Search Results (28)

Fish coloration plays an important role in reproduction and camouflage, yet capturing color variation under field conditions remains challenging. We present a standardized, semi-automated protocol for measuring body coloration in the popular model fish threespine stickleback (Gasterosteus aculeatus). Individuals are photographed in a controlled light box within minutes of capture, and color is sampled from eight anatomically defined standard sites in human-perception-based CIELAB space. Analyses combine univariate color metrics, multivariate statistics, and the ΔE* perceptual difference index to detect subtle shifts in hue and brightness. Validation on pre-spawning fish shows the method reliably distinguishes males and females well before full breeding colors develop. Although it currently omits ultraviolet signals and fine-scale patterning, the approach scales efficiently to large sample sizes and varying lighting conditions, making it well suited for population-level surveys of camouflage dynamics, sexual dimorphism, and environmental influences on coloration in sticklebacks. Full article

Numerous existing methods demonstrate impressive performance in brightening low-illumination images but fail in detail enhancement and color correction. To tackle these challenges, this paper proposes a dual-branch network including three main parts: color space transformation, a color correction network (CC-Net), and a light-boosting network (LB-Net). Specifically, we first transfer the input into the CIELAB color space to extract luminosity and color components. Afterward, we employ LB-Net to effectively explore multiscale features via a carefully designed large–small-scale structure, which can adaptively adjust the brightness of the input images. And we use CC-Net, a U-shaped network, to generate noise-free images with vivid color. Additionally, an efficient feature interaction module is introduced for the interaction of the two branches’ information. Extensive experiments on low-light image enhancement public benchmarks demonstrate that our method outperforms state-of-the-art methods in restoring the quality of low-light images. Furthermore, experiments further indicate that our method significantly enhances performance in object detection under low-light conditions. Full article

Tofu is obtained by heating soymilk, to which a coagulant, such as calcium sulfate or magnesium chloride, is added to make it curdle. This study aimed to parameterize the effects of the following three alternative organic coagulant types: apple, rice, and white vinegars, used in different proportions. Six treatments were established with three concentrations (1%, 3%, and 5%), evaluating the coagulation time and curd yield. The treatments with the lowest coagulation time were analyzed for texture by TPA, color through the CIEL*a*b scale, protein content, and moisture. The results showed that the rice vinegar + 3% white vinegar (T6C3) treatment showed the lowest coagulation time (0.78 min). The 5% apple vinegar (T1C5) treatment provided the highest curd yield, averaging 23.73%. This treatment’s protein and moisture contents were 3.93% protein and 69.73% moisture, confirming that better texture characteristics are recorded in tofu at lower pH values. The TPA results showed that using apple and rice vinegars as coagulants provided a challenging, less cohesive, more adhesive, and less elastic tofu. White vinegar provided a soft, more cohesive, less adhesive, and more elastic tofu. In the color analysis, it was observed that tofu coagulated with apple vinegar showed a tendency toward a yellow color, and tofu coagulated with rice and white vinegars showed a tendency toward a white color. These findings parameterize the effects of using each type of vinegar as a coagulant. These organic coagulants provide faster coagulation times and desirable texture characteristics, thus offering a practical alternative to traditional coagulants in tofu manufacturing. Full article

The aim of this study was to cover biopolymeric packaging films based on PLA/PHBV blend with a functional composite coating (to retain their ecological character) and to investigate their antimicrobial properties before and after UV irradiation. As an active coating, the carrier hydroxypropyl methyl cellulose (HPMC), as well as its modified form with Achillea millefolium L., Hippophae rhamnoides L., and Hypericum L. extract (E) and a combined system based on the extracts and nano-ZnO (EZ), was used to obtain active formulations. Additionally, film surface morphology (SEM, FTIR-ATR) and color (CIELab scale) analysis of the pre- and post-UV-treatment samples were performed. The results confirmed that the E and EZ-modified films exhibited antibacterial properties, but they were not effective against phage phi6. Q-SUN irradiation led to a decrease in the activity of E coating against Staphylococcus aureus, Pseudomonas syringae, and Candida albicans. In this case, the effectiveness of EZ against C. albicans at 24 h and 72 h UV irradiation decreased. However, the irradiation boosted the antiviral effectiveness of the EZ layer. SEM micrographs of the film surface showed that UV treatment did not significantly influence the native film morphology, but it had an impact on the coated film. FTIR analysis results showed that the coatings based on HPMC altered the IR absorption of the nonpolar groups of the biopolyester material. The applied coatings only marginally affected film color changes and increased their yellowness after UV irradiation, whereas a composite layer of nano-ZnO limited these changes. Full article

