Spectral Test Instrument for Color Vision Measurement

Common displays such as CRT or LCD screens have limited capabilities in displaying most color spectra correctly. The main disadvantage of these devices is that they work with three primaries and the colors displayed are the mixture of these three colours. Consequently these devices can be confusing in testing human color identification, because the spectral distribution of the colors displayed is the combined spectrum of the three primaries. We have developed a new instrument for spectrally correct color vision measurement. This instrument uses light emitting diodes (LEDs) and is capable of producing all spectra of perceivable colors, thus with appropriate test methods this instrument can be a reliable and useful tool in test~ing human color vision and in verifying color vision correction.

Effect of Antimicrobial Edible Films on the Sensory and Physical Properties of Organic Spinach in Salad Bags

The effects of antimicrobial edible films containing carvacrol and cinnamaldehyde on organic baby spinach were determined via sensory analysis and changes in physical properties. Edible films made from pulp of hibiscus, apple, or carrot containing carvacrol or cinnamaldehyde at 0.5%, 1.5%, or 3% concentrations were added to organic baby spinach in plastic bags. These bags were stored at 4°C for 20-24h before performing sensory evaluation and measuring changes in physical properties. A randomized block design with an affective test was used. Preference liking was evaluated based on a 9-point hedonic scale for aroma, color, freshness, mouthfeel, flavor, and overall acceptability. Additionally, panelists quantified each sample using a 5-point hedonic scale for pungency, browning, bitterness, off-odor, and sourness. The color and texture of spinach samples were measured. Edible films containing cinnamaldehyde had the highest preference liking based on aroma, color, freshness, mouthfeel, flavor, and overall acceptability than those containing carvacrol and were the most likely to be purchased by panelists;therefore, cinnamaldehyde can potentially be used as an alternative sanitization option. There were no significant (p ≤ 0.05) changes in firmness or color values between spinach treated with antimicrobial films and controls. The results provide the produce industry with options for incorporating antimicrobial films into salad bags without influencing the physical or sensory properties of baby spinach.

Impact of Plant-Based Antimicrobial Washes on Sensory Properties of Organic Leafy Greens

The objective was to study the sensory attributes of organic leafy greens treated with plant antimicrobials and identify treatments most accepted by panelists. Organic leafy greens were washed with antimicrobials and stored at 4°C for 24 h prior to serving panelists. Antimicrobials evaluated include: 0.1% clove bud, lemongrass, oregano, or cinnamon essential oils;0.1% carvacrol or citral;3% grapeseed, apple, or 10%/7% olive extract;combination of essential oils with extracts;3% hydrogen peroxide;and untreated control. A randomized block design with an affective test was used and 60 panelists were asked to evaluate samples for preference liking based on a 9-point hedonic scale and for sensory attributes based on a 5-point hedonic scale. Changes in texture and color of leafy greens were measured using a Texture analyzer and a Chroma Meter, respectively. On the basis of preference liking, overall acceptability of spinach and lettuce treated with 0.1% cinnamon oil was ranked the highest (7.5 ± 1.4 and 7.1 ± 1.7, moderately liked), respectively. For texture analysis, washing iceberg lettuce with 0.1% oregano oil + 10% olive extract and spinach with 0.1% lemongrass oil + 1% apple extract yielded the highest firmness values of F = 783.1 ± 53.8 Newtons and 939.30 ± 35.2 Newtons, respectively. Based on the International Commission on Illumination CIE LAB color schemes, treatment with 0.1% oregano oil + 10% olive extract had the greatest impact on color of iceberg lettuce with the lowest L value* (44.5 ± 6.2) indicating the darkest color. These results will help identify plant antimicrobials that have the least impact on sensory properties of organic leafy greens and are preferred by consumers.

