The first processor element (PE) interprets a display list, generates pieces of edge information of objects contained in one line, sorts the pieces of edge information for each line, and transfers the level data containing link information linking to width information of between the edges of the objects, the pieces of edge information and overlapping information of the objects. When the level data corresponding to the pixel count in the sub-scanning direction is stored in a memory, a DMAC controls the readout order of the level data to read out the level data from the memory and transfers the readout level data to the second processor.