[postgis-users] OSS application to serve file based images

[Brent Wood]

--- Intengu Technologies <sindile.bidla at gmail.com> wrote:

> Hello
> 
> I understand that most experts are saying it is far better not to load
> images in a database but rather to serve them from a file based system.
> There are two commercial products that I know of ER Mapper - Image Web
> Server and ArcGIS Image Server what OSS products provide comparable
> functionalities.  If these are available are there any bench mark studies
> done and also I would like to integrate such products with ArcGIS Server.

As I understand it, these applications are only for georeferenced images, ie,
images covering a defined area of the planet. So in PostGIS you'd not only need
to store teh image, but also the georeferncing informnation (eg, the world file
contents).

I'm not sure if you are referring to just these types of images (typically
geotiffs, MrSID composites, or other formats with world files) or other types
of images.

At NIWA (where I work) we are using a package called Atlas (www.atlasmd.com).
This is a commercial digital asset management application. We partially funded
the Atlas port to PostGIS and the development of a mapserver based interface to
enable searches for images with a known location (lat/long) associated with
them. The application manages images as files, with all relevant metadata in
PostGIS. We are very pleased with the functionality it offers. The images are
optionally associated with a location, but are not georeferenced.

We had severe performance issues with the Windows server running Atlas also
running the mapserver, but addressed this by abstracting the background map
data to a remote Linux (or BSD) server providing the maps via WMS, with the
Atlas server overlaying image locations on the WMS background. This proved much
faster  and easier to manage. We are also using the separate WMS server in a
similar role to support other applications. 


If anyone is interested, contact me or the atlas developers from their web
site, listed above. As I mentioned, Atlas itself is a commercial application,
but utilises FOSS GIS programs. 


Cheers,

  Brent Wood