1. An image forming apparatus which has reading means for reading an original and generating image data, color process means for performing a color process in accordance with a color process condition, and image forming means for forming an image on a medium in accordance with another process condition, said apparatus comprising: a first calibration system for automatically calibrating the color process condition and the another process condition, based on data obtained from patterns which are read by said reading means, said patterns being formed by said image forming means; and a second calibration system for automatically calibrating the another process condition, based on patterns formed by said image forming means, without calibrating the color process condition on said image forming means.