interferometry using monochrome CCD makes the measurement process slow for metrology applications. WLI integrated with Red-Green-Blue (RGB) CCD camera is finding imaging applications in the fields optical metrology and bio-imaging. Wavelength dependent refractive index profiles of biological samples were computed from colour white light interferograms. In recent years, whole-filed refractive index profiles of red blood cells (RBCs), onion skin, fish cornea, etc. were measured from RGB interferograms. In this paper, we discuss the bio-imaging applications of colour CCD based white light interferometry. The approach makes the measurement faster, easier, cost-effective, and even dynamic by using single fringe analysis methods, for industrial applications.

Biomimetic superwettable materials with structural colours.

Science.gov (United States)

Wang, Zelinlan; Guo, Zhiguang

2017-12-05

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

Transform coding for hardware-accelerated volume rendering.

Science.gov (United States)

Fout, Nathaniel; Ma, Kwan-Liu

2007-01-01

Hardware-accelerated volume rendering using the GPU is now the standard approach for real-time volume rendering, although limited graphics memory can present a problem when rendering large volume data sets. Volumetric compression in which the decompression is coupled to rendering has been shown to be an effective solution to this problem; however, most existing techniques were developed in the context of software volume rendering, and all but the simplest approaches are prohibitive in a real-time hardware-accelerated volume rendering context. In this paper we present a novel block-based transform coding scheme designed specifically with real-time volume rendering in mind, such that the decompression is fast without sacrificing compression quality. This is made possible by consolidating the inverse transform with dequantization in such a way as to allow most of the reprojection to be precomputed. Furthermore, we take advantage of the freedom afforded by off-line compression in order to optimize the encoding as much as possible while hiding this complexity from the decoder. In this context we develop a new block classification scheme which allows us to preserve perceptually important features in the compression. The result of this work is an asymmetric transform coding scheme that allows very large volumes to be compressed and then decompressed in real-time while rendering on the GPU.

Chemistry of Colours

Indian Academy of Sciences (India)

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

Connected Colourings of Complete Graphs and Hypergraphs

OpenAIRE

Leader, Imre; Tan, Ta Sheng

2014-01-01

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

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

Science.gov (United States)

Nopparatjamjomras, Suchai; Chitaree, Ratchapak; Panijpan, Bhinyo

2009-01-01

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

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

Science.gov (United States)

Alexander, Neeske; Costandius, Elmarie

2017-01-01

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

Colourism: a global adolescent health concern.

Science.gov (United States)

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

2018-05-08

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

New NaSrPO4:Sm phosphor as orange-red emitting material

Indian Academy of Sciences (India)

Because NaSr1−xPO4:xSm3+ phosphor features a high colour-rendering index and chemical stability, it is potentially ... use blue LED chips (GaN or InGaN) with a yellow phosphor ... excitation by doping Sm3+ rare earth ions into a suitable.

Association between masticatory performance using a colour-changeable chewing gum and jaw movement.

Science.gov (United States)

Komagamine, Y; Kanazawa, M; Minakuchi, S; Uchida, T; Sasaki, Y

2011-08-01

The purpose of this study was to investigate the relationship between masticatory performance as determined using a colour-changeable chewing gum and mandibular movements. Subjects comprised 45 fully dentate adults (23 men, 22 women; mean age, 28·1 years). The gum was chewed for a specified number of chewing strokes (20, 40, 60, 80, 120 or 160 strokes) without any instructions as to chewing side. A colourimeter was used to measure L*, a* and b* values (CIE-L*a*b* colour system) for the chewed gum, then the difference between two colours in the CIE-L*a*b* colour space (ΔE) for each number of chewing strokes was calculated according to a formula. Index of masticatory performance (ΔE60) for each subject was obtained using ΔE for 20, 40, 60, 80, 120 and 160 strokes. Mandibular movements were recorded using an opto-electric system with six degrees of freedom. Twelve parameters of mandibular movements relating to amplitude, duration, velocity and angle were computed for each cycle, and mean values for 10 cycles (from cycle 11 to 20) were calculated separately. Stepwise multiple regression analysis identified maximum closing velocity and closing angle as predictors accounting for 18% of the variation in ΔE60. These results suggest that lower angles of approach to intercuspation and faster speed during closing duration are associated with colour changes in the colour-changeable chewing gum. © 2011 Blackwell Publishing Ltd.

Legal and Illegal Colours

DEFF Research Database (Denmark)

Larsen, John Christian

2008-01-01

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

The twelve colourful stones

International Nuclear Information System (INIS)

Doria, R.M.

1984-01-01

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

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

Science.gov (United States)

Tennant, David R; Klingenberg, Andreas

2016-06-01

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

On colour categorization of nature

NARCIS (Netherlands)

Yendrikhovskij, S.N.

1998-01-01

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

Discrepancies between descriptions and illustrations of colours in Congo red-stained amyloid, and explanation of discrepant colours.

Science.gov (United States)

Howie, Alexander J; Owen-Casey, Mared P

2010-09-01

Congo red-stained sections of amyloid may show various colours between crossed polariser and analyser. The aims were to see how papers described the colours, to compare descriptions with illustrations, and to explain the colours. In 160 papers on Congo red-stained amyloid, the commonest descriptions were 'green birefringence' and 'apple-green birefringence'. In 191 figures in 82 papers, 59 (31%) showed a pure green colour, 62 (32%) showed green and yellow or blue and yellow, 38 (20%) showed green and a colour other than yellow, mostly red, and 32 (17%) showed other colours. Discrepancies between colours reported and illustrated were noted in 127 figures (66%). Most (77) were between green alone in descriptions and green and another colour in figures, and 30 were between green in descriptions and no green at all in figures. Pure green can be seen in ideal conditions, but more often there are green and yellow, explained by strain birefringence, and green and red or other combinations, explained by uncrossing of polariser and analyser. These other anomalous colours are just as characteristic of amyloid as the pure green colour. Many papers on Congo red-stained amyloid appear to describe what is expected theoretically rather than what is actually seen.

Les couleurs de Peterhof The colours of Peterhof

Directory of Open Access Journals (Sweden)

Nina V. Vernova

2008-05-01

pierres de couleur naturelle furent choisies pour la décoration des façades : granit rouge foncé et calcaire gris, ainsi que des briques vernissées.Peterhof, the ‘Russian Versailles’, is the emperors’ summer residence founded by Peter the Great on the shores of the Gulf of Finland. From the first stage of its construction, in the early eighteenth century, a chromatic range was established, as the colours of an imperial residence had great importance. The first palace, Monplaisir (1714–22, located in the Lower Gardens, imitated Dutch houses, with brick masonry and white mortar joints, roofs painted the colour of terracotta tiles and facades featuring light-coloured details. These same colours also appear on the facades of the Hermitage and the Great Orangery. Built in the same period, the Grand Palace, Marly Palace and later the Catherine II wing were also in stuccoed brick painted in a yellow ochre colour. Later, despite numerous restorations, these buildings retained this hue and yellow ochre became the principal colour of the imperial buildings of Peterhof. Almost all the monuments built in the nineteenth century (the Cottage, Nicholas I Palace, the Farm, Alexander II Palace have rendering of this colour: yellow surfaces with white motifs. Several edifices did not follow this chromatic pattern, however, such as the monochrome grey neo-Gothic chapel built after a project by the German architect Karl-Friedrich Schinkel, and the pink-coloured Tsaritsyn pavilion reminiscent of Pompeian buildings. In the twentieth century other colours related to new building materials were introduced. All the technical innovations and new finishing materials were used in the last palace built at Peterhof, Nicolas II's Dacha. Natural-coloured stone was used for the cladding of the facades: dark red granite and grey limestone, and varnished bricks.

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

Influence of colour in working environment

OpenAIRE

Gabrovšek, Barbara

2014-01-01

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

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

OpenAIRE

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

2012-01-01

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

Colour correct: the interactive effects of food label nutrition colouring schemes and food category healthiness on health perceptions.

Science.gov (United States)

Nyilasy, Gergely; Lei, Jing; Nagpal, Anish; Tan, Joseph

2016-08-01

The purpose of the present study was to examine the effects of food label nutrition colouring schemes in interaction with food category healthiness on consumers' perceptions of food healthiness. Three streams of colour theory (colour attention, colour association and colour approach-avoidance) in interaction with heuristic processing theory provide consonant predictions and explanations for the underlying psychological processes. A 2 (food category healthiness: healthy v. unhealthy)×3 (food label nutrient colouring schemes: healthy=green, unhealthy=red (HGUR) v. healthy=red, unhealthy=green (HRUG) v. no colour (control)) between-subjects design was used. The research setting was a randomised-controlled experiment using varying formats of food packages and nutritional information colouring. Respondents (n 196) sourced from a national consumer panel, USA. The findings suggest that, for healthy foods, the nutritional colouring schemes reduced perceived healthiness, irrespective of which nutrients were coloured red or green (healthinesscontrol=4·86; healthinessHGUR=4·10; healthinessHRUG=3·70). In contrast, for unhealthy foods, there was no significant difference in perceptions of food healthiness when comparing different colouring schemes against the control. The results make an important qualification to the common belief that colour coding can enhance the correct interpretation of nutrition information and suggest that this incentive may not necessarily support healthier food choices in all situations.

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

Science.gov (United States)

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

2016-10-01

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

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

Science.gov (United States)

Berggren, Nick; Eimer, Martin

2016-11-01

To investigate the time course of attentional object selection processes in visual search tasks where targets are defined by a combination of features from the same dimension, we measured the N2pc component as an electrophysiological marker of attentional object selection during colour/colour conjunction search. In Experiment 1, participants searched for targets defined by a combination of two colours, while ignoring distractor objects that matched only one of these colours. Reliable N2pc components were triggered by targets and also by partially matching distractors, even when these distractors were accompanied by a target in the same display. The target N2pc was initially equal in size to the sum of the two N2pc components to the two different types of partially matching distractors and became superadditive from approximately 250 ms after search display onset. Experiment 2 demonstrated that the superadditivity of the target N2pc was not due to a selective disengagement of attention from task-irrelevant partially matching distractors. These results indicate that attention was initially deployed separately and in parallel to all target-matching colours, before attentional allocation processes became sensitive to the presence of both matching colours within the same object. They suggest that attention can be controlled simultaneously and independently by multiple features from the same dimension and that feature-guided attentional selection processes operate in parallel for different target-matching objects in the visual field.

Colorimetry and prime colours--a theorem.

Science.gov (United States)

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

2005-08-01

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

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

Science.gov (United States)

Stevens, Martin; Cuthill, Innes C

2005-08-30

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

Colour revolutions: criminal-legal aspect

Directory of Open Access Journals (Sweden)

Sergey Alekseyevich Gordeychik

2015-03-01

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

RenderGAN: Generating Realistic Labeled Data

Directory of Open Access Journals (Sweden)

Leon Sixt

2018-06-01

Full Text Available Deep Convolutional Neuronal Networks (DCNNs are showing remarkable performance on many computer vision tasks. Due to their large parameter space, they require many labeled samples when trained in a supervised setting. The costs of annotating data manually can render the use of DCNNs infeasible. We present a novel framework called RenderGAN that can generate large amounts of realistic, labeled images by combining a 3D model and the Generative Adversarial Network framework. In our approach, image augmentations (e.g., lighting, background, and detail are learned from unlabeled data such that the generated images are strikingly realistic while preserving the labels known from the 3D model. We apply the RenderGAN framework to generate images of barcode-like markers that are attached to honeybees. Training a DCNN on data generated by the RenderGAN yields considerably better performance than training it on various baselines.

Colour Day: an innovative project

CERN Multimedia

Staff Association

2016-01-01

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

Block colourings of 6-cycle systems

Directory of Open Access Journals (Sweden)

Paola Bonacini

2017-01-01

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

Colour dependence of zodiacal light models

Science.gov (United States)

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

1973-01-01

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

Skin Colour Analysis of Iraqi Kurdish Population

OpenAIRE

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

2015-01-01

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

Plasmonic colour laser printing

DEFF Research Database (Denmark)

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

2016-01-01

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

Synaesthetic colour in the brain: beyond colour areas. A functional magnetic resonance imaging study of synaesthetes and matched controls.

Science.gov (United States)

van Leeuwen, Tessa M; Petersson, Karl Magnus; Hagoort, Peter

2010-08-10

In synaesthesia, sensations in a particular modality cause additional experiences in a second, unstimulated modality (e.g., letters elicit colour). Understanding how synaesthesia is mediated in the brain can help to understand normal processes of perceptual awareness and multisensory integration. In several neuroimaging studies, enhanced brain activity for grapheme-colour synaesthesia has been found in ventral-occipital areas that are also involved in real colour processing. Our question was whether the neural correlates of synaesthetically induced colour and real colour experience are truly shared. First, in a free viewing functional magnetic resonance imaging (fMRI) experiment, we located main effects of synaesthesia in left superior parietal lobule and in colour related areas. In the left superior parietal lobe, individual differences between synaesthetes (projector-associator distinction) also influenced brain activity, confirming the importance of the left superior parietal lobe for synaesthesia. Next, we applied a repetition suppression paradigm in fMRI, in which a decrease in the BOLD (blood-oxygenated-level-dependent) response is generally observed for repeated stimuli. We hypothesized that synaesthetically induced colours would lead to a reduction in BOLD response for subsequently presented real colours, if the neural correlates were overlapping. We did find BOLD suppression effects induced by synaesthesia, but not within the colour areas. Because synaesthetically induced colours were not able to suppress BOLD effects for real colour, we conclude that the neural correlates of synaesthetic colour experience and real colour experience are not fully shared. We propose that synaesthetic colour experiences are mediated by higher-order visual pathways that lie beyond the scope of classical, ventral-occipital visual areas. Feedback from these areas, in which the left parietal cortex is likely to play an important role, may induce V4 activation and the percept of

Synaesthetic colour in the brain: beyond colour areas. A functional magnetic resonance imaging study of synaesthetes and matched controls.

Directory of Open Access Journals (Sweden)

Tessa M van Leeuwen

Full Text Available BACKGROUND: In synaesthesia, sensations in a particular modality cause additional experiences in a second, unstimulated modality (e.g., letters elicit colour. Understanding how synaesthesia is mediated in the brain can help to understand normal processes of perceptual awareness and multisensory integration. In several neuroimaging studies, enhanced brain activity for grapheme-colour synaesthesia has been found in ventral-occipital areas that are also involved in real colour processing. Our question was whether the neural correlates of synaesthetically induced colour and real colour experience are truly shared. METHODOLOGY/PRINCIPAL FINDINGS: First, in a free viewing functional magnetic resonance imaging (fMRI experiment, we located main effects of synaesthesia in left superior parietal lobule and in colour related areas. In the left superior parietal lobe, individual differences between synaesthetes (projector-associator distinction also influenced brain activity, confirming the importance of the left superior parietal lobe for synaesthesia. Next, we applied a repetition suppression paradigm in fMRI, in which a decrease in the BOLD (blood-oxygenated-level-dependent response is generally observed for repeated stimuli. We hypothesized that synaesthetically induced colours would lead to a reduction in BOLD response for subsequently presented real colours, if the neural correlates were overlapping. We did find BOLD suppression effects induced by synaesthesia, but not within the colour areas. CONCLUSIONS/SIGNIFICANCE: Because synaesthetically induced colours were not able to suppress BOLD effects for real colour, we conclude that the neural correlates of synaesthetic colour experience and real colour experience are not fully shared. We propose that synaesthetic colour experiences are mediated by higher-order visual pathways that lie beyond the scope of classical, ventral-occipital visual areas. Feedback from these areas, in which the left parietal

Colour preferences in nest-building zebra finches.

