Hue Angle Difference Research Articles

Visual Communication Design Features Based on Traditional Animal and Plant Patterns

Abstract This paper contributes to the visual communication design of traditional animal and plant patterns by recreating the traditional pattern graphics based on the specific skeletal laws of traditional patterns. Based on the demand for vectorization of traditional animal and plant tattoos, a vectorization algorithm based on edge structure extraction is proposed to pre-process the tattoos using the gradient minimization model, and the tattoos are processed by image vectorization using the edge structure extraction algorithm of clustered segmentation and the Bézier curve fitting algorithm of the least squares method. Based on the image vectorization rendering of traditional animal and plant patterns, the visual communication design is carried out, and the color matching effect is analyzed in terms of single-factor color matching and comprehensive color matching. 10 extracted colors are analyzed in terms of the hue angle difference on the color ring, and the two comparative colors are the contrasting colors when the angle difference is 120~180°. The contrast height is highest when the difference value is 180°.

Effect of Drying on Lettuce Leaves Using Indirect Solar Dryer Assisted with Photovoltaic Cells and Thermal Energy Storage

The thin layer drying behavior of lettuce leaves was investigated using an indirect pilot solar dryer with thermal energy storage in water, equipped with solar collectors and photovoltaic cells. The drying procedure consisted of shredded lettuce leaves, temperature ≤ 52 °C, airspeed, 1.0 m∙s−1, and process time ~10.0 h. Fifteen drying models were adjusted to the experimental data obtained; three models with maximum values of coefficient of determination (R2)—Page, Midilli, and Kucuk, and Weibull Distribution, whose values of R2 ≥ 0.998, and other statistical parameters, χ2, SSE, and RMSE values closer to zero were chosen. The initial browning index BI = 120.5 ± 0.7 decreased compared to the dry sample BI = 78.99 ± 0.5, with chromatic coordinate degradations a* and b*; but not the luminosity L*; where ΔE = 8.26; whose meaning is that the dry sample is a “more opaque brownish color” due to the difference in the chroma ΔC = 6.65, and with a change from the yellow-green to yellow-red zone, and a difference in hue angle, Δh° = 14.27, between the fresh and the dried sample. Deff values for shredded lettuce leaves were 1.8 × 10−9 m2 s−1 for values ≤ 52 °C.

LC–MS untargeted metabolomics reveals early biomarkers to predict browning of fresh-cut lettuce

A complete untargeted metabolomics study was developed to identify biomarkers related to the browning of fresh-cut lettuce which is the main cause of quality loss. For this purpose, UPLC-MS-QTOF analysis was optimized to explore the metabolome of 30 selected cultivars of romaine lettuce with different browning susceptibility harvested at three different harvest dates. Different multivariate analyses and statistics software, such as Agilent Mass Profiler Professional (MPP), SIMCA and The Unscrambler, were used for the selection of entities correlated with browning induced after cutting and storage. A group of metabolites that were identified through the analysis of different databases and comparison with authentic standards when available, highly correlated with browning measured by image analysis measuring Hue angle difference between day 0 and day 5 of storage at 7 °C. A Multiple Linear Regression (MLR) model combined entities matrix and browning. At day 0 the metabolites that correlated positively (P ≤ 0.01) with browning development at day 5 were caffeoylquinic acid and 3-hydroxy-tetradecadienoic acid while ferulic acid methyl ester and 2-O-p-hydroxyphenyl-6-O-galloyl glucose correlated negatively (P ≤ 0.01). This study also confirmed the involvement of different types of metabolites (phenolic compounds, lipids and, terpenes) in the development of browning. A ratio ferulic acid methyl ester/caffeoylquinic acid at time 0 was able to predict browning after 5 days of storage in 70% of the cases.

Detection of nickel in maize roots: A novel nondestructive approach by reflectance spectroscopy and colorimetric models

