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i.gensig(1grass) | Grass User's Manual | i.gensig(1grass) |
NAME¶
i.gensig - Generates statistics for i.maxlik from raster map.KEYWORDS¶
imagery, classification, supervised, MLCSYNOPSIS¶
i.gensigParameters:¶
- trainingmap=name
-
- group=name
-
- subgroup=name
-
- signaturefile=name
-
DESCRIPTION¶
i.gensig is a non-interactive method for generating input into i.maxlik. It can be used as the first pass in the GRASS two-pass classification process (instead of i.cluster or i.class). It reads a raster map layer, called the training map, which has some of the pixels or regions already classified. i.gensig will then extract spectral signatures from an image based on the classification of the pixels in the training map and make these signatures available to i.maxlik. The user would then execute the GRASS program i.maxlik to actually create the final classified map.OPTIONS¶
Parameters¶
- trainingmap=name
-
- group=name
-
- subgroup=name
-
- signaturefile=name
-
INTERACTIVE MODE¶
If none of the arguments are specified on the command line, i.gensig will interactively prompt for the names of these maps and files. 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.NOTES¶
The structure of the SIG files generated by i.gensig is as follows (ASCII file, used internally by i.maxlik):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
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Line 2: text label
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Line 3: number of points in class
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Line 4: mean values per band of the class
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Line 5-10: (semi)-matrix of band-band covariance
SEE ALSO¶
i.group for creating groups and subgroups. 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.AUTHOR¶
Michael Shapiro, U.S.Army Construction Engineering Research Laboratory Last changed: $Date: 2013-06-09 14:37:33 +0200 (Sun, 09 Jun 2013) $ Full index © 2003-2014 GRASS Development TeamGRASS 6.4.4 |