1. A printing apparatus which prints a composite image formed of a background image and an input image on a recording medium, the apparatus comprising: a display; a display image data generating section which generates data of a display image to be displayed on the display; a display controller which controls the display to display the display image based on the data of the display image generated by the display image data generating section; an input region determining mechanism which determines at least one input region in which the input image is to be inputted on the background image displayed on the display; an image capturing mechanism which captures the input image inputted via the display; a composite image data generating section which generates data of the composite image from data of the background image and data of the input image captured by the image capturing mechanism; and a printing mechanism which prints the composite image on the recording medium based on the data of the composite image generated by the composite image data generating section, wherein when the input region determining mechanism determines the at least one input region, the display image data generating section generates data of an enlarged image of a portion which is included in the background image and includes the at least one input region as the data of the display image, and after the display controller controls the display to display the enlarged image based on the data of the enlarged image, the image capturing mechanism captures an image inputted in the at least one input region which is included in the enlarged image displayed on the display, as the input image.