Science.gov (United States)

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

2013-10-01

Some bird species are selective in the materials they choose for nest building, preferring, for example, materials of one colour to others. However, in many cases the cause of these preferences is not clear. One of those species is the zebra finch, which exhibits strong preferences for particular colours of nest material. In an attempt to determine why these birds strongly prefer one colour of material over another, we compared the preferences of paired male zebra finches for nest material colour with their preferences for food of the same colours. We found that birds did indeed prefer particular colours of nest material (in most cases blue) but that they did not generally prefer food of one colour over the other colours. It appears, then, that a preference for one colour or another of nest material is specific to the nest-building context. This article is part of a Special Issue entitled: insert SI title. Copyright © 2013 Elsevier B.V. All rights reserved.

Bio deterioration behaviour in different colour roofing tiles (red and straw coloured)

International Nuclear Information System (INIS)

Guzulla, M. F.; Sanchez, E.; Gonzalez, J. M.; Orduna, M.

2014-01-01

Bio colonization of building materials is a critical problem for the durability of constructions. Industrial experience shows that straw coloured roofing tiles are more prone to colonization than red roofing tiles, even having similar characteristics. The aim of this work is to explain the difference of bio colonization between different colour roofing tiles. The chemical composition of the surface of straw coloured and red roofing tiles, the phase composition and the microstructure of the roofing tiles were determined by WD-XRF, XRD and SEM-EDX, respectively. The pore size distribution was carried out by Hg porosimetry. The solubility was studied by determining the soluble salts (Ca, Mg, Na, K, Cl and SO 4 2-) by ICP-OES and ionic chromatography. Roofing tile bio receptivity was evaluated by determining fluorescence intensity using a pulse amplitude- modulated (PAM) fluoro meter, and cyanobacteria Oscillator sp. The results obtained show higher concentration of calcium and sulphur in straw coloured roofing tiles surface, and higher solubility than red roofing tiles. Moreover, according to the results obtained in bio receptivity assays, straw coloured roofing tiles are more prone to colonization than red roofing tiles, so, there is a relationship between surface properties of roofing tiles and bio colonization, as it is observed in industrial products. (Author)

Colour differences in Caucasian and Oriental women's faces illuminated by white LED sources.

Science.gov (United States)

Melgosa, M; Richard, N; Fernández-Maloigne, C; Xiao, K; de Clermont-Gallerande, H; Jost-Boissard, S; Okajima, K

2018-04-10

-inconstancy indices: 17.1 and 11.5 CIELAB units, under reference illuminants D65 and A, respectively. Colour contrasts in women's faces under CIE standard illuminants for outdoor and indoor conditions may be strongly altered by using specific white LEDs. More research needs to be done on the impact of spectral power distribution of light sources with high colour rendering indices on visual colour appearance of cosmetic products. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The Metric of Colour Space

DEFF Research Database (Denmark)

Gravesen, Jens

2015-01-01

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

Colour pyrometer. Farbpyrometer

Energy Technology Data Exchange (ETDEWEB)

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

1980-12-11

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

Attentional capture by masked colour singletons.

Science.gov (United States)

Ansorge, Ulrich; Horstmann, Gernot; Worschech, Franziska

2010-09-15

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

Ultrasonic colour Doppler imaging

DEFF Research Database (Denmark)

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

2011-01-01

Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue...... anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been...

An unconventional colour superconductor

International Nuclear Information System (INIS)

Huang Mei

2007-01-01

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

What triggers colour change? Effects of background colour and temperature on the development of an alpine grasshopper.

Science.gov (United States)

Valverde, J Pablo; Schielzeth, Holger

2015-08-21

Colour polymorphisms are a fascinating facet of many natural populations of plants and animals, and the selective processes that maintain such variation are as relevant as the processes which promote their development. Orthoptera, the insect group that encompasses grasshoppers and bush crickets, includes a particularly large number of species that are colour polymorphic with a marked green-brown polymorphism being particularly widespread. Colour polymorphism has been associated with the need for crypsis and background matching and background-dependent homochromy has been described in a few species. However, when and how different environmental conditions influence variation in colour remains poorly understood. Here we test for effects of background colour and ambient temperature on the occurrence of colour morph switches (green to brown or brown to green) and developmental darkening in the alpine dwelling club-legged grasshopper Gomphocerus sibiricus. We monitored individually housed nymphae across three of their four developmental stages and into the first week after final ecdysis. Our data show an absence of colour morph switches in G. sibiricus, without a single switch observed in our sample. Furthermore, we test for an effect of temperature on colouration by manipulating radiant heat, a limiting factor in alpine habitats. Radiant heat had a significant effect on developmental darkening: individuals under low radiant heat tended to darken, while individuals under high radiant heat tended to lighten within nymphal stages. Young imagoes darkened under either condition. Our results indicate a plastic response to a variable temperature and indicate that melanin, a multipurpose pigment responsible for dark colouration and presumed to be costly, seems to be strategically allocated according to the current environmental conditions. Unlike other orthopterans, the species is apparently unable to switch colour morphs (green/brown) during development, suggesting that

Advanced Material Rendering in Blender

Czech Academy of Sciences Publication Activity Database

Hatka, Martin; Haindl, Michal

2012-01-01

Roč. 11, č. 2 (2012), s. 15-23 ISSN 1081-1451 R&D Projects: GA ČR GAP103/11/0335; GA ČR GA102/08/0593 Grant - others:CESNET(CZ) 387/2010; CESNET(CZ) 409/2011 Institutional support: RVO:67985556 Keywords : realistic material rendering * bidirectional texture function * Blender Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2013/RO/haindl-advanced material rendering in blender.pdf

Determinants of Colour Constancy and the Blue Bias

Science.gov (United States)

Gegenfurtner, Karl

2017-01-01

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

RenderSelect: a Cloud Broker Framework for Cloud Renderfarm Services

OpenAIRE

Ruby, Annette J; Aisha, Banu W; Subash, Chandran P

2016-01-01

In the 3D studios the animation scene files undergo a process called as rendering, where the 3D wire frame models are converted into 3D photorealistic images. As the rendering process is both a computationally intensive and a time consuming task, the cloud services based rendering in cloud render farms is gaining popularity among the animators. Though cloud render farms offer many benefits, the animators hesitate to move from their traditional offline rendering to cloud services based render ...

Interactions between colour-producing mechanisms and their effects on the integumentary colour palette.

Science.gov (United States)

Shawkey, Matthew D; D'Alba, Liliana

2017-07-05

Animal integumentary coloration plays a crucial role in visual communication and camouflage, and varies extensively among and within species and populations. To understand the pressures underlying such diversity, it is essential to elucidate the mechanisms by which animals have created novel integumentary coloration. Colours can be produced by selective absorption of light by skin pigments, through light scattering by structured or unstructured tissues, or by a combination of pigments and nanostructures. In this review, we highlight our current understanding of the interactions between pigments and structural integumentary tissues and molecules. We analyse the available evidence suggesting that these combined mechanisms are capable of creating colours and optical properties unachievable by either mechanism alone, thereby effectively expanding the animal colour palette. Moreover, structural and pigmentary colour mechanisms frequently interact in unexpected and overlooked ways, suggesting that classification of colours as being of any particular type may be difficult. Finally, we discuss how these mixtures are useful for investigating the largely unknown genetic, developmental and physical processes generating phenotypic diversity.This article is part of the themed issue 'Animal coloration: production, perception, function and application'. © 2017 The Author(s).

Conspicuous plumage colours are highly variable.

Science.gov (United States)

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

2017-01-25

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

Effect of Pigment Colouring on Physico-mechanical Properties of Hardened Cement Paste and Response of Colour Intensity to UV Radiation

International Nuclear Information System (INIS)

Khattab, M.M.; Abdel-Rahman, H.A.; Hassan, M.S.

2010-01-01

In this work, different ratios of pigment colour was mixed with cement paste during mixing. The pigment colour used was Phthalocyanine Green. The effect of pigment colouring on hardened cement paste (HCP) was characterized in terms of compressive strength, IR spectroscopic analysis and X-ray diffraction. In addition, the effect of UV radiation on the colour strength of hardened cement paste/pigment colour composites was investigated. The results indicated that the increase in the ratio of pigment colour was accompanied with a slight decrease in the values of compressive strength. The exposure of the coloured hardened cement paste to UV radiation for long lengths of time causes a little effect on the colour intensity

Long-term repetition priming and semantic interference in a lexical-semantic matching task: Tapping the links between object names and colours

Directory of Open Access Journals (Sweden)

Toby Jonathan Lloyd-Jones

2014-06-01

Full Text Available Using a novel paradigm to engage the long-term mappings between object names and the prototypical colours for objects, we investigated the retrieval of object-colour knowledge as indexed by long-term priming (the benefit in performance from a prior encounter with the same or a similar stimulus; a process about which little is known. We examined priming from object naming on a lexical-semantic matching task. In the matching task participants encountered a visually presented object name (Experiment 1 or object shape (Experiment 2 paired with either a colour patch or colour name. The pairings could either match whereby both were consistent with a familiar object (e.g., strawberry and red or mismatch (strawberry and blue. We used the matching task to probe knowledge about familiar objects and their colours pre-activated during object naming. In particular, we examined whether the retrieval of object-colour information was modality-specific and whether this influenced priming. Priming varied with the nature of the retrieval process: object-colour priming arose for object names but not object shapes and beneficial effects of priming were observed for colour patches whereas inhibitory priming arose with colour names. These findings have implications for understanding how object knowledge is retrieved from memory and modified by learning.

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

Directory of Open Access Journals (Sweden)

Cuthill Innes C

2005-08-01

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

IRIS COLOUR CLASSIFICATION SCALES--THEN AND NOW.

Science.gov (United States)

Grigore, Mariana; Avram, Alina

2015-01-01

Eye colour is one of the most obvious phenotypic traits of an individual. Since the first documented classification scale developed in 1843, there have been numerous attempts to classify the iris colour. In the past centuries, iris colour classification scales has had various colour categories and mostly relied on comparison of an individual's eye with painted glass eyes. Once photography techniques were refined, standard iris photographs replaced painted eyes, but this did not solve the problem of painted/ printed colour variability in time. Early clinical scales were easy to use, but lacked objectivity and were not standardised or statistically tested for reproducibility. The era of automated iris colour classification systems came with the technological development. Spectrophotometry, digital analysis of high-resolution iris images, hyper spectral analysis of the human real iris and the dedicated iris colour analysis software, all accomplished an objective, accurate iris colour classification, but are quite expensive and limited in use to research environment. Iris colour classification systems evolved continuously due to their use in a wide range of studies, especially in the fields of anthropology, epidemiology and genetics. Despite the wide range of the existing scales, up until present there has been no generally accepted iris colour classification scale.

Independent effects of colour on object identification and memory.

Science.gov (United States)

Lloyd-Jones, Toby J; Nakabayashi, Kazuyo

2009-02-01

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

Scalable, full-colour and controllable chromotropic plasmonic printing

Science.gov (United States)

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

2015-01-01

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

Grapheme-colour synaesthesia improves detection of embedded shapes, but without pre-attentive 'pop-out' of synaesthetic colour.

Science.gov (United States)

Ward, Jamie; Jonas, Clare; Dienes, Zoltan; Seth, Anil

2010-04-07

For people with synaesthesia letters and numbers may evoke experiences of colour. It has been previously demonstrated that these synaesthetes may be better at detecting a triangle made of 2s among a background of 5s if they perceive 5 and 2 as having different synaesthetic colours. However, other studies using this task (or tasks based on the same principle) have failed to replicate the effect or have suggested alternative explanations of the effect. In this study, we repeat the original study on a larger group of synaesthetes (n = 36) and include, for the first time, an assessment of their self-reported colour experiences. We show that synaesthetes do have a general advantage over controls on this task. However, many synaesthetes report no colour experiences at all during the task. Synaesthetes who do report colour typically experience around one third of the graphemes in the display as coloured. This is more consistent with theories of synaesthesia in which spatial attention needs to be deployed to graphemes for conscious colour experiences to emerge than the interpretation based on 'pop-out'.

Image Based Rendering and Virtual Reality

DEFF Research Database (Denmark)

Livatino, Salvatore

The Presentation concerns with an overview of Image Based Rendering approaches and their use on Virtual Reality, including Virtual Photography and Cinematography, and Mobile Robot Navigation.......The Presentation concerns with an overview of Image Based Rendering approaches and their use on Virtual Reality, including Virtual Photography and Cinematography, and Mobile Robot Navigation....

n-Colour even self-inverse compositions

Indian Academy of Sciences (India)

An -colour even self-inverse composition is defined as an -colour self-inverse composition with even parts. In this paper, we get generating functions, explicit formulas and recurrence formulas for -colour even self-inverse compositions. One new binomial identity is also obtained.

A Bayesian Model of the Memory Colour Effect.

Science.gov (United States)

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

2018-01-01

According to the memory colour effect, the colour of a colour-diagnostic object is not perceived independently of the object itself. Instead, it has been shown through an achromatic adjustment method that colour-diagnostic objects still appear slightly in their typical colour, even when they are colourimetrically grey. Bayesian models provide a promising approach to capture the effect of prior knowledge on colour perception and to link these effects to more general effects of cue integration. Here, we model memory colour effects using prior knowledge about typical colours as priors for the grey adjustments in a Bayesian model. This simple model does not involve any fitting of free parameters. The Bayesian model roughly captured the magnitude of the measured memory colour effect for photographs of objects. To some extent, the model predicted observed differences in memory colour effects across objects. The model could not account for the differences in memory colour effects across different levels of realism in the object images. The Bayesian model provides a particularly simple account of memory colour effects, capturing some of the multiple sources of variation of these effects.

Game Coloured Petri Nets

DEFF Research Database (Denmark)

Westergaard, Michael

2006-01-01

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

Thirteen-colour photometry of Be stars

Energy Technology Data Exchange (ETDEWEB)

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

1981-01-01

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

Thirteen-colour photometry of Be stars

International Nuclear Information System (INIS)

Alvarez, M.; Schuster, W.J.

1981-01-01

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

Colour vision and computer-generated images

International Nuclear Information System (INIS)

Ramek, Michael

2010-01-01

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

The colour of gender stereotyping.

Science.gov (United States)

Cunningham, Sheila J; Macrae, C Neil

2011-08-01

Despite legislative attempts to eliminate gender stereotyping from society, the propensity to evaluate people on the basis of their sex remains a pernicious social problem. Noting the critical interplay between cultural and cognitive factors in the establishment of stereotypical beliefs, the current investigation explored the extent to which culturally transmitted colour-gender associations (i.e., pink is for girls, blue is for boys) set the stage for the automatic activation and expression of gender stereotypes. Across six experiments, the results demonstrated that (1) consumer choice for children's goods is dominated by gender-stereotyped colours (Experiment 1); (2) colour-based stereotypic associations guide young children's behaviour (Experiment 2); (3) colour-gender associations automatically activate associated stereotypes in adulthood (Experiments 3-5); and (4) colour-based stereotypic associations bias impressions of male and female targets (Experiment 6). These findings indicate that, despite prohibitions against stereotyping, seemingly innocuous societal practices may continue to promote this mode of thought. ©2011 The British Psychological Society.

Colour chemistry

International Nuclear Information System (INIS)

Hong-Mo, C.

