neugebauer equation
124377894
Theoretical analysis of the index correction method of Neugebauer Equation
Neugebauer Equation reveals the physical basis and quantitative relationship on the formation of halftone printing color.It is a very useful matching tool for printing color Gamut mapping in this digital age.The Index correction method is proposed to reduce the application error of Neugebauer Equation.But,the results are still unsatisfactory despite industry's unremitting efforts.For this reason,theoretical research and simulation analysis are conducted in this paper.The results indicate that the Index correction method of Neugebauer Equation used for more than half a century is unscientific and unable to eliminate its systemic error.
Gheng Gangh
123136220
A Spectral Improved Neugebauer Equation Model
Neugebauer equations are the basic formula in color printing. However, this is a theoretical model. If the printing conditions and complexity of overprinting are not considered, the result obtained by Neugebauer equations will not be very accurate. The Neugebauer equations need to be corrected in practice. There are some methods such as Yule Nielson correction, Cellular correction, dot gain correction and so on. In order to improve the precision and analyze the cause of errors of Neugebauer equations, a model using a spectral dot gain correction is given in the paper. The dot gain is generally a function of wavelength. Dot gain in each wavelength of a primary is treated in calculating the Demichel equations, and the corrected dot area is used as weighting factors in two color overprint and three color overprint process. The experiment and calculation show that this method can improve the precision of the equations a lot.
Zewen Liu Hao Liu Xiao hui He
123936278
Study on the Color Reproduction Model of Concentric Dot Based on Neugebauer Equation
There are many studies on correcting methods of Neugebauer equation aiming to research the solid dots such as round dots and square dots mostly.But the concentric dot which is hollow dot hasn't been modeled.In this study,the establishment of color model for four color offset printing of concentric screening was analysed.Firstly,the concentric screening test plate was designed.The modeling color blocks and the testing color blocks were chosen from the printing samples to measure their color values.Secondly,the color reproduction model was developed by the 1~(st) order linear regression for the Neugebauer equation.Then,SAS software was used to calculate the coefficient of the color reproduction model and it was modified again by the quadratic curve regression method.Finally,the prediction accuracy of the color reproduction model was calculated by the testing color blocks.The experiment confirmed that the accuracy of the mathematical model through the 2~(nd) order regression can meet the requirements of high quality reproduction.
Wan Xiao-bo
124933299
Research of Black Plate Generation Method Based on Neugebauer Equation
In color printing process,a black plate was added to compensate dark shortage of printing image in general.A black plate generation method based on Neugebauer Equation was proposed.Part of color blocks of IT8.7/3 were selected as the sample,and the XYZ values of the sample were transformed into corresponding CMY dot area rate through Neugebauer Equation.Value of relevant parameters was determined to get the black plate value by using the calculation formula of black plate.The experiment results showed that the black plate generation method has certain reliability and practicability,which has reference value and theoretical significance for color separation in printing and black plate generation.
Wang Xiao-jing
123556528
Errors Analysis of Three Color Separation Algorithms Based on Subarea Neugebauer Equation
Arithmetic principles of linear regression,exponent modification,and cellular element partition were analyzed.Experiments were designed to evaluate the accuracy and stability of the three algorithms with the purpose looking for optimizing and improving direction of Subarea Neugebauer Equation.The results showed that linear regressed Neugebauer Equation is the worst in;exponent modified Neugebauer Equation is in the middle;cellular element partition Neugebauer Equation is the best in accuracy and stability under the environment of high fidelity printing.
Liu Zhen
124390418
Screening Error Analysis Based on Neugebauer Equation
Neugebauer Equation reveals the physical basis of the formation of the halftone printing color and the basic logic of the formation of the color perception.In this paper,based on Neugebauer Equation,the objective necessity of screening error was revealed from both theoretical and simulation analysis,in the case without considering the process factors.Through the analysis of the screen dot morphology,it pointed out the relativity of color separation and screening in theory.The theoretical color difference of the different digital screening methods was worked out through Neugebauer Equation simulation analysis and the calculation of color perarea ratio statistics.
Zhou Wei
124493980
Application Error Analysis to Neugebauer Equation
In order to find the root of the application error caused by Neugebauer equation,in this paper,the inherent theory flaw of Neugebauer equation is revealed by the combination of mathematical derivation with simulation analysis based on its theoretical basis and popular treatment methods in pre press.The result shows that it is impossible to solve the problems by Neugebauer equation in mathematics properly on quantitative calculating of color separation,and the calculation errors can not be avoided by the absence of practical support of the superimposition relation assumption(including dot shape and distribution)
Wang Xizhen
124702477
Study on Theoretical Value and Limitations of Neugebauer Equation
Neugebauer Equation is a kind of model and method of color space conversion in common use,and plays an important role in the color analysis.So it is wildly used in printing engineering and image analysis and processing.In order to improve model accuracy and reduce color separation error,Neugebauer Equation has also been developing and improving.In this paper,the theoretical value of Neugebauer Equation was summarized,the limitations of its application were analyzed, and the inevitability of color separation error was revealed according to the variation of color cell area ratio caused by screening calculation after color separating.
Xiong Kangpeng
18686346
Researche on Neugebauer equation correction algorithm
In order to realize accurate colorimetric characterization for a output device, several different correction algorithm models were evaluated. There are three Neugebauer equation correction methods in common use, namely: The dot gain correction, the Yule Nielsen exponential correction and the Cellular correction. This article analyzes these correction methods of Neugebauer equation, and put forward a new correction method that is using exponential correction method with considering the impact of dot gain. An identical output device was colorimetrically characterized with these algorithm models utilizing IT8.7/3 as color targets. Experimental results showed that this new correction method can improve the accuracy of calculation of Neugebauer equation, When using to creating output profile, It can significantly improve the accuracy of output profile, and the process of calculation is simple and convenient to actualize.
2010 3rd International Congress on Image and Signal Processing
Lili Si Xinli Tian
123402569
Study on the Color Performance of Flexograph Based on Neugebauer Equation
The establishment of precise mathematical model of three color flexography was studied in this paper,firstly linear regression of one order and robust regression were employed to reserve the data for modeling,then curvilinear regression of second degree was used to further modify the coefficients of the mathematical model,in the end the precise model of flexography was realized.Validation result showed that desired requirement of color reproduction could be acquired by the established model.
Zhou Shisheng