Patent ID: 8213045

Claim:
An image forming apparatus, comprising: a scaling correction unit configured to correct scaling in a sub-scanning direction of image data according to scaling data at least by deleting or inserting one main scanning line of image data according to the scaling data; an identifying unit configured to identify a screen area within the image data, wherein the scaling correction unit is configured to undo the deleting or inserting of the one main scanning line within the screen area and then re-correct scaling in the sub-scanning direction within the screen area at least by deleting or inserting another main scanning line at a different position within the screen area; a screen processing unit configured to, of image data whose scaling in the sub-scanning direction has been corrected or re-corrected by the scaling correction unit, perform screen processing on image data included in the screen area; and an image forming unit configured to form an image based on the image data that has been processed by the screen processing unit.