An image processing apparatus comprises a first acquisition unit configured to acquire a first image obtained by scanning a first printed material printed based on print data, a second acquisition unit configured to acquire one or more second images obtained by scanning a second printed material printed based on the print data, and a generation unit configured to generate an image obtained from the first image and at least one second images among the one or more second images acquired by the second acquisition unit, as a reference image to be compared with a third image obtained by scanning a third printed material printed based on the print data in order to inspect presence or absence of a defect in the third image.