Patent ID: 7408672

Claim:
An image forming apparatus, comprising: a reading unit which reads an image of a document and outputs image data; a storage unit which stores a plurality of line thinning arguments; a setting unit which sets an enlargement rate or a reduction rate with respect to the image data; a selecting unit which selects the line thinning argument corresponding to the enlargement rate or the reduction rate set by the setting unit from the storage unit; an enlarging/reducing unit which enlarges or reduces the image data at the enlargement rate or the reduction rate set by the setting unit; an edge determination unit which determines as to whether or not the image data is an edge; a line thinning suppression determination unit which determines as to whether or not the image data is to be suppressed from line thinning by the use of the line thinning argument selected by the selecting unit; a calculating unit which calculates a logical multiplication of a determination result of the line thinning suppression determination unit and a determination result of the edge determination unit; a density conversion unit which converts a density of the image data according to a logical calculation result of the calculating unit using the line thinning argument selected by the selecting unit; and an image forming unit which forms an image based on the image data undergone density conversion by the density conversion unit.