%A %T Preliminary Study in Spectral Mixing Model of Mineral Pigments on Chinese Ancient Paintings-Take Azurite and Malachite for Example %0 Journal Article %D 2018 %J SPECTROSCOPY AND SPECTRAL ANALYSIS %R 10.3964/j.issn.1000-0593(2018)08-2612-05 %P 2612-2616 %V 38 %N 08 %U {https://www.gpxygpfx.com/CN/abstract/article_10004.shtml} %8 2018-08-01 %X Hyperspectral remote sensing technology is completely non-invasive for cultural relics, and suitable for identification and analysis of pigments of Chinese ancient paintings and other cultural relics, but the quantitative analysis of the mixed pigments composition in the ancient paintings is still a difficulty. For the mixed pigments phenomenon which often appears in Chinese ancient paintings, taking an example of azurite and malachite, two typical mineral pigments, we choose the two kinds of mineral pigment powder with the same size, precisely compound these two kinds of pigments to obtain pigment samples, and then obtain their spectra understrict control of experimental conditions . For mixed spectra, we use fully constrained least square method for spectral unmixing with full bands and use derivative of ratio spectroscopy for spectral unmixing with single band, then evaluate the unmixing accuracy, compare and analyze the unmixing results, and finally discuss the spectral mixing model of these two kinds of mineral pigments. Experimental results show that the spectral mixtures of azurite and malachite display strong nonlinear mixing characteristics overall, but are in accordance with linear mixing model in some strong linear bands. Using derivative of ratio method for spectral unmixing at these bands, we can achieve much higher unmixing accuracy than spectral unmixing with full bands.