数字影像输出设备色域边界的插值计算方法

Interpolation method for calculating gamut boundaries of digital imaging output devices

提出了一种数字影像输出设备色域边界的插值计算方法,并对其精度进行了实验分析。基于CIELAB色空间中色域的连通性和三角形插值技术,该方法直接在CIELABL*a*b*坐标中进行插值计算,得到有规律变化的色域边界点。对3个不同类型的输出设备进行了精度分析,采用386个采样点确定色域边界,296个检验点的色度值与实际输出色度值CIELAB色差ΔEab的平均值/最大值分别为2.31/6.93、2.03/6.70和0.40/2.11,接近于各自设备机械稳定性引起的色差。此外,将色域表面映射为色域球,在色域球上进行插值三角形的预查找,使得插值三角形的确定时间由2.5 min缩短到10 s,降低了15倍。

A interpolation method to define the gamut boundaries of digital imaging devices was presented, and the calculating precision was given experimentally. Based on the connectivity of sample points and the triangular interpolation technique, regularly spaced gamut boundary points were solved directly in the CIELAB L ＊ a ＊ b ＊ coordinates. Experiments were carried oul with 386 samples for three devices of different types, and the mean/maximum CIELAB ΔEab, for 296 test samples were 2.31/6.93,2.03/6.70, and 0.40/2.11, respectively, which were close to their corresponding device errors induced by their stability. Besides, by mapping gamut boundary into a gamut sphere and by using a pre-searching process, the interpolation triangle researching time was reduced from 2.5 min to 10 s, decreased 15 times.