A device and method for modifying a video image of a display apparatus method, for efficiently modifying a size and aspect ratio of a video image, is disclosed. The device includes an on-screen display (OSD) generator providing an on-screen display (OSD) on a display for programming a size and an aspect ratio of a video image, and a video processor modifying a displayed video image in accordance with the size and aspect ratio of the displayed video image programmed by a user. Herein, the video processor modifies the video image from a center point of the video image.