The method of computer color matching gradually replaces the artificial color matching method of giving pigment formula by experience.According to the calculation method of the cie color system, the color of the object can be measured by the instrument.The basic color of computer color matching and its chromaticity value play a decisive role in the efficiency and quality of computer color matching.However, the spectral characteristics and chromaticity values of the basic colors of computer color matching are easily affected by many factors, and the stability of chromaticity values is not strong.This topic intends to study the spectral properties of a large number of pigment samples and calculate the color value, select the red, yellow and blue base pigments that meet the camouflage requirements, and then study the factors that may cause the color chromaticity value of the camouflage. Within the required range, the camouflage base color and its chromaticity value are determined, which lays a foundation for constructing a color database related to the color matching and chromaticity of the computer color matching.
It is an important factor for affecting camouflage effects, but copying background color with empirical color matching has poor accuracy. This paper chose cadmium red, cadmium yellow and other colors basing on the performance requirements of same-color same-spectrum; prepared pastes and swatches with different grinding times particle sizes, were to measure their spectral reflection characteristics; then selected cadmium red, cadmium yellow and cobalt blue as the base pigments, which are roughly the same as the natural background-green in the infrared band spectral reflectance curve. Carried out a large number of experiments to prepare several green color samples from pale green, light green, medium green to blackish green and recorded the basic color ratio to construct a basic green pigment formula library according to the color reduction principle of color mixing. Respectively establish a mathematical model of the chromaticity values and the mass ratio of the yellow and blue base pigments, verify the model by using multiple nonlinear regression methods in SPSS, and verify the regression significant effect of the model built. Using the color-difference calculation formula, a nonlinear function model is established, and the minimum point of the function is found by MATLAB neural network genetic algorithm, and the mass ratio of the base pigment of the simulated background color is obtained. The results show that the spectral curve satisfies the requirement of the same-color same-spectrum compared to the background, which can meet the needs of camouflage color matching and provide a scheme for camouflage color matching automation and intelligent.
The development of materials with spectral characteristics of plants is a hot topic in the field of camouflage.Based on the similarity and molecular modifiability of phthalocyanine (Pc) and chlorophyll-porphyrin structures, tetra nitro cobalt phthalocyanine(TNCoPc) with central cobalt ion and alpha position nitro substituted are designed and analysed.Structural optimization of phthalocyanine, cobalt phthalocyanine (CoPc), tetra nitro phthalocyanine (TNPc) and TNCoPc are carried out using the density functional theory B3LYP / 6-31G (d), after which the TD-DFT is used to calculate the UV-Vis spectra. The HOMO-LUMO level comparison diagram of CoPc and Pc molecules and frontier molecular orbital map according to the calculation results of TD-DFT which is based on the optimized geometry are drawn out and compared respectively. The results show that, affected by the d7 electronic structure of cobalt ion and the ligands, 7 electrons of 3d orbitals involved in forming four equivalent dsp2 hybrid orbitals so that the valence electron layer has unpaired single spins, resulting in two kinds of energy gaps of alpha and beta.The energy difference of CoPc is 0.1ev larger than that of Pc so that the blue shift of Q band is observed.The absorption of TNPc is influenced by the electron withdrawing group and the conjugation of the C=O double bond on the nitro group,the energy level difference decreases and the absorption band shifts to longer wavelengths.The absorption of TNCoPc at 652.84nm is mainly the transition of electrons from orbit 188HOMO-1 to 191LUMO+2, and the absorption at 603.19nm is mainly the transition of electrons from orbit 190HOMO to 191LUMO.The results of TNCoPc quantitative calculation provides a reliable and convenient method for the use of phthalocyanines to fit the spectrum of plants.