Visual color determination is part of the daily routine in dental practice. However, it is not a part of dental education so far. The aim of this study was to evaluate whether visual or digital tooth color determination of 3D-printed teeth is a reliable tool for inexperienced dentistry students. Preclinical dental students evaluated eleven 3D-printed, tooth-shaped samples (VarseoSmile Crown plus, BEGO, Bremen, Germany) of different color shades. Visual shade determination using a reference scale (3D-Master Toothguide (3DM_TG), VITA Zahnfabrik, Bad Säckingen, Germany), followed by a digital color determination using a spectrophotometer (VITA Easyshade V, (ES_V), VITA Zahnfabrik), was performed. Color deviation was calculated in the Lab* color space (ΔE00) and converted into CIELAB 2000. The results were evaluated using the Mann–Whitney U test and the Wilcoxon Rank Sum test (α = 0.05). Significant differences between visual and digital color determination were proven (p < 0.001). Visual color determination (3DM_TG) showed a mean deviation (ΔE00 ± 95%CI) of 6.49 ± 0.47. Digital color determination (ES_V) showed significantly lower mean deviations of ΔE00 of 1.44 ± 0.58. Digital tooth color measurement using a spectrophotometer was a more reliable tool for the color determination of 3D-printed teeth for inexperienced dentistry students. Full article

Visual color determination (VCD) requires color competence and individual training. The aim of this study was to evaluate the deviations in students’ VCD with two different reference scales. The research hypothesis was that none of the color references would provide a better result. Participants evaluated nine templates randomly using two reference scales (VITA-classical (VC) and 3D-Master-Toothguide (3DM_TG)). The color distance to the chosen color (ΔE_ab) was calculated in the CIELAB 2000. The sum’s changes in the parameters (LCh°) represented the target variable. Results were evaluated with non-parametric, rank-scaled methods, utilizing the median with a 25%-75% quartile. The significance level (α = 0.05) is determined using the Student’s t-test. The mean ± 95%CI (SD) was −1.27 ± −1.09 (3.18); the median ΔE₀₀ was −1.49 (−1.97; 0.96) for dC_{3DM_TG}. The determination with VC showed noticeable differences (dC_VC), with a mean ΔE₀₀ of 0.00 ± 0.00 (2.20) and a median ΔE₀₀ of 0.00 (1.17; 1.71). The standard error was 0.19 for the dC_VC and 0.27 for the dC_{3DM_TG}. dC_{3DM_TG} vs. dC_VC showed significant differences at p < 0.001. The dental student’s VCD resulted in color deviations, regardless of the reference template used. The color deviations in hue and chroma were comparable, regardless of the reference scale. VCD’s early implementation in dental education is useful to avoid shade misjudgments and potentially expensive remakes of dentures. Full article

Self-cleaning products are commercially available to protect surfaces against soiling and avoid the high consumption of energy and chemical detergents necessary for cleaning. They are based on semiconductor oxides, mostly titanium dioxide (TiO₂), which induce photocatalytic oxidation activity and superhydrophilicity. Therefore, we present an experimental procedure at a lab scale to assess the self-cleaning ability of various photocatalytic coatings (five TiO₂-based commercial products and one lab-grade zinc oxide (ZnO) product) applied to mortar surfaces. The samples were artificially stained with three types of soiling: Congo red dye, diesel soot, and motor oil. They were exposed to the environmental cycle of UV illumination and water flow for two weeks and the changes in stain colors were first assessed with visual inspection. Then, spectrophotometry measurements were conducted before and after the self-cleaning experiment to calculate the color differences for each stain in the CIELab color space data. In addition, the coatings were characterized via X-ray diffraction analyses and water contact angle measurements. Results highlighted color changes for each stain and higher wettability (induced by OH radicals) of the coated surfaces, which favored surface washing and thus stain removal. Light also had a positive effect on the attenuation of the stains, particularly for the Congo red dye. Full article

