An image processing method includes a step of generating a calibration condition for an image forming unit, a step of generating a calibration condition for a reading unit, and a discrimination step. The calibration condition for the image forming unit is generated by reading a first chart formed by the image forming unit with the reading unit and generating a calibration condition for the image forming unit based on the data obtained by the reading. The calibration condition for the reading unit is generated using a second chart printed in advance. In the discriminating step, the first and second charts are discriminated. The discrimination step discriminates whether a chart read in each of the step of generating the calibration condition for the image forming unit and the step of generating the calibration condition for the image reading unit is an appropriate chart.