基于色调区域分割的扫描仪颜色转换

Color Transformation Based on the Hue Division for Color Scanners

扫描仪的颜色响应数值RGB与对应CIE视觉色度值间的转换用于颜色的正确捕获。实验建立了从RGB到CIEXYZ的转换关系。基于扫描仪响应数值RGB与颜色三刺激值CIEXYZ的形成机理,设计了将颜色空间分割为红、黄、绿、蓝、青、品红共6个色调区域,分别进行关系建立的方法。在两台扫描仪上的实验表明,对IT8.7/2标准色标,采用2阶10项的多项式拟合关系,颜色转换的CIEL*a*b*平均色差可达到1.0左右,最大色差小于4;对检验色标具有同样的转换精度,表明了该方法较强的泛化能力。实验同时表明,采用该方法,RGB到CIEXYZ的转换精度高于到CIEL*a*b*的转换。

The color transformation from the RGB values of a scanner to the CIE colorimetric values is used for color capture correctly. The relationships between them were built by the fitting in six color spaces respectively, based on the division of hue into red, yellow, green, cyan, blue, and magenta. Polynomials consisting of 10 terms were introduced, and the average conversion CIEL＊a＊b＊ color differences for IT8. 7/2 color target on two scanners were all about 1, and the maximal color differences were less than 4. And the same results were got in the case of the test target. It was also showed that the transformation from the RGB to the CIEXYZ has a higher accuracy than that to the CIEL＊a＊b＊