Patent ID: 8861003

Claim:
An image forming apparatus, comprising: a dot image forming unit configured to selectively execute one of: (i) a default mode of forming, if printable data described in a specific page description language includes a rectangle drawing instruction, a dot image of an entire rectangle by placing an internal dot group corresponding to a fill of an inside portion of a rectangle in a coordinate space based on a first dot placement rule and placing a contour dot group corresponding to a contour of the rectangle in the coordinate space based on a second dot placement rule; or (ii) a change mode of forming the dot image of the entire rectangle by unifying dot placement rules into either the first dot placement rule or the second dot placement rule and placing the internal dot group and the contour dot group in the coordinate space; and an image formation control unit configured to cause, while the change mode is selected, the dot image forming unit to unify the dot placement rules into either the first dot placement rule or the second dot placement rule and to place the internal dot group and the contour dot group in the coordinate space, wherein the coordinate space includes a coordinate space defined by reference lines having predetermined intervals and a plurality of grid squares formed by those reference lines intersecting at right angles, wherein the first dot placement rule includes a rule indicating that at least one grid square whose center point is included in a drawing range is identified from the plurality of grid squares and a dot is placed in a predetermined grid point among grid points existing on the identified at least one grid square, wherein the second dot placement rule includes a rule indicating that at least one grid point included in the drawing range among a plurality of grid points in the coordinate space and the predetermined grid point among the grid points existing on the grid square including the drawing range in an inside portion thereof are identified and dots are placed in the identified grid points, wherein the change mode includes a Mode 1 and a Mode 2, wherein the Mode 1 comprises unifying the dot placement rules into the first dot placement rule and placing the internal dot group and the contour dot group in the coordinate space, wherein the Mode 2 comprises unifying the dot placement rules into the second dot placement rule and placing the internal dot group and the contour dot group in the coordinate space, and wherein the image formation control unit is configured to select the Mode 1 or the Mode 2 in the change mode.