均衡集束网点密度的伪随机混合抖动半色调化算法的研究

Research on Balancing Clustered Dot Density for Hybrid Halftone Dithering Algorithm

该研究发现,基于现有混合加网算法的阳集束网点和阴集束网点密度的比例大致是1∶2,而这样悬殊的比例将制约集束网点密度的提高.现有混合加网算法通过一个平面的几何划分形成集束网点.文中通过欧拉公式推导出了两个关于平面几何划分性质的定理.根据定理2提出的优化算法可以生成集束网点密度均衡的混合半色调化抖动矩阵.文中实验中用优化算法得到的半色调化抖动矩阵的阴阳集束网点的比例由优化前的0.502195提高到0.903919.

This study found that the ratio between the clustered dot density in shadow and high-light area is roughly 1：2, based on existing hybrid halftone algorithms. The ratio will bring un- wanted constraint to increase clustered dot density. The hybrid halftone algorithms formed clustered dot with a geometric divide of a halftone plane. With the theorems deducted from Euler formula, a new algorithm to optimize the ratio is proposed. In the experiment to test the new algorithm, the ratio between clustered dot densities in shadow and highlight was improved to 0. 903919 from original 0. 502195.