1978-10-01

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

Earth mortars and earth-lime renders

Directory of Open Access Journals (Sweden)

Maria Fernandes

2008-01-01

Full Text Available Earth surface coatings play a decorative architectural role, apart from their function as wall protection. In Portuguese vernacular architecture, earth mortars were usually applied on stone masonry, while earth renders and plasters were used on indoors surface coatings. Limestone exists only in certain areas of the country and consequently lime was not easily available everywhere, especially on granite and schist regions where stone masonry was a current building technique. In the central west coast of Portugal, the lime slaking procedure entailed slaking the quicklime mixed with earth (sandy soil, in a pit; the resulting mixture would then be combined in a mortar or plaster. This was also the procedure for manufactured adobes stabilized with lime. Adobe buildings with earth-lime renderings and plasters were also traditional in the same region, using lime putty and lime wash for final coat and decoration. Classic decoration on earth architecture from the 18th-19th century was in many countries a consequence of the François Cointeraux (1740-1830 manuals - Les Cahiers d'Architecture Rurale" (1793 - a French guide for earth architecture and building construction. This manual arrived to Portugal in the beginning of XIX century, but was never translated to Portuguese. References about decoration for earth houses were explained on this manual, as well as procedures about earth-lime renders and ornamentation of earth walls; in fact, these procedures are exactly the same as the ones used in adobe buildings in this Portuguese region. The specific purpose of the present paper is to show some cases of earth mortars, renders and plasters on stone buildings in Portugal and to explain the methods of producing earth-lime renders, and also to show some examples of rendering and coating with earth-lime in Portuguese adobe vernacular architecture.

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

Science.gov (United States)

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

2004-07-01

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

Colouring outside the lines

Science.gov (United States)

Commissariat, Tushna

2017-10-01

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

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

Science.gov (United States)

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

2013-01-01

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

Exposure of Polish children to Southampton food colours.

Science.gov (United States)

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

2017-01-01

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

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

Science.gov (United States)

Kuchenbecker, J

2017-07-01

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

Exploring the benefit of synaesthetic colours: testing for "pop-out" in individuals with grapheme-colour synaesthesia.

Science.gov (United States)

Rich, Anina N; Karstoft, Karen-Inge

2013-01-01

In grapheme-colour synaesthesia, letters, numbers, and words elicit involuntary colour experiences. Recently, there has been much emphasis on individual differences and possible subcategories of synaesthetes with different underlying mechanisms. In particular, there are claims that for some, synaesthesia occurs prior to attention and awareness of the inducing stimulus. We first characterized our sample using two versions of the "Synaesthetic Congruency Task" to distinguish "projector" and "associator" synaesthetes who may differ in the extent to which their synaesthesia depends on attention and awareness. We then used a novel modification of the "Embedded Figures Task" that included a set-size manipulation to look for evidence of preattentive "pop-out" from synaesthetic colours, at both a group and an individual level. We replicate an advantage for synaesthetes over nonsynaesthetic controls on the Embedded Figures Task in accuracy, but find no support for pop-out of synaesthetic colours. We conclude that grapheme-colour synaesthetes are fundamentally similar in their visual processing to the general population, with the source of their unusual conscious colour experiences occurring late in the cognitive hierarchy.

Brown colour in natural diamond and interaction between the brown related and other colour-inducing defects

International Nuclear Information System (INIS)

Fisher, D; Sibley, S J; Kelly, C J

2009-01-01

Absorption spectroscopy results on a range of type II diamonds are presented which enable the electronic states associated with them to be mapped out. High pressure, high temperature treatment of brown type IIa diamonds has enabled an activation energy for the removal of the brown colour of 8.0 ± 0.3 eV to be determined and this is consistent with expectations associated with the currently accepted vacancy cluster model for the defect. Theoretical calculations suggest that this defect will generate partially filled gap states about 1 eV above the valence band. Data on the photochromic behaviour of bands producing pink colour and their relation to brown colour are presented; these suggest that the pink bands are produced from two independent transitions with ground states close to each other just below the middle of the band gap. Compensation of neutral boron by charge transfer from states associated with brown colour is demonstrated via the correlated increase in neutral boron and decrease in brown colour on high pressure, high temperature treatment to remove the defects causing the brown colour.

Colours as Non-Verbal Signs on Packages

OpenAIRE

Kauppinen, Hannele

2005-01-01

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

Colour-grapheme synaesthesia affects binocular vision

Directory of Open Access Journals (Sweden)

Chris L.E. Paffen

2011-11-01

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

Laser-induced plasmonic colours on metals

Science.gov (United States)

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

2017-07-01

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

Colour Vision Impairment in Young Alcohol Consumers.

Directory of Open Access Journals (Sweden)

Alódia Brasil

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

Human colour in mate choice and competition.

Science.gov (United States)

Rowland, Hannah M; Burriss, Robert P

2017-07-05

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

Colour Perception on Facial Expression towards Emotion

Directory of Open Access Journals (Sweden)

Rubita Sudirman

2012-12-01

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

An RGB Approach to Prismatic Colours

Science.gov (United States)

Theilmann, Florian; Grusche, Sascha

2013-01-01

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

Colour development in the apple orchard

NARCIS (Netherlands)

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

2011-01-01

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

Tuneable light-emitting carbon-dot/polymer flexible films prepared through one-pot synthesis

Science.gov (United States)

Bhunia, Susanta Kumar; Nandi, Sukhendu; Shikler, Rafi; Jelinek, Raz

2016-02-01

Development of efficient, inexpensive, and environmentally-friendly light emitters, particularly devices that produce white light, have drawn intense interest due to diverse applications in the lighting industry, photonics, solar energy, and others. We present a simple strategy for the fabrication of flexible transparent films exhibiting tuneable light emission through one-pot synthesis of polymer matrixes with embedded carbon dots assembled in situ. Importantly, different luminescence colours were produced simply by preparing C-dot/polymer films using carbon precursors that yielded C-dots exhibiting distinct fluorescence emission profiles. Furthermore, mixtures of C-dot precursors could be also employed for fabricating films exhibiting different colours. In particular, we successfully produced films emitting white light with attractive properties (i.e. ``warm'' white light with a high colour rendering index) - a highly sought after goal in optical technologies.Development of efficient, inexpensive, and environmentally-friendly light emitters, particularly devices that produce white light, have drawn intense interest due to diverse applications in the lighting industry, photonics, solar energy, and others. We present a simple strategy for the fabrication of flexible transparent films exhibiting tuneable light emission through one-pot synthesis of polymer matrixes with embedded carbon dots assembled in situ. Importantly, different luminescence colours were produced simply by preparing C-dot/polymer films using carbon precursors that yielded C-dots exhibiting distinct fluorescence emission profiles. Furthermore, mixtures of C-dot precursors could be also employed for fabricating films exhibiting different colours. In particular, we successfully produced films emitting white light with attractive properties (i.e. ``warm'' white light with a high colour rendering index) - a highly sought after goal in optical technologies. Electronic supplementary information (ESI

Colour From the Perspective of Hadith: an Overview

Directory of Open Access Journals (Sweden)

Zainan Nazri Mohd Khairul Nizam

2015-01-01

Full Text Available Colour is mentioned a few times in the Prophetic Traditions, signifying its values and symbolic representation for the people. The Prophet PBUH highlighted the significance of certain colours by describing his preferred colours for his clothing and he also approved or discouraged the usage of certain colours. Among the colours that are specifically mentioned and found in the hadith are white, red, green, black and yellow. These colours give different connotations as they were used in the Prophet’s attires during battles and other occasions; and some bring about specific understanding, as stated by the Prophet PBUH. Interestingly, the use of certain colours as found in the hadith corresponds to that mentioned in the Qur’an. Thus, this paper will observe the discussion among Muhaddithin regarding to the topic of colours in terms of its definition, function, significance and impact on the human life. The variety of meaning and understanding of colours according to different perspectives and cultures will also be discussed. The implications of using specific colours psychologically and scientifically will also be exposed in order to discover the connection between colours in the Prophetic Traditions and in our contemporary life.

New particles and breaking the colour symmetry

International Nuclear Information System (INIS)

Krolikowski, W.

1975-01-01

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

Culture of colour in the city

Directory of Open Access Journals (Sweden)

Vasiljević-Tomić Dragana

2009-01-01

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

A Bayesian Model of the Memory Colour Effect

OpenAIRE

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

2018-01-01

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

A Bayesian model of the memory colour effect.

OpenAIRE

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

2018-01-01

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

Colour reconstruction of underwater images

OpenAIRE

Hoth, Julian; Kowalczyk, Wojciech

2017-01-01

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

The Attentional Capture of Colour in Visual Interface Design

DEFF Research Database (Denmark)

Andersen, Emil; Maier, Anja

2017-01-01

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

Hybrid rendering of the chest and virtual bronchoscopy [corrected].

Science.gov (United States)

Seemann, M D; Seemann, O; Luboldt, W; Gebicke, K; Prime, G; Claussen, C D

2000-10-30

Thin-section spiral computed tomography was used to acquire the volume data sets of the thorax. The tracheobronchial system and pathological changes of the chest were visualized using a color-coded surface rendering method. The structures of interest were then superimposed on a volume rendering of the other thoracic structures, thus producing a hybrid rendering. The hybrid rendering technique exploit the advantages of both rendering methods and enable virtual bronchoscopic examinations using different representation models. Virtual bronchoscopic examinations with a transparent color-coded shaded-surface model enables the simultaneous visualization of both the airways and the adjacent structures behind of the tracheobronchial wall and therefore, offers a practical alternative to fiberoptic bronchoscopy. Hybrid rendering and virtual endoscopy obviate the need for time consuming detailed analysis and presentation of axial source images.

Forbidden Structures for Planar Perfect Consecutively Colourable Graphs

Directory of Open Access Journals (Sweden)

Borowiecka-Olszewska Marta

2017-05-01

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

Colour constancy in natural images through colour naming and sensor sharpening

OpenAIRE

Vázquez Corral, Javier

2014-01-01

Advisors: Maria Vanrell, Graham Finlayson. Date and location of PhD thesis defense: 28 February 2011, Universitat Autònoma de Barcelona Colour is derived from three physical properties: incident light, object reflectance and sensor sensitivities. Incident light varies under natural conditions; hence, recovering scene illuminant is an important issue in computational colour. One way to deal with this problem under calibrated conditions is by following three steps, 1) building a narrow-band ...

Colour: code, mode, modality

DEFF Research Database (Denmark)

van Leeuwen, Theo

2014-01-01

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

Colour discrimination and categorisation in Williams syndrome.

Science.gov (United States)

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

2013-10-01

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

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

DEFF Research Database (Denmark)

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

2013-01-01

In this study, we present a new objective method for measuring the eye colour on a continuous scale that allows researchers to associate genetic markers with different shades of eye colour. With the use of the custom designed software Digital Iris Analysis Tool (DIAT), the iris was automatically...... and TYR rs1393350) on the eye colour. We evaluated the two published prediction models for eye colour (IrisPlex [1] and Snipper[2]) and compared the predictions with the PIE-scores. We found good concordance with the prediction from individuals typed as HERC2 rs12913832 G. However, both methods had......-score ranged from −1 to 1 (brown to blue). The software eliminated the need for user based interpretation and qualitative eye colour categories. In 94% (570) of 605 analyzed eye images, the iris region was successfully extracted and a PIE-score was calculated. A very high correlation between the PIE...

Balancing selection maintains cryptic colour morphs.

Science.gov (United States)

Wellenreuther, Maren

2017-11-01

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

Colour Vision Deficiency and Physics Teaching

Science.gov (United States)

Maule, Louise; Featonby, David

2016-01-01

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

The colour wheels of art, perception, science and physiology

Science.gov (United States)

Harkness, Nick

2006-06-01

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

Radiation-reversible material carriers of different colour

International Nuclear Information System (INIS)

Hofmann, G.

1976-01-01

A suggestion is made instead of using coloured material carriers - the cones and cylindrical tubes in spinning mills and weaving mills are given as example - to use such ones which change colour with irradiation and keep this colour until a new radiation impulse causes a new colour which differs well from the first one. (No data on material or type of radiation are given.) (UWI) [de

Colour-specific differences in attentional deployment for equiluminant pop-out colours: evidence from lateralised potentials.

Science.gov (United States)

Pomerleau, Vincent Jetté; Fortier-Gauthier, Ulysse; Corriveau, Isabelle; Dell'Acqua, Roberto; Jolicœur, Pierre

2014-03-01

We investigated how target colour affected behavioural and electrophysiological results in a visual search task. Perceptual and attentional mechanisms were tracked using the N2pc component of the event-related potential and other lateralised components. Four colours (red, green, blue, or yellow) were calibrated for each participant for luminance through heterochromatic flicker photometry and equated to the luminance of grey distracters. Each visual display contained 10 circles, 1 colored and 9 grey, each of which contained an oriented line segment. The task required deploying attention to the colored circle, which was either in the left or right visual hemifield. Three lateralised ERP components relative to the side of the lateral coloured circle were examined: a posterior contralateral positivity (Ppc) prior to N2pc, the N2pc, reflecting the deployment of visual spatial attention, and a temporal and contralateral positivity (Ptc) following N2pc. Red or blue stimuli, as compared to green or yellow, had an earlier N2pc. Both the Ppc and Ptc had higher amplitudes to red stimuli, suggesting particular selectivity for red. The results suggest that attention may be deployed to red and blue more quickly than to other colours and suggests special caution when designing ERP experiments involving stimuli in different colours, even when all colours are equiluminant. Copyright © 2013 Elsevier B.V. All rights reserved.

The theory and phenomenology of coloured quark models

CERN Document Server

Close, F E

1975-01-01

A general introduction to coloured quark models is given and their phenomenology is described with particular reference to the new particles. It is shown that there are essentially three types of colour models with colour excitation when the colour group is SU(3)- Han-Nambu, Greenberg and a model which has the same charges as that of Tati and which can be thought of as the Gell-Mann colour scheme with excitation of the colour degrees of freedom. Particular attention is paid to the four problems of colour models for psi phenomenology-the radiative decays, the G parity conservation, the lack of deep inelastic threshold phenomena and the apparent discovery of dileptons at SPEAR. (40 refs).

The theory and phenomenology of coloured quark models

International Nuclear Information System (INIS)

Close, F.E.

1975-01-01

A general introduction to coloured quark models is given and their phenomenology is described with particular reference to the new particles. It is shown that there are essentially three types of colour models with colour excitation when the colour group is SU(3) - Han-Nambu, Greenberg and a model which has the same charges as that of Tati and which can be thought of as the Gell-Mann colour scheme with excitation of the colour degrees of freedom. Particular attention is paid to the four problems of colour models for PSI phenomenology - the radiative decays, the G parity conservation, the lack of deep inelastic threshold phenomena and the apparent discovery of dileptons at SPEAR. (author)

Value of three-dimensional volume rendering images in the assessment of the centrality index for preoperative planning in patients with renal masses.

Science.gov (United States)

Sofia, C; Magno, C; Silipigni, S; Cantisani, V; Mucciardi, G; Sottile, F; Inferrera, A; Mazziotti, S; Ascenti, G

2017-01-01

To evaluate the precision of the centrality index (CI) measurement on three-dimensional (3D) volume rendering technique (VRT) images in patients with renal masses, compared to its standard measurement on axial images. Sixty-five patients with renal lesions underwent contrast-enhanced multidetector (MD) computed tomography (CT) for preoperative imaging. Two readers calculated the CI on two-dimensional axial images and on VRT images, measuring it in the plane that the tumour and centre of the kidney were lying in. Correlation and agreement of interobserver measurements and inter-method results were calculated using intraclass correlation (ICC) coefficients and the Bland-Altman method. Time saving was also calculated. The correlation coefficients were r=0.99 (ppresent study showed that VRT and axial images produce almost identical values of CI, with the advantages of greater ease of execution and a time saving of almost 50% for 3D VRT images. In addition, VRT provides an integrated perspective that can better assist surgeons in clinical decision making and in operative planning, suggesting this technique as a possible standard method for CI measurement. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Energy losses (gains) of massive coloured particles in stochastic colour medium

International Nuclear Information System (INIS)

Leonidov, A.; Rossijskaya Akademiya Nauk, Moscow

1995-01-01

The propagation of massive coloured particles in stochastic background chromoelectric field is studied using the semiclassical equations of motion. Depending on the nature of the stochastic background we obtain the formulae for the energy losses of heavy coloured projectile in nonperturbative hadronic medium and for the energy gains in the stochastic field present, e.g., in the turbulent plasma. The result appears to be significantly dependent on the form of the correlation function of stochastic external field. (orig.)

