r.quant [-tr] input=name[,name...] [basemap=map] [fprange=dmin,dmax] [range=min,max]
map=name The map for which the rules be to be created. If more than one map is specified,
then this implies that the floating-point range is the miniumum and maximum of all the maps together,
unless either basemap=map or fprange=min,max is specified.
basemap=map The quant rules of this map set the quantization.
fprange=min,max This sets the floating-point range for the quantization.
-t flag Truncate floating point data
-r flag Round floating point data
range=min,max This sets the integer range for the quantization. Otherwise a default of 1-255 is used.
If rules is specified, the input has the form:
value1:value2:cat1:[cat2]
where value1 and value2 are floating point values and cat1 cand cat2 are integers. If cat2 is missing, it is taken to be equal to cat1. All values can be "*" which means infinity.