You might want to talk with the OpenAerialMap team about what they've been doing. Somehow they shrunk 25TB to 5TB of NAIP imagery using some fancy gdal techniques (as best I understand). http://www.openaerialmap.org/Main_Page
Enjoy, Alex On 07/15/2011 11:58 AM, John Callahan wrote: > I'm looking for advice on sharing raster data for download. We distribute > several raster datasets such as DEMs and orthophotography. Sometimes these > are divided into rectangular tiles, sometimes by geography/boundaries. Most > of our audience has some level of GIS or CAD experience. We also have WMS > services but there are many times where people need the actual data files. > > I had been creating JP2 files using JP2ECW compression. Great file size > reduction with very good quality. However, I'm thinking it may be difficult > for people to view these (and more difficult for me to create) due to the > restrictions on the codec distribution. The other JP2 options, OpenJPEG and > libjasper, seems like they also require users to obtain this codec/driver > and install into the software first. Same for the commercial Kakadu and > MrSID. netCDF is great but not widely supported; IMG are good but not any > advantage over TIFs (except for > 4 GB file sizes) > > Since I want to serve the widest possible audience (and not cater only to > our Windows/ArcGIS audience), I'm down to serving TIFs with JPEG compression > at around quality=75, which is what I started with years ago! Good quality, > decent compression, wide support. Is this the best bet? Is there > something else out there I'm overlooking? > > - John > > *********************************** > John Callahan, Research Scientist > Delaware Geological Survey > University of Delaware > URL: http://www.dgs.udel.edu > ******************************* _______________________________________________ Qgis-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-user
