在400~720 nm波段范围,采用基于液晶可调谐滤波器(LCTF)和CMOS相机组合的多光谱成像系统对蜡染的布料进行每隔5 nm成像。讨论了多光谱成像的基本原理和多角度下彩色图像的实现过程,并且通过计算光谱反射率展示了光谱合成颜色的基本方法。对再现后的橘色、绿色、白色、蓝色、黄色、黑色六种颜色色块进行多角度下明度值、彩度值的分析。实验结果表明,六种颜色的明度值均呈现正态分布,并且通过计算六种颜色色块的色品坐标值a*、b*和彩度c*ab的均方差,得出在一定的范围内,六种颜色的色品坐标值a*、b*近似不随角度变化,其中蓝色和黑色随角度的变化更小,近似于一条直线。

Multispectral images of batik cloth at the wavelength range of 400~720 nm with an interval of 5 nm are captured by using a multispectral imaging system which mainly consists of liquid crystal tunable filter(LCTF) and CMOS camera.The paper discussed the basic principle of multispectral imaging and analyzed the implementation process of color image under multi-angles.Besides that,the paper showed the basic approach of synthetic color spectrum by calculating the spectral reflectance.Brightness values,chroma values under multi-angle of the reproduction of the orange,green,white,blue,yellow,black were analyzed.The results proved that all the six-color brightness values showed a normal distribution.Meanwhile,by calculating the six-color chromaticity coordinate values a*,b* and c*ab of standard deviation,the chromaticity coordinates a* and b* are merely changed in angle.Among them,the change of blue and black is smaller than the others,approximately as a straight line.