Comparison of radiation-induced colouration images, thermoluminescence, and after-glow colour images with aluminium impurity distribution in Japanese twin quartzes

International Nuclear Information System (INIS)

Hashimoto, Tetsuo; Ojima, Tetsu; Takahashi, Eishi; Konishi, Masayoshi; Kanemaki, Motoko.

1995-01-01

After-glow colour images (AGCI) and thermoluminescence (TL) from Japanese twin quartz slices have been successfully photographed by means of a commercially available negative colour film after the irradiation of X-rays. After-glow colour images (AGCI) offered very interesting distinction of colour images; the core part showed the colour changed from sky blue with zonal orange to blue with increasing absorbed doses, whereas the outer parts maintained orange AG colour giving clear boundary. On the other hand, the radiation-induced colour (blackish or brownish) center image (CCI) appeared at the core portion, while thermoluminescence colour images (TLCI) also consisted of two portions distinguishable into stripe and zonal bluish core and faint TL emission part in outer ones. These luminescence colour images, probably reflecting the formation mechanism of Japanese twin quartzes, are evidently correlated with the concentration patterns of aluminium impurity obtained by an EPMA (electron probe microanalyzer) method. From these radiation-induced images, it was assumed that the conditions of crystal formation should be greatly different between the core and the outer parts; the outer parts were secondarily started to grow from hydrothermal solution with higher Al-concentration after the initial formation of single core. (author)

Shell Colour Polymorphism in Bulla ampulla

DEFF Research Database (Denmark)

Cedhagen, Tomas

1999-01-01

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

Rendering the Topological Spines

Energy Technology Data Exchange (ETDEWEB)

Nieves-Rivera, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2015-05-05

Many tools to analyze and represent high dimensional data already exits yet most of them are not flexible, informative and intuitive enough to help the scientists make the corresponding analysis and predictions, understand the structure and complexity of scientific data, get a complete picture of it and explore a greater number of hypotheses. With this in mind, N-Dimensional Data Analysis and Visualization (ND²AV) is being developed to serve as an interactive visual analysis platform with the purpose of coupling together a number of these existing tools that range from statistics, machine learning, and data mining, with new techniques, in particular with new visualization approaches. My task is to create the rendering and implementation of a new concept called topological spines in order to extend ND²AV's scope. Other existing visualization tools create a representation preserving either the topological properties or the structural (geometric) ones because it is challenging to preserve them both simultaneously. Overcoming such challenge by creating a balance in between them, the topological spines are introduced as a new approach that aims to preserve them both. Its render using OpenGL and C++ and is currently being tested to further on be implemented on ND²AV. In this paper I will present what are the Topological Spines and how they are rendered.

Evaluating progressive-rendering algorithms in appearance design tasks.

Science.gov (United States)

Jiawei Ou; Karlik, Ondrej; Křivánek, Jaroslav; Pellacini, Fabio

2013-01-01

Progressive rendering is becoming a popular alternative to precomputational approaches to appearance design. However, progressive algorithms create images exhibiting visual artifacts at early stages. A user study investigated these artifacts' effects on user performance in appearance design tasks. Novice and expert subjects performed lighting and material editing tasks with four algorithms: random path tracing, quasirandom path tracing, progressive photon mapping, and virtual-point-light rendering. Both the novices and experts strongly preferred path tracing to progressive photon mapping and virtual-point-light rendering. None of the participants preferred random path tracing to quasirandom path tracing or vice versa; the same situation held between progressive photon mapping and virtual-point-light rendering. The user workflow didn’t differ significantly with the four algorithms. The Web Extras include a video showing how four progressive-rendering algorithms converged (at http://youtu.be/ck-Gevl1e9s), the source code used, and other supplementary materials.

Whorfian effects on colour memory are not reliable.

Science.gov (United States)

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

2015-01-01

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

Scalable, full-colour and controllable chromotropic plasmonic printing

OpenAIRE

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

2015-01-01

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

Colour vision experimental studies in teaching of optometry

Science.gov (United States)

Ozolinsh, Maris; Ikaunieks, Gatis; Fomins, Sergejs

2005-10-01

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

IRIS COLOUR CLASSIFICATION SCALES – THEN AND NOW

Science.gov (United States)

Grigore, Mariana; Avram, Alina

2015-01-01

Eye colour is one of the most obvious phenotypic traits of an individual. Since the first documented classification scale developed in 1843, there have been numerous attempts to classify the iris colour. In the past centuries, iris colour classification scales has had various colour categories and mostly relied on comparison of an individual’s eye with painted glass eyes. Once photography techniques were refined, standard iris photographs replaced painted eyes, but this did not solve the problem of painted/ printed colour variability in time. Early clinical scales were easy to use, but lacked objectivity and were not standardised or statistically tested for reproducibility. The era of automated iris colour classification systems came with the technological development. Spectrophotometry, digital analysis of high-resolution iris images, hyper spectral analysis of the human real iris and the dedicated iris colour analysis software, all accomplished an objective, accurate iris colour classification, but are quite expensive and limited in use to research environment. Iris colour classification systems evolved continuously due to their use in a wide range of studies, especially in the fields of anthropology, epidemiology and genetics. Despite the wide range of the existing scales, up until present there has been no generally accepted iris colour classification scale. PMID:27373112

Colour reconnection in WW events

CERN Document Server

D'Hondt, J

2003-01-01

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

Rockpool gobies change colour for camouflage.

Directory of Open Access Journals (Sweden)

Martin Stevens

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

Rockpool gobies change colour for camouflage.

Science.gov (United States)

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

2014-01-01

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

The role of colour in implicit and explicit memory performance.

Science.gov (United States)

Vernon, David; Lloyd-Jones, Toby J

2003-07-01

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

Salience of Primary and Secondary Colours in Infancy

Science.gov (United States)

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

2008-01-01

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

Pseudoisochromatic test plate colour representation dependence on printing technology

International Nuclear Information System (INIS)

Luse, K; Ozolinsh, M; Fomins, S

2012-01-01

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

Relationship between natural tooth shade and skin colour.

Science.gov (United States)

Nourbakhsh, M; Mousavinejad, N; Adli, A R; Harati, M

2013-06-01

The purpose of this study was to assess the correlation of skin colour and tooth shade. One hundred and twenty six individuals aging between 18 to 25 years participated in this study. Colour of the maxillary central incisors was examined by VITA easy shade. Tooth shades were assigned to four ordinal values. Nivea Beauty Protect Foundation shade sample was used as a guide to assess facial skin colour Shin colours were also assigned to four ordinal values. Spearman test revealed that there was a significant relationship between tooth shade and skin colour Total co-relation factor was 51.6% (p men (p <0 .01). The highest tooth shade prevalence belonged to the second group and the highest skin colour prevalence was also in the second skin colour group.

Looking at anything that is green when hearing "frog": how object surface colour and stored object colour knowledge influence language-mediated overt attention.

Science.gov (United States)

Huettig, Falk; Altmann, Gerry T M

2011-01-01

Three eye-tracking experiments investigated the influence of stored colour knowledge, perceived surface colour, and conceptual category of visual objects on language-mediated overt attention. Participants heard spoken target words whose concepts are associated with a diagnostic colour (e.g., "spinach"; spinach is typically green) while their eye movements were monitored to (a) objects associated with a diagnostic colour but presented in black and white (e.g., a black-and-white line drawing of a frog), (b) objects associated with a diagnostic colour but presented in an appropriate but atypical colour (e.g., a colour photograph of a yellow frog), and (c) objects not associated with a diagnostic colour but presented in the diagnostic colour of the target concept (e.g., a green blouse; blouses are not typically green). We observed that colour-mediated shifts in overt attention are primarily due to the perceived surface attributes of the visual objects rather than stored knowledge about the typical colour of the object. In addition our data reveal that conceptual category information is the primary determinant of overt attention if both conceptual category and surface colour competitors are copresent in the visual environment.

An Urban Colour Space in the Context of Culture

Directory of Open Access Journals (Sweden)

Olga Zheleznyak

2015-08-01

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

Several ways of breaking the colour symmetry

International Nuclear Information System (INIS)

Krolikowski, W.

1975-01-01

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

Dimensionality of the Consumer Perceived Value of Product Colour

OpenAIRE

Kiehelä, Hanna

2014-01-01

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

Colour Consideration for Waiting areas in hospitals

Science.gov (United States)

Zraati, Parisa

2012-08-01

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

Exploring the benefit of synaesthetic colours: Testing for “pop-out” in individuals with grapheme–colour synaesthesia

Science.gov (United States)

Rich, Anina N.; Karstoft, Karen-Inge

2013-01-01

In grapheme–colour synaesthesia, letters, numbers, and words elicit involuntary colour experiences. Recently, there has been much emphasis on individual differences and possible subcategories of synaesthetes with different underlying mechanisms. In particular, there are claims that for some, synaesthesia occurs prior to attention and awareness of the inducing stimulus. We first characterized our sample using two versions of the “Synaesthetic Congruency Task” to distinguish “projector” and “associator” synaesthetes who may differ in the extent to which their synaesthesia depends on attention and awareness. We then used a novel modification of the “Embedded Figures Task” that included a set-size manipulation to look for evidence of preattentive “pop-out” from synaesthetic colours, at both a group and an individual level. We replicate an advantage for synaesthetes over nonsynaesthetic controls on the Embedded Figures Task in accuracy, but find no support for pop-out of synaesthetic colours. We conclude that grapheme–colour synaesthetes are fundamentally similar in their visual processing to the general population, with the source of their unusual conscious colour experiences occurring late in the cognitive hierarchy. PMID:23768150

Colour and lighting in hospital design

Science.gov (United States)

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

2006-06-01

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

Tuning of Ag-SPR band position in refractive index controlled ...

Indian Academy of Sciences (India)

Wintec

incorporated films were prepared from sols derived from a mixture of silicon tetraethoxide (STE), ... Ag-plasmon tuning; inorganic–organic hybrids; refractive index tailoring; coloured coat- .... and one small drop of this dispersion was deposited.

Moisture movements in render on brick wall

DEFF Research Database (Denmark)

Hansen, Kurt Kielsgaard; Munch, Thomas Astrup; Thorsen, Peter Schjørmann

2003-01-01

A three-layer render on brick wall used for building facades is studied in the laboratory. The vertical render surface is held in contact with water for 24 hours simulating driving rain while it is measured with non-destructive X-ray equipment every hour in order to follow the moisture front...

ANALYSES OF ROCK SURFACE COLOUR CHANGES DUE TO WEATHERING

OpenAIRE

GOKAY, Mehmet Kemal

2018-01-01

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

ANALYSES OF ROCK SURFACE COLOUR CHANGES DUE TO WEATHERING

OpenAIRE

GÖKAY, Mehmet Kemal

2018-01-01

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

Plants and colour: Flowers and pollination

Science.gov (United States)

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

2011-03-01

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

Sketchy Rendering for Information Visualization.

Science.gov (United States)

Wood, J; Isenberg, P; Isenberg, T; Dykes, J; Boukhelifa, N; Slingsby, A

2012-12-01

We present and evaluate a framework for constructing sketchy style information visualizations that mimic data graphics drawn by hand. We provide an alternative renderer for the Processing graphics environment that redefines core drawing primitives including line, polygon and ellipse rendering. These primitives allow higher-level graphical features such as bar charts, line charts, treemaps and node-link diagrams to be drawn in a sketchy style with a specified degree of sketchiness. The framework is designed to be easily integrated into existing visualization implementations with minimal programming modification or design effort. We show examples of use for statistical graphics, conveying spatial imprecision and for enhancing aesthetic and narrative qualities of visualization. We evaluate user perception of sketchiness of areal features through a series of stimulus-response tests in order to assess users' ability to place sketchiness on a ratio scale, and to estimate area. Results suggest relative area judgment is compromised by sketchy rendering and that its influence is dependent on the shape being rendered. They show that degree of sketchiness may be judged on an ordinal scale but that its judgement varies strongly between individuals. We evaluate higher-level impacts of sketchiness through user testing of scenarios that encourage user engagement with data visualization and willingness to critique visualization design. Results suggest that where a visualization is clearly sketchy, engagement may be increased and that attitudes to participating in visualization annotation are more positive. The results of our work have implications for effective information visualization design that go beyond the traditional role of sketching as a tool for prototyping or its use for an indication of general uncertainty.

Producing colour pictures from SCAN

International Nuclear Information System (INIS)

Robichaud, K.

1982-01-01

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

Local and Global Illumination in the Volume Rendering Integral

Energy Technology Data Exchange (ETDEWEB)

Max, N; Chen, M

2005-10-21

This article is intended as an update of the major survey by Max [1] on optical models for direct volume rendering. It provides a brief overview of the subject scope covered by [1], and brings recent developments, such as new shadow algorithms and refraction rendering, into the perspective. In particular, we examine three fundamentals aspects of direct volume rendering, namely the volume rendering integral, local illumination models and global illumination models, in a wavelength-independent manner. We review the developments on spectral volume rendering, in which visible light are considered as a form of electromagnetic radiation, optical models are implemented in conjunction with representations of spectral power distribution. This survey can provide a basis for, and encourage, new efforts for developing and using complex illumination models to achieve better realism and perception through optical correctness.

Synchronization analysis of coloured delayed networks under ...

Indian Academy of Sciences (India)

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

Flare colours and luminosities

International Nuclear Information System (INIS)

Cristaldi, S.; Rodono, M.

1975-01-01

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

Fundamentals of colour awareness: a literature review

Directory of Open Access Journals (Sweden)

A. Rubin

2005-12-01

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

Long-range correlations from colour confinement

International Nuclear Information System (INIS)

Jurkiewicz, J.; Zenczykowski, P.

1979-01-01

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

String Formation Beyond Leading Colour

CERN Document Server

Christiansen, Jesper R.

2015-08-03

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

Counting with Colours? Effect of Colours on the Numerical Abilities of House Crows (Corvus splendens) and Common Myna (Acridotheres tristis)

OpenAIRE

Rahman, Nor Amira Abdul; Ali, Zalila; Zuharah, Wan Fatma; Fadzly, Nik

2016-01-01

We conducted several aviary experiments to investigate the influence of colours in quantity judgments of two species of birds; house crow (Corvus splendens) and common myna (Acridotheres tristis). Different quantity (in seven different food proportions) of mealworms were presented nonsequentially to all birds using artificially coloured red mealworms, for experiment 1, and using artificially coloured green mealworms, for experiment 2. Both red and green coloured mealworms have no significant ...

Application of Modern Colour Measurement Dervices in Coloration Industries

Institute of Scientific and Technical Information of China (English)

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

2002-01-01

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

Biological Components of Colour Preference in Infancy

Science.gov (United States)

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

2010-01-01

Adult colour preference has been summarized quantitatively in terms of weights on the two fundamental neural processes that underlie early colour encoding: the S-(L+M) ("blue-yellow") and L-M ("red-green") cone-opponent contrast channels ( Ling, Hurlbert & Robinson, 2006; Hurlbert & Ling, 2007). Here, we investigate whether colour preference in…

Colour Management as a Precondition of Quality

Directory of Open Access Journals (Sweden)

Stefan Brues

2004-12-01

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

Fundamentals of colour awareness: a literature review

OpenAIRE

A. Rubin

2005-01-01

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

Influence of drug colour on perceived drug effects and efficacy.

