A image is printed from a source of drawing instructions. The image is reducible
to pixels arranged in a plurality of ranked image lines. The system employs a storage
device having compressed and uncompressed regions. Each region has a designated
capacity and each is arranged to store pixels of one or more of the plurality of
image lines. A drawing processor is coupled to the storage device and can be coupled
to the source of drawing instructions for responding thereto. This drawing processor
can store new pixels in the storage device for successively selected ones of the
image lines. The drawing processor has a conditional device, a decompression device
and an insertion device. The conditional device can compressively encode and move
from the uncompressed region to the compressed region, a remote one of the image
lines, if: a) the selected one of the image lines is in the compressed region,
and b) the uncompressed region has reached its designated capacity. The decompression
device can expansively decode the selected one of the image lines, if located in
the compressed region. The insertion device can insert one or more new pixels according
to the drawing instructions into the selected one of the image lines by storing
the selected one in the uncompressed region. The printing system also has a printing
engine coupled to the storage device for printing the plurality of image lines
in rank order, decompressing compressed ones of the image lines from the compressed
region before printing.
