[mapguide-users] Rasterlite file on MGOS

[Riccardo Pucci]

Hi All,

I successfully managed to connect MGOS to a rasterlite db using FDO GDAL 
Provider.
Rasterlite is a library designed to give fast read access to large 
raster dataset. Data are stored in a sqlite db. When loaded into the db, 
raster are automatically tiled and pyramidal set of overview can be 
built. Follow the link below for better explanation.

http://www.gaia-gis.it/spatialite
http://www.gdal.org/frmt_rasterlite.html

Since GDAL Provider shipped with MGOS is not built with rasterlite 
support, I have followed the instruction to add ECW, MrSID as per

http://trac.osgeo.org/mapguide/wiki/MGOS22GdalProvider

Since I tested it with MGOS 2.5 I grabbed the needed dll from:

http://www.gisinternals.com/sdk/PackageList.aspx?file=release-1600-gdal-1-9-0-mapserver-6-0-1.zip

If you want to give it a try you can use the gdal utilities to create a 
new rasterlite db (from a large geotiff for example):

gdal_translate -of Rasterlite <yourfle.tiff> 
RASTERLITE:<filename>.sqlite,table=source -co DRIVER=JPEG -co 
BLOCKXSIZE=1024 -co BLOCKYSIZE=1024 -co QUALITY=100
gdaladdo RASTERLITE:<filename>.sqlite,table=source 2 4 8 16

After that you just have to create a new GDAL feature source using 
Maestro and select the newly created  sqlite file.
I made a little test with a small (20000x10000) jpeg, performance are 
nearly 10 times better compared with original raster used as is.

Hopes it helps :)

Riccardo Pucci