NAME

       r.rescale.eq   - Rescales histogram equalized the range of category values in a raster map
       layer.

KEYWORDS

       raster, rescale

SYNOPSIS

       r.rescale.eq
       r.rescale.eq --help
       r.rescale.eq   input=name    [from=min,max]    output=name   to=min,max     [title=phrase]
       [--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui]

   Flags:
       --overwrite
           Allow output files to overwrite existing files

       --help
           Print usage summary

       --verbose
           Verbose module output

       --quiet
           Quiet module output

       --ui
           Force launching GUI dialog

   Parameters:
       input=name [required]
           The name of the raster map to be rescaled

       from=min,max
           The input data range to be rescaled (default: full range of input map)

       output=name [required]
           The resulting raster map name

       to=min,max [required]
           The output data range

       title=phrase
           Title for new raster map

DESCRIPTION

       The  r.rescale.eq  program rescales the range of category values appearing in a raster map
       layer with equalized histogram.  A new raster map layer, and an appropriate category  file
       and  color  table  based  upon  the original raster map layer, are generated with category
       labels that reflect the original  category  values  that  produced  each  category.   This
       command is useful for producing representations with a reduced number of categories from a
       raster map layer with a large range of category values (e.g.,  elevation).   Rescaled  map
       layers  are  appropriate  for  use  in  such  GRASS GIS commands as r.stats, r.report, and
       r.coin.

EXAMPLE

       To rescale an elevation raster map layer with category values ranging from 1090 meters  to
       1800  meters  into  the range 0-255, the following command line could be used (without the
       from parameter, the full value range will be used):
       r.rescale.eq input=elevation from=1090,1800 output=elevation.255 to=0,255

NOTES

       Category values that fall beyond the input range will become NULL.  This allows  the  user
       to  select  a subset of the full category value range for rescaling if desired.  This also
       means that the user should know the category value range for the input raster  map  layer.
       The  user  can  request the r.rescale.eq program to determine this range, or can obtain it
       using the r.describe or r.info command.  If the category value range is  determined  using
       r.rescale.eq, the input raster map layer is examined, and the minimum and maximum non-NULL
       category values are selected as the input range.

SEE ALSO

        r.coin,  r.describe,  r.info,  r.mapcalc,  r.reclass,  r.rescale,  r.report,  r.resample,
       r.stats

AUTHOR

       Michael Shapiro, U.S.Army Construction Engineering Research Laboratory

SOURCE CODE

       Available at: r.rescale.eq source code (history)

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       © 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual