Removal or mitigation of artifacts in incremental printing

Abstract

One aspect of the invention lowers boundary artifacts by depleting selectively at a boundary, only in high-color-saturation areas. In another aspect, printmasking defines depletion regions. In yet another, a printer treats different drop-to-pass allocations as of opposite sign. Some preferred embodiments exploit the multilayer Shakes mask system: each mask represents a number of drops to fire, and masks are additive, depending on image content. In preferred embodiments the high-value mask is used in opposition, reducing the number of drops to fire. Bits are set in this mask at pixels close to boundaries, to define depletion regions that negate artifact-causing boundary coalescence. An adaptive version measures nonuniformity in an area-fill test pattern, and uses results to define localized depletion bits for high-value mask(s).