New Color-Difference Formula Based on CIECAM97s

To deduce a new color difference formula based on CIE 1997 Color Appearance Model(CIECAM97s), a color space J a 1 b 1 is first constructed with color appearance descriptors J,a,b in CIECAM97s. The new formula is then deduced in the space and named CDF CIECAM97s. The factors for lightness, chroma and hue correction in the formula are derived by linear regression according to BFD? CP data sets. It is found by statistical analysis that CDF CIECAM97s is in closer accordance with the visual assessments when compared with CMC(1∶1), CIE94 and CIE L *a *b * color difference formulae. Based on color appearance model, the new color difference formula can be used to predict color difference perception in a varity of different viewing conditions.

Colorimetric characterization of imaging device by total color difference minimization

Colorimetric characterization is to transform the device-dependent responses to device-independent colorimetric values, and is usually conducted in CIEXYZ space. However, the optimal solution in CIEXYZ space does not mean the mini-mization of perceptual error. A novel method for colorimetric characterization of imaging device based on the minimization of total color difference is proposed. The method builds the transform between RGB space and CIELAB space directly using the downhill simplex algorithm. Experimental results showed that the proposed method performs better than traditional least-square (LS) and total-least-square (TLS) methods, especially for colors with low luminance values.

Effects of Modular Threshing and Redrying on Color Difference and Polyphenols of Tobacco Leaves

[Objectives]This study was conducted to analyze changes of color difference and polyphenols and their relationship in the process of threshing and redrying.[Methods]The change trends of color difference parameters L,a,b,H^(0),C and polyphenol contents in tobacco leaves in the middle leaf module and the Pearson correlation between them were analyzed.[Results]During threshing and redrying,L and H^(0)of tobacco showed a decreasing trend,but H^(0)changed slightly;the values of a and C showed an inverted"S"change trend,and the differences between various processes were significant;and the value of b decreased first and then increased.The content of chlorogenic acid and scopoletin decreased first,then increased,and then decreased during threshing and redrying;rutin content showed a significant decreasing trend.The value of L was in an extremely significant positive correlation with rutin content;the value of a was in an extremely significant negative correlation with chlorogenic acid content;b value was also significantly correlated with rutin;and H^(0)was in significant correlation and extremely significant correlation with rutin and total polyphenols,respectively.[Conclusions]This study provides technical support for online detection of tobacco leaf components by the color difference method and for the homogenization of threshing and redrying.

Linked color imaging vs Lugol chromoendoscopy for esophageal squamous cell cancer and precancerous lesion screening: A noninferiority study

BACKGROUND Lugol chromoendoscopy(LCE)has served as a standard screening technique in high-risk patients with esophageal cancer.Nevertheless,LCE is not suitable for general population screening given its side effects.Linked color imaging(LCI)is a novel image-enhanced endoscopic technique that can distinguish subtle differences in mucosal color.AIM To compare the diagnostic performance of LCI with LCE in detecting esophageal squamous cell cancer and precancerous lesions and to evaluate whether LCE can be replaced by LCI in detecting esophageal neoplastic lesions.METHODS In this prospective study,we enrolled 543 patients who underwent white light imaging(WLI),LCI and LCE successively.We compared the sensitivity and specificity of LCI and LCE in the detection of esophageal neoplastic lesions.Clinicopathological features and color analysis of lesions were assessed.RESULTS In total,43 patients(45 neoplastic lesions)were analyzed.Among them,36 patients(38 neoplastic lesions)were diagnosed with LCI,and 39 patients(41 neoplastic lesions)were diagnosed with LCE.The sensitivity of LCI was similar to that of LCE(83.7%vs 90.7%,P=0.520),whereas the specificity of LCI was greater than that of LCE(92.4%vs 87.0%,P=0.007).The LCI procedure time in the esophageal examination was significantly shorter than that of LCE[42(34,50)s vs 160(130,189)s,P<0.001].The color difference between the lesion and surrounding mucosa in LCI was significantly greater than that observed with WLI.However,the color difference in LCI was similar in different pathological types of esophageal squamous cell cancer.CONCLUSION LCI offers greater specificity than LCE in the detection of esophageal squamous cell cancer and precancerous lesions,and LCI represents a promising screening strategy for general populations.