The genus Passiflora spp. stands out as an important source of bioactive compounds and health promoters; however, not all its species have been studied in depth, as in the case of Passiflora pinntistipula, or “puro puro”. In this sense, the main objective of this research is to study the antioxidant capacity, physicochemical properties and rheological behavior of “puro puro” juice from the Pamuri Community, Tayacaja Province, Huancavelica. The physicochemical characterization was carried out according to the official methods of international analysis (AOAC). The parameters evaluated were the percentage of humidity (66%), ashes (3%), fat (1.5%), proteins (4.5%), carbohydrates (25%), total energy (100%), pH (4.5), total acidity (1.3%), and soluble solids (18.5%). The color was determined on the CieLab scale and was L* (34.5), a* (1.2), b (4.4), C* (4.5) and h* (74.3). The antioxidant capacity was evaluated with the 2,2′-azino-bis (3-ethylbenziozoline-6)-sulfonic acid (ABTS) method, and the value obtained was 5.2 µmol-Equi. Trolox/g. The rheological parameters of the pure cigar juice were evaluated using a rotary viscometer at temperatures of 15, 20, 25, and 30 °C; and in concentrations of 18.5, 20, 25, 30, and 35 °Brix. The power law model fitted the experimental results and showed non-Newtonian flow behavior. The value of the flow behavior index (n) was less than unity at all temperatures and concentrations, indicating the pseudoplastic nature of the juice. The Arrhenius model was able to relate apparent viscosity to temperature. The consistency index (k) varied in the range between 0.42 and 1.38 Pa sⁿ, and flow behavior index (n) was in the range between 0.26 and 0.55. Full article

Cucurbita moschata, commonly known as winter squash, tropical squash, and calabaza, is native to Central America. This tropical squash thrives in tropical and subtropical climates, including parts of the southeastern U.S. and is very popular among people of Hispanic and West Indian heritage. Development of calabaza cultivars that meet consumer acceptability is a major goal in breeding programs. The current study aims to determine and compare the quality parameters of novel calabaza germplasm lines with that of commercially available cultivars of calabaza (La Estrella and Soler) and butternut squash (Whatman Butternut). All cultivars ranged greatly in quality parameters, with the most promising germplasms highlighted within the study including UFTP 8 and UFTP 24. The basis of this ranking was dependent on these germplasm lines’ desirable attributes, including their color saturation (chroma (>80) (using the CIELAB scale)), °Brix (11.6 and 10.7 respectively), yeast fermentable extract (>67%), and firmness/hardness, (>3600). These findings show the potential to enhance consumer preferences for calabaza through breeding and provides a basis for commercial release of the superior germplasm identified. Full article

The color appearance of residential carpets under different illuminants can influence the purchase decisions of consumers, visual merchandisers, and interior designers. This study was designed to investigate and characterize the color appearance of residential carpets under average Noon Daylight (D65), Incandescent (A), and Cool White Fluorescent (F02) illuminants commonly used in retail and household settings. The objective of this study was to identify the key features significantly affecting the apparent color of the carpets under those three illuminants. Four different carpets were dyed with light, medium, and dark shades of red and green colors to identify the difference in color perception when illuminated by different lighting arrangements. A spectrophotometer was used to measure the lightness, chroma, and hue of the carpets via the CIELAB scale developed by Commission Internationale de l’Eclairage (CIE). Statistically significant differences among the L*, a*, and b* values of the carpets were evaluated using Analysis of Variance (ANOVA). Regression analyses were carried out to identify key parameters affecting the L*, a* and b* values. Multiple linear regression (MLR) was applied to generate equations to predict L*, a* and b* values under different illuminant for different carpet features. A decreasing trend in the L*, a*, and b* values have been observed from lighter to darker shades under the illuminants for all the carpets. The deposition of dye molecules over the carpet surface had significant effects on the CIELAB values, and the distribution of dye molecules over the carpet surface was influenced by the constructional parameters of the carpets. The study provides an overview of the effects of carpet structures on color perception under different illuminants, which could help the researcher to determine the apparent color of different carpets under various illuminants. Full article