In this paper, a novel method capable of assessing nickel (Ni) uptake in intact plant roots is proposed and validated. Dimethylglyoxime (DMG) was used to stain roots of seven-day-old maize (Zea mays L.) seedlings grown in solutions containing 0, 0.025, 0.1, 0.2, and 0.5mM Ni2+. A nondestructive approach by using reflectance spectroscopy and CIE XYZ and CIE L*a*b* color systems was used to investigate their optical properties. The maximum intensity in reflectance spectra at 545nm (A545) was used to monitor the development of DMG–Ni complexes. The values of A545 were polynomially related to the concentration of Ni2+ in the growing solution (R2=0.98), and significant correlations were also observed between A545 and the two indicators of phytotoxicity, namely, root growth inhibition (I) and variations in the shoot-to-root ratio (S/R). The variation of dominant wavelength (λd) and excitation purity (Pe) graphically derived from the x, y color gamut in the CIE XYZ system paralleled the two highest Ni concentrations. Most of the color parameters in the CIE L*a*b* system were closely related to both Ni2+ concentrations in plant growing medium and the values of (I) and (S/R) used here as markers of Ni toxicity. The revealed dependences confirm that the prelaminar method proposed here is capable of nondestructive estimating of Ni concentrations in intact root tissue. The values of A545 in the reflectance spectra of stained roots and color parameters, namely, opponent redness–greenness (a*), integral color difference (ΔE)*, lightness color difference (ΔL)*, and hue angle difference (ΔH)*, showed the highest potential for diagnostic purposes.

Chromatic adaptation to illumination investigated with adapting and adapted color

AbstractThe state of chromatic adaptation was investigated by using the two‐room technique. This technique involves a subject in a room who looks a white board in a separate test room through a window and judges the color of the window using the elementary color naming method. When the subject room is illuminated with a colored light and the test room with a white light, the window appears to be a very vivid color, for which the apparent hue depends on the color of the subject room. The color is referred to as the adapted color. The subject also evaluated the appearance of the illumination color of the subject room, which is called the adapting color. Two types of illuminating light in the subject room, fluorescent lamps with 7 colors and LED lamps with 19 colors, were employed. The adapting and the adapted colors were plotted on a polar diagram that was used in the opponent color theory, from which the hue angles were obtained. The hue angle difference between the two colors did not appear to be 180° except for one pair of adapting and the adapted colors, which implies that chromatic adaptation does not follow the opponent color concept. An improvement was achieved to explain the results by introducing complementary colors relation between the adapting and adapted color.

Effect of hyperbaric pressure and temperature on respiration rates and quality attributes of tomato

Previous work with hyperbaric treatment of tomato focused on application at lower temperature (13°C). In this work, hyperbaric treatment at varying pressure levels (i.e., 0.1, 0.3, 0.5, 0.7 and 0.9MPa) at ambient temperature (20°C) was tested as a potential alternative to conventional refrigerated storage (0.1MPa at 13°C) to preserve tomato quality. The experiments were divided into 3 phases: (1) 4 day of hyperbaric treatment, (2) 5 day of post-treatment ripening, and (3) 10 day of post-treatment ripening. Respiration rate (RR) of the tomatoes was continuously monitored during the course of the hyperbaric treatments. Quality attributes were assessed immediately after removal from the hyperbaric treatments and after 5 and 10 day ripening at 20°C after removal from the treatments. Hyperbaric treatments at ≥0.3MPa resulted in RR equal or higher than the RR in control fruit (0.1MPa at 20°C). The lowest RR was obtained from tomato stored at 0.1MPa at 13°C. Hyperbaric treatment at 0.5, 0.7 and 0.9MPa significantly reduced weight loss, retained color, firmness, total soluble solid (TSS), titratable acidity (TA) and TSS:TA ratio at similar levels as the tomato treated at 13°C and 0.1MPa. Firmness after treatment was highest for fruit from 0.1MPa at 13°C and from 0.5, 0.7 and 0.9MPa at 20°C. The higher firmness advantage declined by 5 day of ripening after treatment, with higher firmness only being retained for fruit from the 0.9MPa at 20°C and the 0.1MPa at 13°C treatments. After 10 day ripening, firmness was similar for all treatments. Lightness (L*) and hue angle were greater for all treatments compared with the 0.1MPa at 20°C treatment. However, only the greater hue angle difference was maintained after 5 day of ripening. After 10 day ripening, no significant differences were found in color attributes. Only 0.1MPa at 13°C retained higher soluble solids, lower titratable acidity and higher TSS:TA ratios after treatment and after 5 day ripening. At 10 day of ripening none of the quality attribute differences noted were retained for any of the treatments. These results show that the only consistent effect of hyperbaric treatment at 0.5, 0.7 and 0.9MPa was to reduce weight loss and enhance firmness retention up to 5 day ripening after treatment.

