目的 研究非规整的墨点（非二值理想墨点）形态对光谱反射率的影响， 为预测模型的理论研究提供一个新的思路。方法 通过讨论墨点的非规整形态对网点大小、 厚度及油墨透射率的影响， 采用二维高斯函数模拟墨点表面的形态， 由此建立一个Clapper-Yule扩展模型。结果 模型的数值模拟结果表明墨点的非规整性导致了网点的物理扩大， 增加了油墨对光的吸收， 降低了最终的光谱反射率。结论 采用Clapper-Yule分程模型对颜色进行预测时需考虑墨点的非规整所带来的物理网点扩大， 该模型适用于单色半色调的颜色预测与控制。

This paper aimed to study the effect of irregular ink dot (non-bilevel halftone image) on the spectral reflections, in order to provide a new angle of thought for prediction model theory. The new extended Clapper-Yule model was established by introducing the two-dimensional Gaussian function to describe the surface of irregular ink dot and discussing the effect of the irregularity of ink dot on the dot size, dot thickness and the ink transmittances. The numerical simulation of our new model showed that the irregularity of ink dot caused the physical dot gain, which increased the absorption of light by the ink and consequently decreased the ultimate spectral reflections. Using the Clapper-Yule model to predict the reflections must take the physical dot gain caused by irregular ink dot into account, and the new extended model can be applied in the color prediction and control of monochrome halftone images.