To emphasize a register mark on an output image in a part in which the output image and the register mark are overlapped, and to improve workability when cutting.

When obtaining an output object by cutting the periphery of an image area of a recording material in a size larger than a side of the output image, a DRAM control IC 56 inputs register mark data including an output position of the register mark, and image data for forming the output image to extract the part in which the output image and the register mark are overlapped from the image data and the register mark data. An operation display part 48 accepts setting data for emphasizing the part in which the output image and the register mark are overlapped, the part being extracted by the DRAM control IC 56. A trimming circuit 71 emphasizes the extracted part in which the output image and the register mark are overlapped based on the setting data accepted by the operation display part 48. In this configuration, a standard at cutting is clearly recognized.