A digital photo frame includes a processing unit (110), a display controller (120), a display unit (130) and a control panel (150). The processing unit modifies an original image from an original image file (210) stored in a first storage (20) according to modifying instructions received from the control panel, saves modifying parameters relating to the modification in an image modification file (220) that is stored in a second storage (30) and corresponds to the original image file. After the modification, if the original image is selected at a later time, the processing unit automatically modifies the original image according to the modifying parameters, thereby producing a modified image to be displayed on the display unit.