Science.gov (United States)

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

2018-02-01

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

Standardized rendering from IR surveillance motion imagery

Science.gov (United States)

Prokoski, F. J.

2014-06-01

Government agencies, including defense and law enforcement, increasingly make use of video from surveillance systems and camera phones owned by non-government entities.Making advanced and standardized motion imaging technology available to private and commercial users at cost-effective prices would benefit all parties. In particular, incorporating thermal infrared into commercial surveillance systems offers substantial benefits beyond night vision capability. Face rendering is a process to facilitate exploitation of thermal infrared surveillance imagery from the general area of a crime scene, to assist investigations with and without cooperating eyewitnesses. Face rendering automatically generates greyscale representations similar to police artist sketches for faces in surveillance imagery collected from proximate locations and times to a crime under investigation. Near-realtime generation of face renderings can provide law enforcement with an investigation tool to assess witness memory and credibility, and integrate reports from multiple eyewitnesses, Renderings can be quickly disseminated through social media to warn of a person who may pose an immediate threat, and to solicit the public's help in identifying possible suspects and witnesses. Renderings are pose-standardized so as to not divulge the presence and location of eyewitnesses and surveillance cameras. Incorporation of thermal infrared imaging into commercial surveillance systems will significantly improve system performance, and reduce manual review times, at an incremental cost that will continue to decrease. Benefits to criminal justice would include improved reliability of eyewitness testimony and improved accuracy of distinguishing among minority groups in eyewitness and surveillance identifications.

Kac's ring: The case of four colours

Indian Academy of Sciences (India)

2017-03-15

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

A 60-year ocean colour data set from the continuous plankton recorder

KAUST Repository

Raitsos, Dionysios E.

2012-11-20

The phytoplankton colour index (PCI) of the Continuous Plankton Recorder (CPR) survey is an in situ measure of ocean colour, which is considered a proxy of the phytoplankton biomass. PCI has been extensively used to describe the major spatiotemporal patterns of phytoplankton in the North Atlantic Ocean and North Sea since 1931. Regardless of its wide application, the lack of an adequate evaluation to test the PCI\\'s quantitative nature is an important limitation. To address this concern, a field trial over the main production season has been undertaken to assess the numerical values assigned by previous investigations for each category of the greenness of the PCI. CPRs were towed across the English Channel from Roscoff to Plymouth consecutively for each of 8 months producing 76 standard CPR samples, each representing 10 nautical miles of tow. The results of this experiment test and update the PCI methodology, and confirm the validity of this long-term in situ ocean colour data set. In addition, using a 60-year time series of the PCI of the western English Channel, a comparison is made between the previous and the current revised experimental calculations of PCI. © 2012 The Author 2012. Published by Oxford University Press. All rights reserved.

A 60-year ocean colour data set from the continuous plankton recorder

KAUST Repository

Raitsos, Dionysios E.; Walne, Anthony W.; Lavender, Sam; Licandro, Priscilla; Reid, Philip Chris; Edwards, Martin

2012-01-01

The phytoplankton colour index (PCI) of the Continuous Plankton Recorder (CPR) survey is an in situ measure of ocean colour, which is considered a proxy of the phytoplankton biomass. PCI has been extensively used to describe the major spatiotemporal patterns of phytoplankton in the North Atlantic Ocean and North Sea since 1931. Regardless of its wide application, the lack of an adequate evaluation to test the PCI's quantitative nature is an important limitation. To address this concern, a field trial over the main production season has been undertaken to assess the numerical values assigned by previous investigations for each category of the greenness of the PCI. CPRs were towed across the English Channel from Roscoff to Plymouth consecutively for each of 8 months producing 76 standard CPR samples, each representing 10 nautical miles of tow. The results of this experiment test and update the PCI methodology, and confirm the validity of this long-term in situ ocean colour data set. In addition, using a 60-year time series of the PCI of the western English Channel, a comparison is made between the previous and the current revised experimental calculations of PCI. © 2012 The Author 2012. Published by Oxford University Press. All rights reserved.

Remote volume rendering pipeline for mHealth applications

Science.gov (United States)

Gutenko, Ievgeniia; Petkov, Kaloian; Papadopoulos, Charilaos; Zhao, Xin; Park, Ji Hwan; Kaufman, Arie; Cha, Ronald

2014-03-01

We introduce a novel remote volume rendering pipeline for medical visualization targeted for mHealth (mobile health) applications. The necessity of such a pipeline stems from the large size of the medical imaging data produced by current CT and MRI scanners with respect to the complexity of the volumetric rendering algorithms. For example, the resolution of typical CT Angiography (CTA) data easily reaches 512^3 voxels and can exceed 6 gigabytes in size by spanning over the time domain while capturing a beating heart. This explosion in data size makes data transfers to mobile devices challenging, and even when the transfer problem is resolved the rendering performance of the device still remains a bottleneck. To deal with this issue, we propose a thin-client architecture, where the entirety of the data resides on a remote server where the image is rendered and then streamed to the client mobile device. We utilize the display and interaction capabilities of the mobile device, while performing interactive volume rendering on a server capable of handling large datasets. Specifically, upon user interaction the volume is rendered on the server and encoded into an H.264 video stream. H.264 is ubiquitously hardware accelerated, resulting in faster compression and lower power requirements. The choice of low-latency CPU- and GPU-based encoders is particularly important in enabling the interactive nature of our system. We demonstrate a prototype of our framework using various medical datasets on commodity tablet devices.

The evolutionary history of colour polymorphism in Ischnura damselflies.

Science.gov (United States)

Sánchez-Guillén, Rosa A; Cordero-Rivera, Adolfo; Rivas-Torres, Anais; Wellenreuther, Maren; Bybee, Seth; Hansson, Bengt; Velasquez-Vélez, María I; Realpe, Emilio; Chávez-Ríos, Jesús R; Villalobos, Fabricio; Dumont, Henri

2018-05-10

A major challenge in evolutionary biology consists of understanding how genetic and phenotypic variation is created and maintained. In the present study, we investigated the origin(s) and evolutionary patterns of the female-limited colour polymorphism in ischnuran damselflies. These consist of the presence of one to three colour morphs: one androchrome morph with a colouration that is similar to the male, and two gynochrome morphs (infuscans and aurantiaca) with female-specific colouration. We (i) documented the colour and mating system of 44 of the 75 taxa within the genus Ischnura, (ii) reconstructed the evolutionary history of colour and mating system to identify the ancestral state, (iii) evaluated the stability of the colour morph status over time, and (iv) tested for a correlation between colour and mating system. We found that the ances tral female colour of Ischnura was monomorphic and aurantiaca and that colour morph status changed over time; characterised by many gains and losses across the species tree. Our results further showed that colour polymorphism is significantly more frequent among polyandric species, whereas monandric species tend to be monomorphic. Research on some Ischnura species has shown that colour morphs have evolved to reduce male mating harassment, and our finding that the same phenotypic morphs have evolved multiple times (convergent evolution) suggests that several species in this genus might be experiencing similar selective pressures. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

A five-colour colour-coded mapping method for DCE-MRI analysis of head and neck tumours

International Nuclear Information System (INIS)

Yuan, J.; Chow, S.K.K.; Yeung, D.K.W.; King, A.D.

2012-01-01

Aim: To devise a method to convert the time–intensity curves (TICs) of head and neck dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) data into a pixel-by-pixel colour-coded map for identifying normal tissues and tumours. Materials and methods: Twenty-three patients with head and neck squamous cell carcinoma (HNSCC) underwent DCE-MRI. TIC patterns of primary tumours, metastatic nodes, and normal tissues were assessed and a program was devised to convert the patterns into a classified colour-coded map. The enhancement patterns of tumours and normal tissue structures were evaluated and categorized into nine grades (0–8) based on the predominance of coloured pixels on maps. Results: Five identified TIC patterns were converted into a colour-coded map consisting of red (maximum enhancement), brown (continuous slow rise-up), yellow (rapid wash-in and wash-out), green (rapid wash-in and plateau), and blue (rapid wash-in and rise-up). The colour-coded map distinguished all 21 primary tumours and 15 metastatic nodes from normal structures. Primary tumours and metastatic nodes were colour coded as predominantly yellow (grades 1–2) in 17/21 and 6/15, green (grades 3–5) in 3/21 and 5/15, and blue (grades 6–7) in 1/21 and 4/15, respectively. Vessels were coded red in 46/46 (grade 0) and muscles were coded brown in 23/23 (grade 8). Salivary glands, thyroid glands, and palatine tonsils were coded into predominantly yellow (grade 1) in 46/46 and 10/10 and 18/22, respectively. Conclusion: DCE-MRI derived five-colour-coded mapping provides an objective easy-to-interpret method to assess the dynamic enhancement pattern of head and neck cancers.

Phenomenology of colour exotic fermions

International Nuclear Information System (INIS)

Luest, D.

1986-01-01

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

Behavioural evidence for colour vision in an elasmobranch.

Science.gov (United States)

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

2011-12-15

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

The "Human Colour" Crayon: Investigating the Attitudes and Perceptions of Learners regarding Race and Skin Colour

Directory of Open Access Journals (Sweden)

Neeske Alexander

2017-07-01

Full Text Available Some coloured and black learners in South Africa use a light orange or pink crayon to represent themselves in art. Many learners name this colour “human colour” or “skin colour”. This is troublesome, because it could reflect exclusionary ways of representing race in images and language. This case study, conducted with two schools in the Western Cape, investigated Grade 3 learners’ attitudes and perceptions regarding race and skin colour through art processes and discussion. The aim was to promote critical engagement with race in Foundation Phase educational contexts. Suggestions include changing the language used to describe skin colour, just recognition and representation of races in educational resources and the promotion of critical citizenship education. This research indicates the need to create practical curriculum guidelines to discuss race issues in the South African classroom.

Special Section on Coloured Petri Nets

DEFF Research Database (Denmark)

1998-01-01

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

The colour of the solar corona and dust grains in it

International Nuclear Information System (INIS)

Ajmanov, A.K.; Nikolsky, G.M.

1980-01-01

The photometry of coronal negatives is carried out. The films were obtained at the March 7, 1970 and July 10, 1972 eclipses. A distribution of the coronal brightness in the red (635 mm), green (545 nm), and blue (455 nm) wavelength intervals up to distances of (6-7)Rsub(sun) is deduced (Figure 1). Colour indexes of the corona (the emission ratio red/blue-Csub(rb) and green/blue-Csub(gb)) have been obtained. We assume Csub(rb) = Csub(gb) = 1 in the inner corona ( = 1 μm. RED brightness is evaluated to be 4 x 10 -10 anti Bsub(sun). There is 1 grain of dust in the elementary volume with cross section of 1 cm 2 along the line of sight. The intensity of dust emission in wavelength interval 10 μm deduced by the authors is approximately 1 μ W cm -2 sm -1 . That is in agreement with Mankin et al. (1974) and Lena et al. (1974) observations. The whole dust mass of RED is -11 cm -3 . Determination of the colour of the solar corona have been made by a number of scientists (Tikhov, 1940, 1957; Allen, 1946; Blackwell, 1952; Michard, 1956; Sharonov, 1958; Nay et al. 1961). The corona colour was found to be somewhat redder than the Sun's. However this question is not finally settled to date. (orig.)

A Sort-Last Rendering System over an Optical Backplane

Directory of Open Access Journals (Sweden)

Yasuhiro Kirihata

2005-06-01

Full Text Available Sort-Last is a computer graphics technique for rendering extremely large data sets on clusters of computers. Sort-Last works by dividing the data set into even-sized chunks for parallel rendering and then composing the images to form the final result. Since sort-last rendering requires the movement of large amounts of image data among cluster nodes, the network interconnecting the nodes becomes a major bottleneck. In this paper, we describe a sort-last rendering system implemented on a cluster of computers whose nodes are connected by an all-optical switch. The rendering system introduces the notion of the Photonic Computing Engine, a computing system built dynamically by using the optical switch to create dedicated network connections among cluster nodes. The sort-last volume rendering algorithm was implemented on the Photonic Computing Engine, and its performance is evaluated. Prelimi- nary experiments show that performance is affected by the image composition time and average payload size. In an attempt to stabilize the performance of the system, we have designed a flow control mechanism that uses feedback messages to dynamically adjust the data flow rate within the computing engine.

Genetics and evolution of colour patterns in reptiles.

Science.gov (United States)

Olsson, Mats; Stuart-Fox, Devi; Ballen, Cissy

2013-01-01

The study of coloration in the polyphyletic reptilians has flourished in the last two decades, in particular with respect to the underlying genetics of colour traits, the function of colours in social interactions, and ongoing selection on these traits in the wild. The taxonomic bias, however, is profound: at this level of resolution almost all available information is for diurnal lizards. Therefore, we focus on case studies, for which there are as complete causal sequences of colour evolution as possible, from phenotypic expression of variation in colour, to ongoing selection in the wild. For work prior to 1992 and for a broader coverage of reptilian coloration we refer the readers to Cooper and Greenburg's (Biology of the Reptilia, 1992) review. There are seven major conclusions we would like to emphasise: (a) visual systems in diurnal lizards are broadly conserved but among the wider range of reptiles in general, there is functionally important variation in the number and type of photoreceptors, spectral tuning of photopigments and optical properties of the eye; (b) coloration in reptiles is a function of complex interactions between structural and pigmentary components, with implications for both proximate control and condition dependence of colour expression; (c) studies of colour-variable species have enabled estimates of heritability of colour and colour patterns, which often show a simple Mendelian pattern of inheritance; (d) colour-polymorphic lizard species sometimes, but not always, show striking differences in genetically encoded reproductive tactics and provide useful models for studying the evolution and maintenance of polymorphism; (e) both male and female colours are sometimes, but not always, a significant component of socio-sexual signalling, often based on multiple traits; (f) evidence for effects of hormones and condition on colour expression, and trade-offs with immunocompetence and parasite load, is variable; (g) lizards show fading of colours

GPU Pro 5 advanced rendering techniques

CERN Document Server

Engel, Wolfgang

2014-01-01

In GPU Pro5: Advanced Rendering Techniques, section editors Wolfgang Engel, Christopher Oat, Carsten Dachsbacher, Michal Valient, Wessam Bahnassi, and Marius Bjorge have once again assembled a high-quality collection of cutting-edge techniques for advanced graphics processing unit (GPU) programming. Divided into six sections, the book covers rendering, lighting, effects in image space, mobile devices, 3D engine design, and compute. It explores rasterization of liquids, ray tracing of art assets that would otherwise be used in a rasterized engine, physically based area lights, volumetric light

Fast algorithm for the rendering of three-dimensional surfaces

Science.gov (United States)

Pritt, Mark D.

1994-02-01

It is often desirable to draw a detailed and realistic representation of surface data on a computer graphics display. One such representation is a 3D shaded surface. Conventional techniques for rendering shaded surfaces are slow, however, and require substantial computational power. Furthermore, many techniques suffer from aliasing effects, which appear as jagged lines and edges. This paper describes an algorithm for the fast rendering of shaded surfaces without aliasing effects. It is much faster than conventional ray tracing and polygon-based rendering techniques and is suitable for interactive use. On an IBM RISC System/6000TM workstation it renders a 1000 X 1000 surface in about 7 seconds.

