An object of this invention is to process image data in which a plurality of link destinations are set in one region. Another object of this invention is to allow the user intuitively to recognize the setup states of links, since link regions have different display patterns in correspondence with the numbers of link destinations upon displaying the link regions. If the designated link region has only one link destination, a dotted circle (for example) is displayed on the link region (S407). If the designated link region has two link destinations, a solid circle (for example) is displayed (step S409). If the designated link region has three or more link destinations, a double circle (for example) is displayed (step S408). Again, if the designated link region has only one link destination, an image at the link destination is set as display data (S421), while if the designated link region has a plurality of link destinations, all the link destinations may be displayed in a list (S415). An image at a link destination selected by the operator from the list is set as display data (S419).