Raster Analysis and MapServer

[Ari Jolma]

Fischer, Brian wrote:
> 
> 3. Some tool would do a raster calculation (raster1 minus raster2) to
> produce a final raster

The software which I work on from time to time is Geo::Raster. The
current version uses GDAL for accessing the data, a C library for the
raster calculations (libral), and the main interface is a Perl module
which overloads arithmetical functions and some others for raster
objects (so you can easily write for example $c = $a + $b, where $a and
possibly $b are rasters). The homepage is libral.sf.net (the version in
CPAN is not the most recent)

I haven't used this with mapserver so I don't know how it would
integrate with its mapscript. I have used Geo::Raster with some web apps
though.

The one limitation of libral is that it needs to have the whole raster
in memory rather than on disk. This is however probably not a big
limitation for web-based apps.

If you decide to try Geo::Raster out, I'd be willing to help with my
spare time.

Ari

-- 
Prof. Ari Jolma
Kartografia ja Geoinformatiikka / Cartography and Geoinformatics
Teknillinen Korkeakoulu / Helsinki University of Technology
POBox 1200, 02015 TKK, Finland
Email: ari.jolma at tkk.fi URL: http://www.tkk.fi/~jolma