Well, you've covered most of the tradeoffs - proprietary/open, general availability, etc. At the end of the day, it's hard to beat compressed TIFFs. (lzw-compressed TIFFs are nice too - maybe a bit less supported than jpeg-compressed, but no quality loss)
-mpg From: discuss-boun...@lists.osgeo.org [mailto:discuss-boun...@lists.osgeo.org] On Behalf Of John Callahan Sent: Friday, July 15, 2011 11:59 AM To: OSGeo Discussions; qgis-u...@lists.osgeo.org Subject: [OSGeo-Discuss] format for raster data distribution, JP2? 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 *******************************
_______________________________________________ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
