An image processing unit executes an image process on a target image based on process-setting contents, and generates a processed image. An area extracting unit compares the processed image with the target image, and extracts a partial area of a predetermined size showing a notable effect of the image process executed on the target image, as a checking area. A checking-image display unit displays the processed image corresponding to the extracted checking area on a display unit, as a checking image for checking the process-setting contents of the image process.