Dot depletion in pixel-array printing

A method for depleting pixels in a pixel image plane, comprising the steps of:

• a) creating a depletion plane having locations mapped to all locations in the pixel image plane, wherein some depletion plane locations identify corresponding pixels as candidates for depletion;
• b) choosing a pixel in the image plane for examination;
• c) examining whether the chosen pixel is a candidate for depletion, by referring to its mapped location in the depletion plane;
• d) if the chosen pixel is not a depletion candidate, proceeding directly to step (g);
• e) determining whether the chosen pixel is an edge pixel;
• f) depleting the chosen pixel if it is not an edge pixel;
• and
• g) choosing a different pixel and returning to step (c).

In an image composed of pixels arranged as binary elements in an input plane, a method for depleting pixels, comprising the steps of:

• a) shifting the input plane the distance of one pixel in each of four planar directions, thereby producing four shifted planes;
• b) generating a non-edge-pixel plane as the logical AND of the four shifted planes;
• c) creating a depletion plane having locations mapped to pixels in the image plane, wherein some locations are designated as candidates for pixel depletion;
• d) producing a pixel-depletion locator plane as the logical AND of the depletion plane and the non-edge-pixel plane;
• e) logically inverting the pixel-depletion locator plane;
• and
• f) combining, by a logical AND, the inverted pixel-depletion locator plane with the input plane to produce a depleted-pixel image plane.