Patent ID: 7825928

Claim:
An image processing apparatus which renders, in a screen coordinate system, unit figures each constituting the surface of a three-dimensional object to be rendered, comprising: a rasterizing unit which divides a unit figure into a plurality of unit areas on the screen coordinate system and outputs the unit areas; an area divider which divides each of the unit areas output from the rasterizing unit into a plurality of subareas; an area discarder which discards a subarea obtained by the division by the area divider and not including any valid pixels, which locates subareas that survived the discarding according to a predetermined rule that arranges the subareas in a predetermined order without creating any intervals between the subareas, while allowing a change in the relative position of the subarea in the originating unit area to which the subarea belonged before the division, so as to generate a merged area, and which generates positional information indicating the relative position of each subarea included in the merged area within the unit area to which the subarea belonged before the division; and an area writer which writes the subareas included in the merged area into a memory and which relocates each subarea in its original position by writing the subarea in an address corresponding to the positional information.