Distribution of Leaf Color and Nitrogen Nutrition Diagnosis in Rice Plant

Greenness and nitrogen content of each leaf on main stem of different japonica and indica rice varieties under different nitrogen levels were investigated. Results showed that the fourth leaf from the top exhibited active changes with the change of plant nitrogen status. When the plant nitrogen content was low, its color and nitrogen content were obviously lower than those of the three top leaves. With the increase of plant nitrogen content, the color and nitrogen content of the fourth leaf increased quickly, and the differences of color and nitrogen content between the fourth leaf and the three top leaves decreased. So, the fourth leaf was an ideal indication of plant nutrition status. In addition, color difference between the fourth and the third leaf from the top was highly related to the plant nitrogen content regardless of the variety and development stage. Therefore, color difference between the fourth and the third leaf could be widely used for diagnosis of plant nutrition. Results also indicated that the minimized color difference between the fourth and the third leaf at the critical effective tillering, the emergence of the second leaf from the top, and the heading was the symbol of high yield. Plant nitrogen content of 27 g kg-1 DW for japonica rice and 25 g kg-1 DW for indica were the critical nitrogen concentrations.

A New Method of Color Edge Detection Based on Local Structure Analysis

Human's real life is within a colorful world. Compared to the gray images, color images contain more information and have better visual effects. In today's digital image processing, image segmentation is an important section for computers to "understand" images and edge detection is always one of the most important methods in the field of image segmentation. Edges in color images are considered as local discontinuities both in color and spatial domains. Despite the intensive study based on integration of single-channel edge detection results, and on vector space analysis, edge detection in color images remains as a challenging issue.

Effects of Target and Distractor Saturations on the Cognitive Performance of an Integrated Display Interface

Color coding is often used to enhance decision quality in complex man-machine interfaces of integrated display systems. However, people are easily distracted by irrelevant colors and by the numerous data points and complex structures in the interface. Although an increasing number of studies are seriously focusing on the problem of achieving efficient color coding, few are able to determine the effects of target and distractor saturations on cognitive performance. To study the performances of target colors among distractors, a systematic experiment is conducted to assess the influence of high and low saturated targets on cognitive performance, and the affecting extent of different saturated distractors of homogeneous colors on targets. According to the analysis of the reaction time through the non-parametric statistical method, a calculation method of the cognitive performance of each color is proposed. Based on the calculation of the color differences and the accumulation of the reaction times, it is shown that with the different saturated distractors of homogeneous colors, the high saturated yellow targets perform better than the low saturated ones, and the green and blue targets have moderate performances. When searching for a singleton target placed oll a black background, the color difference between the target and the distractor should be more than 20AE＊ab units in the yellow saturation coding, whereas the color difference should be more than 40△E＊ab units in the blue and green saturation coding. In addition, as regards saturation coding, the influence of the color difference between the target and the background on cognitive performance is greater than that of the color difference between the target and the distractor. Seemingly, the hue attribute determines whether the saturation difference between the target and the distractor affects thc cognitive performance. Based on the experimental results, the simulation design of the instrument dials in a flight situation awareness interface is completed and tested. Simulation results show the feasibility of the method of choosing the target and distractor colors, and the proposed research provides the instruction for the color saturation design of the interface.

