According to one embodiment, an image processing method for inspecting an image includes creating synthetic image information in which information is synthesized with main image information in a visible state which the human eyes perceive in an invisible state which is hard to perceive with the human eyes, printing the synthetic image information onto a medium, acquiring an image printed on the medium as an inspection image information, extracting information embedded in the main image information from the inspection image acquired, and determining a fault in the image printed on the medium based on an extraction result of information.