A comparison of animal color measurements using a commercially available digital color sensor and photograph analysis

An animal's pelage,feather,or skin color can serve a variety of functions,so it is important to have multiple standardized methods for measuring color.One of the most common and reliable methods for measuring animal coloration is the use of standardized digital photographs of animals.New tech no logy in the form of a commercially available handheld digital color sensor could provide an alter native to photography-based animal color measurements.To determine whether a digital color sensor could be used to measure animal coloration,we tested the ability of a digital color sensor to measure coloration of mammalian,avian,and lepidopteran museums specimens.We compared results from the sensor to measurements taken using traditional photography methods.Our study yielded significant differences between photography-based and digital color sensor measurements of brightness(light to dark)and colors along the green to red spectrum.There was no difference between photographs and the digital color sensor measurements for colors along the blue to yellow spectrum.The average difference in recorded color(AE)by the 2 methods was above the threshold at which humans can perceive a difference.There were sign讦icant correlations between the sensor and photographs for all measurements indicating that the sensor is an effective animal coloration measuring tool.However,the sensor's small aperture and narrow light spectrum range designed for human-vision limit its value for ecological research.We discuss the conditions in which a digital color sensor can be an effective tool for measuring animal coloration in both laboratory settings and in the field.

Color appearance and visual measurements for color samples with gloss effect

We assess the color appearance of the samples with different inks on glossy substrates, five kinds of paper with different gloss levels. The color samples are measured using spectrophotometers under different illuminating/viewing geometries and visually estimated using the psychophysical method of magnitude estimation. The results of the two approaches are compared through the color appearance model of CIECAM02. The experimental data analysis indicates that the 0/45 and 15/0 geometries can be used to describe the two major aspects of gloss effect, the enlargement of color gamut, and the reduction of lightness. The agreement for hue attribute between instrumental measurement and visual assessment is better than those for colorfulness and lightness.

Influence of surface roughness on the color of dental-resin composites

This study deals with the influence of surface roughness on the color of resin composites.Ten resin composites (microfilled,hybrid,and microhybrid) were each polished with 500-grit,1 200-grit,2 000-grit,and 4 000-grit SiC papers.The roughness parameter (Ra) was measured using a Plμ confocal microscope,and field-emission scanning electron microscope (Fe-SEM) images were used to investigate filler morphology.Color was measured using a spectroradiometer and a D65 standard illuminant (geometry diffuse/0° specular component excluded (SCE) mode).Surface roughness decreased with grit number and was not influenced by filler size or size distribution.A significant influence of Ra on lightness (L*) was found.Lightness increased with decreases in roughness,except for specimens that underwent polishing procedure 4 (PP4;500-grit,1 200-grit,2 000-grit,and 4 000-grit SiC papers consecutively).Generally,it was found that surface roughness influenced the color of resin composites.The composites that underwent PP1 (500-grit SiC paper) exhibited significant differences in chroma (C*),hue (h°),and lightness (L*) compared to composites that underwent PP3 (500-grit,1 200-grit,and 2 000-grit SiC papers consecutively) and PP4.Color difference (E*) between the polishing procedures was within acceptability thresholds in dentistry.

Distributed Kalman filter for UWB/INS integrated pedestrian localization under colored measurement noise

Colored Measurement Noise(CMN)has a great impact on the accuracy of human localization in indoor environments with Inertial Navigation System(INS)integrated with Ultra Wide Band(UWB).To mitigate its influence,a distributed Kalman Filter(dKF)is developed for Gauss-Markov CMN with switching Colouredness Factor Matrix(CFM).In the proposed scheme,a data fusion filter employs the difference between the INS-and UWB-based distance measurements.The main filter produces a final optimal estimate of the human position by fusing the estimates from local filters.The effect of CMN is overcome by using measurement differencing of noisy observations.The tests show that the proposed dKF developed for CMN with CFM can reduce the localization error compared to the original dKF,and thus effectively improve the localization accuracy.

An objective method for color vision deficiencies measurement based on visual evoked potential

The equi-luminance of color stimulus in normal subjects is characterized by L-cone and M-cone activation in retina. For the protanopes and deuternopes, only the activations of one relevant remaining cone type should be considered. The equi-luminance turning curve was established for the recorded visual evoked potentials (VEPs) of the luminance changes of the red and green color stimulus, and the position of the equi-luminance was used to define the kind and degree of color vision deficiencies. In the test of 47 volunteers we got the VEP traces and the equi-luminance turning curves, which was in accordance with the judgment by the pseudoisochromatic plate used in clinic. The method fulfills the objective and quantitative requirements in color vision deficiencies test.