In a region determination device and method, when an island contour of a slice model crosses a scanning line in a first direction, the value of an internal level n is increased by a predetermined value. When the island contour crosses the scanning line in a second direction different the first direction, the value of the internal level n is decreased by the predetermined value. When a hole contour of the slice model crosses the scanning line in the second direction, the value of the internal level n is assigned to a temporary retain variable m and “0” is substituted for the internal level n. When the hole contour crosses the scanning line in the first direction, the value of the temporary retain variable m is assigned back to the internal level n. A region corresponding to a value of the internal level n, set as above, that is not 0 is determined to be a printing region, and a region corresponding to the value of the internal level n that is 0 is determined to be a non-printing region.
展开▼