Soak Colored Zirconia Ceramics and its Colorimetric Plate

Objective: To test specimens of soak-colored Vita In-Ceram YZ zirconia ceramics and the colorimetric data of staining solution colorimetric plate. Methods: five sets of specimens were prepared, soaking and coloring them with LL1 to LL5 staining solution for 2 min respectively. Specimens were sintered for 2 h at 1530°C, and grinded one side of the specimens to 1.5 mm in thickness. The colors of the specimens and staining solution colorimetric plate were tested by spectrophotometer in black background. The chromatic aberration between the specimens and colorimetric plate were calculated as well as measured the lightness difference, hue angle difference, and saturation difference. Results: the colorimetric data of the dyed specimens are L: 59.81 ~ 78.93; a: 0.36 ~ 9.36; b: 19.62 ~ 26.91. The color space of the specimens and staining solution colorimetric plate was similar and the chromatic aberration was 4.02-6.96 NBS units. The biggest difference between them was the hue angle difference, mean 7.38, followed by the saturation difference, mean 2.31; minimum lightness difference, mean 2.29. Conclusion: staining solution colorimetric plate was suitable to be colorimetric reference for the color-matching of the basic layer of the ceramic. Proper chromatic aberration leaves color revision space for the translucent porcelain veneer.

Impact of dietary carotenoid and packaging during frozen storage on the quality of rainbow trout (Oncorhynchus mykiss) fed carotenoids

The storage life of frozen salmonids is often limited primarily by oxidation and flesh discolouration due to carotenoid degradation. The objective of this research was to determine the carotenoid changes and therefore the muscle colour modifications during 6 months of frozen storage (-18 °C) of whole rainbow trout fed astaxanthin (100 ppm) or canthaxanthin (80 ppm), kept under two different packagings: plastic film and cardboard box. After 6 months of frozen storage, the carotenoid type effect was seen for dry matter while there was no packaging material effect on carotenoid, total lipids, and TBARS contents of trout fillets. The time under frozen storage had an effect on carotenoid and TBARS fillet concentration. The carotenoid-type effect was noted for the four colour parameters (lightness difference, chroma difference, hue angle difference, and total colour difference) of rainbow trout fillet, while the packaging material effect was observed only for chroma. Frozen storage time had an effect on the four colour parameters of rainbow trout fillet. Carotenoid and packaging material effects were more marked for colour parameters than for biochemical parameters. In this study, as fish were frozen and stored as whole fish, fish skin provided good protection against oxidation.

19.4: Color Management Technologies on WideGamut Display Devices with MultiPrimary Colors

AbstractWe propose two color management systems for the cases of 1 RGB input signals to RGBbased display devices and 2 RGB input signals to multiprimary color MPC display devices. for RGB to RGB, our algorithm reproduces “memory colors” as expected and also uses the capability of a display device. for RGB to MPC, we solve a problem causing the hue angle difference between input signals and an MPC display. This realizes faithful hue reproduction as expected in an input image in addition to impressively widegamut of an MPC system.

Quantification of dichromatism: a characteristic of color in transparent materials

The color of a material, such as solution of a dye, can change by changing parameters like pH, temperature, illumination direction, and illumination type. Dichromatism -- a color change due to the difference in thickness of the material -- has long been known as a property of only a few materials. Here we show that dichromatism is a common property of many substances and materials, and we introduce a method for its quantification. We defined dichromaticity index (DI) as the difference in hue angle (Delta h(ab)) between the color of the sample at the dilution, where the chroma is maximal, and the color of four times more diluted (or thinner) and four times more concentrated (or thicker) sample. The two hue angle differences are called dichromaticity index toward lighter (DI(L)) and dichromaticity index toward darker (DI(D)), respectively. High dichromaticity was found for materials that were previously known as dichromatic (pumpkin oil, bromophenol).

Color Demosaicing Using Asymmetric Directional Interpolation and Hue Vector Smoothing

This paper presents a color demosaicing method applied to the Bayer pattern color filter array (CFA). Reliable estimation of an edge direction, edge-directed asymmetric interpolation, and the use of color samples at immediate neighbors are considered as the key guidelines for smooth and sharp image restoration. Also, special interest is directed to local areas that are rich in high spatial frequency variations. For suppression of false colors likely to occur in those areas, a hue vector representation is introduced so that the spatial correlation between different color components may be exploited in consistent with the local constant-hue principle. Smoothing is repeated in the hue vector field a few times. Experimental results have shown preferable performances in terms of PSNR, CIELAB color difference, hue angle difference, CIE chromaticity and visual appearance, in particular resulting in less false colors.