We aimed to assess the influence of professional dental prophylaxis on the translucency and color stability of a novel simplified shade nanohybrid composite material. Sixty composite disks (5 mm in diameter and 2 mm thick) of light (n = 30) and dark (n = 30) shades were prepared. The specimens were randomly divided into the following three groups (n = 10) according to the prophylaxis procedure used: ultrasonic scaling, air-powder polishing with sodium bicarbonate, and controls. The specimens were submitted to translucency and color analysis based on the CIELab system. Two measurements were performed before and after 48-h storage in coffee. Translucency values of untreated light and dark specimens were 9.15 ± 0.38 and 5.28 ± 1.10, respectively. Air-powder polishing decreased the translucency of the light composite specimens. Storage in coffee resulted in color changes (∆E) ranging between 2.69 and 12.05 and a mean translucency decrease ranging between −0.88 and −6.91. The samples in the light group tended to exhibit greater staining; the treatment method had no effect on ∆E. It can be concluded that light-shade composite restorations are more prone to translucency and color changes resulting from air-powder polishing and contact with staining media. However, further research using other composites and powders is required. Full article

The current color-difference formulas were developed based on 2D samples and there is no standard guidance for the color-difference evaluation of 3D objects. The aim of this study was to test and optimize the CIELAB and CIEDE2000 color-difference formulas by using 42 pairs of 3D-printed spherical samples in Experiment I and 40 sample pairs in Experiment II. Fifteen human observers with normal color vision were invited to attend the visual experiments under simulated D65 illumination and assess the color differences of the 82 pairs of 3D spherical samples using the gray-scale method. The performances of the CIELAB and CIEDE2000 formulas were quantified by the STRESS index and F-test with respect to the collected visual results and three different optimization methods were performed on the original color-difference formulas by using the data from the 42 sample pairs in Experiment I. It was found that the optimum parametric factors for CIELAB were $k_L$ = 1.4 and $k_C$ = 1.9, whereas for CIEDE2000, $k_L$ = 1.5. The visual data of the 40 sample pairs in Experiment II were used to test the performance of the optimized formulas and the STRESS values obtained for CIELAB/CIEDE2000 were 32.8/32.9 for the original formulas and 25.3/25.4 for the optimized formulas. The F-test results indicated that a significant improvement was achieved using the proposed optimization of the parametric factors applied to both color-difference formulas for 3D-printed spherical samples. Full article

Soil water content (SWC) is a critical indicator for engineering construction, crop production, and the hydrologic cycle. The rapid and accurate assessment of SWC is of great importance. At present, digital images are becoming increasingly popular in environmental monitoring and soil property analysis owing to the advantages of non-destructiveness, cheapness, and high-efficiency. However, the capture of high-quality digital image and effective color information acquisition is challenging. For this reason, a photographic platform with an integrated experimental structure configuration was designed to yield high-quality soil images. The detrimental parameters of the platform including type and intensity of the light source and the camera shooting angle were determined after systematic exploration. A new method based on Gaussian fitting gray histogram for extracting RGB image feature parameters was proposed and validated. The correlation between 21 characteristic parameters of five color spaces (RGB, HLS, CIEXYZ, CIELAB, and CIELUV) and SWC was investigated. The model for the relationship between characteristic parameters and SWC was constructed by using least squares regression (LSR), stepwise regression (STR), and partial least squares regression (PLSR). Findings showed that the camera platform equipped with 45° illumination D65 light source, 90° shooting angle, 1900~2500 lx surface illumination, and operating at ambient temperature difference of 5 °C could produce highly reproducible and stable soil color information. The effects of image scale had a great influence on color feature extraction. The entire area of soil image, i.e., 3,000,000 pixels, was chosen in conjunction with a new method for obtaining color features, which is beneficial to eliminate the interference of uneven lightness and micro-topography of soil samples. For the five color spaces and related 21 characteristic parameters, RGB and CIEXYZ spaces and characteristic parameter of lightness both exhibited the strongest correlation with SWC. The PLSR model based on soil specimen images ID had an excellent predictive accuracy and the best stability (R² = 0.999, RMSE = 0.236). This study showed the potential of the application of color information of digital images to predict SWC in agriculture and geotechnical engineering. Full article

