1. A computer-implemented method for generating a background image that is displayed while foreground images are being scrolled, comprising: in response to a first plurality of foreground images being displayed, selecting a first foreground image from the first plurality of foreground images; generating a first background image based on the first foreground image; displaying a first portion of the first background image; displaying a remaining portion of the first background image with an alpha ramp that transitions from opaque to transparent; in response to a second plurality of foreground images being displayed, selecting a second foreground image from the second plurality of foreground images; generating a second background image based on the second foreground image; displaying a cross-fading animation that transitions from the remaining portion of the first background image to a first portion of the second background image; and displaying the first portion of the second background image.