The invention relates generally to improvements in systems used in the development ("authoring") of interactive visual media. More particularly, the invention relates to (a) the automatic or semi-automatic generation of a set of files representing "zoomed-in" sections of a master high-resolution image file, and (b) the automatic or semi-automatic generation of the logical data required to allow navigation of the generated files by an end-user of an interactive visual medium, including but not limited to such optical disc formats as DVD-Video, DVD-Audio, Video CD, and Super Video CD, as well as media hosted by a server and delivered over a network.