RAPD-PCR Analysis on Genetic Relationships Between Cultivars of Tree Peony

Random amplified polymorphic DNA (RAPD) was used to analyze genetic polymophism of 35 Tree Peony cultivars with 7 different color groups. Thirty four primers amplified 418 DNA fragments and 337 polymorphic bands (80.6%), including specific DNA markers for 18 cultivars that could be used to differentiate cultivars. The UPCMA method was used to analyze the genetic relationship among cultivars. The results showed that 35 Peony cultivars could be divided into 2 cluster groups when using similarity criteria of 1.5, and into 4 cluster groups when using similarity criteria of 1.0. The result confirmed that the flower color has no relation to the genetic clusters and the Tree Peony cultivars originated from the same area has close genetic relationship. Therefore, genetic background has no large effect on the genetic relationship. The sequence based on polymorphic rate from high to low was Blue groups > Yellow groups > Bark red groups > Blake groups > White groups>Green groups>Red groups.

Qualitative Analysis of A Sulfur-fumigated Chinese Herbal Medicine by Comprehensive Two-Dimensional Gas Chromatography and High-Resolution Time of Flight MassSpectrometry Using Colorized Fuzzy Difference Data Processing

To investigate the chemical transformation of volatile compounds in sulfur-fumigated Radix Angelicae Sinensis. A comprehensive two-dimensional gas chromatography (GCxGC) and high-resolution time-of-flight mass spectrometry (HR-TOF/MS) with colorized fuzzy difference (CFD) method was used to investigate the effect of sulfur-fumigation on the volatile components from Radix Angelicae Sinensis. Twenty-five compounds that were found in sun-dried samples disappeared in sulfur-fumigated samples. Seventeen volatile components including two sulfur-containing compounds were newly generated for the first time in volatile oils of sulfur-fumigated Radix Angelicae Sinensis. The strategy can be successfully applied to rapidly and holistically discriminate sun-dried and sulfur-fumigated Radix Angelicae Sinensis. GCxGC-HR-TOF/MS based CFD is a powerful and feasible approach for the global quality evaluation of Radix Angelicae Sinensis as well as other herbal medicines.

Development of color density concept with color difference formulas in respect to human vision system

The aims of this study are to develop the color density concept and to propose the color density based color difference formulas.The color density is defined using the metric coefficients that are based on the discrimination ellipses and the locations of the colors in the color space.The ellipse sets are the MacAdam ellipses in the CIE 1931 xy-chromaticity diagram and the chromaticity-discrimination ellipses in the CIELAB space.The latter set was originally used to develop the CIEDE2000 color difference formula.The color difference can be calculated from the color density for the two colors under consideration.As a result,the color density represents the perceived color difference more accurately,and it could be used to characterize a color by a quantity attribute matching better to the perceived color difference from this color.Resulting from this,the color density concept provides simply a correction term for the estimation of the color differences.In the experiments,the line element formula and the CIEDE2000 color difference formula performed better than the color density based difference measures.The reason behind this is in the current modeling of the color density concept.The discrimination ellipses are typically described with three-dimensional data consisting of two axes,the major and the minor,and the inclination angle.The proposed color density is only a one-dimensional corrector for color differences;thus,it cannot capture all the details of the ellipse information.Still,the color density gives clearly more correct estimations to perceived color differences than Euclidean distances using directly the coordinates of the color space.

New LED light source system with uniform illumination for line-scan CCD imaging systems

A system with uniform light reflection in the inner surface within a horizontal 2/3 cylindrical structure for line-scan CCD of the print testing was designed. The design was based on diffuse reflection uniformity of the integrating sphere and requirement of the strip uniform illumination region. This system was called dome light. White light LED array light sources were used for uniform illumi- nation. The LEDs were filtrated to composite array light source based on coefficient of variation of a single LED. The standard white board and SG color checkers were used in the line-scan CCD imaging experiments under the dome light and ordinary illumination light source. The average color difference （AE） of SG color checkers in CIELAB space was 2. 091 under the dome light and 2. 286 under ordinary illumination light source respectively. Experimental results indicate that the dome light can satisfy illumination uniformity and color rendering consistency for line-scan CCD and provide a standard light source for uniform calibration of different cameras.

