[GRASS-dev] GRASS-dev] On i.histo.match (Re: On (Landsat) imagery naming patterns)

Moritz Lennert mlennert at club.worldonline.be
Thu Aug 1 06:15:43 PDT 2013


On 01/08/13 14:01, Nikos Alexandris wrote:
> Moritz:
>>>>>>> r.rescale is just a frontend to r.reclass. and as such is meant for
>>>>>>> CELLmaps. 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"...
>
> Nikos:
>>>> Right, "be more precise" is the key to "freedom" :D.  Indeed, I used to
>>>> say (either in a "rules" file, or directly using "...<<   EOF"
> [..]
>>>> 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).
>
> Moritz:
>>> 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 ?
>
> Nikos:
>> Oh man... I need to rest.  The "-d" flag... that's it :-p
>
> On the other hand, even if I would read it (because I did not read carefully
> the --help before), it reads:
>
> -d   Force output to 'double' raster map type (DCELL)
>
> In this case I have a DCELL Input, recoding in to CELL Output.  How is this
> related?

Sorry, you're right. Got mixed up with another problem I had when I 
tried to recode a 0:2047 image to 0.0:1.0. And even if -d solved my 
problem there AFAICT it shouldn't be necessary.

Trying to do too many things at the same time in the last hours before 
leaving on vacation !!

Moritz


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