Chopping OS 10k raster maps

Another post in the series 'things I found in my mailbox that I mailed myself as an aide-memoire'

This one relates to the chopping up of map tiles. In this case, the tiles were supplied in a directory tree.

The post:

10k files come in a tree so we need to flatten it:

Copy the OS files from the dir tree to a flat dir:

for /R d:\data %i IN (*.jpg) DO xcopy %i c:\dest /S

Add the associated .tab files (in order to provide geo-referencing)

http://www.ordnancesurvey.co.uk/oswebsite/products/georeferencing/aboutpopup.html

Download FWTools

http://fwtools.maptools.org/

and run the shell

Build a virtual raster

gdalbuildvrt 10k.vrt *.tif

Convert virtual raster to actual ECW (ERMapper Compressed Wavelets)

gdal_translate -of ECW -co LARGE_OK=YES -expand rgb -a_srs EPSG:27700 10k.vrt 10k.ecw

Process the ECW with a tiler such as

http://www.klokan.cz/projects/gdal2tiles/

or, with the GUI

http://www.maptiler.org/

A nice summary and related info

http://epsg27700.blogspot.com/2009/09/processing-ordnance-survey-rasters-with.html