[GRASSLIST:3370] Re: [GRASS5] image analysis question - undocumented limitations to i.cluster or i.maxlik
michael.barton at asu.edu
Fri May 7 02:39:04 EDT 2004
In addition to the resolution issue noted below, I discovered another
undocumented limitation to i.cluster or i.maxlik that was causing it
not to classify my ASTER data (I don't know in which it is).
Apparently, one or both of the programs will not handle more than 7
bands (actually I haven't yet tested 8, but know they won't handle 9).
I suppose that when they were written this was a compromise for the
available processing power of normal computers and the kinds of imagery
readily available. Now, with more processing power and imagery with
more bands, I wonder it this limitation could be raised?
C. Michael Barton, Professor
School of Human Origins, Cultures, & Societies
PO Box 872402
Arizona State University
Tempe, AZ 85287-2402
On May 6, 2004, at 5:11 PM, Chris G. Nicholas wrote:
> cool...glad there aren't any fundamental problems here...
> did you ever get i.clust to run, and if so, how were the results?
> -----Original Message-----
> From: Michael Barton [mailto:michael.barton at asu.edu]
> Sent: Thu 5/6/2004 3:07 PM
> To: Chris G. Nicholas
> Cc: GRASS5 list; GRASSLIST at baylor.edu
> Subject: Re: [GRASS5] image analysis question - FORGOT IMPORTANT
> I figured out what is going on...I think. ASTER comes in 3 resolutions:
> 3 15m vnir bands, 6 30m swir bands, and 5 90m tir bands. Because GRASS
> will dynamically adjust resolution on the fly, depending on the region
> setting, I can view any combination of bands at any of these
> resolutions. However, if I want to run i.clust, all the bands I use
> need to be at the same resolution. Hence, I need to change the
> resolution using r.resample to make sure that all the bands I am
> clustering match. The reason it works without a problem with Landsat is
> that all bands (except band 8 for ETM) are the same 28.5m resolution.
> Michael Barton, Professor & Curator
> School of Human Origins, Cultures, & Societies
> Arizona State University
> Tempe, AZ 85287-2402
> voice: 480-965-6262; fax: 480-965-7671
> www: http://www.public.asu.edu/~cmbarton
> On Apr 28, 2004, at 1:00 PM, Chris G. Nicholas wrote:
>> hmmm...not sure about ASTER...but I know that things seem to work on
>> Landsat images.
>> -----Original Message-----
>> From: Michael Barton [mailto:michael.barton at asu.edu]
>> Sent: Tue 4/27/2004 8:41 AM
>> To: GRASS5 list
>> Subject: [GRASS5] image analysis question - FORGOT IMPORTANT
>> I got interrupted by some student questions while finishing my query
>> about problems in using i.cluster, i.maxlik, and i.smap
>> I forgot to mention that I am using GRASS 5.3 (early April build) on a
>> Mac OSX 2.8 platform.
>> Michael Barton, Professor & Curator
>> Department of Anthropology
>> Arizona State University
>> Tempe, AZ 85287-2402
>> voice: 480-965-6262; fax: 480-965-7671
>> www: http://www.public.asu.edu/~cmbarton
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