Innovative Lime Pozzolana Renders for Reconstruction of Historical Buildings

International Nuclear Information System (INIS)

Vejmelkova, E.; Maca, P.; Konvalinka, P.; Cerny, R.

2011-01-01

Bulk density, matrix density, open porosity, compressive strength, bending strength, water sorptivity, moisture diffusivity, water vapor diffusion coefficient, thermal conductivity, specific heat capacity and thermal diffusivity of two innovative renovation renders on limepozzolana basis are analyzed. The obtained results are compared with reference lime plaster and two commercial renovation renders, and conclusions on the applicability of the particular renders in practical reconstruction works are drawn. (author)

Complementary Colours for a Physicist

Science.gov (United States)

Babic, Vitomir; Cepic, Mojca

2009-01-01

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

Improper colouring of (random) unit disk graphs

NARCIS (Netherlands)

Kang, R.J.; Müller, T.; Sereni, J.S.

2008-01-01

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

Mixed colour states in QCD confining vacuum

OpenAIRE

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

2005-01-01

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

Trials to improve the colour of colour fixed cottonseed oil using sodium oleate and sodium stearate in the absence and presence of azeotropic extract of cottonseed meal

Directory of Open Access Journals (Sweden)

Yousef, Elham A. A.

1998-04-01

Full Text Available The effectiveness of two additives, namely, laboratory prepared sodium oleate and sodium stearate to improve the colour of colour fixed cottonseed oil was studied. Also the presence of the azeotropic extract of cottonseed meal together with 5% Na oleate or 10%Na stearate was taken In consideration. Improvement in the colour index of most treated refined and bleached oil samples is observed. This is confirmed with the reduction of gossypol contents of the refined and bleached treated oil samples compared with the untreated oil sample.

Se estudió la eficacia de dos aditivos, a saber, oleato sódico y estearato sódico preparados en laboratorio para mejorar el color del aceite de semilla de algodón con color fijado. También se tuvo en consideración la presencia de extracto azeotrópico de harina de semilla de algodón junto con oleato sódico al 50% o estearato sódico al 10%. Se observó la mejora en el índice de color de la mayoría de las muestras de aceite decolorado y refinado tratado. Esto está confirmado con la reducción de los contenidos en gosipol de las muestras de aceites refinados y decolorados tratados comparado con la muestra de aceite no tratado.

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

Science.gov (United States)

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

2018-01-01

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

The effect of gender on eye colour variation in European populations and an evaluation of the IrisPlex prediction model

DEFF Research Database (Denmark)

Pietroni, Carlotta; Andersen, Jeppe D.; Johansen, Peter

2014-01-01

In two recent studies of Spanish individuals [1,2], gender was suggested as a factor that contributes to human eye colour variation. However, gender did not improve the predictive accuracy on blue, intermediate and brown eye colours when gender was included in the IrisPlex model [3]. In this stud...... and their corresponding predictive values using the IrisPlex prediction model [4]. The results suggested that maximum three (rs12913832, rs1800407, rs16891982) of the six IrisPlex SNPs are useful in practical forensic genetic casework.......In two recent studies of Spanish individuals [1,2], gender was suggested as a factor that contributes to human eye colour variation. However, gender did not improve the predictive accuracy on blue, intermediate and brown eye colours when gender was included in the IrisPlex model [3]. In this study......12203592). A quantitative eye colour score (Pixel Index of the Eye: PIE-score) was calculated based on digital eye images using the custom made DIAT software. The results were compared with those of Danish and Swedish population samples. As expected, we found HERC2 rs12913832 as the main predictor of human...

Colour print workflow and methods for multilayering of colour and decorative inks using UV inkjet for fine art printing

Science.gov (United States)

Parraman, Carinna

2012-01-01

In order to increase density of colour and improve ink coverage when printing onto a range of non standard substrates, this paper will present research into multi-layering of colour and the appearance of colour at 'n' levels of ink coverage. Returning to our original investigation of artist's requirements when making inkjet prints, these observations are based on empirical approaches that address the need to present physical data that is more useful and meaningful to the designer. The study has used multi-pass printed colour charts to measure colour and to provide users with an understanding at a soft-preview level to demonstrate the appearance of printed colour on different substrates. Test results relating to the appearance of print on different surfaces, and a series of case studies will be presented using recent research into the capabilities of UV printing technology, which has widened the opportunities for the designer to print onto non-standard materials. It will also present a study into layering of greys and gloss in order to improve the appearance of printed images onto metal.

Limits of colour vision in dim light.

Science.gov (United States)

Kelber, Almut; Lind, Olle

2010-09-01

Humans and most vertebrates have duplex retinae with multiple cone types for colour vision in bright light, and one single rod type for achromatic vision in dim light. Instead of comparing signals from multiple spectral types of photoreceptors, such species use one highly sensitive receptor type thus improving the signal-to-noise ratio at night. However, the nocturnal hawkmoth Deilephila elpenor, the nocturnal bee Xylocopa tranquebarica and the nocturnal gecko Tarentola chazaliae can discriminate colours at extremely dim light intensities. To be able to do so, they sacrifice spatial and temporal resolution in favour of colour vision. We review what is known about colour vision in dim light, and compare colour vision thresholds with the optical sensitivity of the photoreceptors in selected animal species with lens and compound eyes. © 2010 The Authors, Ophthalmic and Physiological Optics © 2010 The College of Optometrists.

Music-colour synaesthesia: Concept, context and qualia.

Science.gov (United States)

Curwen, Caroline

2018-05-01

This review provides a commentary on coloured-hearing arising on hearing music: music-colour synaesthesia. Although traditionally explained by the hyperconnectivity theory (Ramachandran & Hubbard, 2001a) and the disinhibited feedback theory (Grossenbacher & Lovelace, 2001) as a purely perceptual phenomenon, the review of eight coloured-hearing neuroimaging studies shows that it may not be assumed that these explanations are directly translatable to music-colour synaesthesia. The concept of 'ideaesthesia' (Nikolić, 2009) and the role of conceptual and semantic inducers challenge the likelihood of a single mechanism underlying the cause of synaesthesia and argue for a move away from a purely sensory to sensory explanation. Finally, music-colour synaesthesia forms a challenge for established philosophical theories and the position of synaesthesia is considered within the larger context of musical qualia. Copyright © 2018 Elsevier Inc. All rights reserved.

Please pass me the skin coloured crayon!

DEFF Research Database (Denmark)

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

2015-01-01

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

A familial factor in the development of colour agnosia.

Science.gov (United States)

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

2007-04-09

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

Does ultrasound contrast agent improve the diagnostic value of colour and power Doppler sonography in superficial lymph node enlargement?

International Nuclear Information System (INIS)

Schulte-Altedorneburg, Gernot; Demharter, Johannes; Linne, Renate; Droste, Dirk W.; Bohndorf, Klaus; Buecklein, Wolfgang

2003-01-01

Objective: to analyse whether ultrasound contrast agent (UCA) improves the diagnostic accuracy to differentiate between benign and malignant superficial lymph node enlargement by using colour-coded duplex sonography (CCDS) and power Doppler (PD). Methods: 32 patients with suspected malignant superficial lymph node enlargement prospectively underwent standardised ultrasound examinations using B-mode sonography and native and contrast-enhanced CCDS and PD immediately before biopsy. Solbiati-Index (longitudinal-transverse diameter ratio) and intranodal flow patterns by using different vascularisation types were assessed. Histological and sonographical findings were correlated. Results: 27 malignant and 5 benign lymph nodes were found. Solbiati-Index was lower in malignant lymph nodes than in benign nodes (mean 1.5 vs. 2.4, P<0.045). More intranodal flow patterns could be detected after UCA (53 vs. 43) but the number of correctly identified malignant nodes decreased after UCA (26 vs. 24) and the number of correctly identified benign nodes remained constant compared with native CCDS and PD. In 31% of the colour-mode studies, PD was considered to visualise more clearly intranodal vascular flow patterns than CCDS. Conclusion: despite depicting more intranodal vascular patterns, the use of an ultrasound contrast agent seems not to improve the diagnostic value of CCDS and PD compared with native colour-mode studies in superficial lymph node enlargement

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.

Colour contribution to children's wayfinding in school environments

Science.gov (United States)

Helvacıoǧlu, Elif; Olguntürk, Nilgün

2011-03-01

The purpose of this study was to explore the contribution of colour to children's wayfinding ability in school environments and to examine the differences between colours in terms of their remembrance and usability in route learning process. The experiment was conducted with three different sample groups for each of three experiment sets differentiated by their colour arrangement. The participants totalled 100 primary school children aged seven and eight years old. The study was conducted in four phases. In the first phase, the participants were tested for familiarity with the experiment site and also for colour vision deficiencies by using Ishihara's tests for colour-blindness. In the second phase, they were escorted on the experiment route by the tester one by one, from one starting point to one end point and were asked to lead the tester to the end point by the same route. In the third phase, they were asked to describe verbally the route. In the final phase, they were asked to remember the specific colours at their correct locations. It was found that colour has a significant effect on children's wayfinding performances in school environments. However, there were no differences between different colours in terms of their remembrances in route finding tasks. In addition, the correct identifications of specific colours and landmarks were dependent on their specific locations. Contrary to the literature, gender differences were not found to be significant in the accuracy of route learning performances.

Colour relations for Mira and Semiregular (SR) type stars

International Nuclear Information System (INIS)

Guney, Yavuz; Yesilyaprak, Cahit

2016-01-01

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

Facial Identification in Observers with Colour-Grapheme Synaesthesia

DEFF Research Database (Denmark)

Sørensen, Thomas Alrik

2013-01-01

Synaesthesia between colours and graphemes is often reported as one of the most common forms cross modal perception [Colizolo et al, 2012, PLoS ONE, 7(6), e39799]. In this particular synesthetic sub-type the perception of a letterform is followed by an additional experience of a colour quality....... Both colour [McKeefry and Zeki, 1997, Brain, 120(12), 2229–2242] and visual word forms [McCandliss et al, 2003, Trends in Cognitive Sciences, 7(7), 293–299] have previously been linked to the fusiform gyrus. By being neighbouring functions speculations of cross wiring between the areas have been...... of Neuroscience, 17(11), 4302–4311], increased colour-word form representations in observers with colour-grapheme synaesthesia may affect facial identification in people with synaesthesia. This study investigates the ability to process facial features for identification in observers with colour...

Floral colour versus phylogeny in structuring subalpine flowering communities.

Science.gov (United States)

McEwen, Jamie R; Vamosi, Jana C

2010-10-07

The relative number of seeds produced by competing species can influence the community structure; yet, traits that influence seed production, such as pollinator attraction and floral colour, have received little attention in community ecology. Here, we analyse floral colour using reflectance spectra that include near-UV and examined the phylogenetic signal of floral colour. We found that coflowering species within communities tended to be more divergent in floral colour than expected by chance. However, coflowering species were not phylogenetically dispersed, in part due to our finding that floral colour is a labile trait with a weak phylogenetic signal. Furthermore, while we found that locally rare and common species exhibited equivalent floral colour distances from their coflowering neighbours, frequent species (those found in more communities) exhibited higher colour distances from their coflowering neighbours. Our findings support recent studies, which have found that (i) plant lineages exhibit frequent floral colour transitions; and (ii) traits that influence local population dynamics contribute to community structure.

Media Presentation Synchronisation for Non-monolithic Rendering Architectures

NARCIS (Netherlands)

I. Vaishnavi (Ishan); D.C.A. Bulterman (Dick); P.S. Cesar Garcia (Pablo Santiago); B. Gao (Bo)

2007-01-01

htmlabstractNon-monolithic renderers are physically distributed media playback engines. Non-monolithic renderers may use a number of different underlying network connection types to transmit media items belonging to a presentation. There is therefore a need for a media based and inter-network- type

The cause of 50 million-year-old colour.

OpenAIRE

Parker, Andrew R; McKenzie, David R

2003-01-01

Multilayer reflectors cause structural, 'metallic' colours in a diversity of animals today, yet are unknown in extinct species. We identify a multilayer reflector, causing structural colour, in a 50-million-year-old beetle from Messel, Germany. It is proposed that the original material of this reflector has been preserved, although this is not a precondition for determining original colours from ancient multilayer reflectors. Therefore, the potential exists to reveal the original colours of o...

Geographical variation in colour of female threespine stickleback (Gasterosteus aculeatus

Directory of Open Access Journals (Sweden)

Connor M. French

2018-05-01

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

Extreme simplification and rendering of point sets using algebraic multigrid

NARCIS (Netherlands)

Reniers, D.; Telea, A.C.

2009-01-01

We present a novel approach for extreme simplification of point set models, in the context of real-time rendering. Point sets are often rendered using simple point primitives, such as oriented discs. However, this requires using many primitives to render even moderately simple shapes. Often, one

Volume rendering in treatment planning for moving targets

Energy Technology Data Exchange (ETDEWEB)

Gemmel, Alexander [GSI-Biophysics, Darmstadt (Germany); Massachusetts General Hospital, Boston (United States); Wolfgang, John A.; Chen, George T.Y. [Massachusetts General Hospital, Boston (United States)

2009-07-01

Advances in computer technologies have facilitated the development of tools for 3-dimensional visualization of CT-data sets with volume rendering. The company Fovia has introduced a high definition volume rendering engine (HDVR trademark by Fovia Inc., Palo Alto, USA) that is capable of representing large CT data sets with high user interactivity even on standard PCs. Fovia provides a software development kit (SDK) that offers control of all the features of the rendering engine. We extended the SDK by functionalities specific to the task of treatment planning for moving tumors. This included navigation of the patient's anatomy in beam's eye view, fast point-and-click measurement of lung tumor trajectories as well as estimation of range perturbations due to motion by calculation of (differential) water equivalent path lengths for protons and carbon ions on 4D-CT data sets. We present patient examples to demonstrate the advantages and disadvantages of volume rendered images as compared to standard 2-dimensional axial plane images. Furthermore, we show an example of a range perturbation analysis. We conclude that volume rendering is a powerful technique for the representation and analysis of large time resolved data sets in treatment planning.

Asymmetric chiral colour

International Nuclear Information System (INIS)

Cuypers, F.

1990-01-01

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

Colour, vision and ergonomics.

Science.gov (United States)

Pinheiro, Cristina; da Silva, Fernando Moreira

2012-01-01

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

Fast DRR splat rendering using common consumer graphics hardware

International Nuclear Information System (INIS)

Spoerk, Jakob; Bergmann, Helmar; Wanschitz, Felix; Dong, Shuo; Birkfellner, Wolfgang

2007-01-01

Digitally rendered radiographs (DRR) are a vital part of various medical image processing applications such as 2D/3D registration for patient pose determination in image-guided radiotherapy procedures. This paper presents a technique to accelerate DRR creation by using conventional graphics hardware for the rendering process. DRR computation itself is done by an efficient volume rendering method named wobbled splatting. For programming the graphics hardware, NVIDIAs C for Graphics (Cg) is used. The description of an algorithm used for rendering DRRs on the graphics hardware is presented, together with a benchmark comparing this technique to a CPU-based wobbled splatting program. Results show a reduction of rendering time by about 70%-90% depending on the amount of data. For instance, rendering a volume of 2x10 6 voxels is feasible at an update rate of 38 Hz compared to 6 Hz on a common Intel-based PC using the graphics processing unit (GPU) of a conventional graphics adapter. In addition, wobbled splatting using graphics hardware for DRR computation provides higher resolution DRRs with comparable image quality due to special processing characteristics of the GPU. We conclude that DRR generation on common graphics hardware using the freely available Cg environment is a major step toward 2D/3D registration in clinical routine

Global skin colour prediction from DNA.

