History
At its 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.
Features
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
treatment:
Canonical component analysis
Primary component analysis
Texture classification
Supervised and unsupervised classifications
Radiometric corrections (Fourier)
Contours detection
Forms detection
Frequency filters
Retouching the image histogram
Repositioning (affine and polynomial functions transformations )
Repositioning of ortho -photo
Resampling
Strengthening of the resolution (for RGB and HIS images)
Transformation of an IHS image ( Intensity Saturation hue ) in RGB (RGB) – and vice versa.
Fourier transformation and inverse Fourier transformation
Specific Features
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.
