An original image file and a shortcut image file corresponding to original image data representing the original image file are provided for file management. An address tag representing a location in which the original image file is stored and an additional information tag such as information on printing of the original image file or information on layout are stored in a particular data region in the shortcut image file. In a case where the additional information represents information on image processing to be performed before printing, when an instruction of printing of the shortcut image file is issued, the image processing is performed on image data of the original image file and a resultant image data is printed. Basic data of a thumbnail image included in the shortcut image file is obtained by performing processing represented by the additional information tag on the thumbnail image data.