Is Error Diffusion FM Screening Becoming a Barrier to High Speed, High Quality, Image Printing?

摘要

FM screening has remained the typical choice for high quality image printing on inkjets. The two most common methods of implementing FM screening are error diffusion and stochastic screening. Error diffusion produces excellent quality halftones, but is computationally costly. Stochastic screening has traditionally delivered lower halftone quality, but is computationally cheap and so is much faster. Error diffusion remains the preferred OEM halftoning method in a competitive marketplace where print quality continues to be a product differentiator. This paper looks at advances in hardware print technology that are resulting in higher resolutions, color depths and much higher print speeds. In these circumstances error diffusion is becoming a print performance bottleneck in certain markets. This limits current devices and may hamper the development of new higher speed devices for high quality printing. Stochastic screening methods meet the performance requirements but need to provide higher quality halftones. A recent advance in stochastic screening is used as an illustration of how such a method can deliver halftone quality comparable to high quality error diffusion, but at much faster speeds.