第34卷，第6期 2014年6月
光谱学与光谱分
析
Spectroscopy and Spectral Analysis
Vol, 34, No, 6, pp1635-1639
June,2014
ResearchonCharacteristicSpectrumExtractingand
Matching for High-Fidelity Reproduction
YANG Sheng-wei', LIU Zhen?*, WU Ming-guang", ZHANG Zhen-jie
1. Jiangsu Provincial Key Lab of Pulp and Paper Science and Technology, Nanjing Forestry University, Nanjing 210037, China 2. College of Communication and Art Design, University of Shanghai for Science &. Technology, Shanghai 200093, China
3. Key Laboratory of Virtual Geographic Environment of Ministry of Education, Nanjing Normal University, Nanjing 210046, China
Abstract Reconstructing the spectrum rapidly and accurately is the key to the research on high-fidelity repro-duction. A characteristic spectrum extracting and matching method for high-fidelity printing is proposed aiming at the problem of complex conversion between spectrum and ink combination caused by multi-color. The meth od filters and extracts feature bands of primary ink through derivative spectrum, and a characteristic spectrum multi-threshold coding method is proposed. Considering the problem of subarea judgment in hi-fi printing, an average derivative spectrum is taken as characteristic spectrum of each subarea and a spectrum matching meth-od between target spectrum and average derivative spectrum of sub-spaces is proposed. The results show that the feature bands extracted can represent spectral characteristic of primary color significantly and the precision of color conversion model based on feature bands is higher than the model based on full bands. The spectrum matching method can achieve a high accuracy in sub-space judgments and greatly improve the efficiency of color convention. The spectrum extracting and matching method has the high practicability.
Keywords
Characteristic spectrum; Spectrum extracting; Spectrum matching; High-fidelity reproduction
中图分类号：0433.4
Introduction
文献标识码：A
D0I: 10. 3964/j. issn. 10000593( 2014)06163505
Consequently characteristic spectrum extracting
spectrum.
and matching become more important.
Traditional printing presents colors through overprint of different ink combination of primary colors including cyan, magenta, yellow and black (CMYK). Ideal CMY primary ink pigment can absorb one third of the visible spectrum and re-flect the other two thirds without overlapping. But because of insufficient main absorption, the actual primary ink pigment has a low saturation and displays ‘Black' phenomena like con-taining Black ink. So, high-fidelity printing introduces prima ry colors of higher saturation to solve the problems of low trapping and saturation of secondary color and expand the col-or gamut; however, more primary inks will increase the com plexity of conversion model between ink combination and
Received: 2013-07-08; accepted: 2013-11-12
Based on the research, LI proved that the more the num-ber of feature band of spectrum adopted, the higher the accu racy of color space expression[. Cloutis mentioned that low derivative transform for spectrum is more effective in prac-tice/?], Tzeng proposed extracting spectrum characterization through principal component analysis (PCA) to estimate the primary colors[*J. Professor Wang Qiang introduced the char acteristic spectrum into the field of spatial information color management , and proposed an exact definition for characteris tic spectrum in color reproduction fieldJ, The definition is that characteristic spectrum is the key spectrum ( wavelength or wavebands) in the spectroscopic spectra data for color
characteristic expression.
Wang Binyu and Guo jinyi re-
Foundation item: National Natural Science Foundation Issues (41271446) , Research Innovation Program for Graduate Student of Jiangsu Prov
ince(CXZZ11_0517)
Biography: YANG Sheng-wei, (1984—), doctor candidate in Nanjing Forestry University
+ Corresponding author
e-mail; lunaprint@163. com
e-mail: bestysw@163. com