Your attached map is available to view now and I can see you're talking of doing a global map as opposed to doing smaller areas. Are you able to control the features of the continents or are you limited to what the fractal dictates?
actually what you see on the screenshot is the web-view app (done in leafletjs),
with some java on the web-server taking DEM and ColorRamp from the fractal code.
so basically with the proper reader, any DEM data could be formatted like this.
one could also produce "prerendered" tiles for a static online viewer (like most mapviewer do),
all that is needed is the tile graphics copped into the right size (256x256) and zoom level.
to produce the actual DEM from "artwork" maps is a little bit more serious work.
i have previously done work for a "Neverwinter-Nights 2" server digitizing the FR Moonsea into playable maps,
using a combination of DEM and fractal algorithms (brownian motion and perlin noise).
maybe we should start with the emer map of yours to produce a sample DEM and see where this leads us?
T.