基于纽介堡方程的同心圆网点呈色模型研究

Study on the Color Reproduction Model of Concentric Dot Based on Neugebauer Equation

目前对纽介堡方程常用的修正方法大多针对圆形、方形等实心网点,然而针对同心圆网点这一新型空心网点的数学建模少有研究。本研究分析了四色胶印中同心圆加网印刷呈色模型的建立问题。自行设计同心圆加网测试版,在印刷样张上选择建模色块和检验色块并测量其颜色值,通过对纽介堡方程进行一阶线性回归完成建模,利用SAS软件计算确定建模系数,而后用二次曲线回归法对呈色模型系数进行再次修正,最后通过检验色块计算其预测精度。实验结果证明,二次回归后的数学模型精度满足真实再现原稿的要求。

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 estab- lishment 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 2nd order regression can meet the requirements of high quality reproduction.