DESIGN OF MINIMUM VISUAL MODULATION HALF-TONE PATTERNS

The visibility of binary image noise at low to medium dot densities of current binary printers, i.e., 300-400 dots/in, is not subthreshold. Standard halftoning algorithms such as clustered-dot or dispersed-dot dither produce periodic patterns at these dot densities that are easily visible at normal viewing distances in uniform areas. A new method of halftoning computer-generated uniform areas that reduces noise visibility by using a data base of minimum visual modulation bit patterns is introduced. Applications include all "paint by numbers" printers such as those that offer tint-fill or object highlighting.