An image processing device decides whether the image size of the input image obtained by shooting the image or the edited image is larger than an image size required for printing by the printer. When it is decided that the image size is larger than the image size required at the time of printing, the image processing device automatically resizes the input image or the edited image so that the image size thereof is changed to an image size required for printing, generates a new print image, and transmits the new print image to the printer. Therefore, it is possible to edit an input image, generate a print image from information required for printing, transmit the print image to a printer, and print a desired image in a short time.