基于D/8条件的颜色测量仪器SCE测量光泽修正模型的设计

Gloss Modification Model Design of SCE Measurement Based on D/8 Condition Color Spectrophotometer

对表面光泽度较高的物体表面颜色进行测量,常采用漫射照明、8°观察角、消除镜面反射光的几何条件。在结构设计中,通过积分球内设置的光阱来消除镜面反射光。由于光阱的尺寸、大小的不同,导致不同结构的仪器在测量表面光泽度不同的样品时会产生较大的器间差。从理论上分析了漫射照明、8°观察角、消除镜面反射光的几何条件下不同结构的测量仪器的器间差产生原因;设计了一种可以兼容包含镜面反射光(SCI)和去除镜面反射光(SCE)几何条件的测量结构,通过对样品表面SCI和SCE数据进行同时测量获得样品表面的光泽数据;提出了一种根据被测材料表面光泽数据对SCE测量数据进行修正的修正模型,并设计相关实验进行验证。实验结果证明,应用该修正模型对测量结构进行修正可以显著减小不同仪器结构之间的测量偏差,有显著的工程应用价值。

The geometric conditions of diffuse illumination, 8° observation, and specular light exclusion （SCE） are often employed to measure the surface color. The SCE condition is usually realized by setting light trap on the integrating sphere. Due to the size of the optical trap, different structures of the measurement instrument will lead to inter-instrument disagreement among the measurement of sample with different gloss. The reason of inter-instrument disagreement caused by different measuring structures is analyzed in theory; a measuring structure is designed to measure the SCE and specular light inclusion （SCI） results simultaneously. The gloss value is calculated from the SCE and SCI results. A computing model is proposed to modify the SCE measuring result based on the gloss value, and experimental verification is also carried out. Experimental results show that the modified model effectively reduces inter-instrument disagreement caused by different measuring structures, and is very suitable for engineering applications.