To restrict an amount of memories to be used by developing inputted data with the use of either a YMCK developing means or a YMC developing means in accordance with the judgment result by an area judging means for a first and a second plotting areas.

When a display list to be checked is present after a plotting object is formed, whether or not a plotting logic set in the display list is XOR (inversion) is judged. When the logic is not the XOR, whether or not the plotting logic is overwriting is judged (S301). When the logic is overwriting, whether the display list of the overwriting is within a range set to an XOR list is judged (S302). If the list is within the range, information related to the display list of the overwriting of the XOR list is added (S303). On the other hand, if the logic is not overwriting or the display list is within the range of the XOR list, the display list is made a display list of a YMCK developing means (S304).