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
