i.rescale.rgb.html

<h2>DESCRIPTION</h2>

<em>i.rescale.rgb</em> is a GRASS addon that works similar to <a href="i.colors.enhance.html">i.colors.enhance</a>
but changes and rescales the actual raster values and not the corresponding color table.
This is only useful for visualization purposes outside of GRASS GIS.

The created group can be used as <b>r.out.gdal</b> input parameter for the multi-band export.

<h2>EXAMPLES</h2>

Optimize the raster values of three input bands for RGB visualization; enhance contrast
by limiting input data to the area between the 2% and 98% percentile:

<div class="code"><pre>
i.rescale.rgb red=red_channel green=green_channel blue=blue_channel output=output_group lower_percentile=2 upper_percentile=98
</pre></div>

<p>
In case of export to Byte type with no-data (NULL) values being present, the way to go is 
rescaling to 0..254 range (rather than the default 0..255 range):

<div class="code"><pre>
i.rescale.rgb red=red_channel green=green_channel blue=blue_channel output=output_group output_range=0,254 lower_percentile=2 upper_percentile=98
</pre></div>

<h2>SEE ALSO</h2>

<em>
<a href="r.mapcalc.html">r.mapcalc</a>,
<a href="i.colors.enhance.html">i.colors.enhance</a>
</em>

<h2>AUTHOR</h2>

Guido Riembauer, <a href="https://www.mundialis.de/">mundialis</a>