Effect of Bag Removing with Reflective Film Mulching Before Harvest on Fruit Coloration and Expression of Anthocyanin Related Genes in Peach

Appearance quality is the main element forming the fruit quality. Both bagging and reflective film application can improve appearance comprehensive quality. In order to determine the effects of bagging and reflective film on peach fruit coloration, this study explored the effects of applying reflective film before harvest on fruit appearance quality of peach(Prunus persica), and discussed the influencing mechanism on fruit coloration. Yellow outside and black inside double-layer bags were removed from fruit twelve days d before harvest. Peel color, pigment content, enzyme activity as well as the gene expression related to fruit coloration of a well-colored and late-ripening peach cultivar ‘Xiahui 8' with different treatments(non-bagging with non-reflective film mulching, debagging with non-reflective film mulching, debagging with reflective film mulching) were researched. The results showed that both debagging with non-reflective film mulching and debagging with reflective film mulching could significantly improve red and green color difference value(a*), a*/b*(b* is yellow and blue color difference value), chroma(C), anthocyanin(Ant) content and reduce hue angle(h), while debagging with reflective film mulching had higher Ant content than debagging with non-reflective film mulching(P < 0.05). The two treatments up-regulated the transcript level of anthocyanin biosynthetic related genes(UFGT, CHS) at the beginning of the experiment, however, the expression of DFR, LDOX and F3 H were enhanced along with the testing process. A downward trend on peel phenylalanine ammonia lyase(PAL) activity of non-bagging with non-reflective film mulching was observed during the experiment, however, the peel PAL activity of the other two treatments first increased and then decreased. What's more, peel PAL activity of debagging with reflective film mulching was higher than debagging with non-reflective film mulching. These results suggested that Ant synthesis in the peel was the result of cooperation among several genes, and debagging with reflective film mulching had better effect on promoting Ant accumulation than debagging with non-reflective film mulching.

Influence of different post core materials on the color of Empress 2 full ceramic crowns

Background For esthetic consideration, dentin color post core materials were normally used for all-ceramic crown restorations. However, in some cases, clinicians have to consider combining a full ceramic crown with a metal post core. Therefore, this experiment was conducted to test the esthetical possibility of applying cast metal post core in a full ceramic crown restoration.Methods The color of full ceramic crowns on gold and Nickel-Chrome post cores was compared with the color of the same crowns on tooth colored post cores. Different try-in pastes were used to imitate the influence of a composite cementation on the color of different restorative combinations. The majority of patients could not detect any color difference less than △E 1.8 between the two ceramic samples. So, △E 1.8 was taken as the objective evaluative criterion for the evaluation of color matching and patients＇ satisfaction. Results When the Empress 2 crown was combined with the gold alloy post core, the color of the resulting material was similar to that of a glass fiber reinforced resin post core （△E = 0.3）. The gold alloy post core and the try-in paste did not show a perceptible color change in the full ceramic crowns, which indicated that the color of the crowns might not be susceptible to change between lab and clinic as well as during the process of composite cementation. Without an opaque covering the Ni-Cr post core would cause an unacceptable color effect on the crown （△E = 2.0）, but with opaque covering, the color effect became more clinically satisfactory （△E = 1.8）. Conclusions It may be possible to apply a gold alloy post core in the Empress 2 full ceramic crown restoration when necessary. If a non-extractible Ni-Cr post core exists in the root canal, it might be possible to restore the tooth with an Empress 2 crown after covering the labial surface of the core with one layer of opaque resin cement.

Rapid identification of two-dimensional materials via machine learning assisted optic microscopy

A combination of Fresnel law and machine learning method is proposed to identify the layer counts of 2D materials.Three indexes,which are optical contrast,red-green-blue,total color difference,are presented to illustrate and simulate the visibility of 2D materials on Si/SiO_(2) substrate,and the machine learning algorithms,which are k-mean clustering and k-nearest neighbors,are employed to obtain thickness database of 2D material and test the optical images of 2D materials via red-green-blue index.The results show that this method can provide fast,accurate and large-area property of 2D material.With the combination of artificial intelligence and nanoscience,this machine learning assisted method eases the workload and promotes fundamental research of 2D materials.