Comparison of the color of natural teeth measured by a colorimeter and Shade Vision System

Objectives The objectives were to measure the difference in the color and color parameters of natural teeth measured by a tristimulus colorimeter (CM, used as a reference) and Shade Vision System (SV), and to determine the influence of color parameters on the color difference between the values measured by two instruments. Method Color of 12 maxillary and mandibular anterior teeth was measured by CM and SV for 47 volunteers (number of teeth = 564). Color parameters such as CIE L *, a * and b * values, chroma and hue angle measured by two instruments were compared. Chroma was calculated as C a b * = ( a * 2 + b * 2 ) 1 / 2 , and hue angle was calculated as h° = arctan( b */ a *). The influence of color parameters measured by CM on the color difference ( Δ E a b * ) between the values measured by two instruments was analyzed with multiple regression analysis ( α = 0.01). Results Mean Δ E a b * value between the values measured by two instruments was 21.7 (±3.7), and the mean difference in lightness (CIE L *) and chroma was 16.2 (±3.9) and 13.2 (±3.0), respectively. Difference in hue angle was high as 132.7 (±53.3)°. Except for the hue angle, all the color parameters showed significant correlations and the coefficient of determination ( r 2) was in the range of 0.089–0.478. Based on multiple regression analysis, the standardized partial correlation coefficient ( β) of the included predictors for the color difference was −0.710 for CIE L * and −0.300 for C a b * ( p < 0.01). Conclusion All the color parameters showed significant but weak correlations except for hue angle. When lightness and chroma of teeth were high, color difference between the values measured by two instruments was small. Clinical accuracy of two instruments should be investigated further.

Seasonal variation in pigmentation and anthocyanidin phenetics in commercial Eustoma flowers

The seasonal change in petal color and pigmentation of 29 commercial Eustoma cultivars was studied. The flowers are basically divided into four groups according to the major anthocyanidin phenotype in association with petal coloration, i.e., delphinidin (Dp)-based (purple flower), cyanidin (Cy)-based (reddish purple flower), pelargonidin (Pg)-based (pink flower), and none (white flower) groups. The constitution of petal anthocyanidins was not changed by forcing treatment in most of the flowers. Lightness ( L ∗ ) and chroma ( C ∗ , color saturation) showed a change along with the increase/decrease of hue angle difference (Δ H ∗ ), thus simultaneously the chromatic tonalities tended to move to redder and bluer, respectively. Floral pigment clustering described two flower groups in a dendrogram, based on anthocyanidin constitutions as phenetic markers, which are apparently the Dp- and Pg-based phenotypes of anthocyanidin syntheses. The Cy-based flowers made a subcluster with the Pg-based flowers, indicating a close relationship in the biosynthesis of the two anthocyanidins, and suggesting the Dp- and Pg-syntheses complement one another.

Seasonal variation in pigmentation and anthocyanidin phenetics in commercial Eustoma flowers

The seasonal change in petal color and pigmentation of 29 commercial Eustoma cultivars was studied. The flowers are basically divided into four groups according to the major anthocyanidin phenotype in association with petal coloration, i.e., delphinidin (Dp)-based (purple flower), cyanidin (Cy)-based (reddish purple flower), pelargonidin (Pg)-based (pink flower), and none (white flower) groups. The constitution of petal anthocyanidins was not changed by forcing treatment in most of the flowers. Lightness ( L ∗) and chroma ( C ∗, color saturation) showed a change along with the increase/decrease of hue angle difference (Δ H ∗), thus simultaneously the chromatic tonalities tended to move to redder and bluer, respectively. Floral pigment clustering described two flower groups in a dendrogram, based on anthocyanidin constitutions as phenetic markers, which are apparently the Dp- and Pg-based phenotypes of anthocyanidin syntheses. The Cy-based flowers made a subcluster with the Pg-based flowers, indicating a close relationship in the biosynthesis of the two anthocyanidins, and suggesting the Dp- and Pg-syntheses complement one another.

Changes in colour of beef m. longissimus dorsi muscle during ageing

The effects of vacuum packaging, chilling rate (slow or fast), and fat cover thickness (⩽4 mm or 7–8 mm) on the colour parameters of beef m. longissimus dorsi muscle were assessed during ageing. The m. longissimus dorsi muscle was aged on the carcass or in vacuum packaging. Muscle samples for analysis were taken on days 0 (24 hr post mortem), 2, 4, 8, 12 and 16 to ascertain the parameters. Ageing time influenced all colour parameters, while chilling rate affected lightness (‘ L’), yellowness (‘ b’), and hue angle difference ( HD), and fat cover thickness influenced ‘ L’ and ‘ b’ only.

Viewing‐angle evaluation method of color shift for LCDs with gray‐scale images

Abstract— The viewing‐angle characteristics of LCDs with gray‐scale images were evaluated using parameters related to color. The results were compared with the subjectively estimated results. It was found that iso‐curves of the maximum value of the difference in hue angle are useful in evaluating the viewing‐angle characteristics of LCDs.