1i.oif(1)                    GRASS GIS User's Manual                   i.oif(1)
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NAME

6       i.oif  - Calculates Optimum-Index-Factor table for spectral bands
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KEYWORDS

9       imagery, multispectral, statistics
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SYNOPSIS

12       i.oif
13       i.oif --help
14       i.oif   [-gs]   input=name[,name,...]    [output=name]    [--overwrite]
15       [--help]  [--verbose]  [--quiet]  [--ui]
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17   Flags:
18       -g
19           Print in shell script style
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21       -s
22           Process bands serially (default: run in parallel)
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24       --overwrite
25           Allow output files to overwrite existing files
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27       --help
28           Print usage summary
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30       --verbose
31           Verbose module output
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33       --quiet
34           Quiet module output
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36       --ui
37           Force launching GUI dialog
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39   Parameters:
40       input=name[,name,...] [required]
41           Name of input raster map(s)
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43       output=name
44           Name for output file (if omitted or "-" output to stdout)
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DESCRIPTION

47       i.oif calculates the Optimum Index Factor for multi-spectral  satellite
48       imagery.
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50       The  Optimum  Index  Factor (OIF) determines the three-band combination
51       that maximizes the variability (information) in a multi-spectral scene.
52       The  index is a ratio of the total variance (standard deviation) within
53       and the correlation between all possible band combinations.  The  bands
54       that  comprise  the  highest scoring combination from i.oif are used as
55       the three color channels required for d.rgb or r.composite.
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57       The analysis is saved  to  a  file  in  the  current  directory  called
58       "i.oif.result".
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NOTES

61       Landsat  1-7 TM: Colour Composites in BGR order as important Landsat TM
62       band combinations (example: 234 in BGR order means: B=2, G=3, R=4):
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64           ·   123: near natural ("true") colour; however, because of correla‐
65               tion  of the 3 bands in visible spectrum, this combination con‐
66               tains not much more info than is contained in single band.
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68           ·   234: sensitive to green vegetation (portrayed as red), conifer‐
69               ous  as distinctly darker red than deciduous forests. Roads and
70               water bodies are clear.
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72           ·   243: green vegetation is green but coniferous forests aren’t as
73               clear as the 234 combination.
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75           ·   247:  one of the best for info pertaining to forestry. Good for
76               operation scale mapping of recent harvest areas and  road  con‐
77               struction.
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79           ·   345:  contains  one band from each of the main reflective units
80               (vis, nir, shortwave infra). Green vegetation is green and  the
81               shortwave  band  shows vegetational stress and mortality. Roads
82               are less evident as band 3 is blue.
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84           ·   347: similar to 345 but depicts burned areas better.
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86           ·   354: appears more like a colour infrared photo.
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88           ·   374: similar to 354.
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90           ·   457: shows soil texture classes (clay, loam, sandy).
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92       By default the module will calculate standard deviations for all  bands
93       in  parallel.  To run serially use the -s flag. If the WORKERS environ‐
94       ment variable is set, the number of concurrent processes will  be  lim‐
95       ited to that number of jobs.
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EXAMPLE

98       North Carolina sample dataset:
99       g.region raster=lsat7_2002_10 -p
100       i.oif input=lsat7_2002_10,lsat7_2002_20,lsat7_2002_30,lsat7_2002_40,lsat7_2002_50,lsat7_2002_70
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REFERENCES

103       Jensen,  1996.  Introductory  digital  image processing. Prentice Hall,
104       p.98. ISBN 0-13-205840-5
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SEE ALSO

107        d.rgb, r.composite, r.covar, r.univar
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AUTHORS

110       Markus Neteler, ITC-Irst, Trento, Italy
111       Updated to GRASS 5.7 by Michael Barton, Arizona State University
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SOURCE CODE

114       Available at: i.oif source code (history)
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116       Main index | Imagery index | Topics index | Keywords index |  Graphical
117       index | Full index
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119       © 2003-2020 GRASS Development Team, GRASS GIS 7.8.5 Reference Manual
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123GRASS 7.8.5                                                           i.oif(1)
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