An image processing device which carries out processing for composing a first image (a color patch image for printing simulation) and a second image (a color patch image for printer management) with image data of a print job, and printing-out. When image data is received from an image processing terminal, image data of a first image and a second image are generated by first and second image generating sections. A first image composing section composes image data of an object of printing and first image data. A color correcting section carries out color correction on the composed image. A second image composing section composes the second image and an image which has been composed by the first image composing section and color corrected. In this way, appropriate printing simulation using an output device such as a printer is possible.