Polygon Class Statistics

Brief Description

Computes statistics on a training polygon set.

Tags

Learning

Long Description

The application processes a set of geometries intended for training (they should have a field giving the associated class). The geometries are analyzed against a support image to compute statistics :
- number of samples per class
- number of samples per geometry
An optional raster mask can be used to discard samples. Different types of geometry are supported : polygons, lines, points. The behaviour is different for each type of geometry :
- polygon: select pixels whose center is inside the polygon
- lines : select pixels intersecting the line
- points : select closest pixel to the point

Parameters

Input image (in): Support image that will be classified
Input validity mask (mask): Validity mask (only pixels corresponding to a mask value greater than 0 will be used for statistics)
Input vectors (vec): Input geometries to analyze
Output XML statistics file (out): Output file to store statistics (XML format)
Field Name (field): Name of the field carrying the class name in the input vectors.
Layer Index (layer): Layer index to read in the input vector file.
Elevation management (elev): This group of parameters allows managing elevation values. Supported formats are SRTM, DTED or any geotiff. DownloadSRTMTiles application could be a useful tool to list/download tiles related to a product.
- DEM directory (elev.dem): This parameter allows selecting a directory containing Digital Elevation Model files. Note that this directory should contain only DEM files. Unexpected behaviour might occurs if other images are found in this directory.
- Geoid File (elev.geoid): Use a geoid grid to get the height above the ellipsoid in case there is no DEM available, no coverage for some points or pixels with no_data in the DEM tiles. A version of the geoid can be found on the OTB website(https://gitlab.orfeo-toolbox.org/orfeotoolbox/otb-data/blob/master/Input/DEM/egm96.grd).
- Default elevation (elev.default): This parameter allows setting the default height above ellipsoid when there is no DEM available, no coverage for some points or pixels with no_data in the DEM tiles, and no geoid file has been set. This is also used by some application as an average elevation value.

Available RAM (Mb) (ram): Available memory for processing (in MB)
Load otb application from xml file (inxml): Load otb application from xml file
Save otb application to xml file (outxml): Save otb application to xml file

Limitations

None

Authors

OTB-Team