Natural fortification can be used to increase the mineral content of the edible part of plants. In horticultural crops, foliar fertilization is used extensively, being a way to provide nutrients through leaves (a faster way compared to soil applications). Moreover, Fe and Zn are two important nutrients for plant growth and development, despite the low kinetic mobility. As such, considering the importance of Fe and Zn in plants and the fact that tomato is one of the most consumed horticultural crops worldwide, this study aimed to verify whether, in the middle of a biofortification process (after two foliar applications), Fe and Zn content in tomatoes of Solanum lycopersicum (beef heart variety, also known as Coeur de Boeuf) organically grown can improve. The experimental field was selected and the protocols for tomato growth were followed in accordance with the organic production mode. Two foliar applications were carried out during the production cycle, with a mix of two products of Fe and Zn (Zitrilon–15% and Maxiblend) with two concentrations (treatment 1 and treatment 2, corresponding to a mix of Ziltrilon and Maxiblend of 0.40 and 1 kg·ha⁻¹ and 1.20 and 4 kg·ha⁻¹). Through X-ray fluorescence using a XRF analyzer under He atmosphere, leaves of tomatoes submitted to the biofortification process showed an increase of 76.9% of Fe content and double Zn content, in treatment 2. However, treatment 1 only showed increases in Zn content (by 75.5% compared to control). Regarding tomato fruits, treatment 2 showed an increase of 7% of Zn content, relative to control content. Naturally enriched tomatoes with Fe and Zn showed minor changes in colorimetric parameters (chroma and hue) and no significant differences in L parameter (brightness/luminosity), relative to control. Additionally, biofortification did not affect the tomatoes’ height and diameter at this stage of development, varying between 75.7–84.3 mm and 76.7–93.3 mm, respectively. In conclusion, two foliar sprays of Fe and Zn can improve tomato and leaf content under organic production practices without triggering toxicity to the plants or affecting tomatoes height and diameter, and only minor changes in color parameters were presented (CieLab scale). Full article

Remote sensed data already have an important role in crop management. In fact, NDVI (normalized difference vegetation index) has been use for staple crop management and monitorization since the 1980s, namely, in rice, wheat and maize. Accordingly, this study aimed to monitor, through precision agriculture, the development of a highly produced and consumed rice genotype in Portugal (Ariete variety), submitted to a selenium biofortification workflow. Rice biofortification was promoted during the production cycle, and assessed after two foliar applications with selenium (sprayed with 50 and 100 g Se·ha⁻¹ of sodium selenite). In this context, NDVI showed a high and identical value between control and biofortified plants, which indicated that the culture displayed a higher vigor and was in a healthy state of development despite foliar applications. Analyzes were further carried out for monitor the mobilization of photoassimilates, showing that plants did not demonstrate any negative impact on net photosynthesis and there was even a slight rise in the treatments. Additionally, to characterize the soil of the paddy rice field, some parameters were also analyzed, namely, organic matter, humidity, pH and electrical conductivity, being found that the parameters ranged between from 1.085–1.575%, 12.05–17.45%, 5.70–6.20, respectively, whereas the average conductivity was 223.4 µS cm⁻¹. Concerning to soil color, and considering the parameters L, a* and b* of the CIELab scale, significantly higher values in samples without humidity and without humidity and organic matter were found. In spite of the differences found, it is concluded that biofortification process did not affect any physiological parameters (net photosynthesis–Pn, stomatal conductance to water vapor—gs, transpiration rates—E and instantaneous water use efficiency—iWUE) in rice plants. Full article