Science.gov (United States)

Walsh, Susan; Chaitanya, Lakshmi; Breslin, Krystal; Muralidharan, Charanya; Bronikowska, Agnieszka; Pospiech, Ewelina; Koller, Julia; Kovatsi, Leda; Wollstein, Andreas; Branicki, Wojciech; Liu, Fan; Kayser, Manfred

2017-07-01

Human skin colour is highly heritable and externally visible with relevance in medical, forensic, and anthropological genetics. Although eye and hair colour can already be predicted with high accuracies from small sets of carefully selected DNA markers, knowledge about the genetic predictability of skin colour is limited. Here, we investigate the skin colour predictive value of 77 single-nucleotide polymorphisms (SNPs) from 37 genetic loci previously associated with human pigmentation using 2025 individuals from 31 global populations. We identified a minimal set of 36 highly informative skin colour predictive SNPs and developed a statistical prediction model capable of skin colour prediction on a global scale. Average cross-validated prediction accuracies expressed as area under the receiver-operating characteristic curve (AUC) ± standard deviation were 0.97 ± 0.02 for Light, 0.83 ± 0.11 for Dark, and 0.96 ± 0.03 for Dark-Black. When using a 5-category, this resulted in 0.74 ± 0.05 for Very Pale, 0.72 ± 0.03 for Pale, 0.73 ± 0.03 for Intermediate, 0.87±0.1 for Dark, and 0.97 ± 0.03 for Dark-Black. A comparative analysis in 194 independent samples from 17 populations demonstrated that our model outperformed a previously proposed 10-SNP-classifier approach with AUCs rising from 0.79 to 0.82 for White, comparable at the intermediate level of 0.63 and 0.62, respectively, and a large increase from 0.64 to 0.92 for Black. Overall, this study demonstrates that the chosen DNA markers and prediction model, particularly the 5-category level; allow skin colour predictions within and between continental regions for the first time, which will serve as a valuable resource for future applications in forensic and anthropologic genetics.

Colour learning when foraging for nectar and pollen: bees learn two colours at once.

Science.gov (United States)

Muth, Felicity; Papaj, Daniel R; Leonard, Anne S

2015-09-01

Bees are model organisms for the study of learning and memory, yet nearly all such research to date has used a single reward, nectar. Many bees collect both nectar (carbohydrates) and pollen (protein) on a single foraging bout, sometimes from different plant species. We tested whether individual bumblebees could learn colour associations with nectar and pollen rewards simultaneously in a foraging scenario where one floral type offered only nectar and the other only pollen. We found that bees readily learned multiple reward-colour associations, and when presented with novel floral targets generalized to colours similar to those trained for each reward type. These results expand the ecological significance of work on bee learning and raise new questions regarding the cognitive ecology of pollination. © 2015 The Author(s).

The cause of 50 million-year-old colour.

Science.gov (United States)

Parker, Andrew R; McKenzie, David R

2003-11-07

Multilayer reflectors cause structural, 'metallic' colours in a diversity of animals today, yet are unknown in extinct species. We identify a multilayer reflector, causing structural colour, in a 50-million-year-old beetle from Messel, Germany. It is proposed that the original material of this reflector has been preserved, although this is not a precondition for determining original colours from ancient multilayer reflectors. Therefore, the potential exists to reveal the original colours of other (particularly arthropod) extinct species.

KINETICS OF COLOUR CHANGE OF TOMATOES DURING DRYING

Directory of Open Access Journals (Sweden)

A. Unadi

2016-10-01

Full Text Available Colour is one of the pharameters determining the quality of dried tomatoes. The changes in colour of the skin of tomatoes during drying in an experimental dryer at various temperatures were measured every two hours by using Minolta CR 200 colorimeter and the colours were represented in Hunter-Lab scale. The objective of this research was develop a model for predicting colour changes of tomatoes during drying. The decrease in darkness as represented by dL value varied from 10 to 16%, while decrease in chroma value (dL varied from 20 to 37% of initial values. An empirical logarithmic equation with six constants was derived to fit the data of chroma changes during drying at various temperature and times. The model of colour change of tomatoes can be used for determining the optimum drying temperature to produce acceptable colour of dried tomatoes at reasonable cost.

The existence of panchromatic colourings for uniform hypergraphs

International Nuclear Information System (INIS)

Shabanov, Dmitrii A

2010-01-01

The well-known extremal problem concerning panchromatic colouring of hypergraphs is investigated. An r-colouring of the set of vertices of a hypergraph is said to be panchromatic if each link of the hypergraph is incident to vertices of all colours. The quantity p(n,r) defined as the minimum number of links in an n-uniform hypergraph which admits no panchromatic r-colourings is studied. New lower and upper bounds for p(n,r) are obtained, which improve earlier results for many of the relations between the parameters n and r. In addition, a sufficient condition for the existence of a panchromatic r-colouring of an n-uniform hypergraph is obtained. Bibliography: 18 items.

Selective interference reveals dissociation between memory for location and colour.

Science.gov (United States)

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

1999-08-02

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

Annotating Coloured Petri Nets

DEFF Research Database (Denmark)

Lindstrøm, Bo; Wells, Lisa Marie

2002-01-01

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

Use of colour for hand-filled form analysis and recognition

OpenAIRE

Sherkat, N; Allen, T; Wong, WS

2005-01-01

Colour information in form analysis is currently under utilised. As technology has advanced and computing costs have reduced, the processing of forms in colour has now become practicable. This paper describes a novel colour-based approach to the extraction of filled data from colour form images. Images are first quantised to reduce the colour complexity and data is extracted by examining the colour characteristics of the images. The improved performance of the proposed method has been verifie...

3D rendering and interactive visualization technology in large industry CT

International Nuclear Information System (INIS)

Xiao Yongshun; Zhang Li; Chen Zhiqiang; Kang Kejun

2002-01-01

The author introduces the applications of interactive 3D rendering technology in the large ICT. It summarizes and comments on the iso-surfaces rendering and the direct volume rendering methods used in ICT. The author emphasizes on the technical analysis of the 3D rendering process of ICT volume data sets, and summarizes the difficulties of the inspection subsystem design in large ICT

3D rendering and interactive visualization technology in large industry CT

International Nuclear Information System (INIS)

Xiao Yongshun; Zhang Li; Chen Zhiqiang; Kang Kejun

2001-01-01

This paper introduces the applications of interactive 3D rendering technology in the large ICT. It summarizes and comments on the iso-surfaces rendering and the direct volume rendering methods used in ICT. The paper emphasizes on the technical analysis of the 3D rendering process of ICT volume data sets, and summarizes the difficulties of the inspection subsystem design in large ICT

Edge colouring by total labellings

DEFF Research Database (Denmark)

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

2010-01-01

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

Colouring our view of safety

International Nuclear Information System (INIS)

Spare, P.

2000-01-01

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

The effects of colour and valence on news evaluation.

Science.gov (United States)

Kaspar, Kai; Grümmer, Melanie; Kießler, Antje; Neuß, Celina; Schröter, Franziska

2017-12-01

Research across different fields of psychology has reported effects of colour cues on a variety of cognitive processes. Especially, the colour red has been shown to have striking influences. In the context of media reception, however, colour effects have been widely neglected so far. This study made a first step in this direction by investigating the effects of the colour red (compared with blue and grey) on the way news articles are evaluated. Two types of news were framed by a coloured border while the valence of the news content additionally varied. Based on 369 participants who read and evaluated the news articles online, we observed effects for colour cues and news valence in the absence of an interaction effect, indicating that the colour red induced approach motivation. However, only the contrast between red and grey reached statistical significance, indicating that chromatic and achromatic colours may differ in their perceived visual saliency. Overall, these results provide an important complement to previous studies and have practical implications for media researchers and producers. © 2015 International Union of Psychological Science.

Conjunctions of colour, luminance and orientation: the role of colour and luminance contrast on saliency and proximity grouping in texture segregation.

Science.gov (United States)

Leonards, U; Singer, W

2000-01-01

To examine whether perceptual grouping on the basis of orientation can be performed simultaneously with or only subsequently to grouping according to colour or luminance, we tested whether subjects are able to segregate arrays of texture elements that differ from surrounding elements by conjunctions of either (i) colour and orientation, or (ii) luminance contrast and orientation, or (iii) luminance contrast polarity and orientation. Subjects were able to use conjunctions between luminance and orientation for segregation but not conjunctions between colour or contrast polarity and orientation. Our results suggest that (i) in agreement with earlier findings, there seem to exist no specific conjunction detectors for colour and orientation or contrast polarity and orientation, and (ii) when orientation defined textures are to be distinguished by virtue of differences in luminance, colour, or contrast polarity, luminance provides a much stronger cue than colour or contrast polarity for saliency-based orientation grouping.

A Real-Time Sound Field Rendering Processor

Directory of Open Access Journals (Sweden)

Tan Yiyu

2017-12-01

Full Text Available Real-time sound field renderings are computationally intensive and memory-intensive. Traditional rendering systems based on computer simulations suffer from memory bandwidth and arithmetic units. The computation is time-consuming, and the sample rate of the output sound is low because of the long computation time at each time step. In this work, a processor with a hybrid architecture is proposed to speed up computation and improve the sample rate of the output sound, and an interface is developed for system scalability through simply cascading many chips to enlarge the simulated area. To render a three-minute Beethoven wave sound in a small shoe-box room with dimensions of 1.28 m × 1.28 m × 0.64 m, the field programming gate array (FPGA-based prototype machine with the proposed architecture carries out the sound rendering at run-time while the software simulation with the OpenMP parallelization takes about 12.70 min on a personal computer (PC with 32 GB random access memory (RAM and an Intel i7-6800K six-core processor running at 3.4 GHz. The throughput in the software simulation is about 194 M grids/s while it is 51.2 G grids/s in the prototype machine even if the clock frequency of the prototype machine is much lower than that of the PC. The rendering processor with a processing element (PE and interfaces consumes about 238,515 gates after fabricated by the 0.18 µm processing technology from the ROHM semiconductor Co., Ltd. (Kyoto Japan, and the power consumption is about 143.8 mW.

Colour and camouflage: design issues in military clothing

CSIR Research Space (South Africa)

Baumbach, J

2012-07-01

Full Text Available itself. Colour differences can be defined in terms of hue, chromaticness (or chromaticity) and lightness. A person?s hue discrimination (yellow, red, blue and green are different hues of colour) can be determined by the Farnsworth-Munsell 100 Hue... environment are blue. Yellow is the second-lightest colour of the cube in the blue environment. But, when abovementioned blue and yellow squares are isolated from their respective environments (taken out of context), all of them have the same colour...

Simplification of Visual Rendering in Simulated Prosthetic Vision Facilitates Navigation.

Science.gov (United States)

Vergnieux, Victor; Macé, Marc J-M; Jouffrais, Christophe

2017-09-01

Visual neuroprostheses are still limited and simulated prosthetic vision (SPV) is used to evaluate potential and forthcoming functionality of these implants. SPV has been used to evaluate the minimum requirement on visual neuroprosthetic characteristics to restore various functions such as reading, objects and face recognition, object grasping, etc. Some of these studies focused on obstacle avoidance but only a few investigated orientation or navigation abilities with prosthetic vision. The resolution of current arrays of electrodes is not sufficient to allow navigation tasks without additional processing of the visual input. In this study, we simulated a low resolution array (15 × 18 electrodes, similar to a forthcoming generation of arrays) and evaluated the navigation abilities restored when visual information was processed with various computer vision algorithms to enhance the visual rendering. Three main visual rendering strategies were compared to a control rendering in a wayfinding task within an unknown environment. The control rendering corresponded to a resizing of the original image onto the electrode array size, according to the average brightness of the pixels. In the first rendering strategy, vision distance was limited to 3, 6, or 9 m, respectively. In the second strategy, the rendering was not based on the brightness of the image pixels, but on the distance between the user and the elements in the field of view. In the last rendering strategy, only the edges of the environments were displayed, similar to a wireframe rendering. All the tested renderings, except the 3 m limitation of the viewing distance, improved navigation performance and decreased cognitive load. Interestingly, the distance-based and wireframe renderings also improved the cognitive mapping of the unknown environment. These results show that low resolution implants are usable for wayfinding if specific computer vision algorithms are used to select and display appropriate

Relationship between behavioural factors and colour preferences for clothing

Directory of Open Access Journals (Sweden)

Milena Fornazarič

2018-03-01

Full Text Available The colour of clothing plays an important role in one’s emotional reaction and the selection of clothes, which in turn effects design, the fashion industry and sales. In our behavioural research involving the Slovenian population regarding the selection of colours, we used the results of opportunity sampling, i.e. a web survey using a sample of 204 respondents, who were invited to participate in the research using an email list sampling method. Our aim was determine how demographic and behavioural characteristics affect colour preferences for clothing. Demographic characteristics are not important in terms of the behaviour of different segments of the population, except with regard to gender. Nevertheless, we can use the results of the survey to make a correlation between colour and consumer characteristics. Those who are fond of the colour beige follow fashion trends more closely than the others, while the colour white is associated with those who follow fashion on web and in online shopping. On the contrary, consumers who prefer pink and purple primarily buy clothes in fashion shops. Those who prefer brown and beige enjoy the shopping experience more than others, while lovers of the colour pink are less inclined to buy clothes during sales than others. Consumers who prefer the colour blue are predominant in fitting shops, while those who prefer the colour black do not to buy clothes on Saturdays. Lovers of the colour blue stand out in terms of spending, while people who are fond of the colour white spend the most, although they prefer to buy less expensive clothes. People drawn to the colour grey prefer to buy less expensive jackets, while women who prefer the colour green also buy less expensive jackets. We recommend expanding the scope of the research to include historical determinants, fashion patterns, marketing communication and fashion brands, as well as other, more rational and speculative motives associated with a subject�

Blender cycles lighting and rendering cookbook

CERN Document Server

Iraci, Bernardo

2013-01-01

An in-depth guide full of step-by-step recipes to explore the concepts behind the usage of Cycles. Packed with illustrations, and lots of tips and tricks; the easy-to-understand nature of the book will help the reader understand even the most complex concepts with ease.If you are a digital artist who already knows your way around Blender, and you want to learn about the new Cycles' rendering engine, this is the book for you. Even experts will be able to pick up new tips and tricks to make the most of the rendering capabilities of Cycles.

Global skin colour prediction from DNA

NARCIS (Netherlands)

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

2017-01-01

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

The colour analysis method applied to homogeneous rocks

Directory of Open Access Journals (Sweden)

Halász Amadé

2015-12-01

Full Text Available Computer-aided colour analysis can facilitate cyclostratigraphic studies. Here we report on a case study involving the development of a digital colour analysis method for examination of the Boda Claystone Formation which is the most suitable in Hungary for the disposal of high-level radioactive waste. Rock type colours are reddish brown or brownish red, or any shade between brown and red. The method presented here could be used to differentiate similar colours and to identify gradual transitions between these; the latter are of great importance in a cyclostratigraphic analysis of the succession. Geophysical well-logging has demonstrated the existence of characteristic cyclic units, as detected by colour and natural gamma. Based on our research, colour, natural gamma and lithology correlate well. For core Ib-4, these features reveal the presence of orderly cycles with thicknesses of roughly 0.64 to 13 metres. Once the core has been scanned, this is a time- and cost-effective method.

Three-dimensional rendering of segmented object using matlab - biomed 2010.

