Masking based on interleaving zones

A non-transitory computer-readable storage medium comprising a set of computer-readable instructions that, when executed by a processor, cause the processor to:

• define top and bottom interleaving zones of a print swath;
• generate a top interleaving mask corresponding to the top interleaving zone according to an objective density increasing linearly from a top row to a bottom row;
• generate a bottom interleaving mask corresponding to the bottom interleaving zone, wherein the bottom interleaving mask is based on the top interleaving mask;
• and
• apply the generated top interleaving mask and the generated bottom interleaving mask to a print mask corresponding to a printing pass.

A printer comprising:

• a memory;
• and
• a processor to:
• generate a top interleaving mask corresponding to a top interleaving zone of a print swath based on an objective drop density for each row of the top interleaving mask, local drop density provided by a halftone matrix, and drop locations provided by a print mask;
• generate a bottom interleaving mask corresponding to a bottom interleaving zone of the print swath based on the top interleaving mask;
• select a subset of drop locations provided by the print mask by applying the top and bottom interleaving masks to the print mask;
• and
• cause colorant to be deposited to a substrate according to the selected subset of drop locations.