An image processing method is disclosed. A printer driver is a program for performing the method. The printer driver forms print image data that are printed by an inkjet recording apparatus capable of forming multi-level dots by ejecting droplets of recording liquid. The printer driver transforms image data of a manuscript into manuscript image data corresponding to the multi-level dots capable of being output from the inkjet recording apparatus by applying an image process such as a CMM process, a BG/UCR/γ correction process, and a gradation process to the image data of the manuscript; further, forms the print image data corresponding to the multi-level dots capable of being output from the inkjet recording apparatus by combining the manuscript image data with data corresponding to the multi-level dots of an image pattern indicating that the manuscript is prohibited from being duplicated by a manuscript and tint block pattern combining section.