Color measurement

Our color perception is characterized by subjective influences. Color measurement enables an objective description of colors. In this process, white light is sent onto a color sample and the reflected rays are measured as a percentage compared to a white standard. The physiological standard color values are first calculated from the physical measured values by standardized conversions. From these, the L*a*b* values can be determined as they are given by the CIE (Commission Internationale de l’Éclairage). While one geometry is sufficient for color pigments to describe them, several defined geometries are required for aluminum and interference pigments. These geometries (illumination and observation angles) are specified for the different measuring instruments.

True-Color Reconstruction Based on Hyperspectral LiDAR Echo Energy

With the development of remote sensing technology, the simultaneous acquisition of 3D point cloud and color information has become the constant goal for scientific research and commercial applications in this field. However, since radar echo data in practice refer to the value of the spectral channel and its corresponding energy, it is still impossible to obtain accurate tristimulus values of the point through color integral calculation after traditional normalization and multispectral correction. Furthermore, the reflectance of the target, the laser transmission power and other factors lead to the problems of no echo energy or weak echo energy in some bands of the visible spectrum, which further leads to large chromatic difference compared to the color calculated from the spectral reflectance of standard color card. In response to these problems, the hyperbolic tangent spectrum correction model with parameters is proposed for the spectrum correction of the acquired hyperspectral LiDAR in the 470–700 nm band. In addition, the improved gradient boosting decision tree sequence prediction algorithm is proposed for the reconstruction of missing spectrum in the 400–470 nm band where the echo energy is weak and missing. Experimental results show that there is relatively small chromatic difference between the obtained spectral information after correction and reconstruction and the spectrum of standard color card, achieving the purpose of true color reconstruction.

Simple Method for Detection of Potassium Iodate (KIO3) in a Kitchen Salt Using cassava starch (Manihot esculenta)

This research has been made a simple method for the detection of potassium iodate (KIO3) in a kitchen salt using cassava starch (Manihot esculenta). The process of making this test kits using acid solvent as the reagent, KIO3 solution, and indicator of cassava starch. The used cassava starch is in two conditions are dry starch for H2SO4 and wet starch for H3PO4. Based on the two solvents are then made a standard color series based on KIO3 levels of 10, 20, 30, 40, and 50 ppm. Validation of this method has analyzed using Spectrophotometer UV-Vis. From the results of this analysis obtained calibration curve of each standard with both solvent. Coefficients determination for linearity using H3PO4 and H2SO4 solution is 0.9874 and 0.9656. From that results from the H3PO4 solution applied to the detection of potassium iodate (KIO3) in a kitchen salt using cassava starch (Manihot esculenta) with a concentration in the range 30-40 ppm.

The Consistency Testing and Improving of A Hematuria Colorimetric Card

Background: A Hematuria colorimetric card could unify the description of gross hematuria, but the consistency in assessing hematuria samples of a hematuria colorimetric card for gross hematuria is still inconclusive. The consistency testing and improving of hematuria colorimetric card has potential clinical application value.Methods: According to 6 color scales (0~5), 31 hematuria samples were made. One sample was used to explain the use of hematuria colorimetric cards, and then the evaluator was asked to describe the color. After the remaining 30 samples were arranged in a random number table, 30 evaluators independently completed the hematuria sample assessment under the same conditions. Kendall W coordination coefficient was used to test inter-observer consistency. After 1 hour, 30 hematuria samples were rearranged by random digital table method, 15 of which were randomly selected from 30 evaluators, and 30 samples were evaluated independently under the same conditions. Adopt the method of Kappa to test the consistency of the two evaluation results. Results: In the study, the evaluator lacked unity in describing the same hematuria color, including six groups of descriptive words: gross hematuria, light blood, light red, blood, scarlet, carmine. Inter-observer (inter-group) consistency test, Kendall coordination factor was 0.881(F=766.34), P<0.05), the result indicats higher inter-observer agreement. For intra-observer (intra-group) consistency test, the kappa value of nurses was 0.909~1(P<0.05), the value of doctors was 0.818~0.95(P<0.05), and the value of students was 0.863~0.911(P<0.05), the results showed that intra-observer agreement was also high. Consistency results between grade evaluation results of hematuria samples and standard color numbers: the average consistency of evaluation results of standard color numbers 0~5 was 100%, 100%, 94.2%, 65.2%, 38%, 65.8% respectively. The the 4th color block with low discrimination in the primary hematuria colorimetric card was eliminated, and the 5th color block was reassigned to 4th. Thus the modified hematuria colorimetric card was divided into 5 grades.Conclusions: The improved hematuria colorimetric card has good consistency in hematuria evaluation and is an effective tool for evaluating hematuria grade, which is helpful to unify the evaluation standard of gross hematuria grade.

The relationship between body and substrate color for Ambystoma altamirani (Caudata: Ambystomatidae) from the Arroyo los Axolotes, Mexico

The relationship between body and substrate color for Ambystoma altamirani (Caudata: Ambystomatidae) from the Arroyo los Axolotes, Mexico. To determine whether the coloration of Ambystoma altamirani varies and whether the color is related to the color of the salamander’s substrate, A. altamirani from the Arroyo los Axolotes, state of México, Mexico, was examined. The study was conducted from February 2018 to January 2019, and the colors classified by comparison with a standard color wheel. The most common base color was olive-green (64%) followed by black (21%). The most common color combinations were olive-green with black markings (44%), solid black (14%), and olive-green with black and yellow markings (11%). Olive-green salamanders were present in every month of the study, whereas the other base colors were found in fewer months, with the greatest diversity of base colors being observed from April to July. Olive-green, black, and “light” A. altamirani were found on dark substrates more frequently than expected based on availability compared to intermediate or light substrates. Because there is no evidence for substrate color matching, substrate selection likely is based on other environmental features.