[Freegis-list] C library for raster algebra

Ari Jolma ari.jolma at tkk.fi
Mon Nov 22 20:23:47 CET 2004


I wrote:

> Hi all,
>
> I repackaged the raster algebra / hydrological terrain analysis C 
> library from my old Grid.pm Perl module into a separate module and 
> uploaded it to sourceforge: http://sourceforge.net/projects/libral/


I renamed the Grid.pm as Geo::Raster.pm and uploaded it to CPAN.

The Grid entry in freegis.org should now be removed or at least 
deprecated and replaced with libral and Geo::Raster.

Cheers,

Ari

P.S.

>
> I categorized the library as "production/stable" in sourceforge but it 
> would benefit from more development attention:
>
> - the i/o of the library is not very good, there is support for ESRI 
> .hdr / BIL format and something else but it is assumed that if the 
> library is linked to a system, the system should provide those services
> - the library supports only two data types: short (two byte int) and 
> float (four byte real) and the whole raster is stored in RAM as one 
> large block, this is for simplicity, speed, and size
> - the terrain/hydrological analysis library is rather experimental and 
> not complete


in addition to these,

- libral requires that you work with grids of same size and same 
location (identical world coordinates)
- libral is not interested in projections, i.e. it assumes they are same 
in all grids



-- 
Ari Jolma, ari.jolma at hut.fi, Professor of Geoinformatics
Helsinki University of Technology
POBox 1200, 02015 TKK, Finland
http://www.hut.fi/~jolma/



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