A method and system for rotation-dependent halftone rendering. An image
input is received from a scanning system or other source, the received
image being either a contone image or an error-diffused mage. If a
following right-angle image rotation is to be performed, the image is
clustered by a clustering method which yields reduced file sizes with
respect to the rotated orientation of the image. If no following
right-angle image rotation will be performed, the binary image is
clustered by an alternate clustering method which yields reduced file
sizes with respect to the non-rotated image. The selective clustering
includes dividing the image into a tessellation of cells and then
concatenating like bits in each cell in a preferred direction for the
rotated or non-rotated image. The clustered image is then rotated if
necessary, and compressed.