【摘要】 为解决多光谱图像打印输出问题,提出一种用非线性优化技术实现光谱图像打印分色的方法,以同时提高再现图像的光谱精度和色度精度。从分析打印系统成色机理及Neugebauer光谱模型入手,比较了图像光谱特性和色度特性对打印效果的影响,可知输出图像光谱误差和色度误差对打印质量均至关重要;据此构造了图像光谱误差和色度误差目标函数,分别反映再现图像的光谱精度和色度精度,并根据实际打印过程对各打印基色的墨量控制值进行约束;最后采用非线性优化方法,逐点计算图像光谱对应的墨量控制值,实现打印分色。实验表明,该方法能同时兼顾再现图像的光谱精度和色度精度,与仅考虑光谱误差的迭代分色方法相比,再现色度精度能提高约3～10倍。更多还原

【Abstract】 To reproduce multi-spectral images on a printer,a new spectral-based color separation method using the nonlinear optimization technology was presented,which could improve spectral and the colorimetric precision simultaneously.Based on the color principles of printer systems and the Neugebauer model,the effect of spectral and colorimetric characteristics of images on printing output was analyzed.This led to the conclusion that spectral and colorimetric errors were both important for printed images.For this reason,the spectral error and colorimetric error objective functions were designed firstly,one presenting the colorimetric precision of the printed images and another for spectral precision.Furthermore,the effective area coverage of the printer primary inks was limited according to the actual printing process.Finally the nonlinear optimization method was used,by which the spectral reflectance of the multi-spectral images could be transformed to the effective area coverage of the inks and the color separation was realized.Experiments show that the proposed method improves the spectral and colorimetric precision simultaneously.The output spectral precision is about 3 to 10 times higher than that of the regressive method only based on the spectral error.更多还原