Abstract: A printer comprises a scan axis (14) arranged to receive at least one pen (10), each pen comprising an array of ink ejection elements (20,22) adapted to print a swath on a printing medium. Printer control circuitry is responsive to selection of a multi-pass print mode, to cause a printing medium advance mechanism to incrementally advance the printing medium (26) past the pens in a printing advance direction (PAD) between the printing of a first swath and a second swath. Thus, a first group of ink ejection elements dispenses ink in a swath along respective rows on the printing medium with at least one other group of corresponding ink ejection elements dispensing ink along those rows in subsequent swaths. The printer control circuitry is further arranged to cause the first group of ink ejection elements to dispense proportionally more ink per swath than the other groups of ink ejection elements in subsequent swaths.

Abstract: One aspect of the invention lowers boundary artifacts by diminishing inking selectively at a boundary, only in high-total-inking areas—considering essentially all real colorant planes in the aggregate. In another aspect, printmasking helps define ink-diminishment regions. In yet another, a printer allocates inking-diminishment units within an emulation of a masking plane (e.g. a color plane), analogously to allocation of inking units in real color planes. The entire diminishment plane or “eraser plane”, however, is later applied subtractively. Localized diminishment bits can be set in the mask at pixels close to boundaries, to define diminishment regions that negate artifact-causing boundary coalescence specifically—or such bits can be generated adaptively from results of measuring nonuniformity in an area-fill test pattern.

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).

Abstract: A program controls colorant-applying elements (e.g. nozzles) individually, to apply colorants in an order that yields consistent colorant-addressing sequences. In another aspect, the invention inhibits particular elements in particular installments (e.g. printing passes) to produce a fixed color bias between colorants of at least one colorant pair; the other colorant is statistically downweighted to correct the bias. In a third aspect, a printmask-generating program automatically makes a usable mask based on neighborhood and timing constraints; this program is constrained, so as to minimize or eliminate hue shift.

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).

Abstract: One aspect of the invention lowers boundary artifacts by diminishing inking selectively at a boundary, only in high-total-inking areas—considering essentially all real colorant planes in the aggregate. In another aspect, printmasking helps define ink-diminishment regions. In yet another, a printer allocates inking-diminishment units within an emulation of a masking plane (e.g. a color plane), analogously to allocation of inking units in real color planes. The entire diminishment plane or “eraser plane”, however, is later applied subtractively. Localized diminishment bits can be set in the mask at pixels close to boundaries, to define diminishment regions that negate artifact-causing boundary coalescence specifically—or such bits can be generated adaptively from results of measuring nonuniformity in an area-fill test pattern.

Abstract: A printer comprises a scan axis (14) arranged to receive at least one pen (10), each pen comprising an array of ink ejection elements (20,22) adapted to print a swath on a printing medium. Printer control circuitry is responsive to selection of a multi-pass print mode, to cause a printing medium advance mechanism to incrementally advance the printing medium (26) past the pens in a printing advance direction (PAD) between the printing of a first swath and a second swath. Thus, a first group of ink ejection elements dispenses ink in a swath along respective rows on the printing medium with at least one other group of corresponding ink ejection elements dispensing ink along those rows in subsequent swaths. The printer control circuitry is further arranged to cause the first group of ink ejection elements to dispense proportionally more ink per swath than the other groups of ink ejection elements in subsequent swaths.