“…Spectral imaging technology in accordance with di®erent spectroscopy can be divided into UVvisible spectral imaging,°uorescence spectral imaging, near infrared spectral imaging, mid-infrared spectral imaging, Raman spectral imaging and NMR imaging. 13,14 Traditional infrared spectroscopy obtained the average spectrum of a single point or small area, which is the average composition of the sample or the characteristics, ideally suited for the analysis of homogeneous material. Macro-infrared spectral imaging technology is complementary to traditional IR techniques, which can achieve the spatial and concentration distribution of di®erent components in the nonuniformly mixed sample.…”