1. An image processing method comprising: inputting a first drawing command; and replacing the first drawing command with a second drawing command, wherein the second drawing command includes a first instruction to generate process color plates which represents information of process colors and to generate a spot color plate which represents information of a spot color when the second drawing command is expanded, and a second instruction to draw tag information, into the spot color plate, which represents object information and which does not represent the information of the spot color when the second drawing command is expanded, wherein the tag information does not represent information of process colors, and the object information is information indicating a type of object.