Methods of Dither Array Construction Employing Models of Visual Perception

Digital halftoning refers to the process of converting a continuous-tone image or photograph into a binary pattern of black and white pixels for display on binary devices, such as ink-jet or electrophotographic printers. Early approaches to digital halftoning mimic the analog process of projecting a film negative, through a silk screen, onto high-contrast lithographic film. These early approaches produce periodic patterns of round dot clusters varying in size with tone such that light and dark shades of gray were represented by small and large dot clusters, respectively. By thinking of the size of round clusters as amplitude, these periodic clustered-dot methods are generally referred to halftoning by means of amplitude modulation.