origins (1982 -1995), the core of GRASS was developed in the United States, at the research laboratory of the Army Corps
of Engineers . Its development was later carried on by
an international team, under
the GNU / GPL license.
GRASS is a System of Geographical
Information that supports both, vectors point files (called sites in GRASS) and raster
files (or images). It also possess special functions
for images processing and map production (exported to postscript or html formats ). GRASS includes tools intended for the creation of
screen or paper maps, the manipulation
of rasters files , vectors or points, the image multispectral treatment and the
capture , management , visualization and storage of geographic information.
It differs from most market GIS software by its powerful images treatment.
As example , here a non-exhaustive list of features for the image
and unsupervised classifications
Retouching the image histogram
(affine and polynomial functions transformations )
of ortho -photo
Strengthening of the resolution
(for RGB and HIS images)
of an IHS image ( Intensity
Saturation hue ) in RGB (RGB) – and vice versa.
Fourier transformation and inverse Fourier transformation
It is important not to consider GRASS as an Office GIS tool . It is extremely powerful but difficult to approach.
It runs on Windows from Cygwin and UNIX knowledge is essential. It should be reserved for projects where the processing and production
of information requires a professional reliable and robust tool , leaving the office tasks to its natural interface : QGis.