Mechanisms for displaying text or image over a background such as a video display frame that automatically improve legibility of text or image displayed against a background by increasing the contrast between text or image and background. The display frame may be a single image, but may also be an image within a dynamic sequence of recorded images such as a movie or other video media, or sequence of images captured in real-time by a camera or other device. In one embodiment, color component values are selected, and complementing and filtering applied to achieve contrast. In another embodiment, selecting a minimally used value for color components in the frame achieves contrast. In some cases both text or image, and background, may be altered to achieve contrast. Another embodiment provides background intensity modulation to achieve varying contrast within altered backgrounds, and smoothing over many frames in dynamic material.