ABSTRACT: Green-noise is the mid-frequency component of white noise and has been shown to have visually pleasing attributes when applied to digital halftoning. Unlike blue-noise dither patterns, which are composed exclusively of isolated pixels, green-noise dither patterns are composed of pixel-clusters making them less susceptible to image degradation from non-ideal printing artifacts such as dot-loss. Clearly, these patterns reduce the spatial variation in tone produced by laser printers when printing a constant shade of gray, but to date, no study has been presented showing the amount of reduction. In this paper, we do study the effects of changing the average cluster size in a green-noise dither pattern, measuring the resulting spatial variations in a Lexmark Optra laser printer in 1200dpi mode and looking specifically at the visibility of gear noise and the average change in tone moving across the printed page.
APPEARED: 2000 IS&T's and SPIE's Electronic Imaging Expo, San Jose, Ca. USA, January 22-28.
SPONSORS: This work was sponsored by Lexmark International Inc., Lexington, Kentucky USA.