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i.oif.1grass - Man Page

Calculates Optimum-Index-Factor table for spectral bands


imagery, multispectral, statistics


i.oif --help
i.oif [-gs] input=name[,name,...]  [output=name]   [--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui]



Print in shell script style


Process bands serially (default: run in parallel)


Allow output files to overwrite existing files


Print usage summary


Verbose module output


Quiet module output


Force launching GUI dialog


input=name[,name,...] [required]

Name of input raster map(s)


Name for output file (if omitted or "-" output to stdout)


i.oif calculates the Optimum Index Factor for multi-spectral satellite imagery.

The Optimum Index Factor (OIF) determines the three-band combination that maximizes the variability (information) in a multi-spectral scene. The index is a ratio of the total variance (standard deviation) within and the correlation between all possible band combinations. The bands that comprise the highest scoring combination from i.oif are used as the three color channels required for d.rgb or r.composite.

The analysis is saved to a file in the current directory called "i.oif.result".


Landsat 1-7 TM: Colour Composites in BGR order as important Landsat TM band combinations (example: 234 in BGR order means: B=2, G=3, R=4):

By default the module will calculate standard deviations for all bands in parallel. To run serially use the -s flag. If the WORKERS environment variable is set, the number of concurrent processes will be limited to that number of jobs.


North Carolina sample dataset:

g.region raster=lsat7_2002_10 -p
i.oif input=lsat7_2002_10,lsat7_2002_20,lsat7_2002_30,lsat7_2002_40,lsat7_2002_50,lsat7_2002_70


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

See Also

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


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

Source Code

Available at: i.oif source code (history)

Accessed: Tuesday May 14 13:42:01 2024

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