以色度转换实现承印材料底色的校正的方法研究

Study of Substrate Color Correction Method Based on Colorimetric Conversion

利用Kodak的Approval打样系统测试了13种印刷常用纸张,总结了纸张底色对印刷色彩的影响,并比较了校正纸张底色的3种色度转换方法:不同测量衬垫的色度转换方法、相对色度转换方法和基于测量数据的多项式转换方法。分析比较发现:如果印刷中使用理想黑,则不同测量衬垫的色度转换方法与相对色度转换方法是等效的;印刷色彩由于纸张底色差异所引起的色彩偏差,并非完全符合线性的转换关系,因此基于测量数据的多项式的色度转换方法的转换结果更加准确,特别是当2种纸张间底色的色差大于4ΔEa*b*时;由于多项式的转换需要使用所有复制色彩的测量数据,造成了实际应用中的诸多不便,因此ISO 13655标准中的不同测量衬垫的色度转换方法较适用于纸张底色偏差的校正。

13 kinds of print paper were tested with Approval digital proofing system of Kodak.The effect of paper color on color reproduction was summarized.Three colorimetric correction methods for substrate color correction were compared,which were the linear correction based on measurement backing condition,relative colorimetric correction,and polynomial correction based on color measurement data.It was found that（1） the linear correction based on color measurement data is the same as the relative colorimetric method when ideal black is used in print reproduction workflow;（2） the color difference with different substrate does not fit for linear conversion,so the polynomial correction method is more accurate than the other methods when the color difference is more than 4 ΔE_（a＊b＊） especially;（3） the polynomial correction is based on full measurements data which is not convenient for industry,so the linear correction based on measurement backing condition introduced by ISO 13655 is more fit for color correction due to different substrate.