[Qgis-user] format for raster data distribution, JP2?

[Alex Mandel]

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
> *******************************