A system and process for creating an interactive digital image, which
allows a viewer to interact with a displayed image so as to change it
with regard to a desired effect, such as exposure, focus or color, among
others. An interactive image includes representative images which depict
a scene with some image parameter varying between them. The interactive
image also includes an index image, whose pixels each identify the
representative image that exhibits the desired effect related to the
varied image parameter at a corresponding pixel location. For example, a
pixel of the index image might identify the representative image having a
correspondingly-located pixel that depicts a portion of the scene at the
sharpest focus. One primary form of interaction involves selecting a
pixel of a displayed image whereupon the representative image identified
in the index image at a corresponding pixel location is displayed in lieu
of the currently displayed image.