In the field of printing research, color replication based on spectrum need to solve the issues that how to get cyan, magenta and yellow ink spectrum feature extraction. In this study, based on spectral derivative and spectral image deviation, establish a method to choose special wavelength positions for making up the corresponding relation between ink value and ink spectral reflectivity. The ink scales are printed on papers in the way that the value of the ink dot increase 5% from 0-100%. Ink spectrum reflectivity curves are made up through measuring ink scales. The first-order derivatives of cyan, magenta and yellow ink spectrum reflectivity curves in the range of 380-730nm, in sequence, change smooth at 650nm, 530-560nm, 450nm, and change violently at 530nm, 600nm, 500nm wavelength position. Based on spectral image deviation, the cyan ink spectral wavelength in the range of 630-730nm, the magenta ink spectral wavelength in the range of 500-540nm, include the most information and the least correlation. For the reason that yellow ink spectral images intersect with others, the analysis is combined with first-order derivative of ink spectrum curves. The method proposed in this paper is propitious to get primary ink spectral feature for color spectrum separation.
Feature extraction of On-Load Tap-Changer Based on Improved EMD Energy Spectrum
