Method for reducing pixel density along one axis of a multiple dimension image representation

Claim 1

In a swath type printer having a movable carriage for supporting a plurality of print elements which are controlled to print dots on a rectilinear array of pixels each having an associated pixel data bit in a bit-mapped pixel data array which is logically organized in rows and columns to correspond to the printed pixel array, a method for depleting a pixel data array comprising the steps of: (A) defining for all rows of the pixel data array a starting end such that the bits in each row are in a column sequence that starts at the starting end; and (B) sequentially selecting the second through last in sequence bit in each row, and setting the selected bit to 0 if the immediately adjacent prior in column sequence bit is a 1 by: (a) organizing each row of the pixel data array into non-overlapping immediately adjacent K-bit words which are in a sequence that starts at a starting end that is common for all rows; (b) defining for all rows of the pixel data array a starting row such that the pixel data rows are in a sequence that starts with the starting row; (c) sequentially selecting the first through last in sequence K-bit word in each row, and performing the following on the selected K-bit word: (1) forming an index of K+1 bits comprised of the selected K-bit word and an additional bit that is the bit of the immediately prior in sequence K-bit word that is immediately adjacent the selected K-bit word, except for the first in sequence word in a row for which the additional bit is a 0; (2) accessing a depleter look-up table with the index for the selected K-bit word to obtain a replacement K-bit word; (3) replacing the selected K-bit word with the replacement K-bit word, whereby all K-bit words in the pixel data array are replaced with K-bit words retrieved from the look-up table.