http://stormcrow.ryandor.com/
OSIconversionmod11.zip is the image
You need to be using mod11 which you can also download there.
The map isn't perfect. There were some trans I never bothered to work out for the map2bmp converter. Most of it involves the T2A area, and most of the jungle islands on the main map. Basicly the color assigned to spot FF (the very last one) is used by the map2bmp for any terrain it doesn't know what to do with, but I also used it for cavewall 20. Anywhere outside the dungeonmap that you see that color it needs to be replaced. Also be aware that mod11 doesn't go over 30 Z for most terrains (mountains being the exception) so some areas are clipped in height (most noticeably the higher areas in Britain, Haven/Occlo and Magincia). It should suit your purposes just fine though.