This is a project to make the Ordnance Survey 1:250 000 Scale Colour Raster data usable with devices that support KML overlays, specifically with some Garmin GPS receivers. The 1:250 000 raster is conveniently available as part of OS OpenData under the Open Government Licence, so I can make the resulting KMZ files generally available.
To use the overlays on a Garmin device, copy some of them into
the device's /Garmin/CustomMaps directory.
It should be possible to use five of the KMZ files without exceeding
the device's limit on the number of tiles.
The code used to create the files is available, and is held in Bazaar. You can get a copy by running:
bzr branch http://bjh21.me.uk/ras250kml/code/ ras250kml
To use it, you will also need a copy of the colour raster data, GDAL, and LXML. Oh, and Python itself, of course.
Contains OS data © Crown copyright and database right 2017