The user would then execute the GRASS program i.maxlik to actually create the final classified map.
This map must be prepared by the user in advance. Programs like v.digit or r.digit can be used to define representative areas of the classes the user defines to be in the image. Of course other methods could be devised by the user for creating this training map - i.gensig makes no assumption about the origin of this map layer. It simply creates signatures for the classes defined in the training map for the image to be classified (the image is specified in other options - see below).
This is the name of the group that contains the band files which comprise the image to be analyzed. The i.group command is used to construct groups of raster layers which comprise an image.
This names the subgroup within the group that selects a subset of the bands to be analyzed. The i.group command is also used to prepare this subgroup. The subgroup mechanism allows the user to select a subset of all the band files that form an image.
This is the resultant signature file (containing the means and covariance matrices) for each class in the training map that is associated with the band files in the subgroup select (see above).
It should be noted that interactive mode here only means interactive prompting for maps and files. It does not mean visualization of the signatures that result from the process.
SIG file "lsat7_2000_gensig":
1 # 2 #water 3 4186 4 67.9508 48.7346 37.8915 15.3129 13.8473 12.0855 5 1.74334 6 0.439504 2.07267 7 0.662523 1.63501 4.21189 8 0.530339 2.40757 5.52857 22.433 9 0.561184 2.30762 5.18846 20.5364 20.4926 10 0.393218 1.2184 2.63628 9.61528 9.36025 5.85314
v.digit and r.digit for interactively creating the training map.
i.cluster for unsupervised clustering as an alternative to i.gensig to create signatures.
i.class for a graphic/interactive as an alternative to i.gensig to create signatures.
Last changed: $Date: 2013-06-09 05:37:33 -0700 (Sun, 09 Jun 2013) $
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