On Thursday 01 of August 2013 13:42:03 Moritz Lennert wrote: > On 01/08/13 13:43, Nikos Alexandris wrote: > > Michael: > >>>>>> What about just using r.rescale to rescale this? > > > > Nikos: > >>>>> Already tried (in the past) and I don't think it works from DCELL> > >>>>> 8-bit. It seems to chew-up (silently, as Moritz mentioned I think > >>>>> among > >>>>> the lines in ticket #2^11) values. > >>>>> > >>>>> It seems that "integerising" manually, in this case, is the best > >>>>> approach. With the essential question remaining on "how many fine > >>>>> digits > >>>>> should be preserved?". > > > > Moritz: > >>>> r.rescale is just a frontend to r.reclass. and as such is meant for > >>>> CELL > >>>> maps. It should'nt make a difference whether it is 8-bit or more, > >>>> though. > >>>> For DCELL you can try to use r.recode. > > > > Nikos: > >>> Didn't work also (tried the previous days) -- I can try again. > > > > Moritz: > >> Please be more precise than "didn't work"... > > > > Right, "be more precise" is the key to "freedom" :D. Indeed, I used to > > say > > (either in a "rules" file, or directly using "...<< EOF" > > > > 0.0:1.0:0:255 > > > > This did not work. Both stats and histogram of the recoded raster map, > > e.g. a Red-Reflectance image ranging in > > > > r.info Red_ToAR -r > > > > min=0 > > max=0.774115699104528 > > > > were kinda flattened out > > > > r.stats Red_ToAR_recoded_255 > > > > 100% > > > > 0 > > 255 > > > > Looking at the image I want to recode > > > > r.stats Red_ToAR | head > > > > 100% > > > > 0-0.003036 > > 0.02125-0.024286 > > 0.024286-0.027322 > > 0.027322-0.030357 > > 0.030357-0.033393 > > 0.033393-0.036429 > > 0.036429-0.039465 > > 0.039465-0.0425 > > 0.0425-0.045536 > > 0.045536-0.048572 > > > > I altered the rules file like > > > > 0.001:1.0:0:255 > > > > > > This works-out! Now, the recoded image is > > > > r.recode in=Red_ToAR out=Red_ToAR_recoded_255 rules=recode_rules --o > > r.stats Red_ToAR_recoded_255 > > > > 100% > > > > 5 > > 6 > > 7 > > . > > .. > > ... \ > > ....> Many values in-between > > ... / > > .. > > . > > 195 > > 196 > > 197 > > * > > > > And the histogram looks "nice" as well. I didn't grasp that -- from where > > should I? In the manual there is only an example from int to float > > (however, indeed, instructing 0.1 as the "target" min value). > > There does seem to be a bug in r.recode. Your first rule set should work > if you set the -d flag. Maybe you can file a ticket ?
Oh man... I need to rest. The "-d" flag... that's it :-p Nikos (learning every day new stuff :-)). _______________________________________________ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev