NAME
g.gui.iclass - Tool for supervised classification of imagery data.Generates spectral signatures for an image by allowing the user to outline regions of interest.
KEYWORDS
general, GUI, classification, supervised classification, signaturesSYNOPSIS
Flags:
- -m
- Maximize window
- --help
- Print usage summary
- --verbose
- Verbose module output
- --quiet
- Quiet module output
- --ui
- Force launching GUI dialog
Parameters:
- group=name
- Name of input imagery group
- subgroup=name
- Name of input imagery subgroup
- map=name
- Name of raster map to load
- trainingmap=name
- Ground truth training map to load
Table of contents
KEYWORDS
display, GUI, imagery, classification, supervised classificationDESCRIPTION
Supervised Classification Tool (wxIClass) is a wxGUI component which allows the user to create training areas and generate spectral signatures. The resulting signature file can be used as input for i.maxlik or as a seed signature file for i.cluster. WxIClass can be launched from the Layer Manager menu Imagery → Classify image → Interactive input for supervised classification or via command line as g.gui.iclass.
wxIClass currently allows you to:
- create training areas (using customized vector digitizer)
- show histograms for each band and class (category)
- show coincidence plots for each band
- show raster cells that match training areas (within the number of standard deviations specified)
- specify color of class
- write signature file
- import vector map
- export vector map with attribute table
wxIClass performs the first pass in the GRASS two-pass supervised image classification process; the GRASS module i.maxlik executes the second pass. Both programs must be run to generate a classified map in GRASS raster format.
wxIClass is an interactive program that allows the user to create multiple training areas for multiple classes and calculate the spectral signatures based on the cells that are within the training areas. During this process the user will be shown histograms for each image band. The user can also display the cells of the image bands which fall within a user-specified number of standard deviations from the means in the spectral signature. By doing this, the user can see how much of the image is likely to be put into the class associated with the signature.
wxIClass can also import training areas defined in a vector layer. In that case the program expects the vector layer to have the following columns defined:
- cat: category value
- class: a string with the class name
- color: a color defined using format "RRR:GGG:BBB"
The spectral signatures are composed of region means and covariance matrices. These region means and covariance matrices are used in the second pass (i.maxlik) to classify the image.
Alternatively, the spectral signatures generated by wxIClass can be used for seed means for the clusters in i.cluster.
SEE ALSO
wxGUI, wxGUI components, Interactive Scatter Plot ToolSee also user wiki page and development page.
AUTHORS
Anna Kratochvilova, Czech Technical University in Prague, Czech RepublicVaclav Petras, Czech Technical University in Prague, Czech Republic
SOURCE CODE
Available at: wxGUI Supervised Classification Tool source code (history)
Latest change: Friday Dec 20 12:08:01 2024 in commit: 19f698928e7593f8c38ebd16205e790780c4a6ae
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