Patent ID: 8018480

Claim:
An image forming apparatus for forming a multi-color image by superimposing a first color and a second color, the image forming apparatus comprising: a first process unit which shifts a portion of pixels in a pixel sequence forming a first scanning line of the first color to a pixel sequence forming a second scanning line of the first color, and which adjusts densities of a plurality of pixels existing near a shift point to reduce a bump occurring at the shift point, wherein the shift point refers to a boundary between a pixel that is shifted by the first process unit and a pixel that is not shifted by the first process unit; and a second process unit which performs a thicken process to a pixel sequence of a scanning line of the second color superimposed on the first scanning line of the first color to thicken the pixel sequence of the scanning line of the second color in a sub-scanning direction, wherein the pixel sequence of the scanning line of the second color to be thickened corresponds to the shifted pixels of the first color, wherein said second process unit includes a weighting process unit which changes a density of a pixel of interest existing near the shift point and a density of one or more pixels adjacent to the pixel of interest in the sub-scanning direction, by weighting the densities, depending on a distance from the pixel of interest.