Science.gov (United States)

Anderson, Jeffrey R; Barrett, Steven F

2010-01-01

The three-dimensional rendering of microscopic objects is a difficult and challenging task that often requires specialized image processing techniques. Previous work has been described of a semi-automatic segmentation process of fluorescently stained neurons collected as a sequence of slice images with a confocal laser scanning microscope. Once properly segmented, each individual object can be rendered and studied as a three-dimensional virtual object. This paper describes the work associated with the design and development of Matlab files to create three-dimensional images from the segmented object data previously mentioned. Part of the motivation for this work is to integrate both the segmentation and rendering processes into one software application, providing a seamless transition from the segmentation tasks to the rendering and visualization tasks. Previously these tasks were accomplished on two different computer systems, windows and Linux. This transition basically limits the usefulness of the segmentation and rendering applications to those who have both computer systems readily available. The focus of this work is to create custom Matlab image processing algorithms for object rendering and visualization, and merge these capabilities to the Matlab files that were developed especially for the image segmentation task. The completed Matlab application will contain both the segmentation and rendering processes in a single graphical user interface, or GUI. This process for rendering three-dimensional images in Matlab requires that a sequence of two-dimensional binary images, representing a cross-sectional slice of the object, be reassembled in a 3D space, and covered with a surface. Additional segmented objects can be rendered in the same 3D space. The surface properties of each object can be varied by the user to aid in the study and analysis of the objects. This inter-active process becomes a powerful visual tool to study and understand microscopic objects.

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

Science.gov (United States)

Cernea, Paul

2002-01-01

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

String formation beyond leading colour

Energy Technology Data Exchange (ETDEWEB)

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

2015-08-03

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

Real-Time Location-Based Rendering of Urban Underground Pipelines

Directory of Open Access Journals (Sweden)

Wei Li

2018-01-01

Full Text Available The concealment and complex spatial relationships of urban underground pipelines present challenges in managing them. Recently, augmented reality (AR has been a hot topic around the world, because it can enhance our perception of reality by overlaying information about the environment and its objects onto the real world. Using AR, underground pipelines can be displayed accurately, intuitively, and in real time. We analyzed the characteristics of AR and their application in underground pipeline management. We mainly focused on the AR pipeline rendering procedure based on the BeiDou Navigation Satellite System (BDS and simultaneous localization and mapping (SLAM technology. First, in aiming to improve the spatial accuracy of pipeline rendering, we used differential corrections received from the Ground-Based Augmentation System to compute the precise coordinates of users in real time, which helped us accurately retrieve and draw pipelines near the users, and by scene recognition the accuracy can be further improved. Second, in terms of pipeline rendering, we used Visual-Inertial Odometry (VIO to track the rendered objects and made some improvements to visual effects, which can provide steady dynamic tracking of pipelines even in relatively markerless environments and outdoors. Finally, we used the occlusion method based on real-time 3D reconstruction to realistically express the immersion effect of underground pipelines. We compared our methods to the existing methods and concluded that the method proposed in this research improves the spatial accuracy of pipeline rendering and the portability of the equipment. Moreover, the updating of our rendering procedure corresponded with the moving of the user’s location, thus we achieved a dynamic rendering of pipelines in the real environment.

Metal free structural colours via disordered nanostructures with nm resolution and full CYMK colour spectrum

KAUST Repository

Bonifazi, Marcella

2017-02-28

Structural colours represents a research area of great interest, due to a wide field of application ranging from micro-security to biomimetic materials. At present metallic substrate are heavily employed and only a partial spectra of colours can be realised. We propose a novel, metal-free technology that exploits the complex scattering from a disordered three-dimensional dielectric material on a silicon substrate. We reproduce experimentally the full spectrum of CMYK colours, including variations in intensity. Our resolution lies in the nm range, limited only by the electron beam lithography fabrication process. We demonstrate that this technique is extremely robust, suitable for flexible and reusable substrates. Full of these notable proprieties these nano-structures fits perfectly with the requirements of a real-world technology.

Metal free structural colours via disordered nanostructures with nm resolution and full CYMK colour spectrum

KAUST Repository

Bonifazi, Marcella; Mazzone, Valerio; Fratalocchi, Andrea

2017-01-01

Structural colours represents a research area of great interest, due to a wide field of application ranging from micro-security to biomimetic materials. At present metallic substrate are heavily employed and only a partial spectra of colours can be realised. We propose a novel, metal-free technology that exploits the complex scattering from a disordered three-dimensional dielectric material on a silicon substrate. We reproduce experimentally the full spectrum of CMYK colours, including variations in intensity. Our resolution lies in the nm range, limited only by the electron beam lithography fabrication process. We demonstrate that this technique is extremely robust, suitable for flexible and reusable substrates. Full of these notable proprieties these nano-structures fits perfectly with the requirements of a real-world technology.

Synaesthetic Colour in the Brain: Beyond Colour Areas. A Functional Magnetic Resonance Imaging Study of Synaesthetes and Matched Controls

OpenAIRE

van Leeuwen, Tessa M.; Petersson, Karl Magnus; Hagoort, Peter

2010-01-01

Background In synaesthesia, sensations in a particular modality cause additional experiences in a second, unstimulated modality (e.g., letters elicit colour). Understanding how synaesthesia is mediated in the brain can help to understand normal processes of perceptual awareness and multisensory integration. In several neuroimaging studies, enhanced brain activity for grapheme-colour synaesthesia has been found in ventral-occipital areas that are also involved in real colour processing. Our q...

What Colour Is a Shadow?

Science.gov (United States)

Hughes, S. W.

2009-01-01

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

The guidance of spatial attention during visual search for colour combinations and colour configurations

OpenAIRE

Berggren, Nick; Eimer, Martin

2016-01-01

Representations of target-defining features (attentional templates) guide the selection of target objects in visual search. We used behavioural and electrophysiological measures to investigate how such search templates control the allocation of attention in search tasks where targets are defined by the combination of two colours or by a specific spatial configuration of these colours. Target displays were preceded by spatially uninformative cue displays that contained items in one or both tar...

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

Science.gov (United States)

Kelber, Almut; Osorio, Daniel

2010-06-07

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

Colour terms in the interior design process

OpenAIRE

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

2015-01-01

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

Multi-jet correlations and colour coherence phenomena

Directory of Open Access Journals (Sweden)

Lee Jason S.H.

2017-01-01

Full Text Available In multi-jet events, colour coherence was shown to play a important role in the topology of these events. In modern Monte Carlo generators, the colour coherence effect has become an inherent feature, such that the colour coherence effect can no longer be disentangled in a simple manner. This study looks at the multi-jet correlations by comparing Monte Carlo generators in Parton Shower dominant and Matrix Element dominant regions.

Colour discrimination and categorisation in Williams syndrome

OpenAIRE

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

2013-01-01

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

Synaesthetic colours do not camouflage form in visual search.

Science.gov (United States)

Gheri, C; Chopping, S; Morgan, M J

2008-04-07

One of the major issues in synaesthesia research is to identify the level of processing involved in the formation of the subjective colours experienced by synaesthetes: are they perceptual phenomena or are they due to memory and association learning? To address this question, we tested whether the colours reported by a group of grapheme-colour synaesthetes (previously studied in an functional magnetic resonance imaging experiment) influenced them in a visual search task. As well as using a condition where synaesthetic colours should have aided visual search, we introduced a condition where the colours experienced by synaesthetes would be expected to make them worse than controls. We found no evidence for differences between synaesthetes and normal controls, either when colours should have helped them or where they should have hindered. We conclude that the colours reported by our population of synaesthetes are not equivalent to perceptual signals, but arise at a cognitive level where they are unable to affect visual search.

AFLP genome scans suggest divergent selection on colour patterning in allopatric colour morphs of a cichlid fish.

Science.gov (United States)

Mattersdorfer, Karin; Koblmüller, Stephan; Sefc, Kristina M

2012-07-01

Genome scan-based tests for selection are directly applicable to natural populations to study the genetic and evolutionary mechanisms behind phenotypic differentiation. We conducted AFLP genome scans in three distinct geographic colour morphs of the cichlid fish Tropheus moorii to assess whether the extant, allopatric colour pattern differentiation can be explained by drift and to identify markers mapping to genomic regions possibly involved in colour patterning. The tested morphs occupy adjacent shore sections in southern Lake Tanganyika and are separated from each other by major habitat barriers. The genome scans revealed significant genetic structure between morphs, but a very low proportion of loci fixed for alternative AFLP alleles in different morphs. This high level of polymorphism within morphs suggested that colour pattern differentiation did not result exclusively from neutral processes. Outlier detection methods identified six loci with excess differentiation in the comparison between a bluish and a yellow-blotch morph and five different outlier loci in comparisons of each of these morphs with a red morph. As population expansions and the genetic structure of Tropheus make the outlier approach prone to false-positive signals of selection, we examined the correlation between outlier locus alleles and colour phenotypes in a genetic and phenotypic cline between two morphs. Distributions of allele frequencies at one outlier locus were indeed consistent with linkage to a colour locus. Despite the challenges posed by population structure and demography, our results encourage the cautious application of genome scans to studies of divergent selection in subdivided and recently expanded populations. © 2012 Blackwell Publishing Ltd.

Edges, colour and awareness in blindsight.

Science.gov (United States)

Alexander, Iona; Cowey, Alan

2010-06-01

It remains unclear what is being processed in blindsight in response to faces, colours, shapes, and patterns. This was investigated in two hemianopes with chromatic and achromatic stimuli with sharp or shallow luminance or chromatic contrast boundaries or temporal onsets. Performance was excellent only when stimuli had sharp spatial boundaries. When discrimination between isoluminant coloured Gaussians was good it declined to chance levels if stimulus onset was slow. The ability to discriminate between instantaneously presented colours in the hemianopic field depended on their luminance, indicating that wavelength discrimination totally independent of other stimulus qualities is absent. When presented with narrow-band colours the hemianopes detected a stimulus maximally effective for S-cones but invisible to M- and L-cones, indicating that blindsight is mediated not just by the mid-brain, which receives no S-cone input, or that the rods contribute to blindsight. The results show that only simple stimulus features are processed in blindsight. 2010 Elsevier Inc. All rights reserved.

Inheritanceof seed coat colour pattern in cowpea [ Vigna ...

African Journals Online (AJOL)

Hybridization experiments were conducted in the screen house to study the inheritance of seed colour pattern in cowpea. Cowpea varieties of varying seed coat colour were used as parents for the investigation. Parental, F1 and segregating F2 populations were raised in the field and the study revealed that self colour ...

Fusion of colour and monochromatic images with edge emphasis

Directory of Open Access Journals (Sweden)

Rade M. Pavlović

2014-02-01

Full Text Available We propose a novel method to fuse true colour images with monochromatic non-visible range images that seeks to encode important structural information from monochromatic images efficiently but also preserve the natural appearance of the available true chromacity information. We utilise the β colour opponency channel of the lαβ colour as the domain to fuse information from the monochromatic input into the colour input by the way of robust grayscale fusion. This is followed by an effective gradient structure visualisation step that enhances the visibility of monochromatic information in the final colour fused image. Images fused using this method preserve their natural appearance and chromacity better than conventional methods while at the same time clearly encode structural information from the monochormatic input. This is demonstrated on a number of well-known true colour fusion examples and confirmed by the results of subjective trials on the data from several colour fusion scenarios. Introduction The goal of image fusion can be broadly defined as: the representation of visual information contained in a number of input images into a single fused image without distortion or loss of information. In practice, however, a representation of all available information from multiple inputs in a single image is almost impossible and fusion is generally a data reduction task.  One of the sensors usually provides a true colour image that by definition has all of its data dimensions already populated by the spatial and chromatic information. Fusing such images with information from monochromatic inputs in a conventional manner can severely affect natural appearance of the fused image. This is a difficult problem and partly the reason why colour fusion received only a fraction of the attention than better behaved grayscale fusion even long after colour sensors became widespread. Fusion method Humans tend to see colours as contrasts between opponent

The influence of colour on the aesthetics of wind turbine generators

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-11-01

This paper summarises the results of studies examining the role that colour plays in reducing the visual impact of wind turbines and the development of a method for selecting the colour and pattern focusing on UK rural wind farms. Published material is reviewed, and visual factors relevant to visibility, factors influencing the choice of colour for buildings and other installations in the landscape, issues arising from the choice of colour, theories of camouflage, the testing of different colours, strategies for applying colour to wind turbines, the effectiveness of the different colours, and the effect of the different colour schemes on the visual impact of wind turbine arrays are addressed. Recommendations concerning colour selection are presented. A compact disc is provided with the paper. (UK)

Flower colour and cytochromes P450.

Science.gov (United States)

Tanaka, Yoshikazu; Brugliera, Filippa

2013-02-19

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

The effect of gender on eye colour variation in European populations and an evaluation of the IrisPlex prediction model.

Science.gov (United States)

Pietroni, Carlotta; Andersen, Jeppe D; Johansen, Peter; Andersen, Mikkel M; Harder, Stine; Paulsen, Rasmus; Børsting, Claus; Morling, Niels

2014-07-01

In two recent studies of Spanish individuals, gender was suggested as a factor that contributes to human eye colour variation. However, gender did not improve the predictive accuracy on blue, intermediate and brown eye colours when gender was included in the IrisPlex model. In this study, we investigate the role of gender as a factor that contributes to eye colour variation and suggest that the gender effect on eye colour is population specific. A total of 230 Italian individuals were typed for the six IrisPlex SNPs (rs12913832, rs1800407, rs12896399, rs1393350, rs16891982 and rs12203592). A quantitative eye colour score (Pixel Index of the Eye: PIE-score) was calculated based on digital eye images using the custom made DIAT software. The results were compared with those of Danish and Swedish population samples. As expected, we found HERC2 rs12913832 as the main predictor of human eye colour independently of ancestry. Furthermore, we found gender to be significantly associated with quantitative eye colour measurements in the Italian population sample. We found that the association was statistically significant only among Italian individuals typed as heterozygote GA for HERC2 rs12913832. Interestingly, we did not observe the same association in the Danish and Swedish population. This indicated that the gender effect on eye colour is population specific. We estimated the effect of gender on quantitative eye colour in the Italian population sample to be 4.9%. Among gender and the IrisPlex SNPs, gender ranked as the second most important predictor of human eye colour variation in Italians after HERC2 rs12913832. We, furthermore, tested the five lower ranked IrisPlex predictors, and evaluated all possible 3(6) (729) genotype combinations of the IrisPlex assay and their corresponding predictive values using the IrisPlex prediction model [4]. The results suggested that maximum three (rs12913832, rs1800407, rs16891982) of the six IrisPlex SNPs are useful in practical

Bentonite and Gelatine Impact on the Young Red Wine Coloured Matter

Directory of Open Access Journals (Sweden)

Slobodan Jović

2004-01-01

Full Text Available This paper deals with the impact of two fining agents (bentonite and gelatine on the coloured matters of young red wines Vranac, Pinot Noir and Gamay Noir. Both agents caused decrease in these substances. The effect is more intensive with the dose of bentonite of 1 g/L, but the variability depends on variety. Higher decrease was found in the colour intensity, coloured anthocyanins and polymers (up to 44 %, but lower in the colourless anthocyanins (up to 20 %. The intensity of red and blue colours decreases, while that of yellow colour increases. The use of bentonite in dosages higher than those recommended may cause the wine to obtain more pronounced »brick red« colour (the colour tint increases while the value of the spectrum form decreases. Fewer changes occurred in the coloured matters after treating the wine with gelatine. The colour intensity, colourless and coloured anthocyanins showed a decrease of up to 10 % and polymers of up to 16 %. The intensity of yellow colour decreases, while that of red increases as well as the ΔA/% value.

Colour dematerialization in spiritual literature and painting

Directory of Open Access Journals (Sweden)

Dadang Sudrajat

2017-12-01

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