The
Feature Extraction tool provides algorithms
to compute different types of features for Polygons, Cells and Rasters. Three kinds of features
are available:
-
Spectral Features, which are computed based on statistical and
texture metrics computed over the gray levels of the image pixels inside polygons;
-
Spatial Features, which are computed based on the form of the polygons;
-
Landscape Ecology based Features, which are computed based on the spatial
relationship between two polygon (or cells) layers.
A detailed description of the available features can be accessed in the
GeoDMA web site.
Using the interface
It is accessed through:
GeoDMA >
Feature Extraction
In the
Spectral and Spatial Features tab:
-
In the Kind of Features group, check Spectral check box to compute
Spectral Features and/or Spatial check box to compute Spatial Features.
NOTE: To compute Spectral Features it is MANDATORY to have one
Polygon Layer and one Raster Layer. To compute Spatial Features, it needs only
one Polygon Layer. Both kinds of features can either be computed simultaneously.
-
Raster Layer: select the Raster layer to be used to compute the
Spectral Features.
-
Vector Layer: Select the Vector layer to be used to compute the
Spectral and/or Spatial Features.
-
In the Raster Bands group, select the bands to be used to compute the
Spectral Features.
-
No data output value (Optional): define here the no data value. It will
be used when invalid polygons are found or when the polygon does not intersects the
raster.
-
Repository: define the repository to save the classification. Click
to save into an
ESRI Shape File or
to save into a database.
If you want to save in the same input layer, you don't need to select a repository here.
Just don't change the output layer name.
-
Layer Name: define the name of the layer where the classification data
will be saved. If you want to save in the same input layer, just don't change the
name here. Otherwise, set here the name of the new layer to be created.
-
CSV File (Optional): Define an output CSV file if you want to save in
this format. Click
to select the output CSV file.
-
Click OK to perform the operation or Cancel to close the
interface.
In the
Landscape Ecology tab:
-
Patches Vector: select the classified vector layer containing the classified
patches to compute the Landscape Ecology based features.
-
Classes Column: select the column of the Patches Vector that contains
the labels of the classes of the Patches Polygons.
-
Landscape Vector: select the Vector Layer containing the Landscape Polygons,
i. e., the target polygons where the features will be saved.
-
No data output value (Optional): define here the no data value. It will
be used when invalid polygons are found.
-
Repository: define the repository to save the classification. Click
to save into an
ESRI Shape File or
to save into a database.
If you want to save in the same input layer, you don't need to select a repository here.
Just don't change the output layer name.
-
Layer Name: define the name of the layer where the classification data
will be saved. If you want to save in the same input layer, just don't change the
name here. Otherwise, set here the name of the new layer to be created.
-
CSV File (Optional): Define an output CSV file if you want to save in
this format. Click
to select the output CSV file.
-
Click OK to perform the operation or Cancel to close the
interface.