New dispersed-dot halftoning technique by elimination of unstable pixels for electrophotography

摘要

Printing processes of electrophotography basically involve some unstableness of analog nature. The unstableness causes stochastic reproduction of small dots and degrades image quality. To overcome the analog unstableness, this paper presents a new dispersed-dot halftoning technique for high resolution electrophotography. We combine a Gaussian filter with a sigmoid nonlinear function to compute the probability of toner transfer in print using the characteristic of electrophotography. We can predict an image to be printed out using this nonlinear printer model. Using this model we can produce halftoned images of good image quality with small perceptive error against an original gray scale image. To achieve this, we rely on iterative improvement to remove as many unstable pixels as possible whose transfer probabilities lie within a band in our nonlinear printer model. Experimental results show great improvement of the perceptive error compared to the conventional cluster-dot halftoning.