GRASS GIS is a fully featured Geographic Information System. It supports raster, vector and point data analysis.
GRASS accepts a variety of raster and some vector dataformats - most of the raster formats are equal to standard image formats (8/24 bit as well as negative values). Check the documentation for details. The following table shows an overview of the features integrated in GRASS GIS.
Main topic
|
Modules
|
Raster
analysis
|
Automatic
rasterline and area to vector conversion
|
Buffering
of line structures
| |
Cell
and profile dataquery
| |
Colortable
modifications
| |
Conversion
to vector and point data format
| |
Correlation
/ covariance analysis
| |
Expert
system analysis
| |
Interpolation
for missing values
| |
Neighbourhood
matrix analysis
| |
Raster
overlay with or without weight
| |
Reclassification
of cell labels
| |
Resampling
(resolution)
| |
Rescaling
of cell values
| |
Statistical
cell analysis
| |
Surface
generation from vector lines
| |
Vector
analysis
|
Contour
generation from rastersurface
|
Conversion
to raster and point data format
| |
Digitizing
with board or on screen (scanned rasterimage) with mouse
| |
Reclassification
of vector labels
| |
Superpositioning
of vector layers
| |
Point
data analysis
|
Delaunay
triangulation
|
Surface
interpolation from spot heights
| |
Thiessen
polygons
| |
Topographic
analysis (curvature, slope, aspect)
| |
Image
processing
|
Canonial
component analysis (CCA)
|
Color
composite generation
| |
Edge
detection
| |
Frequency
filtering (Fourier, convolution matrices)
| |
Fourier
and inverse fourier transformation
| |
Histogram
stretching
| |
IHS
transformation to RGB
| |
Image
rectification (affine and polynomial transformations on raster and vector
targets)
| |
Ortho
photo rectification
| |
Principal
component analysis (PCA)
| |
Radiometric
corrections (Fourier)
| |
Resampling
| |
Resolution
enhancement (with RGB/IHS)
| |
RGB
to IHS transformation
| |
Texture
oriented classification (sequential maximum a posteriori classification)
| |
Shape
detection
| |
Supervised
classification (training areas, maximum likelyhood classification)
| |
Unsupervised
classification (minimum distance clustering, maximum likelyhood classification)
| |
DTM-Analysis
|
Contour
generation
|
Cost
/ path analysis
| |
Slope
/ aspect analysis
| |
Surface
generation from spot heigths or contours
| |
Screen
displaying
|
3D
surfaces
|
Color
assignments
| |
Histogram
presentation
| |
Map
overlay
| |
Point
data maps
| |
Raster
maps
| |
Vector
maps
| |
Zoom
/ unzoom -function
| |
Map
creation
|
PPM-image
maps
|
Postscript
maps
| |
Extra
modules
|
Database
interfaces (Informix, Ingres, PostgreSQL)
|
(several
other modules are available)
|
Erosion
modelling (AGNPS, ANSWERS)
|
Landscape
structure analysis
| |
Solution
transport
| |
Watershed
analysis
|