1 An image previewing system, comprising: a display unit comprising a screen configured to show an image; a face portion recognition unit configured to: recognize any human face contained in the image and determine face portions in the image if human face(s) exists in the image; a selecting unit configured to select one of the recognized face portions in the image; a comparing unit configured to compare the number of image pixels of the selected face portion with the resolution of the screen of the display unit and generate a result; and according to the result, a magnifying unit configured to magnify the selected face portion and display the magnified face portion on the screen.