Patent ID: 8885217

Claim:
An image forming apparatus including a plurality of image forming units, comprising: an image data processing unit that converts combined data, in which image data to be used for adjusting image quality is inserted between pieces of print image data, into image forming data, and outputs the converted data; an image forming data counting unit that counts image forming pixels for each divided region obtained by dividing the image forming data at least in a sub-scanning direction; an image forming data information storage unit that stores therein image forming data information relating to the image data to be used for adjusting image quality; and a control data generating unit that generates a control parameter for controlling the image forming units based on count values of the image forming pixels counted by the image forming data counting unit, wherein: the control data generating unit is configured to generate the control parameter based on the image forming data information for a period in which the image data to be used for adjusting image quality is output, the image data to be used for adjusting image quality is a fixed pattern selected from a density adjustment pattern and a color mismatching adjustment pattern, and a boundary between patches in the fixed pattern matches with a boundary between the divided regions.