[GRASS-user] unexpected i.pansharpen results

[Michael Barton]

You are right. That was what I was trying to get at but didn't do so well because I had to run to class.

Michael
______________________________
C. Michael Barton 
Director, Center for Social Dynamics & Complexity
Professor of Anthropology, School of Human Evolution & Social Change
Arizona State University
Tempe, AZ  85287-2402
USA

voice: 	480-965-6262 (SHESC), 480-727-9746 (CSDC)
fax:          480-965-7671(SHESC), 480-727-0709 (CSDC)
www: 	http://csdc.asu.edu, http://shesc.asu.edu
		http://www.public.asu.edu/~cmbarton

On Jan 31, 2013, at 12:52 PM, Markus Metz <markus.metz.giswork at gmail.com>
 wrote:

> On Thu, Jan 31, 2013 at 7:06 PM, Michael Barton <Michael.Barton at asu.edu> wrote:
>> 
>> i.pansharpen uses Python, not Bash. So it is not an integer math problem.
> 
> But it calls r.mapcalc, e.g. in lines 151-153. If k is integer and not
> float, r.mapcalc will do integer division. Equivalent for lines 159,
> 162, 165. This could be fixed by casting the numerator to double with
> double().
> 
> Markus M
> 
>> 
>> However, you might try changing your input maps to float or DCELL. See if that changes things.
>> 
>> Michael
>> ______________________________
>> C. Michael Barton
>> Director, Center for Social Dynamics & Complexity
>> Professor of Anthropology, School of Human Evolution & Social Change
>> Arizona State University
>> Tempe, AZ  85287-2402
>> USA
>> 
>> voice:  480-965-6262 (SHESC), 480-727-9746 (CSDC)
>> fax:          480-965-7671(SHESC), 480-727-0709 (CSDC)
>> www:  http://csdc.asu.edu, http://shesc.asu.edu
>> http://www.public.asu.edu/~cmbarton
>> 
>> On Jan 31, 2013, at 2:11 AM, <grass-user-request at lists.osgeo.org>
>> wrote:
>> 
>> From: Yann Chemin <yann.chemin at gmail.com>
>> Subject: Re: [GRASS-user] unexpected i.pansharpen results
>> Date: January 31, 2013 2:11:33 AM MST
>> To: Hamish <hamish_b at yahoo.com>
>> Cc: GRASS user list <grass-user at lists.osgeo.org>
>> 
>> 
>> hmmm, yes that looks like an old friend to check...
>> 
>> 
>> On 31 January 2013 14:06, Hamish <hamish_b at yahoo.com> wrote:
>>> 
>>> (sorry for the html,top posting)
>>> 
>>> I wonder if the script is doing integer division when it should be doing floating point division?
>>> 
>>> http://trac.osgeo.org/grass/browser/grass/trunk/scripts/i.pansharpen/i.pansharpen.py
>>> 
>>> 
>>> Hamish
>>> 
>>> --- On Wed, 1/30/13, Eric Goddard <egoddard1010 at gmail.com> wrote:
>>> 
>>> 
>>> From: Eric Goddard <egoddard1010 at gmail.com>
>>> Subject: [GRASS-user] unexpected i.pansharpen results
>>> To: grass-user at lists.osgeo.org
>>> Date: Wednesday, January 30, 2013, 8:30 AM
>>> 
>>> 
>>> Hi all,
>>> 
>>> I'm attempting to pansharpen some ikonos imagery using the i.pansharpen tool in Grass7 on windows 7 installed via OSGeo4W (r54756-478).  The range for the sharpened red, green, and blue outputs are 0-30, which seems suspicious given the 16bit range of the input bands. The command I used was:
>>> 
>>> i.pansharpen.py "sharpen=ihs" "ms3=ik_mss.4 at eric" "ms2=ik_mss.3 at eric" "ms1=ik_mss.2 at eric" "pan=ik_pan at eric" "output_prefix=ik_ihs"
>>> 
>>> The input bands are linked via r.external, would that matter?
>>> 
>>> The output from my test area is below. Any assistance would be greatly appreciated.<image.png>
>>> 
>>> 
>>> Thanks,
>>> Eric
>>> 
>>> -----Inline Attachment Follows-----
>>> 
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>> 
>> 
>> 
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