单色实地印刷品颜色预测模型

如果忽略油墨的渗透作用,可将实地印刷品看作是由油墨层、纸张层、纸张-空气界面层以及油墨-空气界面层等叠加而成的多层结构.考虑到纸张的半透明性以及纸张与背衬之间的非光学接触,本文建立了一种单色实地印刷品颜色预测模型.首先,描述了单色实地印刷品的多层结构,列出光通量在各层之间的传递方程;其次,利用在几种不透明背衬条件下单色实地印刷品的光谱反射率,拟合出纸张和油墨的光学特性;最后预测了单色实地印刷品下垫其他背衬时的光谱反射率.实验中所有样品的预测CIEDE2000色差均小于2,这表明无需测量纸张和油墨的光谱折射率,只要提供足够数量的不透明背衬,利用本文所建模型即可实现单色实地印刷品颜色的准确预测.

Color Prediction Model for Single Color Solid Prints

When the ink penetration in paper was ignored, the single color solid print was treated as a multilayer structure. It was made by the superposition of multiple layers, which were solid ink layer, paper layer, paper-air interface layer, ink-air interface layer, etc. Taking into consideration the translucency of paper and the non-optical contact between the paper and the background, this paper established a color prediction model for single color solid prints. Firstly, the multilayer structure of single color solid prints was described and the transfer equations of light fluxes traveling between different layers were listed. Secondly, by making use of the spectral reflectance measurements of single color solid prints with different backgrounds, the optical parameters of the paper layer and the solid ink layer were fitted out. Lastly, the spectral reflectance of single color solid prints was predicted with other backgrounds. The predicted color differences of all samples according to the CIEDE2000 were smaller than 2 in experiments, which means that the proposed model can accurately predict the color of single color solid prints without measuring the refractive index of papers and inks as long as the adequate number of opaque backgrounds can be provided.